Transforming Human Nutrition | Nutrigenetics Blogs


Posted by : Anusha Sunder , on Mon, Jul 06, 2020

An athlete should be fit and fine to achieve his best. Achievement is the output of performance, and performance in turn relies on multiple factors including genetics. Though training is an important aspect of performance, how an individual responds to sports training is hugely influenced by genetics. This is because there are specific regions of DNA that can vary between individuals. And, such variations (mainly Single Nucleotide Polymorphisms or SNPs) may, in part, explain why some individuals have differentiated responses to sports training. Identifying such specific polymorphisms can heighten performance by aiding in sport selection based on stamina and flexibility, tailor-make training plans, bring out the susceptibility to sport-related injuries, and notify on the recovery time needed by the individual1.  

Genes’ impact sports performance, how?

Genes associated with sport abilities and competences have numerous variants. Up to 50% of athletic ability is influenced by genetic variations and, till date, more than 240 genetic variations related to sports qualities such as speed, strength, stamina, endurance, predisposition to sport-related injury and pace of recovery have been identified2,3. The following pictorial representation gives us detail on the vital determinants of sports performance.

Figure 1.  Determinants of sports performance


The significance of understanding athletic potential through genes

The way our genes encode stays unchanged for a lifetime; hence a genetic testing can bring out sports qualities in a potential athlete based on genetic variations in performance-related genes. An understanding of the genetic potential in an athlete can help him choose activities suitable to his genotype or improve his performance by knowing his limitations4,5,6,7.

The genes that significantly affect genetic changes resulting in high physical performance are called performance enhancing polymorphisms (PEP). This can be best understood with the example of ACTN3 or speed gene. ACTN3 gene provides instructions for the synthesis of a protein called alpha (α)-actinin-3, which is predominantly found in fast-twitch muscle fibres. There are two variants of the ACTN3 gene (widely studied single nucleotide polymorphism at rs1815739), the R variant and the X variant. The R variant of the gene produces alpha actinin 3 adequately and hence inheritance of two R alleles, that is, ‘RR’ will exemplify the sprinting qualities and make a person exceptionally good in sprint kind of sports like 100 m sprint, 100 m swimming or power lifting, to name a few. On the other hand, X variant produces comparatively less alpha actinin 3 increasing suitability for endurance sports in its carriers8,9,10,11.


Role of genes in determining sports qualities

Aerobic Capacity

Suitability towards Endurance/Sprint

Propensity to sport-related injury

Recovery pace


What is personalised nutrition and why is it important for enhancing an athlete’s performance?

Training is vital for performance and a desirable performance translates into achievement. Appropriate nutrition is essential in staying fit during training sessions as well as during performance. Identifying key polymorphisms that are likely to influence sports quality of an individual provides an approach to understand and optimize nutrition at the individual level. An individual’s trainability or response to exercise training is influenced by genes53. And hence understanding relevant genetic variations can help in adding gene-specific nutrients to their plate. These gene-specific nutrients can enhance their response to exercise training, and this is exactly what we are going to understand from the following examples.

Gene-specific nutrients enhance aerobic capacity:

UCP3 gene:

UCP3 gene (Uncoupling protein 3) is primarily expressed in skeletal muscle mitochondria. It takes part in energy metabolism. ATP synthesis is matched to ATP utilization during muscle contraction. The uncoupling of the mitochondrial electron transport chain from the phosphorylation of ADP optimizes the efficiency and fine tunes the degree of coupling of oxidative phosphorylation. This prevents generation of reactive oxygen species by the respiratory chain. Uncontrolled production of reactive oxygen molecules can cause the collapse of mitochondrial energy conservation, loss of membrane integrity, and cell death by necrosis.

How to understand its variation?

The commonly studied single nucleotide polymorphism is at rs1800849 of this gene. T allele is associated with increased skeletal muscle UCP3 mRNA expression and increased aerobic capacity. While for C allele carriers, the aerobic capacity or the functional capacity for exercise in the presence of oxygen is sub-optimal, as energy coupling happens less satisfactorily in the mitochondria of muscle cell53,54,19.

Can specific nutrient(s) help to cope with a not-so-favourable variation in this gene?

To cope with such genetic variations, a start slow and steady approach along with adequate rest periods prove remedial. Additionally, gene-specific nutrients like Coenzyme Q10 or CoQ10 can improve your oxygen utilization capacity thereby averting breathlessness. CoQ10 is a cofactor for mitochondrial uncoupling proteins and serves as an integral component of the mitochondrial oxidative phosphorylation system. Coenzyme Q10 is one of the most significant lipid antioxidants that prevents the generation of free radicals in mitochondria. 55,56,57,58,59,60,61.

Gene-specific nutrients can avert muscle fatigue by improving lactate clearance

MCT1 gene:

The removal rate of lactic acid is an important factor of muscle fatigue after intensive trainings, and this has a strong link with MCT1 gene. Lactic acid is a by-product of the anaerobic energy pathway, a process which provides energy to muscles by partially breaking down glucose without the need for oxygen. Lactic acid is formed from glucose, and used by working muscles for energy. Lactate is an efficient energy source and plays an important role in exercise-mediated adaptations. Anaerobic metabolism produces energy for short, high-intensity bursts of activity (lasting no more than a few minutes) before the lactic acid build-up reaches a threshold where it can no longer be absorbed and, therefore, accumulates. This point is known as the lactate threshold wherein lactic acid builds up in the blood stream faster than the body can remove it. Skeletal muscle is the major producer and user of lactate in the body. Therefore, transport of lactate across cells' membrane is of considerable importance. In red skeletal muscle, monocarboxylate (lactate/pyruvate) transporter 1 (MCT1) is required for lactate to enter the myocytes for oxidation.

How to understand its variation?

The A1470T polymorphism (rs1049434) in the MCT1 gene is shown to be associated with lactate transport rates in human skeletal muscles. T allele is associated with reduction of lactate transport rate and elevation in blood lactate levels. This correlates with a higher propensity for muscle fatigue and non-suitability to endurance type of sports28,29,30.

Can specific nutrient(s) help to cope with a not-so-favourable variation in this gene?

Nutrigenetic recommendations point towards magnesium for carriers of this genetic variation as it favours lactate clearance from muscle. Moreover, it increases glucose availability in muscle tissue is critical for basic mitochondrial functions, including the production of ATP; both of which are helpful against muscle fatigue62,63,64,65,66,67.

Gene-specific nutrients prove remedial in sport-related injuries

What’s the importance of COL1A1 gene?

One of the main threats of competitive sports is painful injuries. Athletes’ joints are vulnerable and they are exposed to frequent injuries. Genetic factors also conspire in injuries. Genetic variations contributing to the onset of musculoskeletal injuries, particularly in tendon and ligament tissues, have been identified and these impact the athletic performance. The structural integrity and normal mechanical function of both tendons and ligaments depend on the precise alignment of type I collagen fibrils. Genes encode the production of collagen fibers, implying certain variations in them determine the susceptibility for tendon and ligament injuries during sports. COL1A1 is an important gene as it encodes the production of Collagen type I fibrils which majorly constitute bone matrix, forming strong parallel bundles of fibers in tendons & ligaments.

How to understand its variation?

The widely studied single nucleotide polymorphism is at rs1800012 of this gene. T allele reduces risk of cruciate ligament ruptures, shoulder dislocation ruptures & Achilles tendon ruptures. While G allele results in the production of a weaker type I collagen which increases susceptibility for tendinopathy34,35.

Can specific nutrient(s) help to cope with a not-so-favourable variation in this gene?

This genetic variation can be managed with collagen-strengthening dietary components like anthocyanins, glutathione, vitamin C and certain amino acids like Methionine, Cysteine and Taurine. Flexibility-improving fitness recommendations such as proper pre & post exercise stretching, and random exercising of different muscle groups can also prove beneficial68,69,70. Additionally, intake of Branched chain amino acids (BCAA) including leucine, isoleucine and valineis also recommended as it stimulates protein (collagen ) synthesis in the muscle71,72.

Figure 3. Examples of personalised nutrition to enhance athlete's performance


Humans vary in their ability to achieve success in sports, and this variability mostly depends on genetic factors. Matching the individual's genotype with the appropriate training modality leads to more effective training sessions73,74,75.

Author Bio: Anusha holds a PhD in Human Nutrition from the University of Madras, and ranks in the top 3. She has been the recipient of several esteemed awards and endowment prizes including the NSI award for consecutive years. She has also authored several research publications. Life Science, an exhaustive field where every minute innovations pile up is her consciously chosen domain of education and career. With a rich experience in nutrigenetic counselling, research data analysis, and scientific content writing, she is deeply passionate about exploring how gene-based lifestyle changes can assure good health sustenance and disease prevention in an individualistic manner. She reads extensively and draws concepts from wide ranging researches which are translated into reader-friendly documents. Such documents aim to educate people on the importance of knowing their health demands based on genetic predispositions and the need to harmonize the same with gene-specific nutritional recommendations.
Acknowledgement: Ms.Akshaya. R, Intern, post graduate student in Food Science, Nutrition and Dietetics, S.D.N.B Vaishnav College for Women, Chrompet, Chennai, designed and recreated the images ( figures 2 & 3) in the blog.