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Priority ranking of carcinogens in food
1190
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cancer (RK 1.57,95% CI 1.08-2.30) (Wurzelmann J.I. et al., Càncer Epidemiology, Biomarkers G Prevention 1996, 5, 503).
Calcium and colon cancer A Dutch study provides further support for the hypothesis that dietary calcium reduces the risk of colon cancer by precipitating soluble bile acids in the colon, thus reducing the amount of local cel1 damage induced by these cytotoxic compounds. In a doubleblind study, 13 healthy men were given milk products containing either low concentrations (3 mM) of normal levels (30 mM) of calcium for two l-wk periods (in place of their usual liquid milk products). Daily calcium intake was 765 mg and 1820 mg, respectively. The higher calcium intake resulted in significant increases in the faecal excretion of phosphate, total fat, free fatty acids and bile acids (indicating the formation of insoluble complexes in the intestine) and a marked reduction in the cytotoxicity of faecal water (Govers M.J.A.P. et al., Cancer Research 1996,56, 3270).
Eugenol - an in vivo genotoxin? In a 2-month feeding study in a transgenic mouse stram, eugenol at a daily dose of about 675 mg/kg body weight showed no convincing protective effect against benzo[a]pyrene-induced mutagenicity or against the formation of benzo[a]pyrene-DNA adducts. Furthermore, the TNO investigators detected one spot indicative of a eugenol-associated liver DNA adduct (to be the subject of a separate paper), and could not rule out the possibility that eugenol might be genotoxic in the mouse (Rompelberg C.J.M. et al., Mutation Research 1996, 369, 87).
Allergy to lactase supplements A 35-yr-old Canadian experienced burning and swelling of his throat with difficulty swallowing following his first ingestion of Lactaid tablets, a lactase supplement intended for the treatment of lactose intolerante. He gave positive reactions in skin prick tests with the Lactaid tablets, and to the enzyme (lactase from Aspergiflus oryzae) they contained. The cause of his sensitization was possibly a previous ingestion of a Lacteeze brand of milk, a milk that contains lactase from Saccharomycesfiagilis. He responded to this brand in skin prick tests (hut not to a Lactaid milk brand which contains lactase derived from Kluyveromyces hctis). The investigator claimed this to be the first report of allergie reaction to ingested Aspergihs-
derived lactase (Binkley K.E., journal ofA1krgy and Clinicaf Immunology 1996,97, 1414).
Paraquat and immunosuppression Paraquat has been claimed to exhibit a selective immunotoxic action on a class of white blood cel1 (T-lymphocytes). The effects were reported in rats treated for 8 months with 0.1 pg paraquat/kg body weight/day in their drinking water. Minimal microscopic changes were also seen in the brain (Caroleo M.C. et al., Toxic SubstanceMechanisms 1996, 15, 183).
Thiophanate-methyl genotoxic in human cells This fungicide was found to induce chromosome damage (aberrations and micronuclei) in human lymphocyte cultures (Hrelia P. et al., ATLA 1996, 24,597).
Priorlty ranking of carcinogens in food An approach to the prioritization of chemical carcinogens detected in food has been outlined by scientists from the UK Department of Heahh and the Food Safety Directorate of MAFF. An assessment of the carcinogenic hazard to man combined with estimations of intakes per person and the proportion of the population exposed are used to derive an index referred to as the Population Carcinogenic Index. The aim was to develop a consistent and objective scheme for classifying food chemicals in order to determine priorities for regulatory action (McDonald A.L. et al., Human and Experimental Toxicology 1996, 15,739).
Genotoxicity of 2,4-dichloro-6-aminophenol This metabolite of the herbicide 2,4_dichlor&nitrophenol ammonium induced chromosomal damage (aberrations) in Chinese hamster lung cells treated in culture (Heng 2X. et al., Teratogenesis, Carcinogenesis and Mutagenesis 1996, 16, 8 1).
lmmunosuppressive effects of chlorophenoxy herbicides Various immunological changes were detected in the blood of 10 farmers who mixed and applied two chlorophenoxy herbicides, 2,4-D and 4-chloro-2methylphenoxyacetic acid (MCPA), for a period of 1-3 days. The immunosuppressive effects were evident within 1-12 days, but had generally
Information Section
cancer (RK 1.57,95% CI 1.08-2.30) (Wurzelmann J.I. et al., Càncer Epidemiology, Biomarkers G Prevention 1996, 5, 503).
Calcium and colon cancer A Dutch study provides further support for the hypothesis that dietary calcium reduces the risk of colon cancer by precipitating soluble bile acids in the colon, thus reducing the amount of local cel1 damage induced by these cytotoxic compounds. In a doubleblind study, 13 healthy men were given milk products containing either low concentrations (3 mM) of normal levels (30 mM) of calcium for two l-wk periods (in place of their usual liquid milk products). Daily calcium intake was 765 mg and 1820 mg, respectively. The higher calcium intake resulted in significant increases in the faecal excretion of phosphate, total fat, free fatty acids and bile acids (indicating the formation of insoluble complexes in the intestine) and a marked reduction in the cytotoxicity of faecal water (Govers M.J.A.P. et al., Cancer Research 1996,56, 3270).
Eugenol - an in vivo genotoxin? In a 2-month feeding study in a transgenic mouse stram, eugenol at a daily dose of about 675 mg/kg body weight showed no convincing protective effect against benzo[a]pyrene-induced mutagenicity or against the formation of benzo[a]pyrene-DNA adducts. Furthermore, the TNO investigators detected one spot indicative of a eugenol-associated liver DNA adduct (to be the subject of a separate paper), and could not rule out the possibility that eugenol might be genotoxic in the mouse (Rompelberg C.J.M. et al., Mutation Research 1996, 369, 87).
Allergy to lactase supplements A 35-yr-old Canadian experienced burning and swelling of his throat with difficulty swallowing following his first ingestion of Lactaid tablets, a lactase supplement intended for the treatment of lactose intolerante. He gave positive reactions in skin prick tests with the Lactaid tablets, and to the enzyme (lactase from Aspergiflus oryzae) they contained. The cause of his sensitization was possibly a previous ingestion of a Lacteeze brand of milk, a milk that contains lactase from Saccharomycesfiagilis. He responded to this brand in skin prick tests (hut not to a Lactaid milk brand which contains lactase derived from Kluyveromyces hctis). The investigator claimed this to be the first report of allergie reaction to ingested Aspergihs-
derived lactase (Binkley K.E., journal ofA1krgy and Clinicaf Immunology 1996,97, 1414).
Paraquat and immunosuppression Paraquat has been claimed to exhibit a selective immunotoxic action on a class of white blood cel1 (T-lymphocytes). The effects were reported in rats treated for 8 months with 0.1 pg paraquat/kg body weight/day in their drinking water. Minimal microscopic changes were also seen in the brain (Caroleo M.C. et al., Toxic SubstanceMechanisms 1996, 15, 183).
Thiophanate-methyl genotoxic in human cells This fungicide was found to induce chromosome damage (aberrations and micronuclei) in human lymphocyte cultures (Hrelia P. et al., ATLA 1996, 24,597).
Priorlty ranking of carcinogens in food An approach to the prioritization of chemical carcinogens detected in food has been outlined by scientists from the UK Department of Heahh and the Food Safety Directorate of MAFF. An assessment of the carcinogenic hazard to man combined with estimations of intakes per person and the proportion of the population exposed are used to derive an index referred to as the Population Carcinogenic Index. The aim was to develop a consistent and objective scheme for classifying food chemicals in order to determine priorities for regulatory action (McDonald A.L. et al., Human and Experimental Toxicology 1996, 15,739).
Genotoxicity of 2,4-dichloro-6-aminophenol This metabolite of the herbicide 2,4_dichlor&nitrophenol ammonium induced chromosomal damage (aberrations) in Chinese hamster lung cells treated in culture (Heng 2X. et al., Teratogenesis, Carcinogenesis and Mutagenesis 1996, 16, 8 1).
lmmunosuppressive effects of chlorophenoxy herbicides Various immunological changes were detected in the blood of 10 farmers who mixed and applied two chlorophenoxy herbicides, 2,4-D and 4-chloro-2methylphenoxyacetic acid (MCPA), for a period of 1-3 days. The immunosuppressive effects were evident within 1-12 days, but had generally