INJURY PRONE? It may be in your genes.


It would be rare to come across any keen or competitive athlete who has not experienced the angst of recovering from an injury. There are, however, certain individuals who just seem prone to injuries and are plagued to the point of of having to end a promising career.

Understanding your potential risk for soft tissue injuries and overuse injuries and tailoring your nutrition , supplementation, and training could enhance your recovery and help protect you from further injury.


Genetics is the science of heredity and gene expression is impacted not only by hereditary factors, but individual environment and biology too. Biologically, and emotionally too, we all respond differently to the same diet, training, supplementation, and medication.

Talent and determination may not be enough to get you to the top step nor keep you there.


IT'S A COMPLICATED RELATIONSHIP!

It would be difficult to begin a discussion about genetics of sports injuries without mentioning nutrigenetics and nutrigenomics. These disciplines study the interactions between diet, genes, environment, and their combined impact on wellness and longevity. You may have inherited one or two risk variants that affect soft tissue structure and function, but that does not have to have a gloomy outcome. There are some tools and interventions you can incorporate into your diet and training to support these genes.


CANDIDATE GENES AND MUSCULOSKELETAL INJURY

The genes commonly associated with musculoskeletal injuries, particularly tendons and ligaments include SNP's (single nucleotide polymorphisms) encoding for collagen, matrix metallopeptidase, tenascin, and growth factors.

I have selected two collagen genes COL1A1 rs1800012 G>T and COL5A1 rs12722 C>T.

The COL1A1 gene encodes the major protein component of type 1 collagen; the primary fibrillar collagen found in most connective tissues. Collagen type 1 fibrils are a major constituent of bone matrix, ligaments and cartilage.

COL1A1 produces a component of type 1 collagen chain, which then combines with a chain produced by COL1A2 gene, to make a molecular type 1 pro-collagen. These triple-stranded, rope-like pro-collagen molecules arrange themselves into long, thin fibrils that cross-link to one another to form strong very mature type 1 collagen fibres.

Some studies have shown that the functional Sp1-binding site polymorphism is associated with complex disorders such as osteoporotic fractures, osteoarthritis, myocardial infarction, lumbar disc disease and stress urinary incontinence.

The G allele is the risk allele and produces weaker type 1 collagen and has been associated with cruciate ligament ruptures, shoulder dislocation, and anterior cruciate ligament ruptures. Individuals carrying the GG genotype, participating in sports that require a sudden deceleration , and/or abrupt change in direction, may be more susceptible to greater anterior cruciate ligament ruptures.

On the other hand, individuals homozygous for the T allele are associated with a substantially reduced risk of cruciate ligament ruptures and shoulder dislocation ruptures. This rare TT genotype seems to have a protective effect on it's lucky carriers!

The COL5A1 gene encodes for the alpha-1-chain of type V collagen, one of the minor fibrillar collagens of tendons and ligaments. Type V collagen intercalates (inserts) into the tendons and ligament fibrils where, along with additional proteins, plays a major role in regulating fibrillogenesis, and modulating fibril growth and diameter.

Type V collagen also seems to regulate the assembly of heterotypic fibres, which are composed of both type 1 and type V collagen.

The T allele is the risk allele and has been associated with increased risk for soft tissue injury including achilles tendonopathy and cruciate ligament rupture. There is always a flip side to the coin though. Although the T allele, particularly the TT genotype is associated with a higher risk for soft tissue injury, this genotype is also associated with reduced flexibility which lends itself to better running economy and therefore faster running times. These individuals may not fare as well in ballet, martial arts, or gymnastics, but its a boon for running speed so long as you protect yourself against injury.

The CC genotype, particularly in females, has been associated with greater range of motion and therefore reduced risk of injury and has also been linked to reduced risk of ACL (anterior cruciate ligament) injury.

Altinisik et al.(2015) associated an increased risk for tennis elbow in the T allele. Tennis elbow, as we know is not just for tennis players, but can affect strength training in multiple disciplines.

NUTRITIONAL SUPPORT FOR COLLAGEN GENES

Personalised training and prehabilitative exercises are a core fundamental for any athlete, whether at risk or not.

There is quite a lot one can do to back up this alliance by using targeted nutrition and supplementation. Whether you have a genetic report or are just painfully aware that you are injury prone, tailoring your nutrition to include specific nutrients may be well worth your while.

The traumatic impact an injury has on a competitive athlete's body and mindset impacts not only their sports career but takes its toll on mental health and relationships as well. Sedentary behaviour does not sit well!

Eating patterns and behaviour often alter to either under-nourishment for fear of gaining weight, or over-nourishment due to boredom or depression, or both.

This can be magnified if an athlete has an existing eating disorder. To optimise tissue health and enhance healing, consuming a high-quality wholefoods diet is essential.

The healing process is heavily reliant on collagen and protein synthesis. Immobilisation of a limb results in loss of muscle mass and reduced strength and function.

Energy balance is critical and higher protein intakes ( 2-2.5g/kg/day ) may be warranted . There is good evidence to suggest that creatine supplementation may be a useful protocol to reduce muscle loss and maintain a positive nitrogen balance.

Supplementation with collagen and hyaluronic acid is an obvious recommendation, but vitamin C status is an important component of this strategy. Vitamin C is an essential cofactor (helper molecule) for the enzymes that catalyse the hydroxylation of proline and lysine residues of procollagen, promoting the proper folding of collagen structures, and thus plays an important role in muscle growth and repair.

In addition to collagen synthesis, vitamin C acts as a powerful antioxidant by neutralising ROS (free radicals) responsible for cell apoptosis (programmed cell death) during the inflammatory phase of injury and repair.

Studies have shown that excess vitamin C supplementation during training can blunt the beneficial training-induced physiological adaptations that are so vital for performance. For an injured athlete this is not relevant.

Whether training hard, or recovering from an injury, dietary consumption of vitamin C, up to 250mg from fruit and vegetables, is probably sufficient to counteract oxidative stress without having any negative effects on training.

The additional benefits from consuming a variety of fruit and vegetables cannot be overstressed. The additional fibre, antioxidants, and vitamins contained in a varied diet show greater benefit than consuming single nutrients alone.


The amino acid glycine is another vital molecule for collagen structure. Bone broth, gelatine, and green tea are rich in glycine. Beyond collagen synthesis, glycine acts as a precursor for key metabolites such as creatine, glutathione, haem, and purines. Indirectly, glycine plays a role in absorption and digestion of lipid soluble vitamins and lipids. All of which are essential to healing and wellness.

Other nutrients to add to the list are zinc, copper, silicon, glucosamine, MSM (methylsulphonylmethane), calcium, and phosphorus.

Nutrients multitask within our marvellous bodies and almost never perform one single task on their own, not do they have one single function in our cells.

If you have a high injury risk or are recovering from an injury, follow these guidelines as well as those of your medical team and coaches and keep your body fuelled and nourished.