A phenolic compound derived from ellagitannins commonly found in red raspberries, strawberries, pomegranates, and walnuts, ellagic acid has antiviral, antibacterial and antioxidant properties ^{(1) (2) (8)}. Small clinical studies have shown that it may lower cholesterol in patients with metabolic syndrome ⁽⁷⁾; restore cognitive performance associated with mild age-related decline ⁽¹⁸⁾; lower glycemic index in diabetic patients ⁽²²⁾; and improve quality of life in those with irritable bowel syndrome ^(23) (24). In addition, consumption of red raspberries was associated with improvements in endothelial function ⁽¹⁹⁾; and a pomegranate extract may have beneficial effects by inducing ellagitanin metabolite formation and changing microbiota ⁽²⁰⁾.

Pre-clinical studies indicate anticarcinogenic effects against liver, esophageal, prostate, and colorectal cancer cell lines ^{(3) (4) (5) (6)}. Ellagic acid was also shown to induce apoptosis and potentiate all-trans retinoic acid myeloid differentiation therapy in human leukemia HL-60 cells ⁽⁹⁾. In another study, pomegranate-derived ellagitannins exhibited anti-aromatase activity and suppressed testosterone-induced breast cancer cell proliferation, but ellagic acid did not have such effects  ⁽¹⁰⁾.
In an exploratory study of patients with biochemically recurrent prostate cancer, grape skin comprising ellagic acid, quercetin, and resveratrol was reported to be safe and to affect a non-significant increase in prostate-specific antigen doubling time ⁽²¹⁾. Further research is needed to assess the anticancer potential of ellagic acid.