Phenolic acids
Polyphenols
Chlorogenic acid from coffee and artichoke, ferulic acid attached to cereal bran.
Ferulic acid is chemically bound to arabinoxylan: it is bacteria that release it, not digestion.
Effects and benefits
The largest share of the day's polyphenols often comes from coffee, as chlorogenic acid. A third is absorbed in the small intestine, the rest feeds a bacterial feast in the colon. And studies associate coffee, even decaf, with a lower risk of diabetes.
For many European adults, coffee is the first source of polyphenols, ahead of fruit: a cup contains 70 to 350 mg of chlorogenic acid depending on the roast, a light roast keeping more (Clifford, 1999).
About a third is absorbed in the small intestine; the remaining two thirds reach the colon, where bacteria transform it into smaller phenolic acids, absorbed in turn (Olthof et al., 2001; Stalmach et al., 2009). The ferulic acid of bran is only released slowly, all along the colon (Kroon et al., 1997).
Meta-analyses of observational studies associate coffee with a lower risk of type 2 diabetes, the more so as consumption rises; decaf is associated too, which points to molecules other than caffeine, including chlorogenic acids (Ding et al., 2014).
Sources: Clifford, J Sci Food Agric, 1999 · Olthof et al., J Nutr, 2001 · Stalmach et al., 2009 · Kroon et al., 1997 · Ding et al., Diabetes Care, 2014
Where to find it (24)
- African rice
- Artichoke
- Barley
- Black rice
- Blueberry
- Brown rice
- Carrot
- Chicory / radicchio
- Coffee
- Corn
- Eggplant
- Oats
- Plum
- Potato
- Purple corn
- Red rice
- Roasted chicory
- Rye
- Sumac
- Sunflower seeds
- Sweet potato
- Vanilla
- Whole wheat
- Yerba mate