In the 90’s I remember hearing about scientists working on sequencing the entire human genome. I thought it sounded like an impossible task – how could we map out human potential? I was certain that if we identified our individual genetic blueprints, then this would be the most powerful tool ever created by modern medicine.

In university I was introduced to the idea that certain genes were linked to specific cancers and genetic conditions. I imagined that it was only a matter of time before we would be able to link all causes of cancer and disease to specific genes. Mapping our genes would be how we would know everything about our health, in the present and in the future.

genetic testing geneFast forward to 2017 and we are living in the era of genetic testing. With a small saliva sample, we can now create a map of an individual’s genes. It turns out that genetically human beings are 99.9% identical. Genetic testing identifies the differences, or gene variants, in the remainder of our genes.

The way genetic testing is useful to our health however, is not what I, and maybe others, imagined it would be. Genetic conditions like the ones I learned about in university, where a single gene variant is linked to a specific condition are in fact very rare. Gene variants are not implicitly bad or harmful and while we can identify them, the effects of many of these variants are not fully understood. What we know now is that most individual gene variants have minimal effects. When we identify variants in a group of genes collectively we find that they have a low probability of expressing a disease except in the presence of certain environmental factors.

The role environmental factors play in gene expression is an exciting development in our understanding of health and disease. It means that our genetic variations do not entirely determine our present and future health like I thought they would in university. In fact, knowledge of our genetic variants helps identify areas to support while we optimize our environmental factors- diet, exercise, stress management, toxin exposure, etc. This in turn reduces the negative expression of these genes thereby reducing the risk of negative health outcomes.

Dr. Tom O’Bryan describes gene variants as “weak links in our chain.” Whereas environmental factors like food sensitivities, excess sugar, polluted air and leaky gut are things that “pull on the chain”. Of course, if we don’t want the chain to break, we have to stop pulling on it.

Eating nutritious food, breathing clean air, reducing stress, hydrating well, eliminating waste – remain critical to reducing the strain on the body and improving health.  Identifying our genetic “weak links” or susceptibilities via testing allows us to further refine these naturopathic treatments.

In this age of genetic testing consumers have plenty of tests to choose ranging from ancestry to complete gene sequencing. In my next blog post I’ll talk about the results of my preferred test and what to look for in genetic tests so the test results are actionable and applicable to improving health.


In health,

Dr. Carin Matsushita