By David Fiore, MD
Professor of Family Medicine, University of Nevada, Reno
Dr. Fiore reports no financial relationships relevant to this field of study.
SYNOPSIS: The authors found improving each of four “healthy lifestyle choices” added approximately one year of disease-free life between ages 40 and 75 years. Adopting all four “optimal” lifestyles was associated with nine years of life gained vs. adopting zero optimal lifestyles.
SOURCE: Nyberg ST, Singh-Manoux A, Pentti J, et al. Association of healthy lifestyle with years lived without major chronic diseases. JAMA Intern Med 2020;180:1-10.
In a multicohort analysis of 12 European studies, Nyberg et al investigated the relationship between four “lifestyle factors” and the number of years between ages 40 and 75 living without chronic illnesses. Specifically, the authors examined type 2 diabetes, coronary heart disease, stroke, cancer, asthma, and chronic obstructive pulmonary disease. In a subsidiary analysis, Nyberg et al included dementia and heart failure. The four “lifestyles” chosen for inclusion and analysis were smoking, body mass index, physical activity, and alcohol consumption. Each lifestyle factor was scored as 0 (poor), 1 (intermediate), or 2 (optimal), which created 16 “lifestyle profiles” based on dichotomous grouping of each factor as either “optimal” or “intermediate/poor.”
The researchers used national registers for outcome data. To be included in the analysis, participants had to be free of any of the chronic conditions listed (as well as type 1 diabetes-free). A total of 116,043 participants were analyzed, with a mean age of 43.7 years at enrollment initiation; 61% were women. The mean follow-up was 12.5 years.
There was a linear association between the number of optimal lifestyle factors and years lived without chronic disease. This relationship held for the six initial chronic diseases as well as when dementia and heart disease were added. In a sensitivity analysis, never drinking (intermediate) was combined with moderate drinking (optimal), and no difference in outcomes was found. Compared to the worst lifestyle score (no optimal lifestyles), the best lifestyle score (all four optimal lifestyles), there was a gain of nine disease-free years. Each one-point improvement in lifestyle score was associated with nearly one year of disease-free life gained (0.96 years for men, 0.89 years for women).
This was a well-designed analysis, with a large enough cohort to strongly support the notion that lifestyle choices can make a difference in overall health, even if the effects are delayed. Previous studies have demonstrated longer life expectancy and longer disease-free life expectancy are associated with various healthy lifestyle choices.
Nyberg et al added to these investigations by quantifying the number of disease-free years gained by making healthy lifestyle choices, both individually and in combination.1-3 Recently, other authors drew similar conclusions as Nyberg et al when they found that the same four healthy lifestyles were associated with a gain of almost 10 additional years of disease-free life for women and eight more years for men.4 Importantly, lifestyle choices seemed to be additive. This means patients could be motivated to build on the benefits of each healthy lifestyle choice. Considering its design as a cohort study, the work by Nyberg et al cannot truly lead to definitive conclusions about causation. Also, as with any cohort study, there is the concern of confounding. It is well known that many healthy lifestyles are associated with higher socioeconomic status. Fortunately, Nyberg et al addressed this in one of the electronic supplemental tables, and found that the results held across socioeconomic status.
The evidence from the Nyberg et al investigation and multiple other studies on lifestyle and health is becoming too hard to ignore. This work adds to and supports what most clinicians believe already: A healthy lifestyle is associated with a healthier life.
- May AM, Struijk EA, Fransen HP, et al. The impact of a healthy lifestyle on disability-adjusted life years: A prospective cohort study. BMC Med 2015;13:39.
- Stenholm S, Head J, Kivimäki M, et al. Smoking, physical inactivity and obesity as predictors of healthy and disease-free life expectancy between ages 50 and 75: A multicohort study. Int J Epidemiol 2016;45:1260-1270.
- Licher S, Heshmatollah A, van der Willik KD, et al. Lifetime risk and multimorbidity of non-communicable diseases and disease-free life expectancy in the general population: A population-based cohort study. PLoS Med 2019;16:e1002741.
- Yanping L, Schoufour J, Wang DD, et al. Healthy lifestyle and life expectancy free of cancer, cardiovascular disease, and type 2 diabetes: Prospective cohort study. BMJ 2020;368:l6669.