Want to live up to an additional 24 years? Just add eight healthy lifestyle choices to your life at age 40 and that could happen, according to a new unpublished study analyzing data on US veterans.

Starting at age 50 instead? No problem, you could prolong your life by up to 21 years, the study found. Age 60? You’ll still gain nearly 18 years if you adopt all eight healthy habits.

“There’s a 20-year period in which you can make these changes, whether you do it gradually or all at once,“ said lead study author Xuan-Mai Nguyen, a health science specialist for the Million Veteran Program at the VA Boston Healthcare System.

“We also did an analysis to see if we eliminated people with type 2 diabetes, high cholesterol, stroke, cancer and the like, does it change the outcome? And it really didn’t,” she said. “So, if you start off with chronic diseases, making changes does still help.”

What are these magical healthy habits? Nothing you haven’t heard before: Exercise, eat a healthy diet, reduce stress, sleep well and foster positive social relationships. On the flip side, don’t smoke, don’t drink too much and don’t become addicted to opioids.

“The earlier the better, but even if you only make a small change in your 40s, 50s or 60s, it still is beneficial,” Nguyen said. “This is not out of reach — this is actually something attainable for the general population.”

Lifestyle habits build on each other

The study, presented Monday at Nutrition 2023, the annual meeting of the American Society for Nutrition, looked at the lifestyle behaviors of nearly 720,000 military veterans between the ages of 40 and 99. All were part of the Million Veteran Program, a longitudinal study designed to investigate the health and wellness of US veterans.

Adding just one healthy behavior to a man’s life at age 40 provided an additional 4.5 years of life, Nguyen said. Adding a second led to seven more years, while adopting three habits prolonged life for men by 8.6 years. As the number of additional lifestyle changes climbed so did the benefits for men, adding up to nearly a quarter century of extra life.

Women saw huge leaps in life span as well, Nguyen said, although the numbers added up differently than for men. Adopting just one healthy behavior added 3.5 years to a woman’s life, while two added eight years, three 12.6 years and embracing all the healthy habits extended a woman’s life by 22.6 years.

“Doing all eight had a synergistic effect, sort of an added boost to extend your life, but any small change made a difference,” Nguyen said.

After adjusting for age, body mass index, sex, race and ethnicity, marital status, education level and family income level, the study found “an 87% relative reduction in all-cause mortality for those who adopted all eight lifestyle factors compared to those who adopted none,” Nguyen said.

“An important strength of this analysis was that the population was highly diverse by race, ethnicity, and SES (socioeconomic status),” said senior study author and leading nutrition researcher Dr. Walter Willett, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health and professor of medicine at Harvard Medical School.

The study could only show an association, not a direct cause and effect, and because it focused on veterans, the findings may not translate to all Americans. However, veterans in the study “were retired and not on active duty or attending military training,” Nguyen said. “Still, the numbers might not necessarily translate directly to a general population one-on-one.”

Ranking the lifestyle choices

The study was able to rank the eight lifestyle behaviors to see which provided the biggest boost in longevity.

No. 1: First on the list was exercise, which many experts say is one of the most important behaviors anyone can do to improve their health. Adding that one healthy behavior produced a 46% decrease in the risk of death from any cause when compared with those who did not exercise, Nguyen said.

“We looked at whether they did light, moderate or vigorous activity compared to not doing anything and just sitting on the couch,” Nguyen said. “People who lived longer did 7.5 metabolic equivalent hours of exercise a week. Just to give you a baseline — if you can walk up a flight of stairs without losing your breath, that’s four minutes of the 7.5.”

That finding echoes results from other studies that show you don’t have to do extreme sports to get the health benefits of exercise, although more vigorous activities that cause you to lose your breath are best.

No. 2: Not becoming addicted to opioids was the second most important contributor to a longer life, reducing the risk of early death by 38%, the study found. That’s a significant issue today, with the opioid crisis in the US a national “public health emergency,” an agency within the Department of Health and Human Services reported.

No. 3: Never using tobacco reduced risk of death by 29%, the study found. If a person was a former smoker, that didn’t count: “We did that to make it as strict as we could,” Nguyen said. However, stopping smoking at any point in life confers major health benefits, experts say.

No. 4: Managing stress was next, reducing early death by 22%, the study found. Stress is rampant in the US today, with devastating consequences for health, experts say. And there are ways to revamp your outlook and turn bad stress into good stress.

No. 5: Eating a plant-based diet would raise your chances of living a longer life by 21%, the study found. But that doesn’t mean you have to be a vegetarian or vegan, Nguyen said. Following a healthy plant-based plan such as the Mediterranean diet full of whole grains and leafy green vegetables was key.

No. 6: Avoiding binge drinking — which is having more than four alcoholic beverages a day — was another healthy lifestyle habit, reducing the risk of death by 19%, Nguyen said. Binge drinking is on the rise in the US, and it’s not just college students. Even moderate drinkers are at risk, studies say.

In addition, other studies have found that any amount of drinking may be unhealthy, except perhaps, for heart attacks and stroke, and even that finding has been challenged. One study found than even one drink may trigger an irregular heart rhythm called atrial fibrillation.

No. 7: Getting a good night’s sleep — defined as at least seven to nine hours a night with no insomnia — reduced early death from any cause by 18%, Nguyen said. Dozens of studies have linked poor sleep to all sorts of poor health outcomes, including premature mortality.

No. 8: Being surrounded by positive social relationships helped longevity by 5%, the study found. However, loneliness and isolation, especially among older adults, is becoming more widespread and worrisome, experts say.

“Five percent may seem small, but that’s still a decrease in terms of all-cause mortality,” Nguyen said. “Every little bit helps, whether you pick physical activity or make sure you’re surrounded by positive social support.”

A recent study found people who experienced social isolation had a 32% higher risk of dying early from any cause compared with those who weren’t socially isolated. Participants who reported feeling lonely were 14% more likely to die early than those who did not.