The US-based Academy of Nutrition and Dietetics has published a guideline on flavan-3-ol intake and cardiometabolic health – the first dietary recommendation for a non-essential bioactive food compound. “This is a new era in nutrition science,” says one consultant.
An expert panel concluded that there was “moderate evidence” to show flavan-3-ol intake in the range of 400-600 mg per day offers cardiometabolic protection.
The scientists also ruled that increasing consumption of dietary flavan-3-ols may help to improve blood pressure, cholesterol levels, and blood sugar.
Flavan-3-ols – bioactive compounds that are found in tea, apples, pears, berries, and chocolate or cocoa products – have the potential to contribute to the prevention of cardiometabolic disorders, studies suggest.
A 2013 review of flavan-3-ol intake among the European population found that the main sources were tea (62%), pome fruits (11%), berries (3%) and cocoa products (3%). However, the authors concluded that the average habitual intake of flavan-3-ols was “considerably below the amounts used in most dietary intervention studies”.
Cardiovascular diseases are the leading cause of death globally, according to the World Health Organization (WHO). As plant-based foods containing phytochemicals are known to play an important role in health maintenance and disease risk reduction, there is increasing interest in developing dietary recommendations for such bioactives.
Citing “a rapidly growing body of clinical data reflecting benefits of flavan-3-ol intake that outweigh potential harms,” the Academy of Nutrition and Dietetics established an expert panel with the aim of developing guidelines on intake recommendations.
The guidelines were based on a systematic review and meta-analysis of 157 randomised controlled trials and 15 cohort studies; quality, strength of evidence, and risk of bias in reporting were taken into account. In addition, data assessments and opinions from scientific bodies as to the safety of flavan-3-ols were considered.
This guideline “was based on beneficial effects observed across a range of disease biomarkers and endpoints.” Strength of evidence was strongest for some biomarkers (i.e., systolic blood pressure, total cholesterol, HDL-cholesterol, and insulin/glucose dynamics).
Dr Taylor Wallace, CEO of the Think Healthy Group, a food science and nutrition consulting firm, said: “The intake recommendation for flavan-3-ols is significant in that it ushers in a new era in nutrition science, where scientists are able to formulate diets that not only meet an individual's basic nutrition needs, but those that promote longevity, healthy ageing, and prevention of chronic disease.”
The experts said that the flavan-3-ol intakes guideline presented “a departure from previous recommendations, as it is not based on deficiencies but, rather, improvement in health outcomes.”
While they warned that knowledge gaps had been identified during the review, they said these could be used by scientists running randomised clinical trials in future.
The experts also stressed that this was a food-based guideline and did not apply to flavan-3-ol supplements.
Dr Joy Dubost, head of scientific affairs and nutrition, Americas, at the tea company ekaterra, said: “Based on decades of scientific evidence, the health benefits of consuming unsweetened tea have been established. We applaud the Academy of Nutrition and Dietetics and the expert panel for paving the way to improving public health by recommending a daily amount of flavan-3-ols in the diet.
“Unsweetened tea is the top source of flavan-3-ols in the diet and is a delicious, cost-effective way to support heart health.”
