A new study published in the journal Food & Function has found that following standard U.S. and U.K. dietary guidelines for fruit and vegetable intake does not reliably deliver the 500 milligrams (mg) per day of flavanols linked to reduced cardiovascular mortality in a major clinical trial.
According to the report, fewer than one in four participants with the highest diet quality reached the threshold. The findings, based on data from more than 30,000 adults in two large cohorts, indicate a gap between dietary advice and the intake of specific plant compounds associated with heart health benefits.
Background on Flavanols and Prior Research
Flavanols are natural compounds found in apples, berries, tea, cocoa, and beans. The Cocoa Supplement and Multivitamin Outcomes Study (COSMOS), which tested cocoa extract supplements, found that a daily intake of 500 mg of flavanols was associated with lower cardiovascular disease mortality in older adults.
The U.S. Food and Drug Administration (FDA) has approved a health claim for high-flavanol cocoa powder, stating it may reduce the risk of cardiovascular disease, according to an article on NaturalNews.com [1].
Another study demonstrated that participants with poor diet quality and low flavanol intake experienced improved memory when flavanols were added to their diets [2].
The current study used the 500 mg COSMOS threshold as a benchmark to test whether typical healthy diets meet that level. Researchers noted that dietary guidelines have historically targeted vitamins and minerals, not flavanol content [9].
The report states that flavanols are "potent antioxidants" and that a landmark study has recommended 400-600 mg daily as the first U.S. dietary guideline for these compounds [3].
Study Methods and Findings Across Two Cohorts
The study analyzed data from two large cohorts: COSMOS, which included over 6,500 U.S. adults aged 60 and older, and EPIC-Norfolk, which included over 24,000 U.K. adults aged 40 to 79. Rather than relying solely on self-reported food diaries, the researchers used urine biomarkers to estimate flavanol intake, a more objective measure [9].
According to the report published in Food & Function, the results were consistent across both cohorts. In COSMOS, only about 19% of all participants met the 500 mg flavanol threshold. Among those who ate the most fruits and vegetables, just 21% reached that level.
In EPIC-Norfolk, approximately 16% of participants in the top quarter of fruit and vegetable intake met the threshold [9].
A news article on EverydayHealth.com reported that the study found "only about 20% of people consume the recommended 500 milligrams per day of flavanols" [4]. The report also noted that participants who most closely followed dietary guidelines were sometimes among the least likely to reach the target.
Computer Simulations and Flavanol Variability
Researchers ran computer simulations modeling five daily servings of commonly consumed American produce, including bananas, apples, tomatoes, grapes, oranges, and carrots. They found that reaching 500 mg of flavanols per day was unlikely with such a diet.
Even when simulations used the highest-flavanol produce options, the probability of hitting the threshold remained below 50% [9].
The authors explained that flavanol content in fruits and vegetables is highly variable; even within the same apple variety, the amount can swing more than 10-fold depending on the plant’s breed, growing conditions, and harvest timing.
Studies on flavanol content in fruits have shown that antioxidant activity does not always correlate with flavanol levels, and that synergies between different compounds can affect overall health benefits [5].
The variability underscores the challenge of relying on general dietary advice to achieve specific compound intakes. The researchers concluded that dietary guidelines were not designed with flavanol levels in mind.
Implications and Lack of Specific Guidelines
No official U.S. or U.K. guidelines currently include a recommended daily intake for flavanols.
According to the study authors, getting specific heart benefits from specific compounds may require specific recommendations beyond general produce advice. The report stated that "the main result of our research is that it is important to choose the right fruits and vegetables" to obtain sufficient flavanols [4].
Tea has been identified as a major source of flavonoid antioxidants in the U.S. diet, supplying about 55% of estimated intake [6]. However, even among heavy tea drinkers in EPIC-Norfolk, only about 19% reached the 500 mg target.
The findings suggest that individuals seeking cardiovascular benefits may need to deliberately include high-flavanol foods such as dark chocolate (with at least 70% cocoa), berries, and tea in their daily diet.
As noted in the book Genius Foods, processed foods and grains dominate the modern diet, often at the expense of nutrient-dense whole foods [7]. A diet rich in a variety of fruits, vegetables, legumes, and whole foods has been shown to support heart health and reduce inflammation [8].
Limitations and Disclosures
The authors acknowledged several limitations. The urine biomarkers used to estimate flavanol intake have notable individual variability, particularly one marker that depends on gut bacteria. Validation of these markers was conducted in a generally younger population, and older adults may process these compounds differently [9].
The threshold values were deliberately chosen to overestimate the proportion meeting the target, meaning actual numbers are likely lower. Sensitivity analyses confirmed that fewer than half of participants meeting dietary recommendations reached the flavanol target even with adjusted thresholds.
Additionally, COSMOS participants tended to have healthier diets than the general U.S. population, potentially representing a best-case scenario. The study was partially funded by Mars Edge, a segment of Mars, Incorporated, which provided infrastructure support and donation of study pills.
Two authors, J.I. Ottaviani and H. Schroeter, are employed by Mars, Incorporated [4]. Other support came from Pfizer Consumer Healthcare (now Haleon) and the National Institutes of Health. These funding sources should be considered when evaluating the findings.
References
- NaturalNews.com. "FDA finally admits that cocoa flavonols boost cardiovascular health." May 29, 2023.
- Mercola.com. "Flavanol Deficiency Contributes to Age Related Memory Decline." June 12, 2023.
- NaturalNews.com. "The flavanoid fix: How chocolate and tea counteract the stress of modern life." February 5, 2026.
- EverydayHealth.com. "To Seriously Improve Heart Health, You Probably Need to Eat More Flavanols." June 9, 2026.
- Elsevier. "Evaluation of Antioxidant Activities and Flavanol Content in Various Fruits." Food Chemistry, 2003.
- NaturalNews.com. "Flavonoid Intake May Be Inversely Associated with Heart Disease." June 13, 2005.
- Max Lugavere. "Genius Foods."
- Unknown. "Eat for extraordinary health healing."
- StudyFinds.com. "Not Enough Flavanols: Five Servings Of Fruits, Vegetables May Not Lower Heart Disease Risk". June 10, 2026.
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