Dr. James Greenblatt, M.D.
Thanks to individual genetic makeup, each person is anatomically and biochemically unique, with his or her own way of responding to the environment. This uniqueness frames the way that each of us perceives and interacts with the world. For instance, when a family sits down to enjoy dinner, each member actually tastes a different dinner because of the unique distribution of taste receptors in the tongue.
Taste receptors can have a big impact on overeating, bingeing, or not eating enough. A study funded by the National Institute on Deafness and Other Communication Disorders (NIDCD) has shown that small variations in our genetic code can raise or lower our sensitivity to sweet tastes. This can also explain why some people are especially vulnerable to addiction to sweets.
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Undoubtedly, there is a relationship between genetics and a predisposition for food addiction. A survey of Overeaters Anonymous members conducted in the early 1990s found that a high percentage of overeaters or food addicts had at least one blood relative also addicted to food or alcohol. But this and other research raises the age-old question of nature versus nurture.
Recently, researchers at the UCLA College of Medicine tested a sample of overweight subjects who exhibited a pattern of bingeing on carbohydrates. They found these subjects had exactly the same genetic aberration (a specific D2 dopamine marker) that had been established as a genetic marker for chemical dependency on alcohol.
But genetics is not destiny.
Scientists have come to realize that while the blueprint for a building is unchanging and must be followed to the tiniest specifications, our DNA blueprint is only partially fixed—some parts are actually highly malleable and quite responsive to the environment, to our emotions, and to what we eat.
The Science of Epigenetics
Epigenetics is the study of how people’s environments and experiences affect the function of their genes, which include add-ons—or epigenetic markers—that evolve as an animal adapts to its environment. Your epigenetic code is continually being rewritten, and you are the one who can do the most to rewrite it. It turns out that expression of the genes we were born with is heavily influenced by the way we live.
A healthy lifestyle can make a difference not only for you, but also for your progeny. Epigenetics shows that even things we can’t see—like beliefs, feelings, and attitudes—play an important role in the epigenetic control of our genes, making possible actual changes in our cell structure.
The epigenome can change the expression of genes negatively or positively. Lifestyle choices like eating too much or not enough or smoking, for instance, can not only put your own health at risk, but can also predispose your children to disease and early death.
Researchers are beginning to figure out how to use nutrition to switch on or switch off specific genes. It appears that certain nutrient deficiencies cause alterations in metabolism and lasting changes in genes that amplify physical and mental strain. Too few essential fatty acids in the diet for example, has been linked to a chronic and multi-generational weakening of the immune system and increase in levels of inflammatory disease. Alternatively, biochemical and anthropological evidence has suggested that when the body is nourished fully and nutrient stores balanced, a more stable and resilient genetic state can actually be restored.
When you have a strong family history of disordered eating, depression or other mood disorders, you are at greater risk of developing these disorders than someone who has no family history of any psychiatric illnesses. However, it’s important to remember that while our genes provide the blueprints for who we may become, they do not determine who we are.
This incredible new information on epigenetics creates an opportunity to revitalize approaches to health. It inspires us to see that by combining nutrition, medicine, therapeutic approaches and lifestyle changes, we can achieve the levels of health, weight control and overall well-being we’ve hoped for.
By using epigenetic information, it becomes possible to consciously develop unique lifestyle and nutritional plans that minimize specific personal vulnerabilities around food, appetite and mood.