Fit but Still Sick? Why Exercise May Not Outrun Genetic Risk

Why do some people fall ill or die young despite exercising diligently?

A new study reveals that individuals with a genetic predisposition to cardiovascular diseases may not significantly reduce their risk of premature death, even when consistently following recommended physical activity guidelines.

This research, conducted by a team from the University of Jyväskylä in Finland, examined 22,750 twins born before 1958.

The researchers surveyed participants’ leisure-time physical activity in 1975, 1981, and 1990, then tracked mortality rates through 2020. They compared groups adhering to the World Health Organization’s (WHO) guidelines of 150-300 minutes of moderate exercise or 75-150 minutes of vigorous exercise per week against those who didn’t meet these benchmarks.

The findings showed that individuals with high genetic risk for cardiovascular disease did not experience significant mortality rate reductions or decreased cardiovascular disease risk, even when meeting recommended exercise levels. Notably, the mortality rate difference between twins who consistently exercised for 15 years and their less active siblings was statistically insignificant. This trend held across high, medium, and low genetic risk groups.

The study indicates that while lifestyle and environmental factors play a role, genetic factors account for 40-60% of cardiovascular disease risk. Common conditions include hypertension, heart disease, cerebrovascular disease, and stroke, with family history significantly amplifying genetic influence.

 Dr Laura Joensuu explained that previous research suggesting physical activity lowers mortality rates often stemmed from observational studies, which are prone to bias. She noted that their long-term study could not confirm a direct effect of exercise in mitigating genetic cardiovascular risks or reducing mortality rates.

The researchers also explored the relationship between physical activity and biological aging rates. They discovered that sedentary individuals and those who overexercise age faster biologically, while moderate exercisers show the slowest aging rates.

While the study suggests physical activity may not decisively lower genetic cardiovascular disease risk, it can positively impact overall cardiovascular health and biological aging.

Experts caution that while exercise and healthy habits help prevent cardiovascular diseases, strong genetic factors cannot be completely overcome. They advise individuals with family histories of heart issues to undergo regular check-ups and consult with healthcare providers. Personalized treatment strategies, preventive medications, and ongoing monitoring are crucial for these individuals.