Some dietary fibers reduce the absorption of carotenoids in women

Dietary fiber may be partly responsible for the lower bioavailability of ca rotenoids from food than from purified supplements. Due to the lack of deta iled information available, we investigated the effects of different kinds of dietary fiber on the absorption of carotenoids and alpha-tocopherol. Six healthy young women received an antioxidant mixture consisting of beta-car otene, lycopene, lutein, canthaxanthin and ol-tocopherol together with a st andard meal. The meal did not contain additional dietary fiber or was enric hed with pectin, guar, alginate, cellulose or wheat bran (0.15 g . kg body weight(-1)). The increases in plasma carotenoid and alpha-tocopherol concen trations were followed over 24 h, and the areas-under-curves (AUC(24h)) wer e calculated. The mean AUC(24h) of beta-carotene was significantly (P < 0.0 5) reduced by the water-soluble fibers pectin, guar and alginate with a mea n decrease of 33-43%. All tested fibers significantly reduced the AUC(24h) of lycopene and lutein by 40-74% (P < 0.05). The dietary fiber effect on th e AUC(24h) of canthaxanthin was almost significant (P = 0.059) and there wa s no effect on the AUC(24h) of alpha-tocopherol. We conclude that the bioav ailability of beta-carotene, lycopene and lutein given within a mixed suppl ement is markedly reduced by different kinds of dietary fiber.