HANGZHOU, China — A healthy lifestyle could slash the effects of life-shortening genes by more than 60 percent, a new genetic study reveals. While genes can certainly impact lifespan and chronic illness risk, an unhealthy lifestyle is independently associated with a 78-percent increased risk of premature death, regardless of genetic factors, researchers add.
The polygenic risk score evaluates multiple genetic variants in order to come up with a person’s overall genetic predisposition for living a longer or shorter life. Aside from these gene variants, tobacco use, alcohol consumption, diet quality, sleep, and physical activity level are all important factors for determining life expectancy as well.
Still, it has been unclear how well a healthy lifestyle offsets genetic factors that may shorten someone’s lifespan. To find out, researchers used data from 353,742 adults participating in the UK Biobank between 2006 and 2010. Each person had their health tracked until 2021.
That review created polygenic risk scores for long (20% of participants), intermediate (60%), and short lifespans (20%), pulling on data from the LifeGen cohort study.
Researchers also created a weighted healthy lifestyle score that included no current smoking, moderate alcohol consumption, regular physical activity, healthy body shape, adequate sleep, and a healthy diet — organizing the participants into favorable (23%), intermediate (56%), and unfavorable (22%) lifestyles, according to data from the U.S. NHANES study.
Over an average tracking timeframe of almost 13 years, 24,239 participants died. People genetically predisposed to having a short lifespan were 21 percent more likely to die early than those genetically predisposed to enjoying a longer life, irrespective of lifestyle choices.
Results also showed that those who had an unfavorable lifestyle were 78 percent more likely to die before their time than those with a favorable lifestyle, regardless of genetic predisposition. Those at a high genetic risk of a shorter lifespan and who had an unfavorable lifestyle were twice as likely to die compared to those genetically predisposed to having a longer life with a favorable lifestyle. The team noted that not smoking, regular physical activity, getting enough nightly sleep, and a healthy diet were fundamental trends that made up a favorable lifestyle.
Given this was an observational study, the team was unable to directly link healthy living to life expectancy, but the genetic review shows a clear association. Another limitation of the study was that it only assessed someone’s lifestyle at one point in time, which can skew things as a person’s lifestyle choices often evolve with age. Additionally, the participants were of European ancestry, which makes it difficult to generalize the results and apply them to other populations.
Still, the team believes their findings show that the genetic risk of a shorter life or premature death could be counterbalanced with a better lifestyle.
“This study elucidates the pivotal role of a healthy lifestyle in mitigating the impact of genetic factors on lifespan reduction,” the researchers concluded in a media release. “Public health policies for improving healthy lifestyles would serve as potent complements to conventional healthcare and mitigate the influence of genetic factors on human lifespan.”
A Dietitian’s Take
Epigenetics, the study of how your behaviors and environment can influence how your genes work, is a relatively new area of study. Researchers are racing to understand how it may or may not relate to health and disease prevention.
Your genes change before you’re even born, and as you grow, epigenetics helps determine which function a cell is going to have in your body. Your epigenetics as a newborn were different than they are now. While science is working out the kinks, it’s thought that your choice of lifestyle can influence whether your genes are more likely to work with you or against you. This study is an example of that, showing that it’s possible to offset genes that predispose you to premature death by living a healthier lifestyle by a significant margin. In this case, up to a staggering 62 percent.
The findings are published in BMJ Evidence-Based Medicine.