Eating flavonoid-rich foods, such as berries, apples, pears, and wine, can have a "positive effect" on blood pressure levels.
Flavonoids are compounds found naturally in fruits, vegetables, and plant-based foods such as tea, chocolate, and wine, with previous studies confirming that they offer a variety of health benefits. However, researchers have now discovered that the way flavonoids are broken down by the body's gut microbiome - the bacteria found in the digestive tract - is linked to lower blood pressure.
"Our gut microbiome plays a key role in metabolising flavonoids to enhance their cardioprotective effects, and this study provides evidence to suggest these blood pressure-lowering effects are achievable with simple changes to the daily diet," said lead investigator Dr. Aedin Cassidy of Queen's University in Belfast, Northern Ireland.
For the research, the team recruited a group of over 900 adults aged between 25 and 82, and evaluated the participants' food intake, gut microbiome, and blood pressure levels. Accordingly, they reported that the people who had the highest intake of flavonoid-rich foods, including berries, red wine, apples and pears, had lower systolic blood pressure levels, as well as greater diversity in their gut microbiome than the participants who consumed the lowest levels of flavonoid-rich foods.
In addition, eating at least one serving of berries per day was associated with a reduction in blood pressure levels, and drinking around two glasses of red wine a week was associated with an average of 3.7 mm Hg lower systolic blood pressure level, of which 15 per cent could be explained by the gut microbiome.
"A better understanding of the highly individual variability of flavonoid metabolism could very well explain why some people have greater cardiovascular protection benefits from flavonoid-rich foods than others," added Dr. Cassidy.
Full study results have been published in the journal Hypertension.