Reading, England—A high flavanol diet could help lower blood pressure, according to a new study using data from more than 25,000 people in Norfolk, UK.

Published inScientific Reports,the study compared diet to blood pressure in the 25,000 participants—however, unlike most studies, this research did not rely on self-reporting, but used nutritional biomarkers to measure flavanol intake objectively.

"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 Professor Gunter Kuhnle, a Nutritionist at the University of Reading and the leader of the study, in the 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.”

That association: A difference in blood pressure between those with the lowest 10% of flavanol intake and those with the highest 10% of intake of between 2 and 4 mmHg. This difference is comparable to meaningful changes in blood pressure observed in those following the Mediterranean diet or DASH diet, the press release notes. The effect was more pronounced in participants with hypertension.
Related: Meta Analysis Supports Heart Health Benefits of Aronia Berry Study Associates Low Vitamin K With CVD Risk Healthy Aging
"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. In the British diet, the main sources are tea, cocoa, apples and berries.

"The methodology of the study is of equal importance,” Kuhnle continued. “This is one of the largest ever studies to use nutritional biomarkers to investigate bioactive compounds. Using nutritional biomarkers to estimate intake of bioactive food compounds has long been seen as the gold standard for research, as it allows intake to be measured objectively. The development, validation and application of the biomarker was only possible because of the long-term commitment of all collaborators. In contrast to self-reported dietary data, nutritional biomarkers can address the huge variability in food composition. We can therefore confidently attribute the associations we observed to flavanol intake."

The study was supported by a grant from Mars, Incorporated, and performed by a team of researchers from the University of Reading, Cambridge University, the University of California Davis, and two employees of Mars.

"This study adds key insights to a growing body of evidence supporting the benefits of dietary flavanols in health and nutrition,” commented Hagen Schroeter, Chief Science Officer at Mars Edge, in the press release. “But, perhaps even more exciting was the opportunity to apply objective biomarkers of flavanol intake at a large scale. This enabled the team to avoid the significant limitations that come with past approaches which rely on estimating intake based on self-reported food consumption data and the shortcomings of current food composition databases."