Adam’s Journal
I read an article saying that when it comes to how long we live, only about 25% is determined by our genes, with the remaining 75% due to our lifestyle. Is this true?
Dr. Miller Prescribes
Yes, it is true. While specific studies can vary a bit, most research in this area has generally concluded that lifespan is about three-quarters attributable to how we live and about one-quarter determined by our genes.
First, let’s talk about genes and longevity. In addition to the anecdotes we’ve all heard about people who live to advanced ages despite unhealthy habits, studies on aging show that genetics play a role in lifespan.
In aging research, we use species like roundworms, which only live a couple of months, to study aging over shorter periods of time. These studies show that changing even only a single gene can increase lifespan six-fold.
Studies on centenarians, people who live to be 100 or more, show they have some genetic traits more often than people who do not live as long. Similarly, some rare genetic syndromes accelerate the aging process, which once again points to the role that genes can play in aging.
Still, while genes are important, so-called environmental factors have a bigger effect. Study after study has confirmed that the choices we make play a huge role in how long we live. For example, studies in identical twins, who share their genes, can show differences in lifespan depending on their life choices.
One recent study of more than 200,000 veterans found that adopting eight healthy behaviors – things like eating well, getting regular physical activity, managing stress, having strong relationships, sleeping well, and not smoking, abusing opioids or drinking to excess – could add decades to people’s lives.
From 1900 to 2000, the average American lifespan increased by 30 years, from 47 to 77. Genetically, as a species, we didn’t change much, if at all during this time. So, it’s reasonable to conclude that this giant leap was due largely, if not completely, to changes in the way we live (which, I should note, includes improvements in public health).
In the Aging & Metabolism Research Program at the Oklahoma Medical Research Foundation, our research is more focused on healthspan – the amount of time you can stay active and free of disease and disability – than just lifespan. Our work and that of many others has found, not surprisingly, that both exercise and diet play a big part in this equation.
When considering lifespan or healthspan, it helps to think about a card game. Genes are the hand you are dealt, and environment is how you play the hand.
Talented poker players are not magically dealt great hands every time. Rather, they play their hand well to give themselves the best chance of winning.
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A physiologist and medical researcher, Dr. Benjamin Miller chairs the Aging & Metabolism Research Program at the Oklahoma Medical Research Foundation. Adam Cohen is OMRF’s senior vice president and general counsel. Send your health questions to contact@omrf.org.
