Urinary mutagenicity in vegetarians and people on a mixed-western diet

This investigation was undertaken to determine whether the consumption of an ovolacto-vegetarian diet and a mixed-western diet by a group of 31 and 32 persons respectively resulted in the excretion of different levels of mutagens in the urine of these two dietary groups. All subjects were male participants of the "Deutschlandlauf 1987" and consumed strictly controlled diets with limited energy supply and a defined protein/fat/carbohydrates relation. 24-h Urines were collected before the start of the race, mutagens were extracted by a combination of the XAD-2 method of Yamasaki and Ames (53) and the blue-cotton method of Hayatsu et al. (20), and aliquots were assayed for mutagenicity with Salmonella typhimurium strains TA 98 and TA 1538 in the presence of an activating system (S 9-mix). Urinary mutagenicity was significant but at considerable variance in 26 (13) vegetarians and non-vegetarians as estimated with strain TA 1538 (TA98). No statistically significant difference could be detected between the vegetarian and the mixed-western dietary groups in any urinary mutagenicity parameter given below. In detail the following mean values were obtained: 2.46 +/- 1.87 his+ revertants/ml urine, 3,333 +/- 1,835 revertants in 24-h urines, and 5.01 +/- 3.1 revertants/mg creatinine for vegetarians and 3.13 +/- 2.18 his+ revertants/ml urine, 4,611 +/- 5,913 revertants in 24-h urine, and 8.98 +/- 20.17 revertants/ml creatinine for non-vegetarians with S. typhimurium TA 98 and 3.75 +/- 2.88 his+ revertants/ml urine, 6,094 +/- 7,885 revertants in 24-h urine, and 10.88 +/- 21.14 revertants/mg creatinine for vegetarians and 4.17 +/- 2.71 his+ revertants/ml urine, 5,705 +/- 4,421 revertants in 24-h urines, and 6.97 +/- 9.29 revertants/mg creatinine for non-vegetarians with strain 1538. Considerable individual variation in levels of urinary mutagenicity in spite of consumption of identical, controlled diets may at least in part depend on inherent differences of absorption, metabolism, and excretion patterns of mutagens by individuals, preventing collective comparisons of the extent of exposure to dietary mutagens.