Flavanols are part of the polyphenol family: naturally occurring bioactive compounds known for their antioxidant properties.
They occur in foods like green tea, apples, and blueberries, but cacao stands out as one of the richest natural sources.
Decades of research have examined the relationship between flavanol intake and a range of physiological outcomes: from vascular function and blood flow to cognitive performance and gut microbiota. Cacao stands out as one of the richest dietary sources of flavanols — provided it is not heavily processed.
Cacao is one of the few foods with an officially EU-authorised health claim:
"Cocoa flavanols contribute to maintaining the elasticity of blood vessels, which contributes to normal blood flow."
— EU Regulation 851/2013
This effect is achieved at a daily intake of 200 mg of cocoa flavanols — the threshold established through clinical research and recognised by the European Commission.
In multiple large-scale reviews of clinical trials, participants who consumed flavanol-rich cacao showed average blood pressure reductions of around 3–5 mmHg systolic and 2–3 mmHg diastolic compared to control groups — with stronger effects in people with elevated blood pressure (Ried et al., 2017; Hooper et al., 2012).
Researchers often measure vascular health using a test called flow-mediated dilation (FMD) — essentially how well an artery widens in response to increased blood flow, a direct indicator of blood vessel health. In flavanol intervention studies, FMD improvements of up to 30% have been observed in participants consuming high-flavanol cacao (Schroeter et al., 2006; Heiss et al., 2010).
The COSMOS trial is the largest randomised study on cocoa flavanols to date — 21,442 participants, followed over 3.6 years. Participants who received 500 mg of cocoa flavanols daily had a 27% lower rate of cardiovascular mortality compared to the placebo group (Sesso et al., 2022).
In a sub-study of COSMOS, researchers focused specifically on participants with a low-flavanol diet — the group most likely to show a measurable response. After one year of 500 mg daily, this group showed a 16% improvement on standardised memory tests compared to placebo (Brickman et al., 2023).
Full study references and methodology → The Science Behind Flava'Choc: Our Complete Reference List
The EU-authorised health claim for cocoa flavanols is based on 200 mg per day — the minimum dose established by EFSA for normal blood vessel elasticity and blood flow.
However, the most recent large-scale trials — including COSMOS — used 500 to 750 mg daily. At these higher levels, researchers observed stronger associations across multiple outcomes:
Reaching 500 mg through conventionally processed chocolate is practically impossible. Roasting, alkalisation, and industrial refining destroy the majority of flavanols originally present in the cacao bean — a standard 70% dark chocolate bar typically delivers no more than 20 to 50 mg per serving.
Flava'Choc publishes batch-specific flavanol measurements for each product — allowing you to calculate your actual daily intake.
Daily flavanol intake: Minimal vs. Optimal
Cacao's strength goes beyond flavanols. Raw cacao contains a remarkably diverse spectrum of bioactive compounds — each extensively studied in nutritional science.
The most extensively studied polyphenols in cacao, with the largest body of clinical research on vascular and cognitive outcomes.
A related polyphenol family found alongside flavanols in cacao, actively studied for their role in vascular and cellular processes.
The natural pigments behind cacao's deep colour — and among the most studied polyphenols in nutritional science, with ongoing research into cellular effects.
Large, complex polyphenol structures in cacao that reach the gut microbiota largely intact — actively studied for their effects on microbiome composition and gut health.
Cacao's natural stimulants. Theobromine delivers a slower, milder effect than caffeine — both extensively studied for their effects on alertness and vascular tone.
Cacao is naturally rich in magnesium, copper, iron, and potassium. For each of these minerals, the EU recognises authorised health claims — from energy metabolism to oxygen transport and nervous system function.
Check out our blog to learn how flavanols fit into the broader polyphenol category and explore a full list of references.
