BETA-CAROTENE DECREASES MARKERS OF LIPID-PEROXIDATION IN HEALTHY-VOLUNTEERS

We previously showed that daily intake of beta-carotene, a nontoxic an tioxidant, reduces lipid peroxidation as assessed by serum lipid perox ide levels. An alternative method to detect lipid peroxidation is the measurement of pentane in breath. Pentane is a five-carbon hydrocarbon that is released when an omega-6 unsaturated fatty acid undergoes per oxidation. The aim of this study was to see whether graded doses of be ta-carotene would affect breath pentane excretion in normal subjects p laced on a carotenoid-free liquid diet for two weeks. The subjects wer e then repleted with either 15 (n = 7) or 120 mg (n = 8) of beta-carot ene daily for four weeks while continuing the same diet. Serum beta-ca rotene and breath pentane were measured before and after beta-carotene refeeding. Lipid peroxidation, as assessed by gas-chromatographic mea surement of breath pentane, was significantly (p < 0.05) reduced by da ily supplements of 120 mg beta-carotene (from 3.7 +/- 0.9 to 2.2 +/- 1 .4 nmol/l). However, the decline in pentane exhalation observed with t he 15-mg beta-carotene dose did not achieve statistical significance ( p = 0.13).