Lifestyle changes at middle age and mortality: a population-based prospective cohort study

Background: The effect of modifying lifestyle at middle age on mortality has been sparsely examined.

Methods: Men and women aged 50-54 years randomised to the control group (no intervention) in the population-based Norwegian Colorectal Cancer Prevention trial were asked to fill in lifestyle questionnaires in 2001 and 2004. Lifestyle scores were estimated ranging from 0 (poorest) to 4 (best) based on health recommendations (non-smoking, daily physical activity, body mass index <25.0 kg/m² and healthy diet). Outcomes were all-cause, cancer and cardiovascular mortality before 31 December 2013.

Results: Of the 6886 attainable individuals included in the study, 4211 (61%) responded to the baseline questionnaire in 2001. After a median follow-up of 12.3 years, 226 (5.4%) of the baseline questionnaire responders died; 110 (49%) from cancer and 32 (14%) from cardiovascular disease. For each increment in lifestyle score in 2001, a 21% lower all-cause mortality was observed (HR 0.79, 95% CI 0.67 to 0.94, adjusted for age, sex, occupational working hours and chronic disease or pain during 3 years before enrolment). A one-point increase in lifestyle score from 2001 to 2004 was associated with a 38% reduction in all-cause mortality (adjusted HR 0.62, CI 0.45 to 0.84). The group reporting lifestyle change from score 0-1 (unfavourable) in 2001 to score 2-4 (favourable) in 2004 had 4.8 fewer deaths per 1000 person years, compared with the group maintaining an 'unfavourable' lifestyle (adjusted HR 0.31, CI 0.13 to 0.70 for all-cause mortality).

Conclusions: Favourable lifestyle changes at age 50-60 years may prevent early death.

Trial registration: NCT00119912; pre-results.