Diets High in Flavanol Could Lower Blood Pressure

A new study suggests that diets with flavanol-rich foods and drinks, such as tea, apples, and berries, could lead to lower blood pressure.

The investigation, published in Scientific Reports, examined the diet of more than 25,000 people in Norfolk, England, and compared their diet with their blood pressure. Unlike other studies that have investigated links between nutrition and health, the researchers did not rely on study participants reporting their diet. Instead, they measured flavanol intake objectively using nutritional biomarkers, such as indicators of dietary intake, metabolism, or nutritional status in the blood.

According to a press release, the difference between those with the lowest 10% of flavanol intake and those with the highest 10% of intake was between 2 and 4 millimeters of mercury (mmHg). This is comparable to meaningful changes in blood pressure observed in patients who follow the Mediterranean diet or Dietary Approaches to Stop Hypertension (DASH) diet. The effect was more pronounced in participants with hypertension.

“Previous studies of large populations have always relied on self-reported data to draw conclusions, but this is the first epidemiological study of this scale to objectively investigate the association between a specific bioactive compound and health,” said Dr Gunter Kuhnle, a University of Reading professor, in a press release. “We are delighted to see that in our study, there was also a meaningful and significant association between flavanol consumption and lower blood pressure.”

The study is one of the largest to ever use nutritional biomarkers to investigate bioactive compounds, which the investigators said has long been considered the gold standard for research because it allows intake to be measured objectively. Unlike self-reported dietary data, nutritional biomarkers can address variability in food composition, leading to more reliable attribution of the associations observed by the researchers.

“What this study gives us is an objective finding about the association between flavanols—found in tea and some fruits—and blood pressure,” Kuhnle said. “This research confirms the results from previous dietary intervention studies and shows that the same results can be achieved with a habitual diet rich in flavanols.”

REFERENCE

High flavanol diet may lead to lower blood pressure [news release]. EurekAlert; October 21, 2020. https://www.eurekalert.org/pub_releases/2020-10/uor-hfd101620.php. Accessed October 23, 2020.