Flavonoid diversity, not just quantity, drives better health outcomes

By Dr. Liji Thomas, MDReviewed by Lauren HardakerJul 7 2025

Drinking tea helps, but adding apples, berries, and citrus to your plate to mix up your flavonoid consumption could be the key to a longer, healthier life.

Study: High diversity of dietary flavonoid intake is associated with a lower risk of all-cause mortality and major chronic diseases. Image credit: marilyn barbone/Shutterstock.com

Increased flavonoid consumption is linked to better health outcomes, but the impact of broadening the range of flavonoids has not been studied. A recent paper published in Nature Food demonstrates the health-promoting effects of consuming multiple types of flavonoids and increasing the total quantity.

Introduction

Flavonoids are polyphenols in several foods, from nuts and legumes to tea and wine. Multiple flavonoid categories depend on the chemical structure, including anthocyanins, flavonols, flavon-3-ols, flavanones, and flavones.

Multiple studies show that increased flavonoid consumption from different subclasses is associated with lower incidences of chronic disease. This includes conditions like cardiovascular disease, type 2 diabetes mellitus, cancer, respiratory disease, and neurodegenerative disease.

Different flavonoids have varying types of bioactivity, depending on bioavailability and metabolism. They are potent anti-inflammatory and antioxidant molecules, which may explain why they inhibit the development of chronic diseases driven by chronic inflammation and oxidative stress.

Flavonoids are also heart-protective, improving endothelial structure and function and slowing down age-related tissue deterioration by inhibiting senescence pathways. Additionally, their suppression of cell proliferation is a key mechanism in preventing cancer.

The current study sought to estimate the diversity of flavonoid intake in diet, and the associations of flavonoid intake with mortality and disease risk.

The study cohort included 124,805 UK adults aged 40 years or more, predominantly female (56%). Less than 10% smoked, but 60% were overweight or obese. The prevalence of diabetes mellitus, hypertension, and high cholesterol was 4%, 25%, and 15%, respectively.

Study findings

The median flavonoid consumption was 792 mg/day, with nine flavonoids being consumed on average daily. Flavan-3-ols were the most significant component by far, at 87%. Other categories, anthocyanins, flavonols, and flavanones, made up 4.5% each, with flavones accounting for <1%.

Black or green tea was the primary source of flavonoids, at 67%, while apples made up 6% and red wine 5%. Other sources, including grapes and berries, contributed 2%. Oranges, satsumas, orange juice, and dark chocolate each accounted for 1%. Altogether, these made up 85% of daily intake.

People with higher dietary flavonoids had less diversity overall, relying primarily on tea for their flavonoid intake. In contrast, those with a more diverse flavonoid consumption derived it from fruit and red wine. These were more likely to be women with a leaner physique, older, more physically active, and more educated.

Those with the highest flavonoid diversity had a 14% lower risk of all-cause mortality, a 10% lower risk of cardiovascular disease, and a 20% lower risk of type 2 diabetes mellitus incidence. Respiratory and cancer risks were reduced by 8%. No statistically significant association was observed for neurodegenerative disease with total flavonoid diversity.

Quantitatively, compared to the lowest quintile, participants in the second quintile of flavonoid intake (about 500 mg/day) had a 16% lower risk of death from all-cause mortality. The risk of other diseases was lower by 9%-13%. The risk of type 2 diabetes mellitus was lowest in the highest quintile, 25% less than in the first quintile. For neurodegenerative disease, a 20% lower risk was observed only at the highest quintile of total flavonoid intake, not diversity.

These associations remained after adjusting for demographic, lifestyle, and other medical risk factors. Although no statistical interactions were observed between diversity and quantity (P_interaction > 0.05), both factors independently predicted disease outcomes, suggesting that higher intakes of both contribute more than either factor alone.

In particular, an increased variety of flavan-3-ols and flavanones in the diet reduced the all-cause mortality independent of absolute intake. Quantitatively, the consumption of flavan-3-ols was linked to a stable reduction in mortality risk in the second and higher quintiles. Conversely, a lower chronic disease risk mainly appeared at the fourth or fifth quintile compared to the first.

Class-wise, the most significant reductions included a 13% lower risk of type 2 diabetes mellitus for flavan-3-ols and a 7% lower cancer risk for all flavanones. For flavones, an 18% lower risk of neurodegenerative disease and a 13% lower risk of type 2 diabetes mellitus were observed at the highest quintiles. The previously stated “75% cancer risk reduction” was not supported by the data and has been corrected.

Similar benefits were observed for diversity in flavonoid-rich foods. Having 4.5 different servings of flavonoids reduced all-cause deaths by 16% compared to 1.3 diverse servings.

The overall quantity of flavonoids consumed regularly and flavonoid diversity independently predicted mortality and disease risk. Rather than consuming one or a few flavonoids in higher amounts, it is better to include a broad variety of flavonoid-rich foods. 

Prior research on flavonoid benefits has led to the recommendation that 400-600 mg of flavan-3-ols be consumed. This recommendation could potentially be modified to include the guideline that multiple sources be included in the diet for maximum benefit. The current study's authors have developed the Flavodiet Score, which measures the number of servings of flavonoid-rich foods.

The study also used a novel approach to measuring dietary diversity: applying Hill’s effective number, a metric that accounts for both the variety and proportional intake of different flavonoid compounds.

Conclusion

According to this study, mortality and chronic disease risk are reduced among people who had the greatest variety of flavonoids in their diet, both as foods and as specific subclasses.

These results are biologically plausible due to the known ability of different flavonoids to suppress platelet aggregation and reduce atherosclerosis risk, increase insulin sensitivity and antioxidant capacity, and inhibit inflammation. They also antagonize cancer development processes by killing tumor cells and preventing their proliferation. 

“These findings suggest that consuming several different daily servings of flavonoid-rich foods or beverages, such as tea, berries, apples, oranges or grapes, may lower risk of all-cause mortality and chronic disease.”

However, it is essential to note that this was an observational study, and while associations were strong, causation cannot be confirmed. Future studies should validate these findings and explore the sustainability of flavonoid-rich foods.

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