ABSTRACT
Higher intake of antioxidant-rich foods is clearly associated with health improvement and longevity in adulthood. Nevertheless, a major parameter that determines the final effect of natural antioxidants on the human body is their bioavailability. The antioxidant effect of several foods or beverages has been linked to the absorption and metabolism of its bioactive constituents; that is, a prerequisite for bioactivity is bioaccessibility and bioavailability. Recent research data suggest that the beneficial biological role of natural antioxidants is focused not only on their antioxidant scavenging activity but also on their involvement in multiple metabolic signaling pathways at the cellular level. Vitamin A absorption is increased in the elderly; thus, the recommendations of 800 mg and 1000 mg for women and men, respectively, adequately cover the needs of old age.
