Adherence to healthy lifestyle at mid-life extends life expectancy free of chronic diseases

It is never too late to observe a healthy way of life. According to a recent study, adopting a healthy diet and lifestyle at mid-life can still lead to a longer life expectancy free of major chronic diseases.

“Our findings suggest that promotion of a healthy lifestyle would help to reduce the healthcare burdens through lowering the risk of developing multiple chronic diseases, including cancer, cardiovascular disease (CVD) and diabetes, and extending disease-free life expectancy,” the researchers said.

This prospective cohort study included 73,196 individuals from The Nurses’ Health Study (1980–2014) and 38,366 from the Health Professionals Follow-Up Study (1986–2014). Five low-risk lifestyle factors were measured: never smoking, body mass index (BMI) 18.5–24.9 kg/m², moderate to vigorous physical activity (≥30 minutes/day), moderate alcohol intake (women: 5–15 g/day; men: 5–30 g/day), and a higher diet quality score (upper 40 percent).

For women who adopted none of the low-risk lifestyle factors, the life expectancy free of diabetes, cancer and CVD was 23.7 years (95 percent confidence interval [CI], 22.6–24.7), while those who adopted four or five low-risk factors had a life expectancy of 34.4 years (95 percent CI, 33.1–35.5). [BMJ 2020;368:l6669]

Among men, the life expectancy free of any of these chronic diseases at age 50 was 23.5 years (95 percent CI, 22.3–24.7) with no low-risk lifestyle factors adopted and 31.1 years (95 percent CI, 29.5–32.5) with four or five low-risk lifestyle factors adopted.

On the other hand, disease-free life expectancies of current male smokers who smoked heavily (≥15 cigarettes/day) and obese men and women (BMI, ≥30 kg/m²) accounted for the lowest proportion (≤75 percent) of total life expectancy at age 50.

These results supported those of previous studies that estimated the individual or clustering effect of lifestyle-related risk factors on life expectancy with and without chronic diseases, according to the researchers. [Eur J Epidemiol 2016;31:455-468; Am J Epidemiol 1999;149:645-653; BMC Public Health 2009;9:487; Int J Epidemiol 2016;45:1260-1270]

For instance, the Framingham Heart Study reported that high levels of physical activity, normal weight and never smoking correlated with a lower risk of CVD, higher total life expectancy and greater number of years lived free of CVD. [BMC Public Health 2009;9:487]

“Our study extends previous findings by comprehensively assessing five lifestyle risk factors and three major chronic diseases in combination and by providing broader estimates of longevity and the number of years lived with and without disease in relation to lifestyle factors individually and in combination,” the researchers said.

In addition, the present findings churned out a relatively small difference in life expectancies across different levels of alcohol consumption compared with other lifestyle factors.

“The cardiovascular benefits of moderate alcohol consumption have been consistently observed in large cohort studies, but alcohol consumption and risk of cancer showed a dose-response relation,” the researchers said. “Thus, current guidelines do not encourage a nonalcohol drinker to start drinking just for the benefit of preventing CVD.” [BMJ 2011;342:d671; Br J Dermatol 2017;177:696-707; JAMA 2011;306:1884-1890]