Role of adolescent lifestyle in biological aging

According to findings published in eLife, genetics may contribute to the explanation of the connection between unhealthy lifestyles and increased biological aging in young adults.

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Biological aging is caused by the accumulation of damage to cells and tissues in the body over time. The study’s findings could lead to new methods of detecting young people at risk of establishing unhealthy habits linked with accelerated biological aging, as well as therapies to prevent poor health consequences later in life.

Unhealthy lifestyles during adolescence when cells are rapidly dividing may have lasting harmful effects. Activities like drinking or smoking, for example, may contribute to increased biological aging and related health conditions like heart or lung disease and premature death.”

Anna Kankaanpää, Study Lead Author and Doctoral Researcher, Gerontology Research Center and Faculty of Sport and Health Sciences, University of Jyväskylä

Kankaanpää and coworkers looked into the link between behavior and cellular aging in 824 twins who volunteered in the Finn Twin12 Study to assess the consequences of unhealthy teen behavior on aging at the cellular level.

Participants ranged in age from 21 to 25 years old and had completed behavior surveys at the ages of 12, 14, and 17. The majority of the youths reported overall healthy, active lifestyles, however, two groups were identified as having poor lifestyles by the investigators.

One group had a high body mass index—an estimate of whether a person is at a healthy weight based on height and weight. The other group smoked frequently, drank excessively, and did not exercise consistently.

In blood samples taken from participants, the researchers assessed DNA methylation, which is the insertion of chemical tags on DNA that can turn on or off gene expression. They utilized different algorithms or “epigenetic clocks”—biochemical tests based on DNA methylation levels—to evaluate if the individuals were experiencing accelerated biological aging, and they looked for a link between unhealthy behaviors and faster aging.

Individuals in the two groups classed as having unhealthy behaviors were, on average, 1.7 to 3.3 years older than those who claimed more healthy habits during their adolescence, according to the clocks.

This equates to aging 2 to 3 weeks faster per calendar year. The findings differed depending on the epigenetic clock employed, but the link between lifestyle and hastened aging was mostly attributable to shared genetics.

Previous studies in twins have shown that lifestyle and biological aging are largely inherited. Our study suggests that genetics may underlie the link between unhealthy behaviors and accelerated aging.”

Anna Kankaanpää, Study Lead Author and Doctoral Researcher, Gerontology Research Center and Faculty of Sport and Health Sciences, University of Jyväskylä

The research benefits from a large sample size, prolonged participant follow-up, and the involvement of individuals with similar genetic backgrounds. However, because the teens reported their own activities, the authors believe that some of them may have falsely claimed possessing healthy behaviors to appear more virtuous, which could have distorted some of the results.

More research is needed to completely understand the impact of genetics on lifestyle choices and how these habits influence biological aging in adolescents. Obesity and substance abuse genes may directly cause faster biological aging, or they may indirectly expedite aging by contributing to harmful behaviors that cause cell damage.

Learning more about the aging process and the role of genetics in it may help us identify individuals early in life who may be at risk of unhealthy behaviors during adolescence or who may be prone to faster aging and related diseases later in life. Early identification of at-risk individuals may allow earlier intervention to change behaviors and prevent poor health outcomes later in life.”

Elina Sillanpää, Study Senior Author and Associate Professor, Gerontology Research Center, University of Jyväskylä