Intake guidelines published in Advances in Nutrition “may help improve blood pressure, cholesterol levels, and blood sugar.”
Cardiometabolic disease, a group of disorders including hypertension, dyslipidemia, insulin resistance and abdominal adiposity, underlies and increases the risk of cardiovascular disease as well as type 2 diabetes. According to the World Health Organization (WHO), “cardiovascular diseases are the leading cause of death globally.” An estimated 17.9 million people died from cardiovascular disease in 2019, representing 32% of all global deaths. In addition, WHO notes that “the number of people with diabetes rose from 108 million in 1980 to 422 million in 2014,” with the prevalence rising more rapidly in low- and middle-income countries.
Research has shown the benefits of adhering to a healthy diet to lower the risk of cardiometabolic disease. Moreover, there is a growing body of research that suggests that certain bioactives—specific food components beyond those needed to maintain basic human nutrition—may also play an important role in lowering the risk of cardiometabolic disease.
Among these health-promoting bioactives are flavan-3-ols, the most highly consumed subclass of flavonoids. Flavan-3-ols are commonly found in tea, apples, pears, berries, chocolate, and cocoa products.
In recognition of flavan-3-ols’ potential to lower the risk of cardiometabolic disease, the Academy of Nutrition and Dietetics assembled an Expert Panel to develop an intake recommendation for flavan-3-ols that optimizes cardiometabolic outcomes. The Panel consisted of six members. Each candidate was evaluated based on a set of standard criteria, including experience in the subject matter and conflicts of interests. Candidates with the highest scores were selected for the Expert Panel, with the highest scoring candidate selected as the Chair. The Panel’s intake recommendations, Flavan-3-ols and Cardiometabolic Health: First-Ever Dietary Bioactive Guideline, were published in Advances in Nutrition, the international review journal of the American Society for Nutrition.
In order to make their recommendations, the Panel analyzed the results from 157 randomized controlled trials and 15 cohort studies published between 1946 and March 2019. All the studies used subjects 18 years and older. Moreover, all the studies the Panel analyzed had been previously reviewed in a recently published systematic review and meta-analysis.
Among the general adult population, the Panel recommended “increasing consumption of nutrient-dense foods rich in flavan-3-ols and low (or absent) in added sugars, including but not limited to tea, apples, berries, and cocoa.” Specifically, the Panel found that “moderate evidence supporting cardiometabolic protection resulting from flavan-3-ol intake in the range of 400-600 mg/day was supported by the literature.” Overall, they believe that “consumption of dietary flavan-3-ols may help improve blood pressure, cholesterol levels, and blood sugar.” The Panel stressed that “the beneficial effects were observed across a range of disease biomarkers and endpoints.”
The Panel did caution that “this is a food-based guideline and not a recommendation for flavan-3-ol supplements,” which may cause gastrointestinal irritation or liver injury, particularly when taken in excess or on an empty stomach.”
Overall, the Panel pointed to a growing body of research that demonstrates higher consumption of flavan-3-ols may reduce the risk of certain cardiometabolic diseases and related mortality. The Panel did note that their guideline was developed from research on the general adult population: “additional research evaluating flavan-3-ol intake earlier in the lifespan is warranted as dietary habits adopted earlier in life may contribute to the magnitude of effect of flavan-3-ols on cardiometabolic health.”