Nutrigenomics: Eat according to your genes
There was not so long ago a time when the far-fetched idea that the optimal diet might not be the same for everyone would never have crossed our minds. Advances in nutrigenomics are moving forward in leaps and bounds. Today, eating according to one’s genes has become technologically possible.
Eating according to your genes: what for?
We need to radically rethink our conception of the “ideal diet,” and the way we formulate our recommendations. Nowadays, we hear more and more about personalized nutrition, eating according to our genes, and DNA polymorphisms.
In fact, nutrigenomics has been a reality for decades. There are hundreds of studies linking diet and genetics, and even epigenetics. We no longer speak only of nutrigenomics, but of “omics” science in general, so many variations of the field now exist. Metabolomics, microbiomics, proteomics, phenomics…the prefixes and suffixes keep piling up and are enough to make anyone lose their Latin!
Nutrigenomics: what is it?
Nutrigenomics is the science that studies how genes can influence the way an individual’s or a population’s genetic makeup determines the risks associated with diet (that is, nutrigenetics). We all possess a set of genes that is unique to us. The sequence of genes that codes for the expression of a protein is similar, but not exactly identical from one person to another, even when they possess the same gene. These are called genetic variants, or polymorphisms.
Nutrigenomics to the rescue?
Among other examples, nutrigenomic solutions already exist to improve the living conditions of our species, and they could already be put into practice to eradicate malnutrition. Seeds of fortified cereals, for example with vitamin A or folate, could help correct deficiencies that affect the quality of life of billions of individuals and even lead to the death of thousands of children every day.
For us, citizens of industrialized countries, the reality is somewhat the opposite. Our diet is full of calories, but its nutrient density has greatly declined. To turn things around, a more mindful diet is no longer a luxury. By better understanding the risks associated with our genetics, we can modify our diet in order to consume more of the nutrients that our body is less efficient at absorbing, and less of the nutrients that we do not eliminate as well.
If we adopt a preventive perspective, would it not be economically and socially beneficial to reduce disease simply by adjusting nutritional needs for each individual? Given the enormous health care costs of the health system, the rise in chronic disease, and the failure of today’s “curative” medicine to meet the challenge, all this points to the need to rethink our therapeutic approaches. At least, that is what advocates of nutrigenomics argue.
Two sides of the coin
Just as Einstein did not know that his research would make the atomic bomb possible, nutrigenomics will bring both good and bad. One thing is certain: it is already at our doorstep, and we cannot stop it. Let us rejoice when it can be used wisely, for example to fight world hunger, slow the progression of cancer, or warn a person that their lifestyle is incompatible with their health.
But since what propelled the science of nutrigenomics so far forward was the advent of artificial intelligence and gene-mapping technologies, many researchers are questioning the future impacts on our society. But this is not only about the future. You can have your genes mapped—or those of your child—from birth, and this has been possible for several decades already.
Surprisingly simple
A simple saliva test can reveal what your genes are hiding. Many of the genes tested are also already available through blood samples in hospitals, when physicians deem it appropriate to prescribe them. Nutrigenomics is therefore already an integral part of our health care system. What’s the difference? Commercial nutrigenomic tests are not covered by insurance plans or by the public health insurance system. On the other hand, you do not need any prescription to access them, and your data are not shared with the health care network. That is if you choose a responsible company that works with health professionals, rather than internet servers selling tests in order to collect your biometric data.
Concrete health benefits
Learning that my daughters and I carry a mutation in a gene that prevents us from efficiently metabolizing folic acid helped explain many health issues, which were resolved once I became aware of this fact. A daily preventive supplement helps us avoid the symptoms associated with the absorption deficiency that characterizes us.
As for exercise, surprise: I belong to both the ultra-sprint and ultra-endurance categories, which is very rare. I never would have guessed! It truly made me want to take up certain sports activities again that I had abandoned. The 70 other genes tested also revealed information that I never could have known otherwise. It is fascinating, really—and quite extraordinary when you think about it—to be able to learn so much about our chromosomes just by spitting!
I learned about my genetics, and it did change my life…Genes are not everything. The environment also plays a major role in health. But I know my susceptibilities and those of my family. That reassures me. And even though I do not obsess over it, it still motivated me to adopt a few more good habits specifically tailored for my own uniqueness.
Not a diagnosis, but a motivating factor
And that is what studies show. People who undergo a nutrigenomic test tend to feel motivated to modify their lifestyle in a positive way, especially when they realize they have predispositions to certain diseases. For some, it explains things and provides answers they have been seeking for a long time.
It is never a diagnosis in itself, and a nutrigenomic test should be interpreted with the guidance of a knowledgeable dietitian. Because when we ask our genes, the answer is not always as clear as a crystal ball! Not to mention that, as the saying goes, some skeletons are better left in the closet… Not every truth is always good to tell! Supported by clinical judgment and a code of ethics, dietitians will not tell you nonsense. There are genes for which there is not enough strong evidence, and it is their job to let you know that.
The Human Genome Project
But there is clearly a multitude of genes for which there is an abundance of strong evidence, thanks to the Human Genome Project. Genes and their mutations are nowadays catalogued in this truly astronomical registry. Moreover, the data are commonly combined with other databases through machine learning (artificial intelligence). Yes, computers are scrutinizing us under a magnifying glass and, in some respects, already know us better than we know ourselves! But since they are here to stay, we might as well benefit from them too.
Article by Marie-France Lalancette, Nutri-Génial, nutrigenomics consultant.
