A-type proanthocyanidin

[3] Other A-type proanthocyanidins can be found in cranberries,[2] cinnamon,[4] peanut skins[5][6] and Geranium niveum.

[9] The metabolism of type-A proanthocyanidins is significant since a large number of metabolites are detected in urine and feces soon after ingestion of foods rich in polymers, indicating rapid elimination and absence of physiological effect.

Polymeric type-A proanthocyanidins are depolymerized into epicatechin units in the small intestine, then cleaved into smaller phenolic acids with no known biological role.

[10] In vitro, A-type proanthocyanidins isolated from cranberry juice cocktail demonstrated anti-adhesion activity against E. coli binding to urinary tract epithelial cells, whereas B-type proanthocyanidins from grape exhibited minor activity.

[11] In humans, a 2014 review indicated there was insufficient clinical evidence that cranberry type-A proanthocyanidins are effective in lowering the risk of urinary tract infections (UTIs),[12] while a 2023 review concluded that long-term consumption of cranberry products may reduce the risk of UTIs in certain groups.