Sports scientist Rod Cedaro explores whether nutrigenetics presents the next big step in sports nutrition.
It’s probably a term few people have ever encountered, but in the future it is likely that the science of nutrigenetics will present the next logical step in optimising athletic performance.
To understand the concept, we need to first look at the fundamental component that makes up who we are – our DNA, or genetic makeup.
All multicellular organisms contain genes, which are housed along DNA molecules. These are a blueprint for every cell in the body and every function of those cells.
Will a certain cell become a muscle fibre cell or heart fibre cell? This is all encoded on the genes lying along the chromosomes that make up the DNA.
Our DNA is inherited from our parents with equal contributions from our mother and father. Which characteristics we inherit, however, is completely random.
At the most basic level, human DNA comprises four different nucleotides – adenine (A), cytosine (C), guanine (G) and thymine (T). These nucleotides hold the entire genetic code to the human genome. A change in the sequence of these nucleotides can render one person an elite athletic performer and another predisposed to type 2 diabetes.
While various environmental factors impact the genome (nutrition, climate, training, etc.), it has been estimated that up to 65 per cent of human pre-disposition to certain traits is inheritable.
Over the last 30 years, mapping of the human genome – through the Human Genome Project – has involved one of the largest international scientific collaborations of all time.
The research was designed to determine the sequencing of the base chemical pairs that make up human DNA and identify and map the human genome from both physical and functional standpoints.
Sequencing the human genome holds the potential for various benefits across a multitude of applications, not the least of which includes the areas of athletic performance, medicine and wellness.
To the naked eye, genetic variants, which may distinguish potentially elite athletes from Jack and Jill Average, are completely indistinguishable.
Genetic profiling: the new frontier
Genetic profiling is such a powerful predictor of athletic potential that the British Association of Sport and Exercise Sciences (BASES) Molecular Exercise Physiology Interest Group recently produced a position paper dealing with current issues in genetic research and testing in sports and exercise science.
To paraphrase: the organisation openly acknowledges that the inter-individual variation of sport and exercise-related traits, such as maximal oxygen uptake (VO2 max), muscle fibre composition and trainability, have a strong genetic basis. The inter-individual variations in DNA sequence (or genetic loci) that influence these traits are now being sought. Once identified, these genetic loci will inform us about the mechanisms that regulate performance traits.
However, just because someone has the genetic predisposition towards a particular trait or tendency doesn’t necessarily mean it will eventuate – this relates to a phenomenon known as gene expression. That said, simply knowing an individual has a greater propensity towards slower recovery or an increased chance of injury, or has a greater potential for endurance performance than power sports, will influence the resultant exercise prescription and allow athletes, coaches and exercise scientists to better tailor and individualise training regimens.
And this is already happening in elite sport (and to a lesser extent at a recreational level) with athletes keen to optimise their performances around their innate genetic make up.
This same science can be applied in sports nutrition to further individualise and tailor nutrition plans. A recently published paper looking at weight management (Improved weight management using genetic information to personalise a calorie-controlled diet) by Arkadianos1 et al concluded: the addition of nutrigenetically tailored diets resulted in better compliance, longer-term BMI reduction and improvements in blood glucose levels.
So how does it work?
Athletes (or their support staff) order a test kit online. This arrives in a couple of days.
A sample is collected via a saliva swab and then returned in the mail.
Within a couple of weeks an online report is emailed back to the athlete (and/or coach, support staff) providing a genetic overview of various parameters and suggestions are made outlining how the athlete’s training and nutrition can be modified to best suit their genetic markers.
Some groups are taking this further – certainly in the weight management realm – by providing detailed nutrition plans based around genetic indicators and detailed biomedical questionnaires.
Is genetic testing the holy grail of performance enhancement?
No. It won’t, nor is it designed to, replace VO2max testing, blood tests, interface between the coach and the athlete, input from the dietician, exercise physiologist, medical support team or sports psychologist. It is, however, yet another tool in the ever-evolving technological arsenal that further empowers athletes to reach their athletic potential.
Remember, if you’re standing still or doing the same thing today as you were yesterday – you’re going backwards.
Image by Delly Carr.