Primary prevention of coronary heart disease in women through diet and lifestyle.
Level 3 - non-randomized controlled study
Prospective cohort study with 14 years of follow-up
PubMed 10882764 · doi:10.1056/NEJM200007063430103
What was done
A prospective cohort of 84,129 women participating in the Nurses' Health Study without diagnosed cardiovascular disease, cancer, or diabetes at baseline in 1980 was followed for 14 years. Information on diet and lifestyle was updated periodically. A low-risk group was defined by five factors: not currently smoking, body-mass index under 25, average alcohol consumption of at least half a drink per day, moderate-to-vigorous physical activity for at least half an hour per day, and a diet score in the top 40% (high in cereal fiber, marine n-3 fatty acids, folate, and polyunsaturated-to-saturated fat ratio; low in trans fat and glycemic load). The tracked outcomes were major coronary events, consisting of nonfatal myocardial infarctions and coronary heart disease deaths.
What was found
During 14 years of follow-up, 1,128 major coronary events occurred (296 coronary heart disease deaths and 832 nonfatal infarctions). Women in the low-risk category comprised 3% of the cohort and had a relative risk of coronary events of 0.17 (95% confidence interval, 0.07 to 0.41) compared with all other women, after adjustment for age, family history, diagnosed hypertension, diagnosed high cholesterol, and menopausal status. Lack of adherence to this low-risk lifestyle pattern accounted for 82% (95% confidence interval, 58% to 93%) of coronary events in the cohort.
Why it matters
This study provides strong evidence that the vast majority of coronary heart disease events in women could be prevented through simultaneous adherence to non-pharmacologic lifestyle and dietary guidelines.
Limits
The study design is observational, meaning residual confounding cannot be entirely ruled out. Lifestyle, dietary, and clinical variables were self-reported. The population was restricted to female registered nurses, which may limit generalizability to men and populations with different socioeconomic or demographic characteristics. Only 3% of the cohort met all low-risk criteria.
Cited by
- supports Approximately 80% of heart disease and diabetes cases are preventable with diet and lifestyle modifications.