What Matters More for Longevity: Genes or Lifestyle?

When Dr. Nir Barzilai met the 100-year-old Helen Reichert, she was smoking a cigarette. Dr. Barzilai, the director of the Institute for Aging Research at the Albert Einstein College of Medicine, recalled Mrs. Reichert saying that doctors had repeatedly told her to quit. But those doctors had all died, Mrs. Reichert noted, and she hadn’t. Mrs. Reichert lived almost another decade before passing away in 2011.

There are countless stories about people who reach 100, and their daily habits sometimes flout conventional advice on diet, exercise, and alcohol and tobacco use. Yet decades of research shows that ignoring this advice can negatively affect most people’s health and cut their lives short.

So how much of a person’s longevity can be attributed to lifestyle choices and how much is just luck — or lucky genetics? It depends on how long you’re hoping to live.

Research suggests that making it to 80 or even 90 is largely in our control. “There’s very clear evidence that for the general population, living a healthy lifestyle” does extend the life span, said Dr. Sofiya Milman, a professor of medicine and genetics at the Albert Einstein College of Medicine.

One study published last year, which analyzed the lifestyles of more than 276,000 male and female United States veterans, found that adopting eight healthy behaviors could add up to 24 years to people’s lives. They included eating a healthy diet, getting regular physical activity, sleeping well, managing stress, having strong relationships, and not smoking, abusing opioids or drinking to excess.

If the veterans adhered to all eight behaviors, the researchers calculated that they could expect to live to about age 87. To most people, that probably sounds pretty good; after all, it’s almost 10 years longer than the average U.S. life expectancy. But to 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 100.