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Overview

Caffeine is one of the most popular psychostimulants legally consumed. Psychostimulants are substances that alter the mood and behavior of a person.

Caffeine is majorly present in coffee, tea, energy drinks, and chocolates.

Caffeine produces a small rise in dopamine levels in the brain. Dopamine is called the happy hormone. This is why you feel ‘happy/good’ when you drink a cup of coffee or tea.

While some individuals feel active, happy, and energetic after consuming caffeine, others feel anxious, uncomfortable, and stressed.

The difference lies in how your body metabolizes caffeine. Metabolism is the process of converting the food you eat into energy.

Caffeine Metabolism At Its Molecular Level - Getting Technical

When you consume caffeine, it enters the bloodstream through your mouth, throat, and stomach. The tissues that line your blood vessels, skin, and organs let caffeine pass through quite easily.

It takes just a few minutes for the caffeine to be fully absorbed by the human body. The peak levels of caffeine in the plasma are reached in just 30 minutes.

The liver breaks down caffeine with the help of certain enzymes.

Half-life is the amount of time it takes for caffeine to be reduced to half its initial levels. The half-life of caffeine is about 4 hours. The half-life can increase or decrease depending on both genetic and non-genetic factors.

Caffeine easily crosses the blood-brain barrier. The structure of caffeine is similar to that of adenosine. Adenosine helps the brain relax and sleep. Adenosine receptors usually absorb adenosine. Caffeine attaches itself to the adenosine receptors. This prevents adenosine from acting and keeps people active and fatigue-less.

People develop a better tolerance for caffeine when they consume it regularly.

Apart from developed tolerance, other factors like genetics, age, lifestyle, and diet also affect the rate of metabolism of caffeine.

How Does Genetics Influence Caffeine Metabolism

CYP1A2 gene

The CYP1A2 gene produces the CYP1A2 enzyme. This is responsible for breaking down drugs, hormones, and other chemicals in the body to help retain essential parts and eliminate waste.
This enzyme plays an important role in caffeine metabolism. There are a few types of variations in this gene that affects how your body responds to caffeine.

rs762551 of CYP1A2 Gene and Caffeine Metabolism

The rs762551 SNP is the most discussed variation in the CYP1A2 gene. The AA genotype of this SNP is associated with faster metabolism of caffeine. Individuals with the AA genotype process caffeine quickly and may not experience the negative side-effects of caffeine consumption.

Both the AC genotype and the CC genotype individuals are slow metabolizers. They experience the unpleasant side effects of caffeine consumption, and their bodies process caffeine very slowly.

rs11854147 of CYP1A2 Gene and Caffeine Metabolism

Another SNP that causes an increase/decrease in caffeine metabolism is the rs11854147. Those with the CC genotype metabolize caffeine very rapidly and may not be affected by the negative effects of caffeine consumption.

The CT and the TT genotype individuals are slow metabolizers. They may be prone to the side-effects of caffeine consumption.

Non-genetic Factors Affecting Caffeine Metabolism

Liver diseases - Many studies relate liver diseases to lowered caffeine metabolism. People with liver diseases like liver cirrhosis, hepatitis B, or hepatitis C have lowered plasma clearance rates of caffeine. The more severe your liver disease is the lower the caffeine metabolism rate.
Weight - Caffeine metabolism also depends on body weight. Leaner individuals can increase their calories burnt by 30% when compared to overweight individuals (increase calories burnt by 10%) when they consume caffeine.
Diet - Few types of foods increase or decrease caffeine clearance in the body. Eating such food before you consume caffeine can make changes in caffeine metabolism.
Grapefruit decreases caffeine clearance by about 23%
Broccoli increases caffeine clearance in the plasma
Fruits and vegetables rich in flavonoid affects caffeine metabolism rates
Smoking - Smoking clears caffeine from the body very quickly. Smokers have very high caffeine metabolism rates and can usually handle high amounts of caffeine easily.
Some smokers have almost two times caffeine metabolism rates than non-smokers.
Pregnancy - During the third trimester, the enzyme that helps in caffeine metabolism reduces, increasing the half-life of caffeine. Your body processes caffeine very slowly until delivery, and the metabolism gets better after the child is born.
Medications - Drugs like Ephedrine are recommended to speed up the nervous system. Ephedrine and caffeine can work together and cause extreme jitters, nervousness, and anxiety. Similarly, certain antibiotics and estrogen pills can alter caffeine metabolism and need to be consumed with caution.

Effects of Slow Caffeine Metabolism

For slow caffeine metabolizers, it takes longer for caffeine to pass through the body, and hence the effects of caffeine are more. Such individuals have to restrict their caffeine intake. Here are some of the effects of slow caffeine metabolism.
-Insomnia
-Anxiety
-Digestive troubles
-Upset stomach
-Increased caffeine intake increases the risk of high blood pressure and heart attacks

Effects of Rapid Caffeine Metabolism

For rapid/fast caffeine metabolizers, the caffeine in the body quickly passes through the system. They are hence not affected by the side-effects of caffeine like slow metabolizers. Here are the effects of rapid caffeine metabolism.
-Increased weight loss
-Improved energy levels
-Improved physical performance
-Lowered risks of type II diabetes
-Improved mood and mental state

With time, people can identify the amounts of caffeine that they are comfortable with.

Start with smaller doses and keep a note of how you feel after you consume caffeinated drinks and beverages.’ Self-regulation works well in preventing caffeine overdose.

Recommendations To Improve Caffeine Metabolism

-It is very important you understand how your body processes caffeine. Get your genetic testing done to see if your genes affect the way your body deals with caffeine. If so, increase/decrease your caffeine intake accordingly.
-If your body handles caffeine normally, then do not go beyond the generally recommended levels. Do understand that packaged energy drinks, coffees, and flavored teas all have excess sugar along with caffeine. This is further unhealthy for your body.
-If you are hypersensitive to caffeine, try consuming less than 100 mg of caffeine a day to prevent ruining your metabolic system.
-For those whose bodies process caffeine very slowly, spacing out caffeine intake helps prevent overdoses.
-Staying physically fit, keeping your body hydrated, and eating healthy and fresh produce are all ways to improve your general metabolism. This ensures you can handle caffeine better.

Summary

  1. Caffeine metabolism is the act of how caffeine is processed by the body.
  2. Slow caffeine metabolism and rapid/fast caffeine metabolism are two common ways in which people process caffeine.
  3. Slow metabolizers are more affected by the unpleasant side effects of caffeine as caffeine stays in the body for a longer time.
  4. Fast metabolizers can process caffeine quickly in the body and hence can handle caffeine much better. They are benefitted from caffeine intake.
  5. Certain non-genetic factors like the presence of diseases, pregnancy, consumption of certain types of foods, and habits like smoking can change the way caffeine is metabolized in the body.
  6. Genetically, variations in the CYP1A2 gene can make people more/less sensitive to caffeine.

References

https://archives.drugabuse.gov/blog/post/caffeine-really-addictive
https://pubmed.ncbi.nlm.nih.gov/22302887/
https://medium.com/@viterenergy/3-ways-caffeine-boosts-your-metabolism-d64208b7fbb1
https://www.hsph.harvard.edu/nutritionsource/caffeine/
https://www.caffeineinformer.com/caffeine-metabolism
https://www.coffeeandhealth.org/topic-overview/caffeine-and-metabolism/
https://www.healthline.com/nutrition/caffeine-addiction#TOC_TITLE_HDR_9
https://www.mhc.wa.gov.au/media/1223/caffeine-the-facts-booklet.pdf"

 

Polyunsaturated Fatty Acids - What Are They?

Fats are essential to our bodies and cannot be completely removed from our diet. But too much fat or the wrong type of fat can be harmful to us, especially our hearts. However, there are “good” fats that offer health benefits.

All fats are made up of carbon and hydrogen atoms. The arrangement and the number of hydrogen atoms are what makes them “good” or “bad.” The good fats are called unsaturated fats, while bad fats are called saturated fats. Good fats have fewer hydrogen atoms than bad fats. Another difference that can be noticed is the state (liquid, solid, or gas) at which they are present at room temperature. Good fats are usually present in liquid form at room temperature and harden when chilled.

Polyunsaturated fatty acids or PUFA are a type of good fats. They are mostly found in plant-based oils like vegetable oils or seed oils, fatty fish, and nuts. There are two major classes of PUFA - omega-3 fatty acids and omega-6 fatty acids. Our body cannot produce these fats, and hence we must include them in our diet.

Is There A Relationship Between PUFA And Body Weight?

Omega-3 fatty acid: Animal studies reveal that omega-3 fatty acids (also known as n-3 PUFA) reduce body fat accumulation. Consumption of n-3 PUFA by pregnant and lactating women has a beneficial effect on birth weight and the growth of the infant. In studies that involved adult men and women, no significant gain in body weight was seen due to the consumption of omega-3 fatty acids. On the contrary, the same study observed weight loss in patients who were given fish oil.

Omega-6 fatty acid: For a long time in human history, there was a balance in omega-3 and omega-6 fatty acids consumption. Recently the intake of omega-6 fatty (also known as n-6 PUFA) acids has spiked up. A study showed that high omega-6 fatty acid intake induced weight gain in both animals and humans. The same study concluded that a high intake of n-6 PUFA during pregnancy resulted in fat accumulation across generations.

We need to ensure that we consume omega-3 and omega-6 fatty acids adequately. Neither of them should be ignored completely or over consumed. The ratio of consumption of omega-6 to omega-3 fatty acids must ideally be 1:1 (equal quantities of both).

However, recent studies that analyzed the intake levels revealed that an average American consumed omega fatty acids in the ratio of 17:1. This is extremely unhealthy and may put your health at risk by causing heart diseases and diabetes.

Importance Of Polyunsaturated Fatty Acids

Consuming PUFA instead of saturated or trans fat can have various health benefits:

Studies show that omega-3 and omega-6 fatty acids play a crucial role in the development and functioning of the brain. Any deficiency or imbalance in omega-3 fatty acids during the developmental or adulting phase can significantly affect brain function. Some of the brain disorders that are associated with a lack of omega-3 fatty acids include:

Recommended PUFA Intake

According to the European Scientific Committee on Food (SCF), 2% of daily energy must be derived from omega-6 fatty (n-6 PUFA) acids, and 0.5% of total energy must come from omega-3 fatty acids (n-3 PUFA). This means a typical adult man must consume 6 g of PUFA per day with 5 g of n-6 PUFA and 1 g of n-3 PUFA. Whereas for a woman, the RDA (Recommended Dietary Allowance) is 8 g or PUFA per day - 6.4 g of n-6 PUFA and 1.6 g of n-3 PUFA.

The World Health Organization (WHO) recommends that over 2.5%-9% of the daily energy must be derived from omega-6 PUFA, and over 0.5%-2% of the daily energy must be derived from omega-3 PUFA.

This difference in the recommendation is attributed to the different nutritional goals of the two organizations. While the SCF focuses on correcting PUFA deficiency, the WHO recommends PUFA intake considering its benefits on brain and heart health

Genetics Behind PUFA Intake and Weight Gain

BDNF Gene

The BDNF gene encodes Brain-Derived Neurotrophic Factor, which is a protein found in the brain and spinal cord. This protein plays a role in the development, maturation, and maintenance of cells called neurons.
The BDNF protein is also specifically found in the regions of the brain that control eating, drinking, and body weight.

rs6265
rs6265, also known as Val66Met, is a Single Nucleotide Polymorphism (SNP) in the BDNF gene. A study carried out a detailed examination of eating behavior in persons with different Val66Met types (Val-Val or GG, Val-Met or AG, and Met-Met or AA). It was discovered that people who have the Met-Met (AA) type had a lower BMI than those with the Val-Met (AG) or the Val-Val (GG) genotype.

Effects of Excess PUFA Intake

Over-consumption of PUFA can lead to the following:

  1. Inflammation: Omega-6 fatty acids are pro-inflammatory; that is, they induce inflammation. While inflammation is our body’s natural response to injuries, it is also the root cause of obesity, diabetes, and heart diseases.
  2. Calorie buildup: In our bodies, one gram of fats provides us with nine calories - this is more than the calories provided by the other two macros (carbohydrates and protein) per gram. For this reason, even though PUFAs are healthy, it is important to stay within your calorie needs.
    Apart from health risks, polyunsaturated fatty acids are generally unstable and get spoilt easily.

This is due to their chemical structures (that have double bonds). They react with the oxygen present in the surroundings, and this oxidized form of PUFA is unhealthy. They also smoke easily, and residuals of the smoke have been linked to neurological diseases and cancer in some animal studies.

Effects of PUFA Deficiency

Lack of adequate omega-3 fatty acids can cause:

Lack of omega-6 fatty acids in our diet can have a negative effect on our skin. A study from the University of Illinois found that omega-6 fatty acid is important for our skin. According to this study, a type of omega-6 acid (arachidonic acid) plays a role in the development of dermatitis (an itchy inflammation of the skin). The study observed that the absence of this acid in mice resulted in severe dermatitis, which could be reversed by feeding them with an omega-6-rich diet.

Dietary Sources Of PUFA

Maintaining a healthy ratio of omega-6 fatty acids and omega-3 fatty acids is important.

Plant Sources of Omega-3 Fatty Acids

Animal Sources of Omega-3 Fatty Acids

Plant Sources of Omega-6 Fatty Acids

Animal Sources of Omega-6 Fatty Acids

Summary

  1. Polyunsaturated fats (PUFAs) are a type of healthy fat that includes omega-3 and omega-6 fatty acids.
  2. PUFA is a brain-food that is involved in regulating the development and functioning of the brain.
  3. A region, rs6525 in the BDNF gene regulates your weight on PUFA intake - people with the AA type of rs6525 tend to have a lower BMI on PUDA intake than the AG and GG types.
  4. Some recommended food sources of PUFA include flaxseeds, tofu, and seafood.

References

https://www.health.harvard.edu/staying-healthy/the-truth-about-fats-bad-and-good
https://www.healthline.com/health/all-about-vitamin-e#more-research
https://pubmed.ncbi.nlm.nih.gov/19672626/
https://pubmed.ncbi.nlm.nih.gov/22591885/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808858/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3335257/
https://en.wikipedia.org/wiki/Brain-derived_neurotrophic_factor
https://pubmed.ncbi.nlm.nih.gov/16707914/
https://www.ncbi.nlm.nih.gov/pubmed/29610056
https://pubmed.ncbi.nlm.nih.gov/23527564/
https://pubmed.ncbi.nlm.nih.gov/19925718/
https://www.sciencedaily.com/releases/2010/04/100412121022.htm

Magnesium is the fourth most abundant mineral in the body that plays an important role in over 300 enzymatic reactions.
Magnesium is a macromineral - this means our body requires large quantities of magnesium.
About 60% of the magnesium in your body is found in bone, while the rest is in muscles, soft tissues, and fluids, including blood.
The benefits magnesium offers to the body is not limited to one organ. It plays several important roles in the health of your body and brain.
Despite its importance, according to a study, 68% of Americans don’t meet the recommended intake of magnesium.
Magnesium deficiency is associated with a range of health complications, so it is essential to meet your magnesium requirements.

Magnesium Metabolism - Getting Technical

Distribution of Magnesium

About 60% of the magnesium is present in bone, 20% in skeletal muscle, 19% in other soft tissues, and less than 1% in the extracellular fluid (fluid outside the cells in the body). Magnesium is present in very low levels inside the cells except for situations like hypoxia (lack of oxygen) or extended periods of magnesium depletion.

Intestinal Absorption of Magnesium

When magnesium enters the body via dietary sources, about 30-40% of it is absorbed in the intestines. The factors that interfere with the absorption of magnesium haven’t been well-researched yet. According to a study, the parathyroid hormone (PTH) and vitamin D play a role in intestinal absorption.

Magnesium Reabsorption in the Kidney

Regulation of serum magnesium concentration is achieved mainly by control of renal magnesium reabsorption. 95% of the magnesium is reabsorbed in the kidney. The transport and reabsorption in the kidney are influenced by sodium chloride levels.
Magnesium reabsorption is increased in the kidney by parathyroid hormone and inhibited by hypercalcemia (high levels of calcium).
There are also certain genetic factors that influence the transport of magnesium into the kidney.

Importance of Magnesium

Scientists have been studying the effect of magnesium on health. This is what we know so far:

Magnesium Aids Biochemical Reactions

Magnesium is a cofactor (cofactors are chemical compounds that are required to activate enzymes) for more than 300 enzymes.
These enzymes are required for various chemical reactions that are involved in:

  1. Muscle movements
  2. Energy production
  3. Nervous system functioning

    Magnesium Can Improve Brain Functioning

    Magnesium is essential to communicate the signals from the brain to the rest of the body cells. The magnesium present in the receptor cells prevents unwarranted excitation of the brain cells, thereby preventing brain damage. Lowering of brain activity is also necessary to sleep.

    Magnesium Can Lower Blood Pressure

    Some studies suggest that magnesium consumption helps lower blood pressure. However, this effect was noticed only among people with high blood pressure (hypertensive). No effect was found on those with normal blood pressure levels.

    Magnesium Can Improve Psychological Well-being

    Since magnesium coordinates brain signals, it also keeps your mental health in check. Studies suggest a link between lower magnesium levels and depression.
    Some studies also suggest that supplementing with magnesium can help alleviate symptoms of depression.

    Magnesium Can Enhance Exercise Performance

    Magnesium is required to move blood sugar into cells, which gives the energy-boost during exercise. It is also required to remove the lactate from muscles, which causes fatigue.
    A study suggests that magnesium needs rise by 10-20% when exercising than at rest.

    Magnesium Can Help Prevent Migraines

    A study suggests that people with migraines are more likely to be magnesium deficient than others.
    Some studies even encourage magnesium supplements to prevent and treat headaches.

    Magnesium Can Keep Your Heart Healthy

    The contraction and relaxation of cardiac muscles are required for the beating of the heart - the muscles here follow a rhythmic contracting pattern. Calcium is required for muscle contraction, and magnesium is required for muscle relaxation. This helps in maintaining a steady heart rhythm.

    Magnesium Can Maintain Blood Sugar Levels

    The hormone insulin is required for the transport of sugar into the cells. Magnesium is required for insulin regulation. Any deficiency in this mineral can, therefore, increase your risk for type 2 diabetes.

Discovery of Magnesium

The name magnesium comes from Magnesia, a district of Thessaly/Greece where it was first found.
Even before magnesium was discovered as an element, it had already existed in everyone’s daily life.
In 1618, a farmer in England observed that his cows did not drink water from a particular well - he found that water from that well had a bitter taste. However, the same bitter-tasting water seemed to clear up scratches and rashes.
Eventually, the compound that gave the bitter taste was recognized as Epsom salts or magnesium sulfates (MgSO4).
In 1755, a Scottish physician Joseph Black recognized magnesium as a separate element.
However, it was isolated only in the 1800s by a British chemist Sir Humphry Davy. He also suggested the element to be named ‘magnium.’
In 1831, a French chemist Antoine A.B. Bussy discovered a way to isolate magnesium in large quantities. He published his findings in the journal “Mémoire Sur le Radical métallique de la Magnésie.

RDA of Magnesium

For adult men (aged 19 years and older), the RDA of magnesium is 400-420 mg. Adult women need lesser magnesium - 310-320 mg. For pregnant women 18 or older, the requirements are increased to 350–360 mg per day.
The daily upper intake level (highest levels of daily intake that doesn’t have any adverse health effects) for magnesium is 350 mg for anyone over eight years old, including pregnant and breastfeeding women.

How Does Genetics Affect Magnesium Requirements

TRPM6 Gene and Magnesium Requirements

The TRPM6 gene is located on chromosome 9 and encodes transient receptor potential cation channel subfamily M member 6 (TRPM6). This protein forms a channel that allows the flow of magnesium into the cells - it also allows the flow of small amounts of calcium into the cells.
The TRPM6 protein is primarily present in the large intestine, kidneys, and lungs. When the body requires magnesium, this channel allows the absorption in the intestine - when the body has excess magnesium, it filters out the magnesium ions into the kidneys to be excreted through the urine.
rs11144134 of TRPM6 Gene and Magnesium Deficiency Risk
rs11144134 is an SNP in the TRPM6 gene associated with the regulation of serum magnesium levels. According to a study, the T allele of rs11144134 in TRPM6 is associated with lower serum magnesium levels.
But the T allele was also associated with higher bone mineral density in the femoral neck and lumbar spine.

CASR gene and Magnesium Requirements

The CASR gene is located on chromosome 3 and encodes the ‘calcium-sensing receptor’ protein (CaSR). The protein is primarily present in the parathyroid gland, kidneys, and brain. The CASR gene is concerned mainly with maintaining calcium levels, but it also affects magnesium levels in the body. It especially regulates the reabsorption of magnesium in the kidneys.
rs17251221 of CASR Gene and Magnesium Deficiency Risk
rs17251221 is an SNP in the CASR gene associated with the regulation of serum magnesium levels. The presence of the G allele increases the serum magnesium levels.

Other genes like DCDC5, HOXD9, LUZP2, MDS1, MUC1, and SHROOM3 also influence magnesium requirements.

Non-genetic Factors That Influence Magnesium Levels

Hypomagnesemia - Magnesium Deficiency

Symptoms of Hypomagnesemia

Some early signs of magnesium deficiency are:

Untreated magnesium deficiency can lead to more severe symptoms like:

Effects of Excess Magnesium: Hypermagnesemia

The symptoms of hypermagnesemia include:

Dietary Sources of Magnesium

Animal Sources of Magnesium

Plant Sources of Magnesium

Summary

  1. Magnesium is an essential mineral that acts as a cofactor to over 300 enzymatic reactions involved in processes like energy production and nervous system functioning. It also plays a vital role in lowering blood pressure and enhancing your exercise performance.
  2. Magnesium is a macromineral - our body requires it in higher quantities. While adult males require about 400-420 mg of magnesium per day, adult women need to consume 310-320 mg per day.
  3. Even if you meet the RDA, certain conditions like diabetes, hypercalcemia, and alcoholism can prevent the mineral from being absorbed well by the body.
  4. TRMP6 is an important gene that is required for the transport of magnesium. The presence of the T allele in the SNP rs11144134 of this gene is associated with lower serum magnesium levels.
    TheCASR gene, which is well known for its role in calcium metabolism, also influences the reabsorption of magnesium in the kidney - hypercalcemia leads to poor reabsorption of magnesium.
  5. Lower magnesium levels can be identified with symptoms like nausea, fatigue, and loss of appetite. Magnesium toxicity is also harmful and manifests as hypotension, headache, and fatigue.
  6. Since magnesium is an essential mineral, it needs to be consumed through dietary sources. Some magnesium-rich foods include spinach, avocados, fatty fish, pumpkin seeds, soymilk, and lima beans.

Reference:

https://pubmed.ncbi.nlm.nih.gov/29093983/
https://pubmed.ncbi.nlm.nih.gov/19020533/
https://pubmed.ncbi.nlm.nih.gov/25748766/
https://www.ncbi.nlm.nih.gov/pubmed/16542786
https://www.ncbi.nlm.nih.gov/pubmed/17172008
https://www.ncbi.nlm.nih.gov/pubmed/22426836
https://pubmed.ncbi.nlm.nih.gov/6375330/
https://pubmed.ncbi.nlm.nih.gov/9312016/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1855626/

 

What is Lactose Intolerance?

Lactose is a healthy carbohydrate commonly available in milk and milk products. It has two simpler sugar units, namely glucose and galactose. Lactose improves the absorption of calcium, which is essential for your bone health. Additionally, lactose is the only source of galactose, a simple sugar that is necessary for good brain function and a healthy immune system.

Lactose intolerance occurs when lactose is not digested well by our digestive system.
When we say that the food is digested in our stomach, it is to be understood that the food that we take in is broken down into smaller pieces so that the body can absorb them. In the mouth, the breakdown occurs as we chew the food, but in the stomach, the food is broken down through chemical reactions. This process is aided by certain proteins known as enzymes.
One such enzyme is lactase. This is responsible for breaking down lactose molecules. Any deficiency in this enzyme would ultimately prevent lactose from being digested, thereby causing lactose intolerance.

When lactose intolerant people consume dairy products, they’re usually faced with unpleasant gastrointestinal (stomach and intestines) symptoms. Some of the symptoms that occur immediately include:

How Did Humans Develop Lactose Intolerance?

It is believed that a few thousand ago, only infants were able to digest lactose, and as they grew, they began losing the lactase enzyme. In other words, all adults were lactose intolerant.
But around 8,000 years ago in what's now Turkey — just when humans were starting to milk newly domesticated cows, goats, and sheep — changes in the gene responsible for producing lactase appeared more frequently. Around the same time, adult lactose tolerance developed. But of course, not the entire population was lactose tolerant. There were still human adults who were lactose intolerant.
But how did lactose tolerance continued to prevail?
An evolutionary geneticist, Mark Thomas, seems to think that it is the combination of famine and 'deadly diarrhea.' In times of famine, where the crops failed, the consumption of milk probably increased. While it may just cause some gastrointestinal disturbances in the intolerant, it can be deadly for the malnourished. So, the lactose tolerant people had a better survival advantage at this time and were more likely to pass on the gene that ensured the ability to consume dairy.

The Genetics Behind Lactose Intolerance

The LCT gene is responsible for producing the lactase enzyme, which degrades the lactose molecules. This LCT gene is controlled by another gene, the MCM6.

Located inside the long arm of chromosome 2, the MCM6 gene plays a governing role in our ability to digest milk products. A specific portion of the MCM6 gene - known as a regulatory element - helps control the activity (expression) of the LCT gene, thus influencing how much lactase is produced.

rs4988235
Also known as "C/T(-13910)" or just 13910T, rs4988235 is located in the MCM6 gene. However, it exerts its influence on the lactase-producing-LCT gene. The T allele of rs4988235 is the more common allele and enables the lactase enzyme production. So people who have the T allele are likely to be lactose persistent or lactose tolerant. The lactase activity is more in people with two T alleles than with one.

Secondary Lactose Intolerance

Lactose intolerance due to a deficiency of lactase enzyme in certain LCT gene types (genetic) is referred to as primary lactose intolerance. Secondary lactose intolerance, on the other hand, is caused by any illness or injuries. Any such conditions might affect your small intestine and lead to a reduction in lactase secretion. Celiac disease and Crohn’s disease are the two most common intestinal diseases linked to low lactase secretion.

Can You Be Lactose Tolerant and Suddenly Become Intolerant?

Answering this question also partially solves the mystery of why, for some people, the genetic tests indicate lactose intolerance, despite them being able to consume dairy products without any issues.

Let’s take an example of a person who has been following a vegan lifestyle for a while now. Before taking up veganism, he could comfortably eat and digest dairy products. However, after a few years on a vegan diet, re-introducing dairy products in his diet is suddenly giving him digestive problems. So, what could have happened?

The cells that produce the enzyme to digest lactose (lactase) are present in the intestines and are few in number. When a person goes off-dairy for a while, there’s basically no work for these cells, and they temporarily disappear. When dairy is introduced back into the diet, the person may exhibit lactose intolerance for a while till these cells reappear.

Another factor that could explain this is our gut flora - the millions of bacteria present in our digestive tract. Some of these bacteria may help in breaking down lactose molecules. A diet that includes dairy products will offer a survival advantage to the bacteria that can digest lactose and will let them flourish better. On the other hand, these bacteria will not thrive for long when dairy is removed from the diet. When re-introducing dairy products, due to the lack of lactose-digesting-bacteria, the person may experience temporary lactose intolerance.

Gut bacteria is also the reason why many lactose-intolerant individuals can still consume up to a cup of milk per day.

If lactose-digesting bacteria dominate your gut flora, you may even be able to stick to a normal diet (that includes dairy) even if your gene does not produce lactase!

In fact, introducing some ‘good bacteria’ (with the ability to digest lactose) has been studied to improve and provide relief from lactose intolerance symptoms.

Ethnicity and Lactose Intolerance

The incidence of lactose intolerance varies among different population groups. The population that’s the most affected with lactose intolerance is the East Asian descent, with 70-100% of the people affected.

On the other end is North European descent with 18-26% incidence due to their long-standing dependence on unfermented dairy products - the European ancestors may have nested in a place where dairy farming flourished and passed on the specific gene type that produces lactase.
Ethnicity also influences the age of onset of lactose intolerance.
Lactose intolerance in infancy is the most common in Finland - 1 in 60,000 newborns affected. In white people, intolerance develops in children older than five years. In African Americans, most children become intolerant by the age of two years.

Lactose-intolerance Friendly Diet

A lactose-free diet is the best way to combat lactose intolerance. But before eliminating lactose from your diet, it is important to test your extent of intolerance. Research suggests that many people can have a cup of milk every day (12 grams of lactose) without any or very mild symptoms. This is important because dairy is a common source of vitamin D and calcium. So if you can tolerate a cup of milk a day, it's better to use it to your advantage.
But even if a hint of lactose in your diet puts you in trouble, then it is advisable to cut out dairy and all the other sources of lactose from your diet.

What can you eat?

Some healthy food groups that are also lactose-free include:

Meeting your Calcium and Vitamin D Requirements

Calcium and vitamin D are important for your bone health. Getting adequate levels of these nutrients when on a dairy-free diet can be challenging. Some food sources are naturally high in calcium and vitamin D. Finding a way to incorporate them into your diet can ensure good bone health.

Summary

  1. Lactose intolerance occurs due to an inability to digest lactose, a sugar usually found in dairy products. It is a very common condition, affecting up to 75% of the global population.
  2. Primary lactose intolerance prevents the body from producing the enzyme lactase, which degrades the lactose sugar. It is mostly genetic in nature. Secondary intolerance can occur due to illness/injuries that affect the intestines, resulting in reduced lactase production.
    Ethnicity plays a major role in the differences in incidence and age of onset of lactose intolerance across populations.
  3. The LCT gene is responsible for producing the lactase enzyme. The expression of the LCT gene is governed by another gene called MCM6. People with certain types of the MCM6 gene have reduced expression of the LCT gene, and hence, decreased levels of the lactase enzyme. Such individuals may experience lactose intolerance symptoms upon dairy consumption.
  4. The best way to deal with lactose intolerance is to adopt a lactose-free (dairy-free) diet - at the same time, it is important to enrich your diet with calcium and vitamin D from other food sources.

References

https://evolution.berkeley.edu/evolibrary/news/070401_lactose
https://www.independent.co.uk/life-style/health-and-families/dairy-cut-diet-lactose-intolerant-symptoms-development-skin-cheese-milk-yoghurt-a8302626.html
https://medlineplus.gov/genetics/gene/mcm6/
https://www.snpedia.com/index.php/Rs4988235
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3048992/
https://www.ncbi.nlm.nih.gov/pubmed/25625576?dopt=Abstract
https://link.springer.com/article/10.1007/s12602-018-9507-7
https://medlineplus.gov/genetics/condition/lactose-intolerance/#frequency
https://pubmed.ncbi.nlm.nih.gov/22643754/

Does Fat Count As A Flavor? Can We Taste Fat?

Fat has been classified as a taste as early as 330 BC by Aristotle. However, recent research suggests that fat is associated more with the smooth velvety texture (like in butter) but not with the sense of taste.
To be classified as a ‘ basic taste’ it must meet certain criteria. Some of these include:
1. Effective stimuli that react with the tongue: For fats, the stimuli arise from the breakdown of fatty acids
2. Receptors on the tongue that identify the stimuli: A study published in the Journal of Lipid Research by Pepino et al. claimed that our tongue indeed contains a protein (CD36) that can detect the presence of fats.
3. A transmission of the signal from the fat receptors in the tongue to taste-sensing regions in the brain: The molecules generated from fatty acid breakdown activates neurotransmitters like serotonin, which trigger the orosensory (oral senses) perception.
4. Independent perception of the taste: While sweet and salt tastes can be perceived independently, there’s still a controversy over whether or not ‘fat’ taste can be identified independently.
5. Physiological effects once the taste receptors are activated: Upon consumption of fat, a commonly seen physiological effect is the increase in the triglyceride levels.

Why Do We Like Fat?

Fat is universally palatable because of its desirable properties in smell and texture.
Smell: There’s a reason why we can ‘taste’ the sizzling bacon even before we dig into it. Fats dissolve odor chemicals and concentrated flavors. Upon heating them, these are released, and when you smell the cooked food, the flavor molecules make their way to your nose and mouth.
Texture: Fatty foods have a special mouthfeel, a special texture. Emulsions made with fat are responsible for the creamy texture of many items like ice cream, peanut butter, and chocolate.

Consumption Of Fats: An Evolutionary Need

Our ancestors likely began acquiring a taste for fat 4 million years ago.
Out of the three macronutrients (carbohydrates, protein, and fats), fats provide the most energy per unit gram.
Proteins and carbohydrates (sugars) provide about 4 calories per gram, while lipids provide 9.4 calories per gram.

Fats also make us feel fuller for a longer time because it is absorbed slowly.
When we feel full, our brain releases ‘feel-good’ hormones that make us content and relaxed. So on hunting days, our ancestors gathered as many fatty foods as possible.
Those who consumed more fats than others had a tendency to survive better in times of food scarcity.

The ‘craving’ for fatty foods, the happiness we derive from it, and the fullness we experience are all a result of evolutionary adaptation.

How Does Genetics Fatty Foods Preference?

A recent study from the Journal of Lipid Research claims that we carry a protein (receptor) in the tongue that is sensitive to fat. People who have more of this ‘fat-perceiving’ protein are more sensitive to fat, and vice versa.

CD36 and Tendency to Prefer Fatty Foods

The CD36 gene is located on chromosome 7. It encodes the Cluster of Differentiation protein, also called the fatty acid translocase protein. It is present on the surfaces of many cells in the body. People with certain forms of the CD36 gene have a lower concentration of the ‘fat-perceiving’ protein and may prefer and consume more high-fat foods than people with the other forms of this gene.

rs1527483
rs1527483 is associated with oral sensitivity to and preference for fat. Individuals who had the C/T or T/T genotypes tend to be less sensitive to fat in the diet than those with the C/C genotype. So, people with the TT type tend to prefer fatty foods more than the others.

rs1761667
According to a study, the G-allele of the rs1761667 SNP was associated with a 11-fold lower threshold for oleic acid than the A allele. Thus, people with the * GG type* had a higher sensitivity to oleic acid and thus consumed less fatty foods.

Health Risks Of High Fat Consumption

High Fat Consumption May Increase The Risk of Diabetes

Fatty acid affects glucose levels by influencing the activity of enzymes like insulin. This can alter cell structure and gene expression. Studies show a positive association between trans fatty acids intake and risk of diabetes. Trans fat is found in animal products such as meat, whole milk, and milk products. Mounting evidence suggests that trans fats increase inflammatory cytokines that are related to the risk of diabetes.

High Fat Consumption May Increase The Risk of Heart Disease

The potential for a fatty meal to trigger heart attacks has been discussed in the medical literature for many years. According to a study, when people with heart disease consumed a high-fat meal, EKG changes were observed along with reports of chest pain in nearly half of the participants.

High Fat Consumption May Increase The Risk of Blood Clots

Heart attack, stroke, and pulmonary embolism are examples of diseases caused by blood clots. According to a study, after a meal rich in fatty acids, the volunteers displayed increased activation of blood clotting factors.

High Fat Consumption May Reduce Testosterone Levels

A study investigated the effects of fat-containing meals on plasma sex hormone levels in men. The results revealed reduced concentrations of both total and free testosterone hormone levels.

Consuming Fats The Healthy Way

Studies now show that certain kinds of fats (saturated fats) taken in the right amounts can offer health benefits. Some high-fat foods that are filled with nutrients include:

Animal Sources of Healthy Fats

Plant Sources of Healthy Fats

Summary

  1. Fats are universally palatable owing to the creamy texture it adds to foods like peanut butter.
    Our liking for fats has an evolutionary aspect to it. Fats provide the most energy per unit gram and make us feel fuller. So, our ancestors who consumed more fats had better survival chances than others.
  2. Certain people prefer fatty foods less than others because of their heightened sensitivity to fats - this may help consumers detect small changes in fat intake. As a result, they may be less likely to consume excess amounts of this nutrient.
  3. CD36 gene influences the sensitivity to fat. Two SNPs in this gene - rs1527483 and rs1761667 are associated with oral sensitivity to and preference for fat. People with certain genetic types tend to consume more fats than others.
  4. Increased fat consumption is linked to health conditions like diabetes, heart diseases, and cancer.
  5. Some “healthy fats,” known as saturated fats, are beneficial to health. Some food sources of saturated fats include avocados, fatty fish, eggs, full-fat yogurt, and chia seeds.

Reference

https://www.researchgate.net/figure/Criteria-for-tastes-to-fulfil-to-be-classified-as-either-basic-tastes-or-within-a-new_fig1_330462664
https://www.sciencedaily.com/releases/2019/02/190205161420.htm
https://m.jlr.org/content/53/3/561.full
https://en.wikipedia.org/wiki/CD36
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3743670/
https://www.ncbi.nlm.nih.gov/pm/carticles/PMC4377901/
https://www.ncbi.nlm.nih.gov/pubmed/11689201
https://pubmed.ncbi.nlm.nih.gov/7498102/
https://pubmed.ncbi.nlm.nih.gov/2392062/

What Is Hypertension?

Just like how water exerts pressure on the walls of the pipes when flowing, blood too exerts pressure on the surface blood vessels. The pressure exerted must be constant and of a particular value. A drop or hike in this pressure may likely be a warning of an abnormality.
When the pressure exerted by blood on the walls increases beyond a certain level, it is known as hypertension or high blood pressure. Hypertension is a pretty common health condition, with nearly half the American population expected to be diagnosed with it.

Symptoms Of Hypertension

Most people don't experience any particular symptom until the condition becomes severe. That is why hypertension is rightly known as the "silent killer." Even when people do experience the symptoms, they are almost always associated with other issues.
Some of these warning signals for hypertension include:
- Severe headaches
- Nose bleed
- Difficulty in breathing
- Chest pain
- Extreme tiredness and fatigue
- Sweating and anxiety

What Causes Hypertension?

The causes of hypertension or high blood pressure are still being studied. Some of the well-accepted and scientifically proven causes are smoking, obesity or being overweight, diabetes, having a sedentary lifestyle (one involving very minimal physical activities), and unhealthy eating habits.

What is Riboflavin?

Riboflavin, or vitamin B2, is a water-soluble vitamin. B vitamins are important for making sure the body's cells are functioning properly.
In addition to energy production, riboflavin also acts as an antioxidant and prevents damages by particles called free-radicals. It is involved in the production of folate (vitamin B9), which is crucial for red blood cell formation.
People need to consume vitamin B2 every day because the body can only store small amounts, and supplies go down rapidly.

How Does Riboflavin Affect Blood Pressure Response?

A study published by the American Journal of Clinical Nutrition revealed that one in ten people could significantly lower their blood pressure and, in turn, their risk of heart disease and stroke by increasing their vitamin B2 intake.

Previous studies have found an association between the 677C-->T polymorphism in MTHFR and hypertension. This transition from C to T results in increased homocysteine levels. About 30 to 40 percent of the American population may have a mutation at gene position C677T.

The relationship between riboflavin and hypertension was examined because riboflavin is known to have an important modulating effect on elevated homocysteine.

A study demonstrated that increasing riboflavin status reduced systolic blood pressure by 13 mmHg and diastolic blood pressure by almost 8 mmHg, specifically in patients with the TT genotype.

Another study showed that riboflavin (1.6 mg per day) lowers homocysteine levels in healthy adults with the TT genotype but not in those with CT or CC genotypes.

rs1801133

rs1801133 is an SNP in the MTHFR gene that is commonly studied. It is also known as C677T, Ala222Val, and A222V.
People with the TT type have a lower blood pressure upon riboflavin/vitamin B2 administration than those with the CT or CC type.

Dietary Recommendations

People whose blood pressure responds better to vitamin B2 should consider increasing their riboflavin intake. Vitamin B2 supplements can be taken after consulting with a qualified medical practitioner.

Another way to get vitamin B2 is through dietary sources.

Animal Sources of Vitamin B2

  1. Salmon
  2. Lean beef and pork
  3. Chicken breast
  4. Eggs
  5. Cheese

Plant Sources of Vitamin B2

  1. Fortified tofu
  2. Mushrooms
  3. Spinach
  4. Almonds
  5. Avocados
  6. Grains such as wheat

Summary

  1. Many research studies have clearly outlined the role of the MTHFR gene in regulating blood pressure. A common mutation, C677T, is associated with increased blood pressure or hypertension. C677T also results in increased homocysteine levels.
  2. Observational studies have indicated an inverse relationship between vitamin B2 and homocysteine - the higher the levels of vitamin B2, the lower the homocysteine levels.
  3. The observed relationship between vitamin B2 and homocysteine led researchers to explore the role of riboflavin in regulating blood pressure.
  4. People who have the TT type in rs1801133 of MTHFR gene respond better to vitamin B2 supplementation - riboflavin seemed to have a blood pressure-lowering effect on people with the TT genotype. The same effect was not seen in those with the CC type.
  5. The TT type people can benefit more from vitamin B2 consumption. Some dietary sources of vitamin B2 include salmon, lean meat, eggs, tofu, avocados, and almonds.

Reference

https://www.medicalnewstoday.com/articles/219561
https://www.tandfonline.com/doi/abs/10.1081/CEH-120020391?journalCode=iceh20
https://pubmed.ncbi.nlm.nih.gov/19952781/
https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.105.580332

Antioxidants Overview

Antioxidants are any compounds that help prevent cell damage in the body. One of the common reasons for cell damage is oxidation, where an atom or a molecule loses electrons.

While oxidation is useful for a few processes, excess oxidation leads to cell damage. The use of antioxidants is to regulate the level of oxidation in the body.

Depending on whether the antioxidants are soluble in water or fat (lipids), they are classified into two broad categories:

Antioxidants At The Molecular Level - Getting Technical

There are four basic levels of defense that all antioxidants have:

  1. Neutralizing free radicals by donating their own electrons
  2. Proactively searching and removing free radicals before they cause damage
  3. Self-repair and regulation of the internally produced antioxidants
  4. Adapting themselves to the body’s changes

Inside the body, the following factors determine antioxidant absorption and utilization:

The effectiveness of antioxidants depends on the internal environment they survive in.

Generally, larger molecules of antioxidants are broken down by the gut bacteria to help them enter the cell membranes.

The liver produces a few very important antioxidants. The cell membranes absorb some, while a large part is excreted out through urine.

Did You Know?

Have you heard of the famous egg or chicken question? The debate over whether the egg or the chicken came first to the world is never-ending. Until recently, scientists debated whether antioxidants were produced before or after the earth received oxygen through photosynthesis.

One may assume that microbes developed the ability to produce oxygen through photosynthesis first. This caused oxidative stress, and their bodies adapted themselves to produce antioxidants.

This is not the case, though!

According to this 2017 article, an anaerobic bacterium (oxygen-free bacterium) started producing an antioxidant called ergothioneine before it started the process of photosynthesis.

If not for neutralizing the effects of oxidation, what was the use of this antioxidant? Researchers are still trying to find out the answer to this question.

Why Do Humans Need Antioxidants?

Free radicals are unstable molecules that contain an unpaired electron. Because of this, they are highly reactive. Free radicals start taking electrons from the cells in your body and damages them in this process.

Free radicals are found in the air you breathe in, in the water you drink, in the foods you eat, and even in certain medications!

Antioxidants help by sacrificing/giving up their own electrons to the free radicals, thereby neutralizing them. Instead of damaging your cells, the free radicals damage the antioxidants, keeping you safe.

When your body does not have antioxidants, your cells are damaged faster because of free radicals, and this causes a variety of physical issues, including:

Genetic Association

GPX1 and Antioxidant Needs

Selenium is an important antioxidant that is needed for the healthy functioning of the body. Many enzymes in the body that fight free radicals are affected by how much selenium you get in your food.

Certain variations in the proteins GPX1 because of inadequate selenium intake are associated with increased cancer risk. In the rs1050450 SNP of the GPX1 gene, a minor allele ‘A’ increases your risk of developing cancer when your dietary selenium levels are low.

PON1 and Antioxidant Needs

Lycopene is a type of carotenoid that gives the red color to fruits and vegetables. This is also a very important antioxidant.
The PON1 gene helps produce the PON1 enzyme to protect against the oxidation of Low-Density Lipoprotein (LDL). LDL oxidation results in risks of atherosclerosis, heart attacks, and strokes.

The Q192R (denoted by rs662) is a polymorphism in the PON1 gene. The presence of the TT allele can imply lower or decreased levels of PON1 enzyme activity. The higher the PON1 enzyme activity, the lower is the risk for heart disease.

Non-genetic Factors Affecting Antioxidant levels

Unhealthy food habits - Most of the antioxidants required by your body can be obtained by including various fruits, vegetables, and other plant-based ingredients regularly. If you depend on restaurant takeaways or packaged and frozen foods for your meals, you may be at a higher risk for developing antioxidants deficiency.
Harvesting and handling of fruits and vegetables - Certain methods of harvesting and handling fresh fruits and vegetables can cause a reduction in the antioxidant levels in these produces. Consuming these fruits and vegetables will not give you your recommended values of antioxidants.
Cooking methods - According to a study boiling and pressure cooking the vegetable bring down the antioxidant levels. Opt for gentler cooking methods like steaming and quick frying instead.

Symptoms Of Excess Antioxidants

It is difficult to get an overdose of antioxidants with just food sources. However, it is possible to overdose when you are using antioxidant supplements. Here are some of the symptoms of excess antioxidant consumption:

  1. High doses of beta carotene are associated with an increased risk of lung cancer in those who smoke.
  2. High doses of vitamin E supplements can cause prostate cancer and bleed in the brain.
  3. High doses of vitamin A can lead to liver damages.
  4. Some studies suggest consuming excess antioxidants can make existing symptoms in cancer patients worse.
  5. Selenium overdose leads to nausea, bad breath, and various kidney and heart problems.
  6. Excess antioxidants can interact with certain medications that you take. Talk to your healthcare provider about recommended levels.

Symptoms Of Antioxidant Deficiency

A 2018 study analyzed the intake of 10 antioxidants. The antioxidants under consideration were beta carotene, alpha-carotene, beta-cryptoxanthin, lutein, lycopene, zeaxanthin, selenium, zinc, and vitamins C and E.

The study concluded that those deficient in these ten antioxidants had lowered anti-inflammatory activities and lowered HRQOL - Health-Related Quality Of Life. It includes factors needed for physical, mental, social, and emotional quality of life.

Oxidative stress, over time, can damage healthy cells in the body. This can result in increased risks of:

## Recommendations To Get The Right Amounts Of Antioxidants
**Include a variety of vegetables and fruits** - Vegetables and fruits are very rich sources of different antioxidants. One of the best ways to prevent antioxidant deficiency is to include colorful fruits and vegetables in your diet. Studies show that fresh fruits and vegetables bring down your risk for developing several diseases apart from keeping you fit.
**Prefer food-based antioxidants over supplements** - Unless you have been advised specifically, stay away from supplements and change your food habits to increase your antioxidant intake.
**Know how your genes affect you** - If you are genetically prone to requiring more antioxidants than normal individuals or at a higher risk for developing certain diseases because of antioxidant deficiency, plan your food choices right.
**Supplement antioxidants with caution** - While supplements can easily cause an overdose, supplements can also interact unpleasantly with certain medications you consume.
**Change your cooking methods** - Your cooking methods matter a lot. Choose healthier cooking options like broiling, steaming, and quick frying on a flat pan instead of boiling and pressure cooking.

## Summary
1. Antioxidants are compounds that help prevent cell damage. There are 1000s of individual antioxidants available in nature.
2. While most antioxidants are obtained from food sources, few very vital ones are produced in the body.
3. Antioxidants bring down the risks of several diseases and keep you younger for a longer time.
4. Antioxidant overdose is rare and occurs only upon consuming supplements. Antioxidant deficiency can lead to a lowered Health-Related Quality Of Life (HRQOL).
5. Some people can be genetically inclined to absorb lesser quantities of antioxidants than others. Such individuals may need to compensate with supplements.
6. For healthier individuals, it is recommended to get the dose of antioxidants from food rather than from supplements.

References

https://www.hsph.harvard.edu/nutritionsource/antioxidants/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249911/
https://www.nccih.nih.gov/health/antioxidants-in-depth
https://pubmed.ncbi.nlm.nih.gov/18630141/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3614697/
https://www.ahajournals.org/doi/10.1161/circ.136.suppl_1.12351
https://www.nccih.nih.gov/health/antioxidants-in-depth
https://pubmed.ncbi.nlm.nih.gov/24915343/
https://www.sciencedaily.com/releases/2009/04/090415163730.htm
https://www.health.harvard.edu/staying-healthy/understanding-antioxidants
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249911/
https://www.cbc.ca/news/health/antioxidant-supplement-overload-can-be-hazardous-1.1412993

The Sense of Taste

The flavor you experience when you take a bite of your favorite food is a result of three sensory inputs:
- Taste
- Smell
- The tactile sensation of munching food

Gustation, another term for taste, helps us differentiate the chemicals present in the food. The organ for taste is the tongue.
Scientists generally describe human taste perception in terms of four qualities:
- Saltiness
- Sourness
- Sweetness
- Bitterness.

Different regions of the tongue pick up on different taste qualities. Some studies speculate the existence of other taste categories. A notable one would be “umami” - the taste given out by an amino acid glutamate, present in parmesan cheese, soy sauce, and tomatoes.

Upon chewing the food, various ‘bitter’ molecules (present in foods like cabbage and broccoli) are released in our mouth. Our tongue contains around 35 different proteins that detect and respond to bitter substances.

The Evolution Of Bitter Taste

The usage of “to leave a bitter taste in one’s mouth” to describe unpleasant situations is no coincidence. There’s a reason why the word bitter is often used in a negative connotation. Despite the bitter taste found in healthy food like vegetables, most people still have a strong negative reaction. Why?

Our ancestors have not always been able to taste bitter foods. The bitter taste perception only evolved around 200 million years ago. Taste was a sense that aided our ancestors to predict the nature of the food they were consuming. Most poisonous compounds in nature are bitter. So, bitter meant poisonous - it indicated the presence of toxins.
Plants also adopted this trick to prevent the seeds from being eaten, a defense mechanism called “antifeedant” defense. By “faking” a bitter taste, the seeds had a better chance of germinating.
The healthy bitter foods we find today are the ones trying to fake being poisonous to prevent themselves from being eaten.

Thus, the development of bitter taste was a matter of survival. Individuals who had the proteins that could sense the bitter taste were able to detect toxins in their food. On the other hand, those who didn’t have the “bitter-tasting” proteins would ingest these toxins and die. The individuals who could taste bitter foods would also be able to pass these proteins to their offspring, thus increasing their survivability.

How Does This Evolution Affect You?

The sensitivity to better taste may have offered a survival advantage to our ancestors. But, in modern human society, it can be detrimental. The advent of agriculture resulted in the production of nutritious vegetables. Certain compounds in the vegetables, however, activate the bitter taste receptors. So the “bitter-tasting” proteins, which were supposed to protect us from toxic materials, now prevent some people from consuming vegetables by giving out an undesirable bitter taste.

How Genes Influence Bitter Taste Perception?

TAS2R38 and Tendency to Prefer Bitter Taste

TAS2R38 gene is located on chromosome 7 and encodes the protein taste receptor 38 - a bitter taste receptor. TAS2R38 influences the ability to taste both 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC) - both of these are chemically related compounds that elicit a bitter taste.
Insensitivity to the bitter-tasting compounds PROP and PTC has been proposed as a marker or an ‘indicating factor’ for individual differences in bitter taste perception that influence food preference and intake.

rs713598
rs713598 is one of three important SNPs involved in the perception of bitter taste of molecules like PTC present in foods like broccoli and drinks like coffee.

According to a study, people with the CC and CG types of rs713598 showed sensitivity to PTC , while people with the GG type were unable to taste it.

Here, G is called the ‘non-tasting’ allele, and C is called the ‘tasting’ allele.

rs1726866
rs1726866 is an SNP in the TAS2R38 gene that influences the ability to perceive bitter taste.
The “C” allele of rs1726866 is strongly associated with increased taste sensitivity to PROP/PTC.

Here, *T is called the ‘non-tasting’ allele, and C is called the ‘tasting’ allele.

rs10246939
rs10246939 is an SNP that influences the sensitivity to the bitterness of PROP and PTC. People who have the CC and CT types are known to be sensitive to bitterness, while individuals with the TT type have lower bitterness intensity.

Here, T is called the ‘non-tasting’ allele, and C is called the ‘tasting’ allele.

People who are extremely sensitive to bitter taste are called Supertasters, while those who perceive little or no bitter taste are called Nontasters.

How Does Being a Supertaster Affect Your Health?

Supertasters May Tend to Consume Fewer Vegetables

Many health vegetables like Brussel sprouts, broccoli, and cauliflowers are high in PROP and PTC. Being highly sensitive to these bitter flavors, supertasters are more likely to avoid these vegetables. Thus, the supertasters tend to miss out on nutrition and fiber from the vegetables.

Supertasters May Tend to Consume More Salt

Salt does an excellent job of masking bitter notes. So, supertasters may over-salt their dishes. Consuming excess salt (sodium) has been linked to many health risks like hypertension, heart disease, and stroke.

Supertasters Are More Prone to Burning Mouth Syndrome

Burning Mouth Syndrome is characterized by a burning, scalding, or tingling feeling in the mouth. Supertasters have an unusually high density of taste buds, and as a result, the flavors are much more intense.

Supertasters May Have a Higher Risk for Colon Cancer

Bitter substances have a protective role against certain types of cancers, including colon cancer. Since supertasters tend to avoid bitter substances, they may be more susceptible to colon cancer.

On the brighter side, supertasters also find highly fatty or sugary foods less palatable than nontasters. They also tend to avoid excess alcohol consumption (because of the bitter taste) and smoking.

Tips For Getting Healthy Vegetables Into Your Diet

Lemon helps take away some of the bitterness from the vegetables.
Less bitter vegetables like squash, sweet potatoes, and corn are more palatable and high in nutrients.
Seasoning bitter vegetables like Brussel sprouts with salt and natural sweeteners can help mask the bitterness. However, it is important not to overdo the salt and sugar.

Summary

Reference

https://en.wikipedia.org/wiki/TAS2R38
https://pubmed.ncbi.nlm.nih.gov/28738701/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2938875/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6770895/
https://www.nidcr.nih.gov/health-info/burning-mouth
https://www.aicr.org/news/bitter-taste-sensitivity-can-be-a-factor-in-cancer-risk/

Phosphorus is a mineral that makes up 1% of a person's total body weight. It is also the second most abundant mineral in the body that is important for filtering out waste and building healthy bones and teeth. It is commonly found in many foods, like beer and cheese. Phosphate is a form of phosphorus that can be taken as supplements when you can’t get the required amounts through diet.

Importance Of Phosphate

Our body uses phosphorus for
- Movement of muscles
- Strong bones and teeth
- Providing energy
- Lowering post-exercise muscle pain
- Filtering waste from the kidney
- Formation of DNA
- Nerve conduction
- Maintaining a regular heartbeat

Phosphate is also known to treat urinary tract infections and prevent the development of calcium stones in the kidney.

When Was Phosphate Discovered?

In the quest to create the “philosophers’ stone” like every other alchemist, Henning Brandt, a German scientist, collected and boiled around 1200 gallons of urine. He then mixed the tar-like residue obtained with sand and charcoal and maintained the mixture at the highest temperature the furnace could reach. After several hours of heating the residue, a white vapor was formed, which was then condensed into white drops. These drops had the “glow in the dark” property and hence the substance was named phosphorus.
The discovery of phosphorus made Brandt the first-ever scientist to discover a chemical element. Due to financial constraints, he ended up selling the discovery process to other scientists. Within 50 years of its discovery, phosphorus was being produced and sold to apothecaries, natural philosophers, and showmen. Further down the line, this element was making its way into matches, fertilizer, and bombs.

What Is The RDA Of Phosphate?

The recommended dietary allowance (RDA) of phosphate varies between 100mg and 1250 mg. Infants need about 200mg, while children between the ages of 9 and 18 need 1250 mg. Adults need 700mg.

How Genes Influence Phosphate Requirements?

CASR Gene and Phosphate Needs

The CASR gene encodes the calcium-sensing receptor (CASR). It is found in the plasma membranes of the parathyroid gland and renal tubule cells (in the kidneys). Calcium molecules bind to the calcium-sensing receptors. This receptor also regulates the release of the parathyroid hormone, which is responsible for phosphorus reabsorption in the kidney.

rs17251221 of CASR Gene And Phosphate Deficiency Risk
rs17251221 is an SNP in the CASR gene. The G allele of rs17251221 was also associated with higher serum magnesium levels and lower serum phosphate levels. Each copy of the G allele was also associated with a lower bone mineral density at the lumbar spine.

Non-genetic Factors Influencing Serum Phosphate Levels

  1. Vitamin D3 levels: A deficiency in vitamin D levels could result in poor absorption of phosphate
  2. Alcoholism: Alcoholism is treated with refeeding, which depletes phosphate levels
  3. Dietary intake: Severe malnutrition, such as from anorexia or starvation, can result in phosphate deficiency
  4. Kidney disease: Affects the renal reabsorption of phosphate
  5. Diarrhea: Diarrhea has been shown to increase phosphate losses through the intestines

What Happens When Phosphate Levels Are Too Low?

  1. Low phosphorus levels can result in
  2. Anxiety
  3. Appetite loss
  4. Joint pain
  5. Irritability
  6. Tiredness or fatigue

Children with phosphorus deficiency may also show poor bone development.

What Happens When Phosphorus Levels Are Too High?

Hyperphosphatemia is a rare condition characterized by high levels of phosphorus in the blood. It occurs mainly due to kidney problems or issues in calcium homeostasis (maintenance of calcium levels). The presence of higher levels of calcium in the blood can result in:
1. Diarrhea
2. High vitamin D levels
3. Damage to kidneys
4. Serious infections

"## What Is The Test To Identify Phosphorus Levels?
Phosphorus levels can be determined using a serum phosphorus test. This test is usually carried out to check phosphate levels as an indicator of kidney or bone disease. It also aids in assessing the functioning of parathyroid glands.
"

Dietary Sources Of Phosphorus

Plant Sources Of Phosphorus

Animal Sources Of Phosphorus

Summary

  1. Phosphorus plays an important role in the health of bones, muscles, and kidneys. It works with calcium to regulate bone health.
  2. Most people get enough phosphorus through their diets; however, several factors can affect its absorption in the body.
  3. A region rs17251221 in the CASR gene influences the intestinal absorption of phosphorus; the G allele has been associated with decreased absorption and, thus, decreased phosphate levels in the body.
  4. Low vitamin D3 levels, diarrhea, and alcoholism are also risk factors for phosphate deficiency - it can lead to anxiety, joint pain, and fatigue.
  5. Some dietary sources of phosphorus are dairy, nuts, chicken, and seafood.

Reference

https://medlineplus.gov/genetics/gene/casr/
https://academic.oup.com/hmg/article/19/21/4296/665947
https://www.mayoclinic.org/diseases-conditions/rickets/symptoms-causes/syc-20351943

Saturated Fats Overview

Saturated fats are dietary fats that contain carbon, oxygen, and hydrogen molecules. These types of fats have saturated hydrogen molecules and just one bond between the carbon molecules. As a result, saturated fats remain in a liquid state when the temperature is high and solidify when the temperature drops.

Saturated fats are a common source of fat in the American diet.

Why Are Saturated Fats Considered Unhealthy?

Several studies have proved that excess saturated fat intake increases the risk of the below conditions.
Cardiovascular diseases
Hyperlipidemia (excess lipids in the blood)
Type II diabetes
Obesity and weight gain

Weight gain is a common problem with increased saturated fats intake. Saturated fats add extra calories to your meals and increase your LDL cholesterol levels. These steadily cause an increase in body weight.

Saturated Fats At The Molecular Level - Getting Technical

The digestion of saturated fats starts from the minute you consume fatty food. Saliva contains enzymes that break down fats into smaller molecules. The act of chewing food also helps in breaking down the particles. From here, fat molecules reach the stomach. The bile and stomach enzymes work on saturated fats and break them down into even smaller components. The very small fat molecules reach the bloodstream directly. Bigger ones get passed on to the intestine. In the intestine, fats get converted into triglycerides. Triglycerides are forms of fats that can be stored in the body.

Triglycerides circulate throughout the body and some of them are absorbed by the cells for energy. The rest are stored in the adipose tissue. Saturated fats have different structures than unsaturated fats. This makes it easy for lots of molecules to be packed together at the same location. Because of this tight packaging, it is difficult for the body to break down saturated fats. When you consume more fat than what’s needed by the body, your adipose tissue starts building up and you start putting on weight.

The more saturated fat you keep consuming over the years, the higher will be your body fat percentage.

Getting Technical - How’s Iron Circulated In the Body?

Iron Absorption

A fraction of the ingested iron is absorbed by the body. It can vary from 5% to 35% depending on a few factors like the type of iron (heme or non-heme) and hepcidin levels. Hepcidin is secreted by liver cells and is a circulating peptide hormone that coordinates the use of iron.

Iron Circulation

Iron circulation in the body occurs with the help of a protein called transferrin. The iron laden transferrin binds to its receptor, which leads to the entry of iron into the cell. Iron is then transported to the cell’s mitochondria, where it is used to synthesize heme or iron-sulfur compounds.

Did You Know?

Many people assume that saturated fats are types of trans fat, which are the worst types of fats you can eat. Trans fat is a byproduct of the process called hydrogenation. This process helps increase the shelf life of cooking oils to preserve them for a longer time. Trans fat is commercially produced and has no health benefits at all.

Saturated fats are not commercially produced like trans fats.

These naturally occur in the foods you eat. When had in the right amounts, saturated fats are beneficial to the body and help absorb certain types of vitamins. When you limit your fat intake and make sure you pick unprocessed and fresh sources of saturated fats, saturated fats are not bad! They don’t deserve all the bad rap they have been getting so long!

The History Behind Saturated Fats

In the 1950s, heart diseases were the biggest cause of death in the United States. On September 24th, 1955, the US President Dwight D. Eisenhower had a massive heart attack. Though he recovered and went on to win a second term, this caused an alarm in the US.

Diet and unhealthy lifestyles were both blamed for the increase in cardiovascular problems. It was during this time that fats were largely researched upon.

During the 1950s, researchers found a relationship between hyperlipidemia and heart diseases. This added fuel to the fire.

From the 1950s to the early 1980s, studies conducted all around the world found a positive relationship between saturated fats, weight gain, and cardiovascular problems.

In 1980, the ‘Dietary Guidelines for Americans’ was released by the US Department of Health and Human Services and the US Department of Agriculture. It asked people to limit their consumption of saturated fats and cholesterol.

Since then saturated fats have had a bad reputation globally.

RDA of Saturated Fats

For an average American, the recommended intake of saturated fats should be less than 10% of the total caloric intake.

For instance, if you are on a 1500 calorie diet, just 150 calories have to come from saturated fats.

For those diagnosed with high cholesterol levels or those with existing heart conditions, the recommended intake of saturated fats has to be less than 7% of the daily caloric value.

In terms of weight, the Daily Value (DV) of saturated fats is 20 grams per day.

How Genes Influence Saturated Fat Requirements?

FTO Gene and Saturated Fat Metabolism

The FTO gene is a very popular gene related to obesity and weight gain. Certain variants of the FTO gene seem to worsen the effects of a saturated fat-based diet.

There are two SNPs of the FTO gene that relate saturated fat intake and weight gain.

rs9939609 of FTO Gene and Weight Gain Tendency On Saturated Fats Intake

The A allele of the rs9939609 SNP makes people gain more weight upon saturated fat intake. The T allele does not relate saturated fats and weight gain though.

rs1121980 of FTO Gene and Weight Gain Tendency On Saturated Fats Intake

Similarly, the A allele of the rs1121980 SNP causes weight gain with saturated fats intake while the T allele does not result in weight gain.

APOA2 Gene and Saturated Fat Metabolism

The APOA2 gene helps produce a protein called apolipoprotein A-II. This regulates fat metabolism and also helps in building HDL cholesterol in the body. A primary SNP of the APOA2 gene relates saturated fat intake and weight gain.

rs5082 of APOA2 Gene and Weight Gain Tendency On Saturated Fats Intake
The G allele of the rs5082 SNP is associated with obesity and individuals gain excess weight up on saturated fat intake. The A allele however is not associated with either obesity or weight gain relating to saturated fat intake.

STAT3 Gene and Saturated Fat Metabolism

The STAT3 gene produces a transcription factor that helps in controlling various other genes in the body. There is a link between variations in the STAT3 gene, saturated fat intake and obesity.

rs8069645 and rs744166 of STAT3 Gene and Weight Gain Tendency On Saturated Fats Intake
Men with the G allele of both these SNPs are likely to gain more weight with saturated fats intake. This can also lead to obesity. Those with the A allele are not affected by saturated fats.

rs1053005 and rs2293152 of STAT3 Gene and Weight Gain Tendency On Saturated Fats Intake

The C allele of both these SNPs can weight gain and obesity in men up on excess saturated fats consumption. This relationship is not found in those with the T allele.

Non-genetic Factors Relating To Saturated Fats And Weight Gain

  1. Higher caloric intake - Saturated fats have 9 calories per gram of fat. In comparison to fats, carbohydrates and proteins have about 4-5 calories per gram only. Because of this, it is easier to consume more calories with saturated fat intake, which can lead to weight gain.

  2. Fat storage - When you consume more fat than what’s needed for the body, excess fat is stored in the adipose tissues. When you consume excess saturated fats, your adipose tissue grows and you start putting on weight.

  3. Taste - Fatty foods are generally tastier. Think of buttery bacon, fried chicken, sweet pastries, or a big slice of cheesy pizza. They get addictive with time and this is another non-genetic factor that causes gradual weight gain.

  4. Food combinations - Most packaged foods/ takeaways/ restaurant meals are a mix of carbohydrates and saturated fats. While carbohydrates give the body the needed energy, the excess fat you consume is mostly not used. This gets stored in the body, leading to weight gain.

What Happens When You Do Not Consume Saturated Fats?

Fats are essential sources of nutrition. Fats help absorb and transport certain vitamins throughout the body. Fats also provide you with insulation when the temperature goes down and maintains cell membranes.

The right amounts of saturated fats help produce steroid hormones like testosterone and estrogen. Fats keep you fuller for a longer time and are used by the body as energy when you are glucose deprived.

While it is healthier to bring down your saturated fats intake, do not skip them altogether. Choose unprocessed and fresher saturated fats to enjoy their benefits.

Excess Saturated Fats And Weight Gain

When you consistently include excess saturated fats in your diet (more than 10% of your caloric intake), here are some of the problems it can cause.

Recommendations For Healthy Saturated Fat Consumption To Prevent Weight Gain

  1. Make healthier food choices. Let your sources of saturated fats come from natural plant sources and unprocessed meat. Stay away from processed meat, deep fried goods and pastries and savories.
  2. Low fat dairy products have limited saturated fats and also provide you with essential vitamins and calcium.
  3. Choose healthier cooking methods like broiling, sauteing, boiling, steaming, and baking instead of deep frying and roasting.
  4. Opt for skinless chicken and fish over red meat.
  5. Fill up your plate with healthy fruits and vegetables and smaller portions of fat.
  6. Be calorie conscious. Count your caloric intake for the day to stay fit. Make sure most of your calories come from proteins, natural sources of fat, and complex carbohydrates.
  7. It is ok to treat yourself to fast foods and packaged goods once in a while. For the majority of the time, cook your meals fresh at home.

Summary

Reference

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5642188/
https://www.health.harvard.edu/staying-healthy/new-thinking-on-saturated-fat
https://www.health.harvard.edu/staying-healthy/the-truth-about-fats-bad-and-good
https://pubmed.ncbi.nlm.nih.gov/20934605/

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