Recent observational and clinical studies have raised interest in the
potential health effects of cranberry consumption, an association that
appearsto be due to the phytochemical content of this fruit. The profile of
cranberry bioactives is distinct from that of other berry fruit, being
rich in A-type proanthocyanidins (PACs) in contrast to the B-type PACs present
in most other fruit. Basic research has suggested a number of potential
mechanisms of action of cranberry bioactives, although further molecular
studies are necessary. Human studies on the health effects of cranberry
products have focused principally on urinary tract and cardiovascular
health, with some attention also directed to oral health and
gastrointestinal epithelia. Evidence suggesting that cranberries may decrease the
recurrence of urinary tract infections is important because a nutritional
approach to this condition could lower the use of antibiotic treatment
and the consequent development of resistance to these drugs. There is
encouraging, but limited, evidence of a cardioprotective effect of
cranberries mediated via actions on antioxidant capacity and lipoprotein
profiles. The mixed outcomes from clinical studies with cranberry
products could result from interventions testing a variety of products,
often uncharacterized in their composition of bioactives, using different
doses and regimens, as well as the absence of a biomarker for compliance
to the protocol. Daily consumption of a variety of fruit is necessary to
achieve a healthy dietary pattern, meet recommendations for micronutrient
intake, and promote the intake of a diversity of phytochemicals. Berry
fruit, including cranberries, represent a rich source of phenolic bioactives
that may contribute to human health.