Flavonoid-Rich Food and Drinks May Lower Blood Pressure
From Medical News Today
Dietary advice from healthcare professionals can seem joyless, typically requiring people to stay away from a list of treats that scientists have found to be “bad” for health.
Major exceptions to this rule are flavonoid-rich foods and drinks, which include dark chocolate, blueberries, and strawberries.
Research indicates that flavonoids may protect against:
high blood pressure
heart attack and stroke
type 2 diabetes
certain types of cancer
A new study now suggests that the bacteria that live in our gut, known as the gut microbiota, may be partly responsible for the beneficial effect of dietary flavonoids on blood pressure.
High blood pressure is a major risk factor for cardiovascular disease, which is the leading cause of death in the United States.
Researchers at Queen’s University Belfast in Northern Ireland, United Kingdom, recently led a study that found that individuals who consumed the most flavonoid-rich foods tended to have lower blood pressure.
The diversity of participants’ gut microbiota accounted for a significant portion of the association between flavonoids and blood pressure.
Specifically, the scientists’ analysis found that eating 1.6 servings of berries a day — where one serving equals 1 cup or 80 grams of berries — was associated with an average reduction of 4.1 millimeters of mercury (mm Hg) in systolic blood pressure.
Systolic blood pressure is the pressure in a person’s arteries when their heart contracts, whereas diastolic blood pressure is the pressure when the heart relaxes. In a blood pressure reading, the first number is the systolic blood pressure, and the second is the diastolic value.
A healthy blood pressure is usually less than 120/80 mm, whereas high blood pressure is typically 140/90 mm or above.
The diversity and composition of the gut microbiota explained about 11.6% of the association between berry consumption and blood pressure.
Similarly, drinking 2.8 glasses of red wine a week (125 milliliters per glass) was associated with a 3.7-mm Hg reduction in systolic blood pressure. The gut microbiota accounted for 15.2% of this association.
“Eating 1.5 servings of berries a day resulted in clinically relevant reductions in systolic blood pressure,” said lead author Aedín Cassidy, Ph.D., chair and professor in nutrition and preventive medicine at the Institute for Global Food Security at Queen’s University.
Professor Cassidy believes that a class of flavonoids called anthocyanins appears to be key to this effect.
Anthocyanins are the pigment molecules responsible for the red or blue color of many fruits, including red grapes, blueberries, blackcurrants, and blackberries.
Previous research has found that gut bacteria break down flavonoids into compounds that have more powerful protective effects on the heart.
Conversely, regular consumption of flavonoid-rich foods also influences the composition of the gut microbiota.
“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,” says Prof. Cassidy in a press release on the study.