A PILOT-STUDY OF ANTIOXIDANT INTAKE IN PATIENTS WITH CHOLESTEROL GALLSTONES

Whereas macronutrient intake has been extensively investigated in an a ttempt to unravel the pathogenesis of human cholesterol gallstones, th eoretical considerations and animal models suggest that deficits in mi cronutrient antioxidants may be more relevant. We report a pilot study of this aspect. The plan was to obtain 7-d weighed food inventories o ver a 6-mo period from equal numbers of patients who had not conscious ly changed their diets, patients who were on low-fat diets and age- an d gender-matched controls. Food tables would be used to derive daily i ntakes of 16 known antioxidants, essential amino acids, and essential fatty acids. Under-reporting of food intake, a recognized drawback of this dietary method, would be sought retrospectively by reference to a key publication giving minimum cut-off limits for ratios of energy in takes to basal metabolic rates. There were 18 pairs for study. Analysi s of data for the 9 pairs involving patients on their normal diets sho wed no differences in the intakes of energy, macronutrients, and chole sterol, but the patients ingested lower amounts of 10 among 16 antioxi dants (P < 0.05 for methionine, alpha-tocopherol, manganese, and vitam in D; 0.05 < P < 0.10 for cysteine, beta-carotene, vitamin C, selenium , zinc, and phosphorus). Both subsets of patients ingested lower amoun ts of linoleic acid (diet unchanged P = 0.009, changed P = 0.026) and several essential amino acids than did matched controls. Institution o f a low-fat diet caused the expected fall in intakes of energy and sat urated fatty acids such that the deficit in alpha-tocopherol was ampli fied, but substitution of fruit and vegetables by the patients resulte d in a fortuitous increase in vitamin C, beta-carotene, and manganese intake. Retrospective analysis confirmed under-reporting of food intak e by all four subsets of subjects but there was no significant differe nce in the mean ratio of energy intake to estimated basal metabolic ra te in the subset of patients who had not consciously altered their die ts and the subset of matched controls. Furthermore, the lower daily in take of alpha-tocopherol and linoleic acid by these patients persisted when results were expressed relative to total fat consumption. The re sults support the hypothesis that insufficiency of dietary antioxidant s, particularly alpha-tocopherol, may be germane to human gallstone di sease; they also suggest that low intakes of Linoleic acid and essenti al amino acids may be relevant. Because of the small sample sizes, how ever, these deductions should be regarded as tentative, pending confir mation by biochemical analysis of blood and especially of hepatic bile . (C) Elsevier Science Inc.