In Vitro and In Vivo Lipoprotein Antioxidant Effect of a Citrus Extract and Ascorbic Acid on Normal and Hypercholesterolemic Human Subjects.

Polyphenols and particularly flavonoids are well known in vitro antioxidants. Their consumption in foods has been shown to decrease the risk of heart disease in epidemiological studies. Because flavonoids are consumed with vitamin C in the diet, the combination may prove to be more beneficial than either alone. The combination of citrus extract and vitamin C was found to produce a synergistic antioxidant effect in an in vitro lipoprotein oxidation model. In a double-blind, placebo-controlled study with 26 normal and hypercholesterolemic subjects, the citrus extract and vitamin C, but not vitamin C or vitamin E alone, significantly lowered triglycerides. The combination of citrus extract and vitamin C increased the lag time of lipoprotein oxidation, compared with vitamin C alone or a placebo, and was a significantly better antioxidant than vitamin E. These results and other published studies are highly suggestive of in vitro and in vivo antioxidant synergism between citrus extract and vitamin C.

RCT Entities:   Population Interventions Outcomes