In my last post I reviewed the basics of genetic testing and how the resulting info can help us better understand our health. But examined through lab work or not, our genes and their mutations only tell part of the story. The other, maybe more allusive, main character is what we call epigenetics. By definition this term refers to substances or molecules that turn your genes on and off. Essentially they are factors that are hanging out around your genes and help to inform when and if and how often those genes get coded for – and ultimately used to make enzymes and other proteins.
As I explained in the last post, epigenetics may influence how significant a SNP (a mutation) is to your overall health. This is because one of the main ways that epigenetics operates is through methylation; adding a methyl group (a carbon bound to three hydrogens) to certain regions of DNA can turn genes on or off. Remember that MTHFR gene I mentioned in the last post? That gene codes for an enzyme involved in methylation. Understanding how well you are able to methylate influences the coding of other genes.
While the science behind what our genes do all day is certainly complex, the take home message is that while our genes are given to us, some of the epigenetic factors that influence them are under our control. In some ways, we have the power to turn genes on and off! While research has revealed that epigenetic influences are likely most influential when we are in utero and right out of the womb, epigenetics continue to influence our genes, and in turn our health, throughout our life. In fact, every meal we eat exerts epigenetic influences! This is why the saying “food is medicine” is so true; everything we put in our body can influence our genes. And, unfortunately, other exposures that we have less control over – ie pollution – influence our genes as well. What else exerts epigenetic effects? According to a 2011 paper published in Epigenomics, lifestyle factors with epigenetic interactions include:
- physical activity
- tobacco smoke
- stressful conditions
- nightly shift work
- and intrauterine life
These links are probably most apparent with regard to environmental and dietary factors influencing cancer risk factors and cancer prevention. That is because there are specific genes – oncogenes – that control whether cancer cells are produced or not. This pathway may be more or less straightforward depending on the type of cancer but this is why certain epigenetic influences are so clear in cancer pathology and progression (think cigarette smoke and lung cancer).
Essentially what this all means is what you already know – the healthier a life you lead, the less likely you are (statistically speaking) to be diagnosed with some genetically influenced disease such as cancer. Since we can’t stop the process of aging (which increases the risk of most cancers) and often have little control over our exposure to environmental pollutants, we should work to exert control where we can – avoiding unnecessary stress, eating a healthy diet, moderating alcohol intake and eliminating exposure to tobacco smoke. For those free of disease, this kind of healthy lifestyle will positively influence your genes meaning you may not have to dive further into your genetic make-up . If, however, you are dealing with a number of health concerns and want to take a closer look at your genes through genetic testing, learning what SNPs have contributed to your diagnoses can then shed light on specific epigenetic influences to focus on. Genetic testing is not for everyone, in other words, but epigenetics is! We influence our genes in all sorts of ways every single day. So here’s to healthy living!
- Alegria-Toress JA, Baccarelli A, et al. Epigenetics and lifestyle. Epigenomics. 2011; Jun 3(3): 257-277
- Johns Hopkins Medicine. Low-Carb Diet Alleviates Inherited Forms of Intellectual Disability in Mice. Johns Hopkins Medicine News and Publications. 19 Dec 2016.