MedicalResearch.com Interview with:
Wei Zheng, MD, PhD, Professor of Medicine
Anne Potter Wilson Chair in Medicine
Director, Vanderbilt Epidemiology Center and
Danxia Yu, PhD Research Fellow
Vanderbilt Epidemiology Center
Vanderbilt University School of Medicine
Nashville, TN, 37203
Medical Research: What is the background for this study? What are the main findings?
Response: The Dietary Guidelines for Americans (DGA) provide the most authoritative advice in the US about healthy eating. Higher adherence to the DGA, reflected by a higher Healthy Eating Index (HEI) score, has been found to be associated with lower risk of developing or dying from chronic diseases (e.g. diabetes, cardiovascular disease, and certain cancers) in several US studies. However, these studies recruited mostly non-Hispanic white individuals and middle to high income Americans. It has been reported that racial/ethnical background and socioeconomic status may influence food choices and diet quality. However, no previous study has adequately evaluated the association between adherence to the DGA and risk of death due to diseases in racial/ethnical minorities and low-income Americans. Therefore, it is uncertain whether the health benefits of adherence to the current DGA can be generalized to these underserved populations.
We analyzed diet and mortality data from the Southern Community Cohort Study (SCCS), a large, prospective cohort study including approximately 85,000 American adults, 40-79 years old, enrolled from 12 southeastern states between 2002 and 2009. Two-thirds of the SCCS participants were African-American and more than half reported an annual household income <$15,000.
During a mean follow-up of 6.2 years, we identified 6,906 deaths in the SCCS, including 2,244 from cardiovascular disease, 1,794 from cancer, and 2,550 from other diseases. Using multivariate analysis methods, we found that participants in the top 20% of the HEI score (highest adherence to the DGA) had only about 80% of the risk of death due to any diseases compared with those in the bottom 20% of the HEI score. This protective association was found regardless of sex, race and income levels.