The authors of this study state that there is overwhelming evidence that behavioural factors influence health, but their combined impact on the general population is less well documented. They aimed to quantify the potential combined impact of four health behaviours on mortality in men and women living in the general community.
The study examined the prospective relationship between lifestyle and mortality in a prospective population study of 20,244 men and women aged 4579 years with no known cardiovascular disease or cancer at baseline survey in 19931997, living in the general community in the United Kingdom, and followed up to 2006.
Participants scored one point for each health behaviour: current non-smoking, not physically inactive, moderate alcohol intake (114 units a week) and plasma vitamin C >50 mmol/l indicating fruit and vegetable intake of at least five servings a day, for a total score ranging from zero to four.
After an average 11-year follow up, the age-, sex-, body mass-, and social class-adjusted relative risks (95% confidence intervals) for all-cause mortality (1,987 deaths) for men and women who had three, two, one, and zero compared to four health behaviours were respectively, 1.39 (1.211.60), 1.95 (1.70-2.25), 2.52 (2.133.00), and 4.04 (2.955.54) p < 0.001 trend. The relationships were consistent in subgroups stratified by sex, age, body mass index, and social class, and after excluding deaths within 2 years. The trends were strongest for cardiovascular causes. The mortality risk for those with four compared to zero health behaviours was equivalent to being 14 years younger in chronological age.
The authors conclude that four health behaviours combined predict a 4-fold difference in total mortality in men and women, with an estimated impact equivalent to 14 years in chronological age.
Curtis Ellison comments: For a number of years we have strongly supported the “Healthy Lifestyle” that has been shown by a number of investigators from Harvard to be associated with much lower risk of cardiovascular disease and total mortality. The Harvard index includes (1) not smoking, (2) not being obese, (3) a healthy diet (similar to a Mediterranean Diet), (4) regular physical activity, and (5) moderate alcohol intake. A recent analysis by Mukamal et al. (1) showed that moderate alcohol intake was a key component of this lifestyle in terms of lower risk of cardiovascular disease.
The present study has used an even simpler definition of a healthy lifestyle and found very similar health outcomes in a prospective population study in the UK. Those in the study who were (1) non smokers, (2) active, (3) had a vitamin C level suggesting high intake of fruits and vegetables, and (4) consumed some but no more than 14 typical drinks/week, had about one-fourth the risk of dying over the follow-up period as those who had none of the healthy behaviors. (In the UK, a typical drink is considered to be 8 grams of alcohol, so the equivalent in US typical drinks would be about 9 drinks/week, with 12 grams of alcohol in a drink.)
The study supports an increasing number of previous research reports suggesting that all of these behaviours have a favourable outcome on health, and the total impact among people having all of the behaviours can be a marked reduction in risk of death.
Source: Khaw K-T, Wareham N, Bingham S, Welch A, Luben R, Da N. Combined impact of health behaviours and mortality in men and women: The EPIC-Norfolk Prospective Population Study. www.plosmedicine.org 0002 January 2008;5:e12.