People who get plenty of exercise are less likely to have heart attacks and strokes than their inactive counterparts, even when they have a genetic predisposition for heart disease, a UK study suggests.
Among roughly half a million people in the UK, those with greater grip strength, more physical activity and better cardiovascular fitness had a lower risk of heart disease - even when heart attacks or strokes ran in the family, researchers found.
“Even if you are at a high genetic risk, you can improve your chances of remaining in good cardiovascular health by doing exercise,” said senior study author Erik Ingelsson, a researcher at Stanford University School of Medicine in California.
For example, among people in the study with an intermediate genetic risk for cardiovascular diseases, individuals with the strongest grips were 36 percent less likely to develop coronary heart disease and had 46 percent lower odds of developing atrial fibrillation than people with the weakest grip strength, researcher report in Circulation.
And among people with a high genetic risk for cardiovascular diseases, those with the best cardiorespiratory fitness had a 49 percent lower risk of coronary heart disease compared to participants with the poorest cardiorespiratory fitness. They also had a 60 percent lower risk of atrial fibrillation, a common heart rhythm problem that predisposes people to strokes.
Participants in the study didn’t have heart disease when they enrolled in the research project. They ranged in age from 40 to 69. Half of them stayed in the study for more than six years.
Overall, they experienced 20,914 cardiovascular events such as heart attacks, strokes, atrial fibrillation and heart failure.
Researchers used a physical activity questionnaire to assess how much exercise people got. They also did treadmill tests to assess fitness, hand-held tools to test grip strength, and collected genetic data on most of the participants.
Exercise appeared linked to a lower risk of heart problems even after researchers accounted for factors like age, gender, ethnicity, socioeconomic status, diabetes, smoking, blood pressure, obesity and use of medicines to lower cholesterol.
The study wasn’t a controlled experiment designed to prove whether or how exercise might directly lower the risk of heart disease in general or specifically for people with a genetic predisposition for heart problems.
Another limitation is that researchers relied on participants to accurately recall and report on how much exercise they got. The study can’t offer insights into what type of exercise or how much is needed for optimal heart health.
Even so, it’s been clear for many years that physical activity can help prevent heart disease, noted Donna Arnett, dean of the College of Public Health at the University of Kentucky and a past president of the American Heart Association.
“Being physically fit leads to more lean body mass, less fat mass, and less obesity,” Arnett, who wasn’t involved in the study, said by email. “This leads to less hypertension, less diabetes, better utilization of glucose and insulin, and overall, better metabolic health as well.”