What habits can lead to significant increase in lifespan?

The data used for this study was collected between 2011 and 2019. It featured U.S. veterans between the ages of 40 and 99. Over 30,000 participants died during the follow-up.

“We looked at all-cause mortality in this study using cox proportional hazard regression models and longevity using a multi-lifetable method, calculating the longevity for male veterans and female veterans separately,” Nguyen explained.

Veterans who adopted all eight habits had a 13% reduction in death from any cause compared to those who adopted none of the eight habits.

The study found that men who have adopted all eight habits at the age of 40 would be predicted to live 24 years longer, on average, than men who adopted none of these habits. Women who have adopted all eight habits by age 40 would live 23 years longer on average compared to those who adopted none.

“Take home message: Veterans who commit to a moderate change toward living a healthier lifestyle during middle-age may prolong their life expectancy,” Nguyen stressed to Medical News Today.

The researchers found that low physical activity, opioid use, and smoking had the biggest impact on an individual’s lifespan. During the study period, these habits were associated with a 30% to 45% higher risk of death.

Stress, drinking alcohol excessively, poor diet, and poor sleep hygiene were associated with around a 20-30% increase in the risk of death during the study period. In comparison, the lack of positive social relationships was associated with a 5% increased risk of death.

Mental health likely plays a role in life expectancy.

“We never previously quantified how living with anxiety or depression was associated with mortality. Through this study, we learned that it was associated with 8% of premature death. This study and our findings have made us rethink how we can direct future research to incorporate psychosocial factors more meaningfully,” Nguyen said.

“This study was the first time we looked at psychological lifestyle factors and their association with life expectancy in MVP.”

— Xuan-Mai Nguyen, study author

Preventing chronic disease to increase lifespan

According to the U.S. Centers for Disease Control and Prevention, chronic diseases, such as heart disease and diabetes, are the leading causes of death and disability in the United States.

“Non-communicable chronic diseases are associated with over 80% of all healthcare dollars…,” Nguyen told MNT.

“Living with a chronic disease is costly and a burden to individuals and to society. Studies have found that approximately 90% of diabetes, 80% of coronary heart disease, and 70% of cardiovascular mortality can be attributed to unhealthy lifestyle habits,” she said.

Lifestyle medicine is a specialty that focuses on preventing chronic diseases.

“It provides a potential avenue for altering the course of ever-increasing [healthcare] costs resulting from prescription medicine and surgical procedures,” Dr. Nguyen said of lifestyle medicine. “We chose to explore lifestyle factors among veterans participating in the Million Veteran Program (MVP) because it is a unique opportunity to better understand and care for a specific population of people who have devoted themselves to service.”

Dr. Yanping Li, a research scientist in the Department of Nutrition at the Harvard T.H. Chan School of Public Health and a co-author of the study, previously served as a co-author of a 2018 study that found maintaining five healthy habits as adults — eating a healthy diet, exercising regularly, keeping a healthy body weight, not drinking too much alcohol, and not smoking—may add more than a decade to life.

The researchers were able to add three new healthy habits to this study because the information the MVP gathers is so comprehensive. “Based on the data availability, we extended the previous five lifestyle factors into eight,” Dr. Li said.

It’s never too late to adopt healthy habits

There are benefits to be had even if patients can’t adopt all eight Healthy habits.

“We were really surprised by just how much could be gained with the adoption of one… two… three.. or all eight lifestyle factors!” Nguyen said.

Dr. William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt University Medical Center in Nashville, Tennessee, took particular note of that element of the study.

“It was impressive in the sense that, even if you start, and you don’t do them all…it still is beneficial,” he told MNT.

While the research suggests that adopting Healthy habits at older ages likely results in smaller estimated gains in life expectancy, it’s still probably fruitful.

“Our research findings suggest that adopting a healthy lifestyle is important for both public health and personal wellness,” Nguyen said. “The earlier the better, but even if you make changes in your 40s or 60s, it still is beneficial as seen in our study findings!”

How to add a couple of years to life expectancy

Doctors have long advised patients to eat right and exercise regularly. Studies like this allow them to quantify the benefits of adopting healthy habits.

“The purpose is to let the general audience and the clinical physician to understand how much the difference [is] if they do this or that, so it’s kind of [to help] them to explain to the patient why it’s so important to adopt a healthier lifestyle,” Dr. Li told MNT.

The results of the study make a convincing case, according to Dr. Schaffner.

“If you do wrap them all together, and you start reasonably early, it does seem to predict that you get a substantial increase in your life expectancy,” he said. “We’re not talking about days, weeks, months, or only a couple of years.”

Observational study cannot establish causality

Nguyễn stressed that the research is an observational study.

“I think one of the most important limitations and cautions that people need to understand while interpreting the results of our study is that our estimations are based on observational data and causality cannot be assumed from our findings,” she said.

“Although we have carefully controlled for confounding factors, our results do not imply causal effects. It is critical to not overinterpret the findings considering the observational nature of our study,” she added.

While a committee of experts evaluated the abstracts selected for Nutrition 2023, they did not undergo the same peer review process required for publication in a scientific journal.