Image of Aedín Cassidy, Ph.D.
Aedín Cassidy, Ph.D.

Adults who eat more foods rich in flavonoids, such as berries, red wine and chocolate, have lower systolic blood pressure levels and may have a healthier gut as well.

That’s according to a new study of 904 adults up to age 82 from a German population database. At regular examinations, researchers evaluated the participants’ food intake, gut microbiome and blood pressure levels, among other health factors.

Flavonoids are plant metabolites that appear to have health benefits, including antioxidant effects. Participants who had the highest intake of flavonoid-rich foods, including berries, red wine, apples and pears appeared to have the greatest reduction in systolic blood pressure. This in turn partly explained by the characteristics of their gut microbiome — the many microorganisms that live in the gut and impact digestion and overall health, investigators said.

“Our gut microbiome plays a key role in metabolizing 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,” author Aedín Cassidy, Ph.D.,of the Institute for Global Food Security at Queen’s University in Belfast, Northern Ireland, said.

Among the findings: 

  • Up to 15.2% of the link between flavonoid-rich foods and systolic blood pressure may be explained by the diversity found in participants’ gut microbiomes.
  • Eating about one and a half cups of berries per day was associated with an average reduction in systolic blood pressure levels of 4.1 mm Hg. About 12% of the association was explained by gut microbiome factors.
  • Drinking about 2.8 glasses of red wine a week (125 ml of wine per glass) was associated with an average of 3.7 mm Hg lower systolic blood pressure level. About 5% of this link could be explained by the gut microbiome.

The study was published in the journal Hypertension.