Beer, Tea and Wine Affect Folic acid Uptake

PORTO, PortugalConstituents in beer, wine and tea appear to inhibit the uptake of both folic acid and anti-folate in the intestines, according to results published in the Aug. 28 European Journal of Nutrition (2007; 46(6):329-36). Researchers from University of Porto and VU University Medical Center, Amsterdam, investigated whether beverages like wine, beer and tea, or some of their specific constituents, affect the intestinal uptake of water-soluble H-folic acid or 3H-methotrexate, an anti-folate. All tested beverages significantly inhibited the uptake of 3H-folic acid by Caco-2 cells (mimic intestinal cells); most of these beverages, excluding wine, also inhibited 3H-methotrexate uptake in these cells. Additionally, ethanol, when tested separately, inhibited the uptake of both the folic acid and anti-folate compounds. Some of the tested phenolic compoundsspecifically myricetin, epigallocatechin gallate (EGCG) and isoxanthohumolmarkedly inhibited 3H-folic acid uptake. Myricetin and EGCG also had a concentration-dependent inhibitory effect on the uptake of 3H-methotrexate by Caco-2 cells. Resveratrol, quercetin and kaempferol inhibited the transport of both compounds, but only in the concentration of 100 µM. The researchers concluded dietary constituents from certain beverages may impact on intestinal folate uptake, as demonstrated by the tests on their phenolic compounds.