Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 12/10/1999
Publication Date: 3/15/2000
Citation: Hunt, J.R., Vanderpool, R.A. 2000. Copper absorption from a lactoovovegetarian diet [abstract]. The Federation of American Societies for Experimental Biology Journal. 14:A297. Interpretive Summary:
Technical Abstract: Vegetarian diets often contain more copper than omnivorous diets, but may be less bioavailable. Copper absorption from controlled lactoovovegetarian (V) and nonvegetarian (N) diets was investigated in 17 healthy adult women, 20 to 43 years of age. The women consumed weighed experimental V and N diets for 8 wk each in a randomized, cross-over design. They lived in their own homes, ate breakfast at the research center 5d/wk, and consumed the remainder of the diet elsewhere. The V and N diets provided, respectively, (analyzed) 1.45 and 0.94 mg copper, 8.7 and 10.5 mg zinc, and (calculated) 12 and 16% protein, 38 and 16 g dietary fiber, and 1584 and 518 mg phytic acid per 2200 kcal (energy and other constituents were adjusted for body size). Apparent copper absorption was determined after 4 wk on each diet by extrinsically labeling the entire 2-d cycle menu with 65CuCl2 stable isotope and measuring fecal excretion of isotope. The V diet treduced plasma copper, ceruloplasmin activity and zinc nearly as much (~3- 6%) as observed previously (~5-8%) with the same diets (Hunt et al., AJCN 67:421, 1998). But in contrast with that study, these changes were not statistically significant in the present study. The efficiency of copper absorption from the V diet was less (33%) than from the N diet (42%)(pooled SD 9%; p<0.01). However, because the V diet contained ~50% more copper, more copper was absorbed from the V (0.48 mg/d), than from the N diet (0.40 mg/d)(pooled SD 0.09 mg; p<0.05). Together with previous research, these results suggest that vegetarian diets reduce plasma copper slightly, but this reduction is not caused by reduced dietary copper absorption. Further work should investigate the effect of high dietary phytate on the endogenous fecal excretion of copper.