John Velasquez of the San Antonio Food Bank organizes fresh produce during the Main Plaza Farmers Market. Photo by Iris Dimmick.
John Velasquez of the San Antonio Food Bank organizes fresh produce during the Main Plaza Farmers Market. Photo by Iris Dimmick.

Did you know that you have control of your genes even after you are born?

We’re talking about the 25,000 genes contained within the cells in your body. You may assume that you have no control over your eye color or height, or whether you develop cancer at the age of 40 or die of a heart attack at the age of 50 if it is “in your genes,” but that is not true. Eye color, perhaps, but studies have suggested that up to 20-40% of even the variation of one’s height can be attributed to environmental factors, mainly nutrition.

Yes, lifestyle dictates how our genes behave.

Researchers at the Texas Biomedical Research Institute in San Antonio found in a 2010 study of 1,240 people that exposure to cigarette smoke negatively influenced the expression of 323 genes as well as entire networks of gene interaction. So people who smoke, or are around people who smoke, are turning 323 genes into bad actors in the body. What does that mean? Well, we know that smoking increases your risk of heart attack, stroke and many cancers, but for a particular individual, we cannot be precise as to what this risk is.

The reason is that, despite decoding the entire pool of human DNA in 2003, the complexities of how individual genes interact with one another and the interplay between one’s genetic code and lifestyle choices are far from being deciphered.

From the City of San Antonio's obesity fact sheet.
From the City of San Antonio’s obesity fact sheet.

That is one reason why you never want to compare yourself to someone else. Two neighbors of the same sex with similar height, weight and age who, for example, live next to a major freeway and have similar lifestyles can inexplicably have different fates. One could die of pancreatic cancer at the age of 42, despite not having an apparent family history of it, while the other could live until the age of 82. The future of medicine will largely revolve around figuring this out. Personal genomics companies like 23andMe are getting us off to a good start, but because there are still so many unknowns, these tests could lead to needless angst.

What does all this mean for you and your family? Diet and exercise are, of course, important, and you really are what you eat. If you eat a healthy diet most of the time, including foods like blueberries, kale, salmon and walnuts, you are turning good genes on and bad genes off. This translates into lowering your risk of heart disease, cancer and likely many other diseases.

Watch out if you eat a diet high in sugar and saturated fat, the kind of processed foods typically found in fast food restaurants. That is not to say individuals who eat poorly will experience an early death, but the probability is higher.

We also know that your body reacts immediately to what you eat. If you consume an unhealthy meal and then measure blood markers of inflammation, which are bad, they go up. Inflammation in the blood is one of the main factors that accelerates the buildup of plaque in the arteries and leads to heart attack and stroke.

Hardening of the arteries is a lifelong process. In the U.S. today, this is occurring at younger and younger ages, even in children. These poor lifestyle choices have led to obesity in epidemic proportions. Our children need to understand that what they are eating is markedly affecting their health even if they feel fine. Most kids do not care about what may happen when they are 40 or 50 years old, but if you tell them that their diets affect how well they think and perform on tests and in their athletic endeavors, or how soft and shiny their hair is or how good their skin looks, they may listen.

One analogy I have used on my kids since they were very young is designating particular foods as being either “police officers” or “criminals.” Healthy foods like fruits and vegetables are police officers, and unhealthy foods like candy, soft drinks, hamburgers and hot dogs are criminals. Whenever they would have criminals on their plates at mealtimes, I told them they would have to choose at least one police officer or else the criminals would win and eventually take control of their bodies. That analogy always made sense to them. Now I don’t have to tell them anymore. They are the kids at a hamburger restaurant ordering a side of broccoli.

Readers interested in learning more can check out any of the following links, which will lead you to credible research and data that can help guide you in pursuing better health for you and your family:

How much of human height is genetic and how much is due to nutrition? by Dr. Chao-Qiang Lai for Scientific American.

How The Food You Eat Changes Your Genes by Dr. Joel Kahn for mindbodygreen.

Feed your genes: How our genes respond to the foods we eat at ScienceDaily.

Associations between dietary patterns and gene expression profiles of healthy men and women: a cross-sectional study by Annie Bouchard-Mercier, Ann-Marie Paradis, Iwona Rudkowska, Simone Lemieux, Patrick Couture and Marie-Claude Vohl at Nutrition Journal.

Heart Disease Prevention: What You Can Do” at Centers for Disease Control and Prevention.

Anti-inflammatory Diet: Road to Good Health? by Kathleen Doheny for WebMD.

Top image: John Velasquez of the San Antonio Food Bank organizes fresh produce during the Main Plaza Farmers Market. Photo by Iris Dimmick.

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Dr. Eric Stocker is a staff cardiologist at Methodist and Baptist Hospital Systems. He is a Fellow of the American College of Cardiology, Diplomate of the American Board of Clinical Lipidology, and Board...