Associations of healthy lifestyle with all-cause and cause-specific mortality and life expectancy among UK and US populations

Background Evidence has indicated that a healthy lifestyle is associated with lower mortality and longer life expectancy, but previous healthy lifestyle score did not include sleep quality and psychological factors, which have been considered as important lifestyle factors for health. Purpose We aimed to examine associations of an updated healthy lifestyle score with all-cause and cause-specific mortality and life expectancy. Methods We prospectively followed 413,180 participants from the UK biobank (2006-2022) and US National Health and Nutrition Examination Survey (NHANES) (1999-2019). We collected data on dietary and lifestyle factors using questionnaires at baseline. Using these data, we created an updated healthy lifestyle score, including diet quality, physical activity, alcohol consumption, smoking, sleep quality and depression, where we gave diet quality, physical activity, sleep quality positive scores, and alcohol consumption, smoking and depression reverse scores. We summarized the scores from these components to calculate an updated healthy lifestyle score, which had a theoretical range of 6 to 30 points. We used Cox-regression models to examine the associations of this healthy lifestyle score with all-cause and cause-specific mortality, and used life table to examine the associations of this score with life expectancy. Results During a mean follow-up of 13.3 years, 13,836 deaths in the two cohorts occurred. After multivariable adjustment, a higher healthy lifestyle score was associated with a lower risk of all-cause and cause-specific mortality. The HRs and 95%CIs of highest vs lowest quartile of the healthy lifestyle score were 0.57 (0.46, 0.71) for all-cause mortality, 0.66 (0.62, 0.71) for CVD mortality, 0.63 (0.56, 0.72) for cancer mortality, and 0.48 (0.32, 0.72) for other mortality. Further, a higher healthy lifestyle score was associated with a longer life expectancy. Compared with people in the lowest quartile of healthy lifestyle score, those in the highest quartile of the score had a 5.31-year (3.33, 8.48) longer life expectancy. All components, including higher diet quality, more physical activity, higher sleep quality, non/less-alcohol drinking, non-smoking, and non-depression contributed to these beneficial associations. These results remained consistent across several risk factors, including age, race, sex and BMI. Conclusions Among UK and US adults, a higher healthy lifestyle score was associated with a lower risk of all-cause and cause-specific mortality, and a longer life expectancy. Our findings suggest that promotion of a healthy lifestyle would help to reduce mortality, extend life expectancy, and lower the healthcare burdens.