M Molin1, S M Ulven2, L Dahl3, A-K Lundebye3, M Holck4, J Alexander5, H M Meltzer5, T A Ydersbond6. 1. Oslo and Akershus University College of Applied Sciences, PO Box 4 St. Olavs Plass, N-0130 Oslo, Norway; Bjorknes University College, Lovisenberggata 13, N-0456 Oslo, Norway. Electronic address: marianne.molin@hioa.no. 2. Oslo and Akershus University College of Applied Sciences, PO Box 4 St. Olavs Plass, N-0130 Oslo, Norway; Department of Nutrition, Institute for Basic Medical Sciences, University of Oslo, PO Box 1046 Blindern, 0317 Oslo, Norway. 3. National Institute of Nutrition and Seafood Research, PO Box 2029 Nordnes, N-5817 Bergen, Norway. 4. Oslo and Akershus University College of Applied Sciences, PO Box 4 St. Olavs Plass, N-0130 Oslo, Norway. 5. Norwegian Institute of Public Health, PO Box 4404 Nydalen, N-0403 Oslo, Norway. 6. Statistics Norway, PO Box 8131 Dep, N-0033 Oslo, Norway.
Abstract
BACKGROUND: Exposure to exogenous elements like arsenic (As) may influence thyroid enzymes, thyroid-stimulating hormone (TSH), and the two principal thyroid hormones, free thyroxine (FT4) and free triiodothyronine (FT3), but little is known about how this is related to organic arsenicals, the main form in seafood. AIM: To investigate whether a high intake of dietary arsenic from seafood can impact thyroid function and thyroid hormones by examining possible associations with changes in TSH, FT4, FT3 and the FT4:FT3-ratio in plasma. METHODS:Thirty-eight healthy subjects were randomized into four groups. During a 14-day semi-controlled dietary study, the subjects ingested daily portions of either 150g cod, salmon, blue mussels or potato (control). Plasma concentrations of total As, FT3, FT4, TSH and selenium (Se), and urinary concentrations of iodine were monitored. RESULTS:Plasma concentrations of TSH increased significantly in all seafood groups. The change in plasma As, with different coefficients for each seafood group, was the dominant factor in the optimal multiple regression model for change in TSH (R2=0.47). Plasma Se and iodine were negative and positive factors, respectively. There were also indications of changes in FT4, FT3 and the FT4:FT3 ratio consistent with a net inhibiting effect of As on FT4 to FT3 conversion. CONCLUSION: Ingestion of seafood rich in various organic As species was strongly associated with an increase of the TSH concentrations in plasma. Change in TSH was positively associated with total plasma As, but varied with the type of seafood ingested. These findings indicate that organic dietary As, apparently depending on chemical form, may influence thyroid hormones and function.
RCT Entities:
BACKGROUND: Exposure to exogenous elements like arsenic (As) may influence thyroid enzymes, thyroid-stimulating hormone (TSH), and the two principal thyroid hormones, free thyroxine (FT4) and free triiodothyronine (FT3), but little is known about how this is related to organic arsenicals, the main form in seafood. AIM: To investigate whether a high intake of dietary arsenic from seafood can impact thyroid function and thyroid hormones by examining possible associations with changes in TSH, FT4, FT3 and the FT4:FT3-ratio in plasma. METHODS: Thirty-eight healthy subjects were randomized into four groups. During a 14-day semi-controlled dietary study, the subjects ingested daily portions of either 150g cod, salmon, blue mussels or potato (control). Plasma concentrations of total As, FT3, FT4, TSH and selenium (Se), and urinary concentrations of iodine were monitored. RESULTS: Plasma concentrations of TSH increased significantly in all seafood groups. The change in plasma As, with different coefficients for each seafood group, was the dominant factor in the optimal multiple regression model for change in TSH (R2=0.47). Plasma Se and iodine were negative and positive factors, respectively. There were also indications of changes in FT4, FT3 and the FT4:FT3 ratio consistent with a net inhibiting effect of As on FT4 to FT3 conversion. CONCLUSION: Ingestion of seafood rich in various organic As species was strongly associated with an increase of the TSH concentrations in plasma. Change in TSH was positively associated with total plasma As, but varied with the type of seafood ingested. These findings indicate that organic dietary As, apparently depending on chemical form, may influence thyroid hormones and function.
Authors: Khalid M Khan; Faruque Parvez; R Thomas Zoeller; Barbara A Hocevar; Lisa M Kamendulis; Diane Rohlman; Mahbubul Eunus; Joseph Graziano Journal: Sci Total Environ Date: 2019-04-29 Impact factor: 7.963