It’s a widely held misconception that we can’t overcome our genetics and are doomed to certain fates should our genes point toward a high probability of disease. Yet, evidence continually emerges that suggests vigilance toward a healthy lifestyle can help surmount bad genetic odds.
Now, in one of the largest observational studies on fitness and heart disease, researchers examined data collected from nearly a half-million people in the UK Biobank database. The investigators found that people with higher levels of grip strength, physical activity, and cardiorespiratory fitness had reduced risks of heart attacks and stroke, even if they had a genetic predisposition for heart disease. Findings from the new study were published today in the journal Circulation through an article entitled “Associations of Fitness, Physical Activity, Strength, and Genetic Risk With Cardiovascular Disease: Longitudinal Analyses in the UK Biobank Study.”
“People should not just give up on exercise because they have a high genetic risk for heart disease,” explained senior study investigator Erik Ingelsson, M.D., Ph.D., professor of medicine at Stanford University School of Medicine. “And vice versa: Even if you have a low genetic risk, you should still get exercise. It all ties back to what we have known all along: It's a mix of genes and environment that influence health.”
In the current study, the researchers first determined the fitness and activity levels of participants. The scientists used data previously collected from 482,702 participants who underwent grip-strength tests correlating with overall body strength, answered questions about their levels of physical activity, wore accelerometers on their wrists for seven days, and took stationary-cycling tests. Genetic data from 97 percent of the participants were also used in the study.
Moreover, for participants with an intermediate genetic risk for cardiovascular diseases, those with the strongest grips were 36 percent less likely to develop coronary heart disease and had a 46 percent reduction in their risk for atrial fibrillation compared to study participants with the same genetic risk who had the weakest grips.
“The main message of this study is that being physically active is associated with a lower risk of heart disease, even if you have a high genetic risk,” Dr. Ingelsson, noted.
While the researchers are optimistic about their findings, they did point out a few caveats of the study—namely that it is not a prescription for a specific type or amount of exercise and because the results come from an observational analysis. The authors noted that “we can't definitely claim a causal connection,” as observational studies are designed to establish trends.
Nonetheless, Dr. Ingelsson stressed that the data is robust, and these latest results are worthy of consideration in guidelines. “This is important because of how we advise our patients. It's basically indicating that you can make some lifestyle changes, be more physically active, and it can make a difference to your long-term health.” However, for any individual, Dr. Ingelsson advised that “it would be best to discuss a physical activity plan with a physician.”
