Is fat a flavor?
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:
- Effective stimuli that react with the tongue: For fats, the stimuli arise from the breakdown of fatty acids
- Receptors on the tongue that identify the stimuli: A study published in the Journal of Lipid Research by Pepino et al. showed that our tongue indeed contains a protein (CD36) that can detect the presence of fats.
- 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.
- 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.
- 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 survived 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
Increased Consumption of Certain Types of Fats 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.
Increased Consumption of Certain Types of Fats 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.
Increased Consumption of Certain Types of Fats 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.
Increased Consumption of Certain Types of Fats 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
- Salmon and other fatty fish
- Whole eggs
- Cheddar cheese
- Full fat yogurt
Plant Sources of Healthy Fats
- Avocados
- Tofu
- Chia seeds
- Dark chocolate
- Peanut butter
- Olive oil
Summary
- 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. - Certain people prefer fatty foods less than others because of their heightened sensitivity to fats. As a result, they may be less likely to consume excess amounts of this nutrient.
- 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.
- Increased fat consumption is linked to health conditions like diabetes, heart diseases, and cancer.
- 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/
