The "best lifestyle" for longevity, these 4 factors are the key!

Compiled by: Gong Zixin

We know that genetics and lifestyle are important factors affecting life expectancy. A large-scale long-term research analysis recently published online in the British medical journal BMJ Evidence-Based Medicine shows that a healthy lifestyle can offset the effects of more than 60% of short-lived genes, which will greatly help extend life expectancy and reduce mortality.

While genes and lifestyle appear to have an additive effect on lifespan, the study showed that an unhealthy lifestyle was associated with a 78% increased risk of early death, independent of genetic predisposition.

The polygenic risk score (PRS) combines multiple genetic variants to derive a person's overall genetic predisposition to live longer or shorter. Lifestyle is a key factor, including smoking, alcohol consumption, diet quality, sleep quota, and physical activity levels. But researchers say it is unclear to what extent a healthy lifestyle can offset the effects of genes on shortened lifespan.

To explore this further, the researchers recruited 353,742 adults between 2006 and 2010, and their health was tracked until 2021.

The study used data from the LifeGen cohort study to derive polygenic risk scores for long-term (20% of participants), medium-term (60%) and short-term (20%) life expectancy risks; and used data from the US NHANES study to divide weighted health lifestyle scores (including smoking, drinking, physical activity, healthy body shape, etc.) into favorable (23% of participants), moderate (56%) and unfavorable (22%) lifestyles.

During an average follow-up period of nearly 13 years, 24,239 participants died. Regardless of their lifestyle, those who were genetically predisposed to a short life span were 21% more likely to die prematurely than those who were predisposed to a long life span. Similarly, regardless of genetic predisposition, those with a poor lifestyle were 78% more likely to die prematurely than those with a good lifestyle. People who were genetically at risk for a short life span and had a poor lifestyle were twice as likely to die prematurely as those who were predisposed to a long life span and had a good lifestyle.

The life expectancy at age 40 was 52.52 years for subjects with a genetic predisposition to longevity (low PRS) and a favorable lifestyle, and 45.83 years for subjects with a genetic predisposition to shortevity (high PRS) and an unfavorable lifestyle. The average difference in lifespan was 6.69 years. An unfavorable lifestyle had a large impact on the number of years of life lost regardless of the group, with the longevity and unfavorable lifestyle subgroups losing the most years of life. Among individuals with a genetic predisposition to shortevity, those with a favorable lifestyle lived 5.22 years longer than those with an unfavorable lifestyle.

Given that the largest proportion of participants had 4 healthy lifestyle factors, the magnitude of the effect estimates was ranked as follows:

The "optimal lifestyle combination" for longer life:

▲ Never smoke

▲ Regular physical exercise

▲ Sufficient sleep time

▲ Healthy diet

This is an observational study, so no firm conclusions can be drawn about cause and effect. In addition, there are some limitations to the study, such as lifestyle was only assessed at one point in time and the participants were all of European descent, which may limit the generalizability of the findings.

But the researchers stressed that the findings suggest that genetic and lifestyle factors are independently associated with lifespan. The genetic risk of a shorter lifespan or premature death could be offset by about 62% by a good lifestyle. Therefore, public health policies to improve healthy lifestyles would be a powerful supplement to standard medical care and reduce the impact of genetic factors on human lifespan.