Eating more fruits and vegetables is still one of the most reliable pieces of nutrition advice. But the specific foods people choose may shape the benefits they receive.
A new study found that fewer than one-quarter of people who met standard dietary recommendations consumed at least 500 milligrams of flavanols per day, a level associated with potential cardiovascular benefits in earlier research. Flavanols, also known as flavan-3-ols, are naturally occurring plant compounds found in foods and drinks such as tea, apples, berries, plums, cherries, beans and cocoa.
The study, published in the journal Food & Function, does not show that people need to calculate their daily flavanol intake or that eating a particular combination of foods will prevent heart disease. It also does not mean that fruits and vegetables lower in flavanols are unimportant. Different plant foods provide different combinations of fiber, vitamins, minerals and other beneficial compounds.
Instead, the findings offer another reason to prioritize variety.
Researchers analyzed data from more than 30,000 adults in the United States and United Kingdom. Two authors are employees of Mars Inc., a company involved in flavanol research and flavanol-related commercial activities. Other authors reported research support from Mars and additional organizations.
Rather than relying only on food questionnaires, the researchers used biomarkers to estimate flavanol intake. The analysis included 6,509 participants in the U.S.-based COSMOS study and 24,154 participants in the U.K.-based EPIC-Norfolk study.
People who ate more fruits and vegetables and had higher overall diet-quality scores generally consumed more flavanols. But fewer than 25% of participants who followed dietary guidelines reached the 500-milligram level. The researchers found a similar pattern when they used simulations based on fruits and vegetables commonly eaten in the United States.
“Five-a-day is the right message, but we may need to think more carefully about which five,” said Gunter Kuhnle, a professor at the University of Reading.
Flavanols are not essential nutrients in the same sense as vitamins or minerals. There is no established deficiency level, and U.S. dietary guidance does not set a daily flavanol requirement.
However, researchers have been studying whether flavanol-rich foods may support heart and metabolic health. An earlier expert panel proposed a food-based intake range of 400 to 600 milligrams per day based on moderate evidence. The panel cited potential improvements in blood pressure, cholesterol levels and blood sugar control.
The new study focused on whether people following common dietary recommendations typically reach that range. It did not examine whether participants developed heart disease, experienced a heart attack or died from cardiovascular causes.
The 500-milligram benchmark also deserves context.
It was partly informed by COSMOS, a large randomized trial that studied a daily cocoa extract supplement containing 500 milligrams of flavanols. The supplement did not significantly reduce the trial’s primary outcome of total cardiovascular events. Researchers did observe fewer cardiovascular deaths among participants who received cocoa extract, but that was a secondary finding. Additional studies are needed to understand whether flavanols can meaningfully affect long-term cardiovascular outcomes.
That does not make the new research unimportant. It does mean readers should resist turning a promising area of nutrition science into another rigid rule.
People do not need to track flavanol milligrams at every meal. They also do not need to eat unusually large portions of berries or treat green tea as a heart-health prescription.
A simpler approach is to bring more variety into an already balanced eating pattern. Apples with the skin, berries, plums, cherries, green tea and beans can all contribute flavanols alongside other nutrients. Unsweetened cocoa may also provide flavanols, but chocolate products can vary widely in their flavanol content and may contain substantial amounts of added sugar.
The study also should not be interpreted as evidence that some fruits and vegetables are not worth eating. Foods lower in flavanols may provide vitamin C, potassium, fiber, carotenoids or other plant compounds. No single compound captures the full value of a diverse diet.
For people who already eat fruits and vegetables regularly, the practical takeaway is modest: Rotate the foods on your plate. Try berries when they are in season. Add beans to meals. Choose an apple as a snack. Enjoy tea if you like it.
For people who struggle to eat enough produce in the first place, the priority is even simpler. Start by adding more fruits and vegetables that are affordable, accessible and enjoyable. Variety can come later.
Nutrition advice works best when it helps people build a realistic pattern rather than chase a perfect number. Flavanols may be one part of the heart-health puzzle, but they are not the whole picture.
Two authors, Javier Ottaviani and Hagen Schroeter, are employees of Mars Inc., a company involved in flavanol research and flavanol-related commercial activities. Gunter Kuhnle reported receiving an unrestricted grant from Mars.
The analysis used data from COSMOS and EPIC-Norfolk. COSMOS received support from Mars Edge, a segment of Mars Inc. dedicated to nutrition research and products. That support included infrastructure funding and the donation of study pills and packaging. Pfizer Consumer Healthcare, now Haleon, also provided some study pills and packaging. COSMOS received additional support from the National Institutes of Health.
Several authors reported other research support or professional relationships with Haleon, Abbott Nutrition, Pure Encapsulations, American Pistachio Growers, the Council for Responsible Nutrition, BASF and the National Institutes of Health.
EPIC-Norfolk received support from the Medical Research Council, the National Institute for Health Research and Cancer Research UK.