Is your health determined by the genetic code you inherited from your mother and father? Or do you have the ability to impact your fitness and longevity by practicing a healthy lifestyle? When completion of the Human Genome Project was announced in 2003 many expected that the paradigm that one gene for one malady would leave little control over our wellness.
That this concept was short lived was the center of conversation last night with my friend Evan. His belief was that there was heart disease in his family and it was inevitable that he would suffer the same fate. Evan was no lightweight. He had completed an advanced education degree years ago and was a successful business and community leader. The idea that his health was predetermined by his nature, or his genetic content, weighed on his mind.
The Human Genome Project determined that the human genetic code was smaller than expected, about 22,000 genes, which is "more than a chicken but less than a grape." Indeed, our genes, though not many in number compared to some species, are under the influence of our environment, and specifically our lifestyle. This scientific discovery is called epigenetics. The influence of diet, or nutrigenomics, plays a particularly potent role. While you may not eat your way into blond hair and blue eyes (genetically determined features that are not influenced by lifestyle) your risk of disease can be shifted dramatically and quickly.
The response that I got explaining this to Evan is one I share with many patients and inspires hope that nurturing our nature with a healthy lifestyle can determine the likelihood of years of health or disease. I explained to him some of the findings made by Dr. Dean Ornish in the last decade. For example, in a group of men with low-grade prostate cancer placed on plant based diets along with stress reduction and walking programs, 453 genes controlling tumor growth were less active and 48 genes related to tumor suppression were more active after only 3 months. In another study using the same program in 63 men with heart disease, 3 months after making lifestyle changes 26 genes were expressing different amount of proteins and after 1 year 143 genes were doing the same, reducing proinflammatory activity that harm arteries. Finally, if it is the fountain of youth you are after there is even more hope. Following the Ornish lifestyle program for five years led to measurements of relative telomere length, a marker of aging, disease, and premature morbidity, to increase favorably while a control group demonstrated the usual shortening or aging. Other factors that may play a role in controlling our genes included sleep, stress, exercise, and environmental exposures.
The power of understanding that we are not doomed to live out a pre-determined path controlled entirely by our genes is empowering and Evan responded with excitement. I could sense that relief and hope resulted from my brief scientific overview. While we have much to learn about the amount of control we have over the genetic input to our health, and the most effective methods of producing desired results, we should not wait. Clean food, air, and water along with sleep, and the avoidance of smoking and unmanaged stress is a powerful plan for nurturing our nature.