The Specific Fruits and Vegetables Your Heart Actually Needs Every Day

Why Your Five-a-Day Might Not Be Enough for Your Heart

For decades, the advice has been simple: eat five portions of fruit and vegetables every day. But groundbreaking new research suggests that what you choose to put on your plate matters far more than how much of it you eat — especially when it comes to protecting your heart.

A large-scale study involving 30,000 participants from both the United States and the United Kingdom has found that even among people who consistently meet the five-a-day target, many are still falling short of a critical group of nutrients known as flavanols.

What Are Flavanols and Why Do They Matter?

Flavanols are a type of antioxidant found naturally in certain plant-based foods. According to the research, published in the journal Food and Function, these compounds play a meaningful role in supporting cardiovascular health by reducing inflammation, improving circulation, and helping to maintain blood vessel flexibility.

Despite their importance, fewer than one in five people consume the recommended 500mg of flavanols per day — a threshold identified by the US Academy of Nutrition and Dietetics as beneficial for heart health. Notably, the NHS does not currently set an official daily flavanol target.

The Best Food Sources of Flavanols

Researchers identified several foods that deliver notably high levels of flavanols per portion. To meaningfully increase your daily intake, consider regularly including the following in your diet:

• Blueberries
• Blackberries
• Plums
• Cherries
• Broad beans
• Green tea

Lead investigator Dr. Javier Ottaviani explained that a few targeted food swaps could "make a real difference" to how much of these beneficial compounds the body actually absorbs. "Most people assume that eating plenty of fruit and vegetables covers this," he said, "but what this research shows is that the specific choices you make matter far more than the total amount."

Not All Five-a-Days Are Created Equal

Professor Gunter Kuhnle of the University of Reading, one of the study's investigators, acknowledged that the five-a-day message remains sound — but argued it may need greater refinement. "Different fruits and vegetables offer very different nutritional benefits beyond vitamins and minerals," he noted. "As our understanding of these compounds grows, there is a real opportunity to make dietary guidance more specific and more effective."

The study used both dietary tracking data and urine biomarkers to accurately measure participants' flavanol absorption — a more reliable method than self-reported dietary surveys alone.

What About Dark Chocolate?

The research team has previously collaborated with chocolate manufacturer Mars Inc., which has been exploring cocoa-based flavanol supplements. Cocoa is a recognised source of flavanols, and dark chocolate is often considered the healthier option over milk chocolate due to its lower sugar content and higher cocoa concentration.

However, the British Heart Foundation (BHF) cautions that flavanol levels in commercial chocolate products vary considerably. Two to three squares of dark chocolate may contain anywhere between 22 and 73mg of flavanols, while the same amount of milk chocolate typically provides just 3 to 7mg.

Experts Urge Caution on Cardiovascular Claims

While the findings are promising, some specialists are calling for restraint before drawing firm conclusions. Professor Naveed Sattar of the University of Glasgow pointed out that although certain small-scale trials have shown modest improvements in blood pressure, there is currently insufficient evidence to confirm that increasing flavanol intake directly reduces the risk of serious cardiovascular events such as heart attacks or strokes. He stressed that further clinical trials are needed.

Professor Ana Rodriguez-Mateos, a nutrition expert at King's College London, added that flavanol content in fruit and vegetables can fluctuate significantly depending on a wide range of factors — much like fibre content — and that this variability warrants deeper investigation.

Individual Differences Play a Role Too

Dell Stanford of the BHF highlighted another layer of complexity: how the body processes flavanols is not the same for everyone. The quantity of flavanols in any given food depends on where it was grown, the local climate, its ripeness at the time of consumption, and how it has been stored or prepared.

Furthermore, gut bacteria play a significant role in breaking down flavanols into forms the body can use — and since everyone's gut microbiome is unique, the actual health benefits individuals derive from these nutrients may differ considerably.

The Bottom Line

Both the BHF and the British Nutrition Foundation maintain that the most effective way to support heart health remains following established dietary guidelines: eating a balanced, varied diet rich in a wide range of fruits and vegetables. However, this new research adds an important nuance — being more intentional about which fruits and vegetables you choose could give your cardiovascular health a meaningful extra boost.