Does practice really spread life? Twin Study offers new insights

Physical activity is seen as a way to extend human lifespan, but Finnish twin studies have shown that the benefits of physical activity for a long service life may not be as easy as was previously thought.

Researchers from the University of Jyväskylä, Finland, investigated the connections between long -term physical activity and mortality in the long term, as well as whether physical activity can reduce the increased mortality risk as a result of genetic predisposition for diseases. Moreover, they investigated the relationship between physical activity and later biological aging.

The study included 22,750 Finnish twins born before 1958, whose leisure time physical activity was assessed in 1975, 1981 and 1990. The follow-up of mortality continued until the end of 2020.

The results were published in Medicine and science in sports and exercise and the European Journal of Epidemiology.

Moderate activity yields maximum lifespan benefits

Four different subgroups were identified from the data based on physical activity of leisure time during the 15-year follow-up: sedentary, moderately active, active and very active groups. When the differences in mortality between the groups were investigated during the follow-up of 30 years, it was found that the biggest benefit and 7% lower risk of death reaches between the sedentary and moderately active groups. A higher level of physical activity did not benefit any extra benefits.

When the mortality was investigated separately in the short and long term, a clear association was found in the short term: the higher the level of physical activity, the lower the risk of death. In the long term, however, those who were very active did not differ from those sitting in terms of death.

“An underlying pre-disease state can limit physical activity and ultimately lead to death, not the lack of exercise itself,” says university teacher Elina Sillanpää of the Faculty of Sports and Health Sciences. “This can influence the association between physical activity and mortality in the short term.”

Meeting the guidelines for physical activities does not guarantee a lower risk risk

The researchers also investigated whether following the guidelines of the physical activity of the World Health Organization influences mortality and the risk of genetic diseases. The guidelines suggest 150 to 300 minutes of moderate or 75 to 150 minutes of powerful activity every week. The study showed that complying with these guidelines did not change the risk of death or the risk of genetic diseases. Even for twins that have achieved PA’s recommended levels for a period of 15 years, no statistically significant difference in death rates were found compared to their less active twin couple.

“The generally observed favorable association between physical activity and mortality is based on observational studies that are susceptible to bias from different sources,” says Postdoctoral researcher Laura Joensuu of the Sport and Health Sciences Faculty. “In our studies we wanted to take into account different sources of prejudices, and in combination with the long follow-up period we could not confirm that compliance with the guidelines for physical activity reduces genetic cardiovascular diseases or reduces the mortality.”

Link between physical activity and biological aging is U-shaped

For the Subsample of Gemini, biological aging was determined from blood samples with the help of epigenetic clocks. Epigenetic clocks can estimate the biological aging of a person on the basis of methyl groups that regulate gene expression and are linked to the aging process.

“We found that the association between the physical activity of leisure time and biological aging was U-shaped: biological aging was accelerated with those who have exercised the least and most,” says Sillanpää.

Other lifestyle, such as smoking and alcohol consumption, largely explained the favorable associations of physical activity with biological aging.

Genetic data was available for 4,897 twins. The genetic sensitivity of twins to coronary artery disease, as well as systolic and diastolic blood pressure was assessed with the help of new polygene risk scores, which summarize the genome -wide sensitivity to morbidity. In addition, all causes and cardiovascular mortality were followed in 180 identical twin pairs. The biological aging of 1,153 twins was assessed from a blood sample.

The studies were conducted in collaboration with the Faculty of Sports and Health Sciences and Methodology Center for Human Sciences at the University of Jyväskylä and the Finnish Institute for Molecular Medicine at the University of Helsinki.

The first authors of the studies, doctoral researchers Laura Joensuu and Anna Kankaanpää, are among the genactive research group. The genactive group investigates genetic and lifestyle factors that predict biological aging, health and functional capacity. The group leader is Elina Sillanpää, assistant professor of Health Promotion.