Table 1.
Summary of Genetic Variants that modify the association between various dietary factors and performance-related outcomes.
| Gene (rs number) | Function | Dietary factor | Dietary sources | Performance-related outcome |
|---|---|---|---|---|
| CYP1A2 (rs762551) | Encodes CYP1A2 liver enzyme: metabolizes caffeine; identifies individuals as fast or slow metabolizers | Caffeine | Coffee, tea, soda, energy drinks, caffeine supplements | Cardiovascular health, endurance (21, 22, 57, 58) |
| ADORA2A (rs5751876) | Regulates myocardial oxygen demand; increases coronary circulation via vasodilation | Caffeine | Coffee, tea, soda, energy drinks, caffeine supplements | Vigilance when fatigued, sleep quality (49, 51–53) |
| BCMO1 (rs11645428) | Converts provitamin A carotenoids to Vitamin A | Vitamin A | Bluefin tuna, hard goat cheese, eggs, mackerel, carrots, sweet potato | Visuomotor skills and immunity (93, 95, 98–101) |
| MTHFR (rs1801133) | Produces the enzyme methylenetetrahydrofolate reductase, which is involved in the conversion of folic acid and folate into their biologically active form, L-methylfolate | Folate | Edamame, chicken liver, lentils, asparagus, black beans, kale, avocado | Megaloblastic anemia and hyperhomocysteinemia risk (112, 116–118) |
| HFE (rs1800562 and rs1799945) | Regulates intestinal iron uptake | Iron | Beef, chicken, fish, organ meats (heme iron); almonds, parsley, spinach (non-heme iron) | Hereditary hemochromatosis (130–132) |
| TMPRSS6 (rs4820268), TFR2 (rs7385804), TF (rs3811647) | Regulate the peptide hormone, hepcidin, which controls iron absorption | Iron | Beef, chicken, fish, organ meats (heme iron); almonds, parsley, spinach (non-heme iron) | Iron-deficiency anemia risk (24, 27, 120, 123–125) |
| FUT2 (rs602662) | Involved in vitamin B12 cell transport and absorption | Vitamin B12 | Clams, oysters, herring, nutritional yeast, beef, salmon | Megaloblastic anemia and hyperhomocysteinemia (142) |
| GSTT1 (Ins/Del) | Plays a role in vitamin C utilization via glutathione S-transferase enzymes | Vitamin C | Red peppers, strawberries, pineapple, oranges, broccoli | Circulating ascorbic acid levels Mitigate exercise-induced ROS production (153, 155) |
| GC (rs2282679) and CYP2R1 (rs10741657) | GC encodes vitamin D-binding protein, involved in binding and transporting vitamin D to tissues; CYP2R1 encodes the enzyme vitamin D 25-hydroxylase involved in vitamin D activation | Vitamin D | Salmon, white fish, rainbow trout, halibut, milk | Circulating 25(OH)D levels impacting immunity, bone health, inflammation, strength training and recovery (1, 162, 164, 166, 168) |
| GC (rs7041 and rs4588) | GC encodes vitamin D-binding protein, involved in binding and transporting vitamin D to tissues; Vitamin D is required for calcium absorption | Calcium | Yogurt, milk, cheese, firm tofu, canned salmon (with bones), edamame | Bone/stress fracture risk Muscle contraction, nerve conduction, blood clotting (162, 164, 166, 168) |
| PEMT (rs12325817) | Involved in endogenous choline synthesis via the hepatic phosphatidylethanolamine N-methyltransferase pathway | Choline | Eggs, beef, poultry, fish, shrimp, broccoli, salmon | Muscle or liver damage, reduced neurotransmitters (174, 175, 185, 186) |
| MTHFD1 (rs2236225) | Encodes protein involved in trifunctional enzyme activities related to metabolic handling of choline and folate | Folate/Choline | Folate: Edamame, chicken liver, lentils, asparagus, blck beans, kale, avocado Choline: Eggs, beef, poultry, fish, shrimp, broccoli, salmon |
Muscle or liver damage, reduced neurotransmitters (185, 186) |
| FTO (rs1558902/rs9939609) | Precise function undetermined; plays a role in metabolism and has been consistently linked to weight, BMI and body composition | Protein/SFA:PUFA | Protein: chicken, beef, tofu, salmon, cottage cheese, lentils, milk, Greek yogurt SFA: cheese, butter, red meat, baked goods PUFA: flaxseed oil, grape seed oil, sunflower oil |
Optimizing body composition (190, 191) |
| TCF7L2 (rs7903146) | Involved in expression of body fat | Fat | Nuts/seeds, butter, oils, cheese, red meat, high-fat dairy | Optimizing body composition (192, 193) |
| PPARγ2 (rs1801282) | Regulates adipocyte differentiation | MUFA | Macadamia nuts, almond butter, peanut butter, olive oil, canola oil, sesame oil | Optimizing body composition (194) |