Plant foods rich in flavonoids — chemical compounds long recognized for their potential health benefits — may lead to lower blood pressure in part by their effects on your gut microbiome, according to a new study published in the journal Hypertension.
In recent years, research has shed light on the enormous role played by your gut microbiome — the collection of bacteria that lives in your digestive system — in health and disease. Just in the last year, studies have shown that the composition of your gut microbiome is linked to your risk of developing type 2 diabetes as well as levels of inflammation in your body. Many factors are known to affect the composition of your gut microbiome, including how much you sleep and whether you feel lonely — but, of course, one of the biggest factors is what you eat.
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For the latest study, researchers looked at how differences in the gut microbiome might explain why eating foods rich in flavonoids — such as berries, apples, grapes, and cocoa — is linked to lower blood pressure. A group of 904 participants, ages 25 to 82, had their gut microbiomes sequenced to look at the differences in different types of bacteria, as noted in a Healio article. They also took a detailed dietary questionnaire and had their blood pressure levels measured.
Flavonoid consumption linked to lower blood pressure
The researchers found that participants in the top third for consumption of flavonoid-rich foods had, on average, systolic blood pressure (the “top number” measured during heartbeats) that was 2.9% lower than the bottom group for flavonoid consumption. When participants were grouped based on their consumption of one specific type of flavonoids called polymers, blood pressure in the top consumption group was 3.7% lower, on average, than in the bottom consumption group. When looking at specific foods, a higher intake of berries and red wine was linked to lower systolic blood pressure, and a higher intake of berries and apples or pears was linked to reduced levels of a genus of bacteria called Parabacteroides.
Overall, the researchers found that changes to the gut microbiome due to an intake of flavonoid-rich foods accounted for 15.2% of their effect on blood pressure. The remaining effect on blood pressure was presumed to be due to other beneficial properties of these foods, such as compounds that may help blood vessels function better.
“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,” said study author Aedín Cassidy, PhD, chair and professor in nutrition and preventive medicine at the Institute for Global Food Security at Queen’s University in Belfast, Northern Ireland, in a press release. “Our findings indicate future trials should look at participants according to metabolic profile in order to more accurately study the roles of metabolism and the gut microbiome in regulating the effects of flavonoids on blood pressure.”
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