“It’s not what we don’t know that gets us into trouble.
It’s what we know that ain’t so.”
~ Will Rogers


Conventional wisdom has long held that the genetic cards you inherent from your mother and father are the genetic cards    you are stuck with throughout your life, for better or for worse.  Most clinicians continue to believe that you cannot do anything about the risks you inherit from your parents. Like so many long held truths in medicine, it is now increasingly clear that this is not the case.  You are not a prisoner of your DNA.  Your DNA is not your destiny.  Compelling evidence now suggests that your genes are in fact quite malleable throughout life, designed to change expression in response to changes in one’s environment.  So how well do you fit into your genes?

While having a family history of a particular health problem e.g. depression, heart disease, cancer and  diabetes certainly puts you on a trajectory of greater risk, how this risk ultimately manifests is mostly  determined by the environmental inputs in your life.  These environmental inputs include what you eat; how much you move; how well you sleep; how you interpret and respond to stressful circumstances; the depth of your relationships and social networks (refer to my blog on health and social connection); your burden of environmental toxic exposure; how mindful you are; etc. It would appear that nature has the profound capacity to trump nurture in most matters of health.  In other words, your genes may load the gun but ultimately it’s the environment that perpetually bathes them that pulls the trigger.

The emerging science of epigenetics (how the structure of your DNA above your genes) is shedding unprecedented light on this potential inherent in gene-environment interactions. Humans have approximately 25,000 genes that comprise 23 pairs of chromosomes present in each of the 10 trillion cells that are you.  These genes code for proteins that essentially run every aspect of your human machinery.  The genome project which amazingly elucidated the nature of this “Book of Life” in recent years has led to many unexpected conclusions.

The first surprising conclusion is that it is in fact rare for one abnormal gene to result in a disease later in life e.g. Huntington’s chorea or sickle cell anemia. These diseases in fact comprise less than 5% of the chronic complex diseases that most of us confront as we age.  The gene-disease relationship is much more complex than once thought.  It would appear that we all have millions of typos in our Book of Life and it is the complex pattern of these many typos that in fact puts us at risk.

The second (and this, in my view is a complete game-changer when it comes to self-care and health) is that most of the material on our DNA that does not code for proteins is under the direct influence of our environment.  The very nature of this complex relationship ultimately determines whether our typos express themselves or not.  For example, foods that have a high glycemic effect e.g. bagels, pasta, sugar, high-fructose corn syrup have been found to turn on many genes that produce proteins that increase inflammation.  Foods with a lower glycemic effect e.g. beans, legumes, brown rice, fruits, vegetables, whole grains, turn these genes off. Individuals with a strong family history and gene patterns more commonly found in depression are less likely to manifest in a loving, nurturing environment and more likely to manifest in an environment of abuse, emotionally traumatic events, lower socioeconomic class, etc. Randy Jirtle PhD, a pioneering researcher in epigenetics at Duke University has made some remarkable discoveries in this field.  He has done research with a well-known rodent referred to as the agouti mouse.  The agouti mouse has a genetic defect that inhibits satiety.  Every agouti mouse ever known has been yellowish in fur color, eats uncontrollably, gets very fat at a young age, spends little time on the running wheel, becomes socially isolated, and takes forever to navigate the maze to find the cheese. The agouti mouse, by the way, usually becomes diabetic and manifests the same chronic complex diseases as many Americans do e.g. heart disease, abnormal blood lipids, cancer, etc.

What Jirtle did was provide pregnant agouti mice high-dose supplements of B-vitamins and nutrients that are known to chemically modify DNA, a process known as methylation.  The offspring have never before been seen by researchers. They have darker fir, remain slim, navigate the maze in record time, live much longer, and do not get any of the chronic complex, age-related diseases that have always been seen prior.


And amazingly, when he examined their DNA, the same mutation was there. The difference, these special nutrients modified the epigenome (the parts of the DNA around the genes) in a manner that inhibited the expression of this mutation.  The offspring of the offspring (the grand kids) also had the mutation turned off. In other words, these epigenetic changes were passed to the next generation!  A nutrient-vitamin “environmental input” without changing the genetic mutation, inhibited the expression of the mutation and essentially a different offspring emerged, even two generations later.  One stunning implication of this is that the expression of your genetic endowment might be, influenced by the environmental inputs of your grandparents as well as your parents.  In other words, you inherent the environmental conditions within which your ancestors existed in addition to the genes themselves.

So what does all this mean as you contemplate your health trajectory?  How you bathe your DNA e.g. by the foods you eat; how much you move; how well you sleep; how mindful you are; how you respond to stress; how much meaning you cultivate in your work, love, and play; how you navigate the minefields of conflict in your life; how socially satisfied you are; how you manage the burden of environmental toxins you are exposed to; whether you are likely to forgive in response to a prior hurt or transgression; how you cultivate a spiritual dimension to your life; etc., etc. will ultimately influence how your DNA manifests!!

How your DNA manifests will influence how healthy or unhealthy your cells, tissues, organs, and integrated whole body system, function and ultimately how long and how well you experience life. These inputs have the capacity to turn off bad genes that may have manifested as diseases in your ancestors and profoundly transform the manner with which they currently manifest in your life.  These inputs have the capacity to turn on genes that suppress cancer cells, balance immune function, reduce the stress response, assist detoxification, etc.

It is clear we are not prisoners of our DNA.  We ultimately have the capacity to recreate our very design in each and every moment.  So how well do you fit into your genes?

~ Mark Pettus MD, FACP Medical Director Functional Formularies