Does eating your five-a-day give you enough flavanols for a healthy heart?
No. In two large studies, fewer than 25% of people who met standard fruit-and-vegetable guidelines reached the flavanol level shown to protect the heart. Simply hitting your five-a-day does not guarantee enough of these plant compounds.
Flavanols are natural compounds found in certain fruits, vegetables, and drinks like tea. A major trial called COSMOS found that getting about 500 milligrams of flavanols a day was linked to a lower risk of dying from heart disease. That raised an obvious question. If you already eat plenty of fruits and vegetables, are you getting enough flavanols without even trying? This new study set out to answer it, and the answer is a clear no.
What the data show
Researchers looked at two big groups of people in two different countries. One was the US COSMOS trial, with 6,509 people. The other was the UK EPIC-Norfolk study, with 24,154 people. Instead of relying only on what people said they ate, the team measured flavanols directly using blood and urine markers. These markers are a more honest way to track intake than food diaries alone.
The results were consistent across both groups. Eating more fruits and vegetables did raise flavanol levels, and people with higher overall diet quality tended to get more. But even among those who fully met the dietary guidelines, fewer than one in four reached 500 milligrams of flavanols a day. The same pattern showed up in the UK study and in computer simulations using common American produce.
Dr. Kumar’s Take
What strikes me about this study is how it separates two ideas we usually lump together. Eating fruits and vegetables is good for you, full stop. But “good for you” and “rich in flavanols” are not the same thing. A plate of iceberg lettuce and cucumber technically counts toward your five-a-day, yet it delivers almost no flavanols. That gap matters if you are eating with your heart in mind. I like that the researchers measured flavanols in the body rather than trusting questionnaires, because it removes a lot of guesswork. The honest limitation is that this work shows an intake gap, not whether closing that gap with specific foods lowers deaths. We are connecting two solid findings, but the bridge between them still needs testing.
Why the type of produce matters
Here is the part most people miss. The amount of fruit and veg you eat is only half the story. The kind you choose may matter just as much. Flavanols are not spread evenly across the produce aisle. Some foods are packed with them, while others have very little, even though both count as a serving.
If you want to close the gap, lean toward flavanol-rich choices. Blueberries, plums, blackberries, broad beans, and cherries are strong options. Green tea is another easy way to add flavanols without changing your meals much. Swapping a low-flavanol snack for one of these can shift your daily total in a meaningful way, without forcing you to eat more food overall.
What this means for guidelines
The study raises a practical question for health policy. Right now, dietary advice focuses on the total amount of fruits and vegetables, not on flavanols specifically. This research suggests that approach may not be enough to hit the levels tied to heart benefits. The authors argue that we may need separate intake targets for flavanols if the goal is to reach the 500 milligram mark.
That does not mean current guidelines are wrong. Eating more produce still helps your health in many ways. It simply means the flavanol benefit seen in COSMOS will not happen automatically just because someone eats their five-a-day. Reaching it takes more deliberate food choices.
Practical Takeaways
- Aim for flavanol-rich produce specifically, such as blueberries, blackberries, plums, cherries, and broad beans, rather than counting on any fruit or vegetable to do the job.
- Add a cup of green tea to your day, since it is an easy source of flavanols that does not require changing your meals.
- Remember that meeting your five-a-day is a floor, not a guarantee, because fewer than 25% of guideline-meeting eaters reached the flavanol level linked to heart benefits.
- Focus on variety and color, as deeply colored berries and certain beans carry far more flavanols than pale, watery produce like lettuce or cucumber.
Related Studies and Research
- How beans and soy foods lower your risk of high blood pressure
- Does rosuvastatin prevent heart disease in healthy people with intermediate risk? A look at the HOPE-3 trial
- Being physically fit lowers your risk of depression and dementia
- Does yo-yo dieting actually harm your health?
FAQs
How much green tea would I need to get more flavanols?
Green tea is one of the most reliable everyday sources of flavanols, which is why the researchers highlight it alongside berries and beans. The study does not set an exact number of cups, so it is best to treat tea as one part of a broader strategy rather than a single fix. Pairing a daily cup or two with flavanol-rich fruit is a sensible way to push your intake upward. If you dislike tea, leaning harder on berries and broad beans can fill a similar role.
Are supplements a better way to reach 500 milligrams of flavanols?
This study focused on food and diet quality, not pills, so it cannot tell us whether supplements work as well as whole foods. The COSMOS trial that found the heart benefit used a controlled flavanol supplement, which is part of why the topic is debated. For most people, food first is the safer starting point because whole produce brings fiber, vitamins, and other compounds along with flavanols. If you are considering a supplement, that is a conversation worth having with your own doctor.
Does this mean fruits and vegetables are not worth eating?
Not at all, and that is an important point to keep clear. Eating more fruits and vegetables was still linked to higher flavanol levels and better overall diet quality in both groups studied. The finding is narrower than it first sounds. It says that produce alone, in the amounts most people eat, does not automatically deliver the specific flavanol dose tied to fewer heart deaths. The fix is smarter choices within your produce, not eating less of it.
Bottom Line
Meeting your five-a-day is a good habit, but it does not guarantee the flavanol intake linked to a healthier heart. Across two large studies with more than 30,000 people combined, fewer than a quarter of those who met dietary guidelines reached the 500 milligram flavanol mark seen in the COSMOS trial. The lesson is simple. To get the heart benefit of flavanols, the type of produce you choose matters as much as the amount, so favor berries, plums, cherries, broad beans, and green tea.
