Live Long and Prosper

Can You Predict How Long You Will Live? And What Can You Do to Make Sure You Reach That Number?
Photo credit: (TNS)

As the saying goes, there are two certainties in life: death and taxes. A good accountant can estimate your taxes due, but what about your life span? Is it possible to predict how long you have left?

Health calculators are available that can estimate a person's 10-year risk of having a major cardiovascular event, such as a heart attack or stroke. But that's not the case for almost all other diseases. And when it comes to predicting your own longevity, there are too many individual variables.

 "Calculating longevity is complex because there are multiple factors at play," says Dr. David Sinclair, professor in the Department of Genetics and co-director of the Paul F. Glenn Center for Biology of Aging Research at Harvard Medical School. "A person's age, past health issues, current health status, geography, and lifestyle all have a significant role."


It turns out that the most significant predictor of longevity is something people have zero control over -- their DNA. "Longevity tends to run in the family, and your genetic makeup can often provide the best chance to live a long time," says Dr. Sinclair.

How do your genes help you live longer? Science believes their primary role is to help protect the body against age-related diseases.

A study in the Dec. 3, 2020, issue of Nature, led by Dr. Sinclair, explored this concept. The researchers created a virus that carried three "longevity genes" into mice -- a technique known as gene therapy. They found that these longevity genes protected the mice from becoming obese (even when fed a high-fat diet), developing type 2 diabetes and heart failure, and suffering kidney failure. This was an animal study and may or may not apply to humans. Still, it suggests how people born with good genes can avoid serious health problems.

Photo credit: (Pexels)


This type of gene therapy resides only in the lab. So, what can you do even if you haven't inherited good DNA? No surprise: the habits that keep you healthy right now also can help you live longer.

A 2018 study in Circulation led by researchers at the Harvard T.H. Chan School of Public Health found that maintaining five healthy habits can increase life expectancy. They include not smoking, having a healthy body mass index (18.5 to 24.9), doing at least 30 minutes of daily moderate-to-vigorous activity, consuming no more than moderate amounts of alcohol (up to two 5-ounce glasses of wine per day for men), and following a heart-healthy diet.

The researchers looked at how these factors affected people starting at age 50. They found that men who didn't adopt any low-risk lifestyle factors had an average estimated life expectancy of 25.5 more years. Yet, those who adopted all five factors had a life expectancy of 37.6 more years.


This study, and similar ones, point to weight management as perhaps the biggest controllable influence on longevity. Excess weight is linked to various health problems that can shorten one's life. Keeping your weight down with a proper diet and exercise goes a long way.

Of course, that's always easier said than done. Dr. Sinclair says one way people can address this issue is to focus on calorie reduction. One study showed that lowering average daily calories by only 12% helped overweight people reduce their high blood pressure and cholesterol levels. They also had significant drops in levels of C-reactive protein, an inflammatory factor linked to cardiovascular disease.

 If tracking daily calories is difficult, you could try a system called intermittent fasting, which helps with overeating and late-night snacking.

 A popular pattern is the 16/8 method, where you eat during an eight-hour period -- for example, from noon to 8 p.m. -- followed by 16 hours of fasting, in this case from 8 p.m. until noon the next day, when the pattern repeats. Researchers have found that people who followed 16/8 intermittent fasting lowered their blood pressure, cholesterol, and inflammation levels.

 The end result of all these lifestyle changes -- proper diet, adequate exercise, watching weight and alcohol, and not smoking -- is that they help keep the body healthy. In essence, this is the basic formula for longer life. "Longevity is simply a side effect of not getting sick," says Dr. Sinclair. "Doing everything you can to be healthier now can pay off down the road."


This article was originally published by Harvard Men's Health Watch.


Read More: 

Harder Workout Intensity May Not Increase Your Longevity


Can we slow the aging process?


Should You Try Intermittent Fasting?

Related Articles