Study finds five-a-day may miss heart-protective flavanols

A new study suggests that following the common "five-a-day" fruit and vegetable guideline may not be sufficient for optimal heart health unless those choices specifically include foods rich in certain beneficial compounds. Published on June 8, 2026, in the journal Food and Function, the research analyzed data from more than 30,000 participants in the United Kingdom and the United States and found that fewer than one in five people achieved a daily intake of flavanols linked to cardiovascular benefits, even among those who regularly consumed five portions of produce.

Flavanols are natural, plant-based antioxidants that support heart health, circulation, and blood vessel function. Previous research, notably the large COSMOS clinical trial, indicated that a daily intake of approximately 500 milligrams significantly reduces the risk of dying from cardiovascular disease. However, this new study found that most people fall well short of that level despite adhering to general dietary recommendations.

The research, conducted by scientists from institutions including the University of Reading, Harvard Medical School, and the University of California Davis, utilized biomarker measurements...