According to a study in Nutrition Journal, researchers from the US Department of Agriculture have found that having a greater vegetable variety in the diet may be associated with a decreased risk of coronary artery disease (A).
The findings from this study validate the recommendations from the 2015–2020 Dietary Guidelines for Americans (DGA), which propose that Americans should increase both their vegetable intake and vegetable variety for the prevention of chronic disease risk (B).
A total of 38,981 participants from the 1999–2014 National Health and Nutrition Examination Survey were included in the study. Researchers obtained data on food intake as well as participants’ cardiovascular status. A modified dietary diversity index (ie, Healthy Food Diversity index) adjusted for confounders of vegetable amount was used to assess vegetable variety. Analyses adjusted for multiple variables were performed to estimate the association between vegetable variety/vegetable amount and disease prevalence.
During 1999 and 2014, there was a significant decrease in vegetable variety among US survey participants (P =.035); however, vegetable amount remained stable (P =.864). In addition, starchy vegetables decreased during this period (P <.001) and dark green vegetable intake increased (P <.001).
The researchers observed a significant inverse linear association between vegetable variety and prevalent coronary heart disease (Ptrend =.032) as well as vegetable amount and coronary heart disease (Ptrend =.026). Survey respondents who reported a higher intake of dark green vegetables had lower odds of coronary heart disease (odds ratio [OR] 0.78, 0.65-0.94; P <.05) and cardiovascular disease (OR 0.86, 95% CI: 0.74-0.99; P <.05) compared with respondents who consumed no green vegetables.
A limitation of the analysis includes its reliance on dietary recall for identifying vegetable intake, which may have introduced measurement error and/or social desirability bias.
“Vegetables are rich in key bioactive components that are associated with positive health outcomes,” the study investigators wrote. “Increasing vegetable variety is still an important message for the public, and clinicians should continue to encourage both increased vegetable variety and amount.”
- Conrad Z, Raatz S, Jahns L, et al. Greater vegetable variety and amount are associated with lower prevalence of coronary heart disease: National Health and Nutrition Examination Survey, 1999-2014
. Nutr J. 2018;17(1):67.
- US Department of Health and Human Services and US Department of Agriculture. 2015–2020. Dietary Guidelines for Americans 2015–2020, Appendix 3. 8th ed. U.S. Government Printing Office, Washington, DC. http://health.gov/dietaryguidelines. Accessed July 17, 2018.