Variations in dietary patterns can have a major effect on the development of chronic diseases, according to researchers reporting in the American Journal of Clinical Nutrition this month.
The US-based researchers analysed two long-term epidemiologic studies on the relationships between recommended dietary behaviour and chronic disease risk. They found that men and women whose diets most closely matched healthy dietary guidelines had a significant reduction in risk for all chronic diseases. Most significantly, subjects who ate the healthiest diets cut their risk of cardiovascular disease (CVD) by as much as 48 per cent.
The data involved 38,615 men, aged 40 to 75 years, who participated in the Health Professional's Follow-up Study between 1986 and 1990, and 67,271 women, aged 30 to 55 years, who participated in the Nurses' Health Study between 1984 and 1990.
The authors designed an updated Alternative Healthy Eating Index (AHEI) to target food choices and macronutrient sources that are associated with reduced chronic disease risk, especially CVD risk. The AHEI provides quantitative scoring for adherence to dietary guidelines such as choosing more fish, poultry, and wholegrains, increasing fruit and vegetable consumption, taking a daily multivitamin and drinking alcohol only in moderation. The subjects were divided into quintiles according to their AHEI scores.
Men in the highest-scoring quintile of the AHEI had 20 per cent less risk of developing a major chronic disease. The association of AHEI score with health was somewhat weaker in women - overall disease risk fell by 11 per cent. The AHEI score was more strongly related to development of CVD than it was to cancer or other chronic diseases. After adjustment for age, both men and women in the highest quintile of AHEI compliance were 48 per cent less likely to have an episode of CVD than those in the lowest quintile of compliance.
The authors suggest that future research should focus on identifying more links between dietary patterns and cancer, as well as on examining chronic disease risk in the general population.