Flavanols are a group of biologically active compounds found in the majority of plants, including fruits, teas, and cacao-based products that can help improve blood pressure, cholesterol, and blood sugar in humans.
In chemical terms, flavanols, also called flavan-3-ols, are alcohol derivatives (i.e. contain an OH group) of a larger collection of chemical compounds called flavonoids, biomolecules based on the structure of flavan. Flavanols are chemically distinct from most other flavonoids because they lack the double bond in the central ring. They can be monomeric like catechin or exist as oligomers (where two or three monomers are connected to each other) like in procyanidin and polymers (where many monomers are joined).
Connection to chocolate and health
Flavanols are found in fruits, teas, and cacao-based products. The amounts of flavanoids found in foods can be found in the USDA database. All flavanols are flavanoids but not all flavanoids are flavanols. For general discussion, individuals in the chocolate community can interchangeably use the term flavanols and flavanoids as representative of a larger chemical group of antioxidants.
There is strong evidence that flavanoids like catechin and procyanidin are associated with healthy blood pressure and blood lipids.
Flavanols in chocolate
Cacao pods have significant amounts of four monomeric flavanols: epicatechin, epigallocatechin, catechin, and gallocatechin. Dark and milk chocolate contain epicatechin and catechin. Dark chocolate is high in total procyanidins (~165 mg/serving) (Hammerstone, 2000). Cacao pod storage, fermentation, drying, and roasting reduce flavanols (interestingly catechin increases during roasting as the heat causes epimerization from epicatechin) (Goya, 2022). Alkalization, or Dutching, is an optional step where crushed cacao beans, called cacao nibs, are treated with basic solution (high pH) to change the color, taste, and solubility. Alkalization results in a significant reduction in epicatechin and catechin levels.
Flavanols are the most consumed subclass of flavanoids in food. High amounts are found in black and green teas and moderate amounts in berries and dark chocolate (~300 mg per 8 oz of tea, 8 – 60 mg per cup of berries, and ~20 mg/18 g dark chocolate) (Crowe-White, 2022).
A metanalysis of 157 randomized controlled trials and 15 cohort studies was done to look at the effects of flavanols on human health (Crowe-White, 2022). Measurement of biomarkers like systolic blood pressure, total cholesterol, HDL cholesterol, and insulin/glucose levels in literature studies suggest that consuming 400 – 600 mg of flavanol in food per day can help improve blood pressure, cholesterol, and blood sugar. Data are mixed as to whether flavanols improve cognitive function (Goya, 2022).
Flavanol consumption varies culturally, e.g., American mean intake is 223 mg/day while in Ireland mean consumption is 793 mg/day (Crowe-White, 2022). The human microbiome (microbes in the gut) impacts the bioavailabilty of flavanols (Neilson, 2011). Flavanols act primarily as antioxidants, inhibit neuroinflammation and upregulate antioxidant enzymes throught the mitogen‑activated protein kinase (MAPK) signaling pathway.
Próximamente versión en español
Entry added: July 31, 2023
Verified on: September 14, 2023
Cory G. Toyota, Associate Professor of Chemistry and Biochemistry
Academic / university faculty
Wolfgang H. Kramer, Professor of Chemistry and Biochemistry
Academic / university faculty
“Flavan-3-ols and cardiometabolic health: First ever dietary bioactive guideline,” Kristy M. Crowe-White, Levi W. Evans, Gunter G.C. Kuhnle, Dragan Milenkovic, Kim Stote, Taylor Wallace, Deepa Handu and Katelyn E. Senkus, Adv Nutr, December 22, 2022.
“Cocoa to Chocolate: Effect of Processing on Flavanols and Methylxanthines and Their Mechanisms of Action,” Luis Goya, John Edem Kongor and Sonia de Pascual-Teresa, Int. J. Mol. Science, November 18, 2022.
“USDA Database for the Flavonoid Content of Selected Foods, Release 3.3 (March 2018),” USDA, AG Data Commons U.S. Department of Agriculture, Accessed on August 4, 2023.
“Procyanidin content and variation in some commonly consumed foods,” J.F. Hammerstone, S.A. Lazarus and H.H. Schmitz, J Nutr. August 2000.
“Influence of formulation and processing on absorption and metabolism of flavan-3-ols from tea and cocoa,” Andrew P. Neilson and Mario G. Ferruzzi, Annu Rev Food Sci Technol., 2011.
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