Genetic variations play a major role in determining susceptibility to cardiovascular disease but that doesn't mean biology is necessarily destiny when it comes to heart health.
A new study shows eating a healthy diet can mitigate the risks conferred by a common variant of heart disease, suggesting people may be able to compensate for certain genetic shortcomings.
In the study, published Tuesday in the journal PLoS Medicine, researchers focused on several DNA sequence variations on chromosome 9p21, which they call "one of the most robust genetic associations for cardiovascular disease."
They found that a diet rich in raw fruits and vegetables helped mitigate the risk of cardiovascular disease and heart attack conferred by those alterations.
"This particular variant, 9p21, has been shown to play a role in heart disease, which diet overcame," Dr. James Engert, a professor in McGill University's departments of medicine and human genetics and one of the study's authors, told The Huffington Post.
"That's not suggesting that diet is going to overcome all variants," he continued. "But for all intents and purposes -- in this case -- it suppressed the susceptibility."
The flip-side was true, too: Diet also played a role when it came to compounding risk. People who had two risk alleles, the highest genetic risk, and ate a diet heavy in meat, fried food and salty snacks had nearly twice the risk heart attack.
Engert cautioned that the new study did not explain exactly how the interaction between environmental and genetic factors works. He said that further research is necessary in order to unlock exactly what is happening at a mechanistic level.
But he said the new study is nonetheless promising from a public health perspective. Heart disease is one of the leading causes of death worldwide. It has long been known that there are many modifiable risk factors for heart disease, including diet, exercise, not smoking, stress and poor hygiene. The new study offers the tantalizing suggestion that by controlling those, people may have even more control over their heart health than previously thought.
"I would have thought that harboring a 9p21 variant would be hard to overcome," said Dr. Nehal Mehta, director of inflammatory risk in preventive cardiology at the University of Pennsylvania. "This is eye-opening because it says that even if you have a predisposition to a disease, lifestyle makes a big difference. The effect can be overcome by having a good diet."
Mehta said that future research should look more closely at the role of other non-genetic factors, like smoking and exercise, and the possible impact they might have on various genes known to increase susceptibility.
In the meantime, Mehta said the new study underscores the importance of taking charge of one's health.
"It always come down to the same thing -- diet and exercise," he said. "if you have a predisposition to a disease, lifestyle makes a big difference. Genes are not dooming."
