Healthier lifestyle choices are called healthier lifestyle choices for a reason: they do improve health over the long term. That translates to a reduced risk of suffering any of the common age-related diseases, and a noteworthy delay in their incidence when they do occur. Per the epidemiological research noted here, the difference between healthy and unhealthy lifestyles amounts to eight to ten more years of life free from the common chronic diseases of aging.
Researchers looked at 34 years of data from 73,196 women and 28 years of data from 38,366 men participating in, respectively, the Nurses' Health Study and the Health Professionals Follow-up Study. Healthy diet was defined as a high score on the Alternate Healthy Eating Index; regular exercise as at least 30 minutes per day of moderate to vigorous activity; healthy weight as a body mass index of 18.5-24.9 kg/m2; and moderate alcohol intake as up to one serving per day for women and up to two for men.
They found that women who practiced four or five of the healthy habits at age 50 lived an average of 34.4 more years free of diabetes, cardiovascular diseases, and cancer, compared to 23.7 healthy years among women who practiced none of these healthy habits. Men practicing four or five healthy habits at age 50 lived 31.1 years free of chronic disease, compared to 23.5 years among men who practiced none. Men who were current heavy smokers, and men and women with obesity, had the lowest disease-free life expectancy.
"Previous studies have found that following a healthy lifestyle improves overall life expectancy and reduces risk of chronic diseases such as diabetes, cardiovascular disease, and cancer, but few studies have looked at the effects of lifestyle factors on life expectancy free from such diseases. This study provides strong evidence that following a healthy lifestyle can substantially extend the years a person lives disease-free."