Healthy lifestyle offset predisposition to early death by 62%
A balanced diet, absence of bad habits, physical activity and other components of a healthy lifestyle can compensate for the influence of genes that shorten its duration. At the same time, unhealthy lifestyle has a negative impact on longevity regardless of genetics.
Longevity is affected by both genes and the lifestyle a person leads. Among the factors that are commonly emphasized in this regard are tobacco and alcohol use, diet, quantity and quality of sleep, and the presence and intensity of physical activity. According to a recent study, attention to these aspects can prolong life and inattention can shorten it, regardless of whether a person has a genetic predisposition to early death.
An international team of scientists included 353,742 people over the age of 18 in the study, whose details were entered into the UK Biobank between 2006 and 2010 and who were followed until 2021. The results of the study, which found that a healthy lifestyle can offset the effects of genes that shorten life expectancy by more than 60%, were published in the journal BMJ Evidence Based Medicine.
Using data from previous research papers, the authors of the article assessed the polygenic risk score (PRS) - a common genetic predisposition to a longer or shorter life - and a weighted measure of healthy lifestyle. According to criteria from the LifeGen cohort study, 20% each of the participants in the new paper were predisposed to a long and short life, while 60% were predisposed to a medium life. According to the system from the American NHANES study, 23% of the sample rated their lifestyle as favorable, 56% as average and 22% as unfavorable.
In the nearly 13 years that the study participants were monitored, 24,239 people in the sample died. Those who were predisposed to a short life expectancy were 21% more likely to die early than those whose genetics predisposed them to longevity, regardless of lifestyle. Study participants who had "unfavorable" lifestyles had a 78% higher risk of premature death than those who had "favorable" lifestyles, with no link to genetic predisposition.
And the genetic risk of early death combined with an "unfavorable" lifestyle meant that those with a genetic predisposition were twice as likely to die as those with a combination of longevity predisposition and a "favorable" lifestyle. The main factors that determined a healthy lifestyle were not smoking, regular physical activity, sleeping 7-9 hours a night and a balanced diet.
Having compared and analyzed the observational data, the researchers allowed that the genetic risk of shortened life or premature death can be compensated by a healthy lifestyle by about 62%. According to the authors of the paper, people with a high predisposition to shorter life expectancy can increase it by almost 5.5 years in their forties by adopting a healthy lifestyle. Given that lifestyle habits tend to take hold by middle age, it is important to gradually build them up to that time.
The authors of the paper noted that their study has limitations. For example, they only assessed participants' lifestyle habits at one point in time, although it may have varied at different ages. In addition, the sample consisted of Europeans, which may not allow the findings to be generalized.
Nevertheless, the researchers called the focus on lifestyle a "powerful addition" to traditional health interventions. In their view, the study "sheds light on the key role of healthy lifestyles in mitigating the impact of genetic factors on shortened life expectancy."