There is a theme of members of my extended family suffering from colon cancer. I now know that human genetics play only a relatively small part in all this. Epigenetics, however, can be very influential - these are environmental factors that switch the colon cancer switch. Diet, stress, toxins, microbes, to name but a few.
It makes me think that what we inherit in terms of habits - how and what we eat, our ability to deal with stress (or our inability), how committed we are to exercising regularly, our capacity to make deep and lasting relationships in our lives, may be more important to health than the genetic predispositions we carry from our forefathers and mothers.
This appeals to me immensely because I am a control freak and we have much more control over epigenetics than we do genetics. Also, I believe that the best way to improve health is to bring about behaviour change - this changes our epigenetic environment - it alters which genetic "switch flickers" we are exposing ourselves to.
This short piece by Robert Chapkin illustrates what I mean.
What we eat and drink influences the quantity, diversity and function of our gut bacteria. And this, in turn, impacts our colorectal cancer risk.
Our total fibre intake needs to exceed 50g a day in order to protect us against colon cancer.
Our gut microbes influence immune function. They can support it or undermine it. In the latter situation, they can promote chronic low grade inflammation. This affects the health of our gut barrier and, combined with genetic predisposition and cross-talk between our microbes and a low fibre diet, the effect can be a rise in certain microbial byproducts that drive tumour growth.
The alternative paradigm is the protective effects of fibre intake on what our microbes are doing. Increased fibre intake helps to increase microbial production of short chan fatty acids, which support the health of our gut lining and protect against colorectal cancer.
What we eat modulates what our microbes are doing and what byproducts they are producing. And this affects our colon cancer risk. And whilst it doesn't always feel like it, we have control over what we eat.