New Study Suggests Genetics Play Bigger Role in Longevity

For a long time, scientists have thought that our lifestyle choices primarily influence how long we live. But a recently published study indicates that our genes may actually have a more significant impact on lifespan than previously believed.

The study finds that genetics account for more than half of the differences in how long people live, which is actually much higher than past estimates suggested. This insight might align with common observations, like family health history or discussions during health check-ups.

Dr. Deborah Kado, co-director of the Stanford Longevity Center, who wasn’t involved in this particular research, noted that this finding isn’t particularly surprising. While most specialists agree that traits are shaped both by genetics and environment, lifespan had generally been seen as mostly determined by external factors.

The findings, published in the journal Science, suggest that longevity is similar to complex traits like cholesterol levels or osteoporosis risk, which are influenced by multiple genes but are also shaped by lifestyle and living conditions.

Earlier studies may have downplayed the role of genetics by focusing on data from individuals born before the 19th century. These people often died from infectious diseases or accidents before modern advancements like vaccines and healthcare arose.

When older research included these factors, they obscured the genetic influences on lifespan. Uri Alon, the lead author of the study, explained that by refining the data to eliminate these variables, the impact of genes became clearer.

“There was a common thought that maybe genetics doesn’t matter,” Alon shared. “But what we’ve found is that our genes do play a crucial role in determining lifespan.” However, he suggests that genes alone don’t tell the entire story.

In fact, while 55% of lifespan may be genetically predetermined, there’s still about 45% that remains uncertain. “Some of it is luck, and some of it is our choices,” Alon elaborated.

He pointed out that choices related to diet, exercise, and social interactions could potentially alter a person’s genetically influenced age by as much as five years. “Genetics isn’t the final word,” he noted.

So, someone who is genetically inclined to live to 80 could reach 85 with healthier habits, while poor lifestyle choices could lower that expectancy to 75. Yet, he cautioned, merely adopting healthy habits won’t stretch that lifespan further if genetics cap it at 80.

In the U.S., life expectancy peaked at 79 years in 2024, according to recent data from the CDC. The trend had been on the rise for decades but saw a decline of nearly a year and a half during the Covid-19 pandemic.

That’s why Kado believes that products claiming to enhance longevity are not the ultimate solution. “What truly matters is exercise, diet, and social connections,” she asserted.

Although some genes have been recognized as protective or detrimental regarding aging, Kado emphasizes that longevity is affected by a more intricate interplay of factors beyond just a few genes.

“There’s no single gene responsible for aging,” she remarked. “Biology is complicated,” she added, highlighting that many elements affecting lifespan are still being discovered.

As research continues to uncover the underlying biological mechanisms, there may be new tools developed to target pathways that could possibly shorten lifespan.

“Understanding the genes would help reveal mechanisms,” Alon said. “With that knowledge, we could potentially develop drugs to intervene.” This approach, he suggested, could move beyond treating isolated diseases.

However, achieving this type of future is likely many years away. While genetic screening already identifies inherited risks for specific conditions, no test can reliably predict genetic age. Alon noted that creating such a tool could be a significant initial step toward enhancing genetic lifespan.

Dan Arking, an aging expert at Johns Hopkins University, mentioned that this study opens up an important discussion: how to balance years lived in good health against total lifespan.

“Being healthier for a more extended period holds tremendous value,” Arking argued, adding that living longer may not be worthwhile if those additional years are unhealthy.

He also pointed out that reducing risks of age-related diseases, like osteoporosis, may lead to more years of good health, but extending overall life remains complex. It’s still uncertain if lifespans can exceed the record of 122 years.

“At some point, our bodies may just shut down,” Arking remarked. “There might be a natural limit.”

Alon echoed the importance of prioritizing quality of life alongside longevity, noting that while average life expectancy has doubled over the last 150 years, the maximum lifespan has barely changed. In fact, mortality rates among centenarians have remained steady for the past three decades.

“As we approach 100, we start feeling the effects that limit us from reaching 120,” Alon explained. “Breaking through this barrier would likely require drastic and risky measures.”

Regardless of the debates, Alon believes this study represents meaningful progress. It seeks to reaffirm the genetic component in longevity and may inspire further research in the field.

“Our findings should motivate further investigations into genetics,” he stated. “It’s a blend of nature and nurture, and now we see that longevity follows the same pattern.”