Can a healthy lifestyle reset your genes?

Healthy diet and exercise may help prevent heart disease before it starts.

It's common knowledge that positive health habits such as exercising, eating a
good diet, not smoking, and lowering your cholesterol and blood pressure levels
will protect your heart and blood vessels from damage. If you have a family history of cardiovascular disease, these same steps may also work to quiet the genetic code that puts you at increased risk.

Balancing your risks

"We know that 70% to 80% of heart disease risk can be explained by lifestyle choices. So, even if I know nothing about your genes, I can still give you really
good advice to lower your risk," says Dr. Eric Rimm, professor of medicine at Harvard Medical School and the director of the program in cardiovascular epidemiology at the Harvard School of Public Health. For example, even if you
carry several of the 35 genes known to contribute to obesity, there are many steps you can take to limit the amount of body fat you accumulate, and thereby lower your risk of cardiovascular disease.

Therefore, the prudent advice for everyone is to take early steps to follow a healthy diet, get enough activity, stop smoking, and reduce sodium intake to avoid disease. Coincidentally, it appears that many of these steps may also work to activate beneficial genes and turn off harmful ones. Staples of the heart-healthy Mediterranean diet such as olive oil, vegetables, and fish contain biologically active ingredients that may affect which genes are expressed. In addition, certain vitamins and antioxidant-rich foods may protect against DNA damage.

Family history

Scientists have so far identified dozens of genes which appear to increase some people's predisposition to certain heart risk factors, such as high blood pressure. However, looking at your family history of heart disease is probably a better indicator of your risk than getting your DNA mapped. "If your father died of a heart attack before the age of 60 or 65, you're at two-and-a-half times greater risk of heart disease as someone who doesn't have that history," says Dr. Rimm.

While some of this increased risk may originate in your genes, complex environmental factors also come into play. For example, if you grow up in a household where you are around people who smoke or eat unhealthy food, those influences probably contributed to your parents' history of disease and will increase the likelihood that you will develop heart problems down the road. Despite your background, however, you can still reduce your risk dramatically with well-known lifestyle improvements.

Personalized medicine

More than a decade ago, when the mapping of the human genome was complete, doctors had high hopes that this "blueprint" would open the door to personalized medicine—a finely honed therapeutic approach based on the hardwired risks imprinted in your DNA. So far, the reality has not lived up to the vision. "The impact of genetics on heart disease is small unless you have one of the rare gene mutations that puts you at extremely high risk of cardiovascular disease, and right now we don't have many ways to prevent those conditions," says Dr. Rimm.

In the future, genetic testing may play a key role in determining which people will respond better to certain drugs. In one case, researchers discovered that many African Americans with heart failure respond particularly well to a combination of two older drugs. Interestingly, the use of these drugs had largely fallen out of favor before this discovery because a study in the 1980s showed them to be less effective than newer drugs. However, the subjects of that study were almost all white. Similarly, some people have a gene variation that prevents their bodies from responding fully to certain types of anticlotting drugs. However, researchers are as yet unclear on what to do with that information.

No magic pills

Right now there is no magic pill you can take to reset a particular genetic marker. But you're not necessarily stuck with your genetic profile, either. "The overall genetic risks are still quite small and dwarfed by lifestyle choices. You can counterbalance your family history, and there are many studies that show that even people with strong family history can reduce their risk of heart disease dramatically by targeting known lifestyle methods," says Dr. Rimm.