Your skin colour, body size, hair type, and risk of particular illnesses all depend on how your genes interact with your environment. For instance, your genes may suggest that you’ll grow to somewhere between 5’5″ and 5’ 8″. But your actual height is an interaction between genes and environment. If you grow up malnourished, you won’t ever reach 5’8″. What we eat early in life (and what our parents eat before conception and mothers eat during pregnancy) can affect our genes and regulate our traits- including the development of diseases, even decades later.
Our genes can be influenced by all kinds of things, such as:
- nutrient deficiencies or excesses (especially at crucial developmental stages);
- dietary components (e.g., omega-3 fats, phytoestrogens, cruciferous vegetables, lycopene, folate, carotenoids):
- sunlight and vitamin D:
- toxins (such as industrial chemicals, pesticides, heavy metals);
- bacteria and viruses;
- exercise and activity;
- alcohol and other drugs;
- stress, trauma, and mood;
- circadian rhythms (such as sleep, shift work, light- dark cycles, and travel across time zones); and
- a host of other factors we probably don’t even know about yet.
While we can’t control what genes we have, we can affect their expression to some degree – whether they’re likely to get “switched on” or “off”. Our genetic expression is strongly shaped by our environment, over which we do have some power. In theory, genetic testing may show us the way to individualized nutrition and exercise prescriptions. In practice, it’s not as clear how genetic diversity might play out or how much it even matters.
I recently have given samples for genetic testing. I should get my report in couple of weeks. At this time, there isn’t enough research to use DNA to give you a comprehensive and specific meal plan or exercise program. After all, we also choose food and exercise based on other factors, such as what we like, what’s convenient, what’s affordable, and what other people around us are doing. And, for the most part, even the most sophisticated genetic test will still give us mostly the same advice:
- Follow fundamental health and lifestyle habits consistently.
- Use outcome-based decision making – i.e., what actually happens in real life and real time – to individualise.