Why Your Five-a-Day May Not Be Enough for Heart Health

A new study in Food & Function reveals that standard dietary advice on fruit and vegetable intake may fall short in protecting heart health. Researchers found that most people in the UK and US consume too few flavanols—natural compounds linked to lower cardiovascular risks—despite following general guidelines. The findings suggest a need for more precise nutritional recommendations. Flavanols, found in foods like plums, cranberries, blackberries, and green tea, help reduce oxidative stress and improve blood vessel function. Yet fewer than one in five people in the UK and US consume enough to significantly cut their risk of fatal heart events. The study highlights that a daily intake of around 500mg of flavanols could make a meaningful difference.

The research also introduced a more accurate way to measure nutrient intake. Instead of relying on self-reported food diaries, scientists used biomarkers to track flavanol levels. This method provides clearer data on what people actually consume. Professor Gunter Kuhnle from the University of Reading argues that dietary advice should shift from simply recommending more fruits and vegetables to specifying which types offer the most health benefits. For example, a single cup of green tea contains roughly 200mg of flavanols, while a serving of blackberries can provide over 250mg. Future studies may explore how flavanols work at a molecular level and refine dosage guidelines. Data from the COSMOS clinical trial supports these findings, showing that higher flavanol intake correlates with better cardiovascular outcomes. The study’s authors urge health authorities to update guidelines, focusing on nutrient quality rather than just quantity.

The research points to a gap between current dietary recommendations and optimal heart health. By targeting flavanol-rich foods, people could better protect themselves against cardiovascular disease. Scientists now aim to further investigate how these compounds interact with the body and confirm the best intake levels.