Scientists: Healthy Habits Good for You

After twenty-some years of gathering data from roughly 80,000 women, researchers at the Harvard School of Public Health confirm that healthy lifestyle habits are indeed good for you.

In the first large-scale study estimating the impact of a combination of lifestyle factors on mortality, the research team found that subscribing to healthy lifestyle factors—not smoking, maintaining a healthy weight and diet, and exercising regularly—dramatically reduces the risk of dying.

The findings, published last Wednesday on the Web site of the British Medical Journal, also show that the risk reduction from making any single healthy lifestyle choice pales in comparison to the benefits from following a combination of factors.

School of Public Health professor Rob M. van Dam, who is the first author of the study, said that he and his colleagues collected data from 77,782 married nurses from across the nation over a span of 24 years.

The study’s participants submitted responses to detailed questionnaires about lifestyle and health conditions every two years, beginning in 1980. In a follow-up, 8,882 deaths were recorded—1,790 of which were caused by cardiovascular disease and 4,527 by cancer.

For women who adhered to all four lifestyle factors, van Dam and his team estimated the overall risk of death was reduced by 55 percent, in addition to a 44 percent reduced risk of dying from cancer and a 72 percent lower risk from heart disease.

The percentages surpass those of deaths determined to be caused by an individual risk factor, such as smoking or poor diet.

Though the figures from the study simply confirm what was expected, van Dam said that the novelty of the study lay in quantifying the combined effects of healthy lifestyle factors.

“We really wanted to look at what can be the overall impact of lifestyle on death,” van Dam said, adding that he was interested in getting precise statistics.

While the fact that healthy habits lead to a healthy life may not seem surprising, van Dam said that many people may not be aware of what a difference 30 minutes of moderate physical activity a day, for example, can make on one’s health.

Out of the four primary factors considered in the study (the researchers also studied the impact of alcohol intake), smoking is the only one that public health policy can feasibly influence.

For example, Harvard Medical School Dean Jeffrey S. Flier announced in March that a campus-wide ban on smoking will take effect this spring.

“It is important to consider what may be potential barriers in the environment for people to attain a healthy lifestyle,” van Dam said.

“We have to try to be creative and find solutions for that,” he continued.

Anne C. Lusk, a research fellow at the School of Public Health, spoke of the challenges of implementing public policy to encourage people to follow healthy lifestyle habits.

“We should make it really rewarding,” Lusk said, stating that more punitive measures would not be received favorably by the public. “We should figure out direct ways to motivate people.”

Lusk added as an example that she would walk to work in a skirt if she received a coupon to go to her favorite restaurant or an incentive of comparable magnitude.

—Staff writer June Q. Wu can be reached at junewu@fas.harvard.edu.

For recent research, faculty profiles, and a look at the issues facing Harvard scientists, check out The Crimson's science page.