Humans seem to produce arsenobetaine and dimethylarsinate after a bolus dose of seafood.

Seafood is the predominant food source of several organoarsenic compounds. Some seafood species, like crustaceans and seaweed, also contain inorganic arsenic (iAs), a well-known toxicant. It is unclear whether human biotransformation of ingested organoarsenicals from seafood result in formation of arsenicals of health concern. The present controlled dietary study examined the urinary excretion of arsenic compounds (total arsenic (tAs), iAs, AB (arsenobetaine), dimethylarsinate (DMA) and methylarsonate (MA)) following ingestion of a single test meal of seafood (cod, 780 µg tAs, farmed salmon, 290 µg tAs or blue mussel, 690 µg tAs or potato (control, 110 µg tAs)) in 38 volunteers. The amount of ingested tAs excreted via the urine within 0-72 h varied significantly among the groups: Cod, 74% (52-92%), salmon 56% (46-82%), blue mussel 49% (37-78%), control 45% (30-60%). The estimated total urinary excretion of AB was higher than the amount of ingested AB in the blue mussel group (112%) and also ingestion of cod seemed to result in more AB, indicating possible endogenous formation of AB from other organoarsenicals. Excretion of iAs was lower than ingested (13-22% of the ingested iAs was excreted in the different groups). Although the ingested amount of iAs+DMA+MA was low for all seafood groups (1.2-4.5% of tAs ingested), the urinary DMA excretion was high in the blue mussel and salmon groups, counting for 25% and 11% of the excreted tAs respectively. In conclusion our data indicate a possible formation of AB as a result of biotransformation of other organic arsenicals. The considerable amount of DMA excreted is probably not only due to methylation of ingested iAs, but due to biotransformation of organoarsenicals making it an inappropriate biomarker of iAs exposure in populations with a high seafood intake.

Effect on plasma lipids and lipoproteins of replacing partially hydrogenated fish oil with vegetable fat in margarine.

We have compared the effects on lipoproteins and haemostatic variables of two hard margarines with similar functional properties, one traditional margarine containing partially hydrogenated fish oil (PHFO), and one experimental margarine based on vegetable oil (VO). Both were all-purpose cooking margarines with nearly identical functional properties. Trans fatty acids from PHFO in the traditional margarine were replaced mostly by saturated, monounsaturated and trans fatty acids of vegetable origin in the new formulation. Both test margarines contained approximately the same amount of cis polyunsaturated fatty acids. Sixteen female normolipidaemic students consumed each diet with the two test margarines for 14 d in random order (crossover design). The amount of fat was 31% energy in the PHFO diet and 32% energy in the VO diet. The test margarines provided approximately 26% energy in both diets. In the PHFO diet 7.8% of the energy was derived from trans fatty acids and 9.2% from saturated fatty acids (12:0, 14:0 and 16:0) while in the VO diet, 1.1% energy was derived from trans fatty acids and 13.3% from saturated fatty acids (12:0, 14:0 and 16:0). The natural content of cholesterol in PHFO was deliberately not balanced by addition of cholesterol to the VO diet, thus the PHFO diet contained 215 mg and the VO diet 86 mg cholesterol per 8.5 MJ. LDL-cholesterol concentration was 19% higher in subjects on the PHFO diet compared with the VO diet (P < 0.01). The ratio LDL-cholesterol:HDL-cholesterol was 12.6% higher in subjects on the PHFO diet compared with the VO diet (P < 0.01). The level of apolipoprotein (apo)A-I was 6% lower in subjects on the PHFO diet compared with the VO diet (P < 0.01). The ratio apoB:apoA-I was 10.4% higher in subjects on the PHFO diet than on the VO diet (P < 0.01). There were no significant differences in total cholesterol, HDL-cholesterol, triacylglycerols, apoB, lipoprotein(a) and haemostatic variables between the diets. Our results demonstrate that PHFO, with its unfavourable effects on plasma lipids, can be replaced by vegetable oils in margarine without appreciable loss of functional properties but with significant improvement in the effects on plasma lipoproteins.