Some people live to be 100 or older still. Others aren’t quite so lucky. What separates the two groups? Part of the answer boils down to simple luck: we know that genes play a prominent role in shaping lifespan. For some, this means being naturally predisposed to a longer life, while for others, it means facing an uphill battle.
But the good news is that lifestyle choices—the daily decisions you make about diet, exercise and beyond—also have a say. In fact, a healthy lifestyle may be able to cancel out roughly 60% of the impact of “life-shortening” genes, potentially adding another five years to your life. These are the findings of a new, large-scale study published in the British Medical Journal.
Big Data, Big Findings
To study how lifestyle and genetics interact to influence longevity, the researchers gathered relevant genetic, biological and health data from 353,742 participants. They then tracked their health for roughly 13 years.
Based on their full genetic information, including the presence of any protective or harmful variants, participants were placed into one of three lifespan categories: those whose genes boosted lifespan (20%), those whose genes were suggestive of an intermediate lifespan (60%), and those whose genes set them up for a short lifespan (20%).
Along with the genetic categories, the researchers also slotted each participant into a lifestyle-score category: favorable (23%), intermediate (56%), and unfavorable (21%). Lifestyle “scores” were calculated based on people’s sleeping habits, whether and how much they drank or smoked, what kind of food they ate, and whether or not they were physically active. The optimal combination for a long life includes never smoking, regular exercise, a healthy diet, and getting your full eight hours of sleep.
The findings revealed that people who are genetically predisposed to a short life are 21% more likely to die early compared to those with favorable genes. And this was true regardless of lifestyle decisions. Still, those with life-shortening genes can gain a lot from living healthily: they can offset the effects of the genes by more than 60%, potentially adding up to five additional years to their life.
On the flip side, those with an unhealthy lifestyle were 78% more likely to die early, no matter their genetic status. Even the most favorable genes cannot protect against poor lifestyle choices.
Stacking an unhealthy life on top of unfavorable genes represented the worst of all possible outcomes, more than doubling the risk of an early death compared to those with nourishing lifestyle habits and protective longevity genes.
Takeaways
Although we don’t have a say in the genes we are dealt, we do have some say in how we choose to live our lives. This study makes clear that such lifestyle choices play an outsized role in shaping longevity. And while a lucky set of genes can give you a head start, any advantage can just as easily be undone by a questionable lifestyle. Luckily, the inverse is also true: you can push back against the effects of unfavorable genes by living a healthy life. This cuts down your risk and extends your life.
From a health-systems perspective, it is clear we need to invest in policies that encourage healthy living. As always, an ounce of prevention is worth a pound of cure. But it should also go without saying that nothing happens in a vacuum.
For many, even if they want to make healthy choices, they simply cannot — they may live in a food desert, have no easy and affordable access to sporting facilities, and be priced out of health insurance. A long and healthy life should not be behind a paywall. We need to start considering health and longevity as social issues, not purely individual choices.
