Editor's note: This popular story from the Daily Briefing's archives was republished on Feb. 9, 2021.
There are few key pillars of healthy living nearly everyone's familiar with, like regular exercise and moderate alcohol use—but how many years of healthy life will adhering to these behaviors buy you? A recent JAMA Internal Medicine analysis created a scoring system to find out, Nicholas Bakalar reports for the New York Times.
For the analysis, researchers followed 116,043 people between the ages of 40 and 75 over an average of 13 years and gathered data on whether those people engaged in four healthy behaviors:
- Maintaining a normal weight;
- Not smoking;
- Staying physically active; and
- Consuming alcohol in moderation.
The researchers then gave each participant a score from zero to two based on his or her adherence to each healthy behavior. Specifically, for:
- Body weight—individuals got two points for maintaining a body mass index (BMI) below 25, one point for maintaining a BMI of between 25 and 30, and zero points for a BMI above 30;
- Smoking—individuals got two points for never having smoked, one point for having quit smoking, and zero points for currently being a smoker;
- Physical activity—individuals got two points for logging a minimum of either 2.5 hours of moderate activity or 1.25 hours of strenuous exercise per week, one point if they logged "activity levels falling between the optimal and poor levels," and zero points if they logged little or no exercise per week; and
- Alcohol consumption—individuals received two points for having between one and 14 or one and 21 drinks per week for women and men, respectively; one point for never drinking; and zero points for having more than 15 or 22 drinks per week for women and men, respectively.
The highest total score a person could receive across all four measures—two points for each—was a score of eight. The researchers then looked at how many years participants lived between the ages of 40 and 75 before the onset of one or more of eight major chronic illnesses, including:
- Type 2 diabetes;
- Coronary heart disease;
- Chronic obstructive pulmonary disease;
- Heart failure; and
The researchers found that, compared to those with a score of zero, having a score of eight translated to an additional 9.9 years of life without major chronic illness for men and 9.4 such years for women. Specifically, men with a score of zero lived to age 61.7 and women to age 61.6, but men with a score of eight lived to age 70.9 and women to age 70.7.
The researchers also put together 16 "lifestyle profiles," which consisted of varying levels of adherence to each of the four healthy behaviors, ranging from no adherence to any of the four to adherence to all four.
They found that the profiles associated with the greatest number of disease-free life years were those that maintained a BMI of less than 25 and adhered to at least two of the three remaining healthy behaviors.
"The results of this study suggest a consistent dose-response association of a higher number of healthy lifestyle factors with the number of disease-free years both in men and women and across the socioeconomic strata, and that various healthy lifestyle profiles, particularly those including a BMI less than 25, are associated with a prolonged health span," the researchers wrote.
Solja Nyberg, a postdoctoral researcher at the University of Helsinki and lead author on the study, said, "Nothing is guaranteed, but these results give some insight into the effects of several lifestyle choices" (Bakalar, New York Times, 4/15; Nyberg et. al., JAMA Internal Medicine, 4/6).