When Dr. Nir Barzilai met 100-year-old Helen Reichert, she was smoking a cigarette. Dr. Barzilai, director of the Institute for Aging Research at the Albert Einstein College of Medicine, recalled that Ms. Reichert said doctors repeatedly told her to stop. But those doctors were all dead, Ms. Reichert noted, and she was not. Ms. Reichert lived for almost another decade before passing away in 2011.
There are countless stories about people who reach 100 years oldand their daily habits sometimes disregard conventional advice regarding diet, physical exercise and the consumption of alcohol and tobacco. Yet decades of research show that ignoring this advice can harm most people’s health and shorten their lives.
So, how much of a person’s longevity can be attributed to their lifestyle choices, and how much is simply luck – or lucky genetics? It depends on how long you hope to live.
Research suggests that reaching 80 or even 90 is largely within our control. “There is very clear evidence that for the general population, a healthy lifestyle” extends lifespan, said Dr. Sofiya Milman, professor of medicine and genetics at Albert Einstein College of Medicine.
A study published last year, which analyzed the lifestyles of more than 276,000 U.S. veterans, both men and women, found that adopting eight healthy behaviors could extend people’s lives by up to 24 years. They included a healthy diet, regular physical activity, good sleep, stress management, strong relationships, and not smoking, abusing opioids, or drinking excessively.
If veterans adhered to all eight behaviors, researchers calculated that they could expect to live to about 87 years old. To most people, this probably sounds pretty good; after all, it’s almost 10 years older than the average life expectancy in the United States. But for Dr Milman, who was not involved in the study, the results showed that “even if you do everything right”, you still can’t expect to live to be 100.
If you want to become a centenarian, you’re going to need a little help from your ancestors. Because the older a person gets, the more important genetics seem to be.
Overall, scientists believe that our lifespan is about 25 percent attributable to our genesand 75 percent attributable to our environment and lifestyle. But as people approach 100 and older, those percentages begin to reverse, said Dr. Thomas Perls, a professor of medicine at Boston University’s Chobanian and Avedisian School of Medicine.
Indeed, studies have found that many people with exceptionally long lives I don’t have any healthier habits than the average American. And yet, they live longer and have lower rates of age-related diseasessuch as heart disease, cancer and dementia.
In the Long life family studyfor example: “We have families where we smoke a lot; we have some families where they are couch potatoes,” said Michael Province, a professor of genetics and biostatistics at the University of Washington School of Medicine, who is leading the study with Dr. Perls.
But these families also tend to have special genetic variants that experts say help them avoid disease and live longer.
Certain genes can affect the likelihood of developing specific diseases. For example, the APOE gene is known to influence the risk of Alzheimer’s disease: those who carry the APOE4 variant poses increased riskwhile those with the APOE2 version are at reduced risk. Dr. Province said long-term families have a higher prevalence of APOE2 than the average population.
Other genes appear to influence aging process itself. The one that has appeared in several studies of centenarians is called FOXO3which is involved in many fundamental aspects of cellular health. Because these genes affect the biology of aging, it’s possible they could protect against several age-related diseases, Dr. Milman said.
One of the main benefits of these types of longevity genes could be combating unhealthy behaviors. A study Studies by Drs Milman and Barzilai comparing the offspring of centenarians with a control population found that in both groups, those with healthy lifestyles had an equally low prevalence of cardiovascular disease. But among those with unhealthy lifestyles, the centenarian offspring still had low rates of disease, unlike the control group.
Experts have pointed out that many of these genes are very rare and are likely present in less than 1% of the population. (This is probably not a coincidence, an equally small percentage of people reach the age of 100.) There is also no single gene that provides protection against all diseases associated with aging and age; it’s more likely that there are hundreds that combine to make a difference.
Having the right set of genes to impact longevity is “like winning the lottery,” Dr. Perls said. So even if your mother reached 100, you should still practice the behaviors you know are good for you, just in case you didn’t hit the genetic jackpot.
And whatever you do, don’t follow the health advice of a centenarian. For them, lifestyle probably didn’t matter much, Dr. Barzilai said. For the rest of us, this is really the case.