The Tumor Necrosis Factor Alpha (TNFA) gene is associated with the synthesis of TNFA, a pro-inflammatory cytokine that regulates immune responses such as inflammation. Specific alleles of this gene are known to either increase or decrease the levels of TNFA. People with the A variant of the gene are found to synthesize more TNFA which affects fatigue, inflammatory response, diabetes and cardiovascular risk and response to training.
Association with speed of recovery:
People with the A variant require longer recovery times compared to people with the G variant. A study which was part of the HERITAGE study measured CRP before and after an endurance training programme lasting 20 weeks. The baseline CRP levels were higher among people with the A variant when compared to people with the G Variant. After the training programme, there was a higher increase in CRP among people with the A variant than among people with the G variant. This shows that people with the A variant required longer recovery periods in between intense exercise. A study conducted to identify the association between physical exercise and anti-inflammatory response found that polymorphisms in TNFA gene was associated with the levels of serum C reactive protein after moderate to vigorous physical activity. People with the G variant had a greater decrease in C reactive protein upon physical activity than people with the A variant.
Does your 23andme, Ancestry DNA, FTDNA raw data have TNFA gene variant information?
| CHIP Version | TNFA SNPs |
| 23andMe (Use your 23andme raw data to know your TNFA Variant) | |
| v1 23andme | Present |
| v2 23andme | Present |
| v3 23andme | Present |
| v4 23andme | Present |
| V5 23andme (current chip) | Present |
| AncestryDNA (Use your ancestry DNA raw data to know your TNFA Variant) | |
| v1 ancestry DNA | Present |
| V2 ancestry DNA (current chip) | Present |
| Family Tree DNA (Use your FTDNA raw data to know your TNFA Variant) | |
| OmniExpress microarray chip | Present |
Association with fatigue:
In a study conducted on the influence of TNFA gene polymorphisms on fatigue, people with the A variant of the gene were associated with increased sleep disturbance and fatigue than people with the G variant. In another study conducted on elderly women, people with the G variant had a better physical performance independent of their exercise modality.
Association with Cholesterol levels In a study aimed at understanding the metabolic response of people on a high protein/low carbohydrate diet showed that people with the GG genotype had a greater reduction in total cholesterol, triglycerides and LDL cholesterol.
Association with Diabetes/ Impaired Glucose tolerance:
In a study conducted as a part of the Finnish Diabetes Prevention Study, the presence of the A variant was shown to be a predictor for the conversion from Impaired Glucose Tolerance (IGT) to type 2 Diabetes. Another study showed that the presence of the A variant of the gene was associated with an increased risk for diabetes and higher glucose levels in the body.
Association with Bone Mineral Density:
In a study conducted on postmenopausal women, people with the A variant were associated with increased risk for osteoporosis. Higher levels of cytokines lead to an increase in bone breakdown.
Association with Cardiovascular Diseases:
People with the A variant were shown to have an increased risk for acute myocardial infarction.
| Genotype rs1800629 | Phenotype | Recommendation |
| AA | [Limitation] More likely to have higher TNFA level [Limitation] More likely to have higher levels of inflammation after intense exercise [Limitation] More likely to require longer period of recovery [Limitation] More likely to have higher level of fatigue [Limitation] More likely to have higher risk for Diabetes [Limitation] More likely to have higher risk for Myocardial Infarction [Limitation] More likely to have lower reduction in triglyceride, cholesterol levels on a high protein/ low carbohydrate diet | Likely to have lower reduction in inflammation upon exercising than G variants. Increased risk for fatigue post exercises requires optimum periods of rest between repetitions Include 3g of Omega 3 fatty acids in the diet which is found to lower the levels of inflammation |
| AG | Moderate level of C reactive protein and more likely to have moderate level of risk for diabetes | Likely to have lower reduction in inflammation upon exercising than G variants. Increased risk for fatigue post exercises requires optimum periods of rest between repetitions Include 3g of Omega 3 fatty acids in the diet which is found to lower the levels of inflammation |
| GG | [Advantage] More likely to have normal level of TNFA [Advantage] More likely to have lower levels of inflammation after intense exercise [Advantage] More likely to require shorter period of recovery [Advantage] More likely to have lower level of fatigue [Advantage] More likely to have lower risk for Diabetes [Advantage] More likely to have lower risk for Myocardial Infarction [Advantage] More likely to have higher reduction in triglyceride, cholesterol levels on a high protein/ low carbohydrate diet | Likely to have higher reduction in inflammation upon exercising Include Omega 3 fatty acids in the diet |
References:
- https://www.ncbi.nlm.nih.gov/pubmed/27706628
- https://www.ncbi.nlm.nih.gov/pubmed/27513494
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4983298/
- https://www.ncbi.nlm.nih.gov/pubmed/23430759/
- https://www.ncbi.nlm.nih.gov/pubmed/20361391
- https://www.ncbi.nlm.nih.gov/pubmed/12829659
- https://www.ncbi.nlm.nih.gov/pubmed/26914399
“Nutrigenetics, fitness genetics, health genetics are all nascent but rapidly growing areas within human genetics. The information provided herein is based on preliminary scientific studies and it is to be read and understood in that context.”
