DNA doesn't doom you to heart disease, experts say

If your parent or sibling died young from cardiovascular disease, take heart: There are ways you can counter any genetic predisposition to the illness.

New research shows that people can minimize an inherited risk for heart attack by living right -- exercising, eating healthy, staying slim and quitting smoking.

Even with a little effort in these areas, people can cut their high genetic risk of heart disease by more than half, said senior researcher Dr. Sekar Kathiresan, director of the Center for Human Genetic Research at Massachusetts General Hospital in Boston.

But the opposite also is true, Kathiresan warned. People born with a genetic advantage protecting them against heart disease can ruin their good luck through unhealthy lifestyle choices.

“For heart attack at least, DNA is not destiny,” Kathiresan said. “You have control over your risk for heart attack, even if you’ve been dealt a bad hand.”

Kathiresan presented his findings Sunday at the American Heart Association’s annual meeting, in New Orleans. The study was published simultaneously in the New England Journal of Medicine.

For their research, Kathiresan and his colleagues pooled data on more than 55,000 participants in four large-scale health studies.

The researchers analyzed each person’s genetic risk for heart disease using a panel of 50 gene variants previously associated with elevated heart attack risk.

They also judged each person’s lifestyle based on four factors: smoking, body weight, diet and exercise.

The requirements to have a good lifestyle were not rigorous, Kathiresan said. The person essentially had to not smoke, not be obese, get physical activity at least one day a week, and regularly meet at least half of the American Heart Association’s recommendations for a healthy diet.

“It’s safe to say we’re not being that aggressive in terms of the lifestyle score,” Kathiresan said.

For example, a person could be overweight, but not obese, and still meet the criteria for a healthy lifestyle in this study, he said. People also didn’t need to meet current U.S. physical activity guidelines, which call for two and a half hours of moderate physical activity or one and a half hours of vigorous physical activity.

Even these minimal lifestyle changes mattered greatly for people at high genetic risk of heart disease.

The study looked at the risk for a “coronary event” -- heart attack, cardiac arrest or the need for angioplasty or other procedures to open a blocked artery.

A person with high genetic risk and a bad lifestyle had a nearly 11 percent chance of having a coronary event within the next 10 years, the study found. However, a person at high risk who lived well cut the 10-year risk of such a health crisis down to 5 percent, Kathiresan reported.

Lifestyle also mattered for people who won the genetic lottery.

Those with low genetic risk and a good lifestyle had a 3 percent risk of a coronary event over the next 10 years, but a bad lifestyle would drive their risk up to 5.8 percent, Kathiresan said.

“If you’ve been dealt a good hand, you could really harm yourself by having an unfavorable lifestyle,” he said. “You basically take your heart attack rate up into the ranges of the people with the highest genetic risk.”

Patients often ask cardiologists whether they should get genetic testing for their heart health risks, and the doctors usually aren’t keen on it, said Dr. Martha Gulati, division chief of cardiology at the University of Arizona-Phoenix.

“Once you get those test results, it becomes, ‘what do you do with them?’ Often you hear from patients, ‘Now I’m doomed to this disease,’ “ said Gulati, who also serves as editor-in-chief of CardioSmart, an online patient education program of the American College of Cardiology. “Their genetics make them feel very negative and helpless.”

But this new study shows there is cause for optimism even for those facing the roughest road.

“We can change this with lifestyle,” Gulati said. “We always say 80 percent of heart disease is preventable with lifestyle changes. This just gives more evidence; where people at the highest risk of heart disease, there were still things that were modifiable.”

Gulati noted that the study does not prove a direct cause-and-effect link between lifestyle and heart health risk, however. She hopes a follow-up clinical trial will be conducted where people are directed in their lifestyle changes, to see how that affects their heart risk.

“That would be, to me, the next study,” Gulati said.