Written by Harold Oster, MD. Results suggest that increased flavonol intake is associated with decreased mortality risk.

couple cooking healthyFlavonoids are phenolic compounds found in various plants. Flavonols, a subclass of flavonoids, are abundant in fruits, vegetables, tea, and wine. They have antioxidant properties and have been shown to have various health benefits, including a decreased risk of cardiovascular disease1. Zhiqiang Zong et al. studied the beneficial effects of the dietary intake of flavonols on overall and cause-specific mortality.

The authors analyzed data gathered between 2007 and 2018 by the National Health and Nutrition Examination Survey (NHANES), a population-based cross-sectional study conducted by the National Center for Health Statistics at the Centers for Disease Control and Prevention2. The participants completed questionnaires assessing demographics, health history, lifestyle, and other possible confounding variables. Flavonol intake was ascertained by comparing 24-hour dietary recall surveys to the United States Department of Agriculture’s Database of Flavonoid Values3. The participants were divided into quartiles based on total flavonol consumption and intake of the specific flavonols isorhamnetin, kaempferol, myricetin, and quercetin. Mortality data was gathered from the National Death Index, a database managed by the National Center for Health Statistics4.

The authors noted the following:

  • Based on inclusion criteria, data from 11,679 participants was used for the study.
  • The average age of participants was 47 years.
  • The median follow-up was 7.8 years.
  • After adjustment for known covariables, there was a significant correlation between total flavonol intake and all-cause mortality. (Hazard ratio [HR] 0.64 between the highest quartile and the lowest)
  • Intakes of isorhamnetin (HR 0.72), kaempferol (HR 0.74), myricetin (HR 0.77), and quercetin (HR 0.66) were related to all-cause mortality risk, comparing the highest quartile and the lowest.
  • Total flavonol intake in the highest quartile was associated with decreased mortality due to cancer and cardiovascular disease. (HR 0.45 and 0.67 respectively)
  • In subgroup analysis stratified by race and ethnicity, total flavonol intake was significantly associated with lower overall mortality risk in non-Hispanic white individuals but not in non-Hispanic Black or Mexican American individuals.

Results suggest that increased flavonol intake is associated with decreased overall, cancer, and cardiovascular mortality. The study’s limitations include its cross-sectional design, the use of dietary questionnaires to determine levels of flavonol intake, and the possibility of residual confounding.

Source: Zong, Zhiqiang, Xiang Cheng, Yang Yang, Jianchao Qiao, Jiqing Hao, and Fanfan Li. “Association between dietary flavonol intake and mortality risk in the US adults from NHANES database.” Scientific Reports 14, no. 1 (2024): 4572.

© The Author(s) 2024

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Posted April 24, 2024.

Harold Oster, MD graduated from medical school in Miami, Florida in 1992 and moved to Minnesota in 2004. After more than 25 years of practicing Internal Medicine, he recently retired. Dr. Oster is especially interested in nutrition, weight management, and disease prevention. Visit his website at haroldoster.com.

References:

  1. Panche AN, Diwan AD, Chandra SR. Flavonoids: an overview. J Nutr Sci. 2016;5:e47. doi:10.1017/jns.2016.41
  2. Dwyer J, Picciano MF, Raiten DJ. Future directions for the integrated CSFII-NHANES: What We Eat in America-NHANES. J Nutr. Feb 2003;133(2):576s-81s. doi:10.1093/jn/133.2.576S
  3. Sebastian RS, Fanelli Kuczmarski M, Wilkinson Enns C, et al. Application of the Database of Flavonoid Values for USDA Food Codes 2007-2010 in Assessing Intake Differences Between the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) Study and What We Eat in America (WWEIA), NHANES. J Food Compost Anal. Dec 2021;104doi:10.1016/j.jfca.2021.104124
  4. Ter-Minassian M, Basra SS, Watson ES, Derus AJ, Horberg MA. Validation of US CDC National Death Index mortality data, focusing on differences in race and ethnicity. BMJ Health Care Inform. Jul 2023;30(1)doi:10.1136/bmjhci-2023-100737