Flavanols and procyanidins
Polyphenols
Catechins and their assemblies: the bitterness of cocoa, tea and grape skin.
Heavy roasting and the alkalization of cocoa cause the greatest losses. On the tea side, green keeps them intact where black has traded part of them for theaflavins.
Effects and benefits
Cocoa, tea, apples and grapes share molecules that make blood vessels more flexible: 200 mg a day of cocoa flavanols contribute to it. In a large trial, a year of flavanols also improved memory in adults who ate few of them.
The story begins with the Kuna of Panama: these islanders drank several cups of minimally processed cocoa every day and kept low blood pressure with age, which those who moved to the city lost (Hollenberg et al., 1997). Researchers eventually isolated the cause: flavanols.
They prompt the artery wall to produce nitric oxide, which relaxes it. Cocoa flavanols help maintain the elasticity of blood vessels, which contributes to normal blood flow, with 200 mg a day: 2.5 g of powder or 10 g of dark chocolate rich in flavanols (Regulation 851/2013).
Memory was tested in the COSMOS-Web trial, in 3,500 older adults: those who ate few flavanols and took 500 mg a day saw their memory improve within a year (Brickman et al., 2023).
The large COSMOS trial, in more than 21,000 older people, did not show a drop in cardiovascular disease overall, but about a quarter fewer cardiovascular deaths, a secondary result still to be confirmed (Sesso et al., 2022).
Eggerthella lenta and Flavonifractor cut them into valerolactones — the molecules actually found in the blood after a square of dark chocolate.
Sources: Hollenberg et al., Hypertension, 1997 · EU Regulation 851/2013 · Brickman et al., PNAS, 2023 · Sesso et al., AJCN, 2022
Where to find it (9)
- Apple
- Aronia
- Cocoa / very dark chocolate
- Cranberry
- Grape
- Matcha
- Pu-erh tea
- Red wine
- Tea (black, green, oolong)