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Bioavailability and Kinetics of Sulforaphane in Humans after Consumption of Cooked versus Raw Broccoli Martijn Vermeulen*, Ineke W. A. A. Klpping-Ketelaars†, Robin van den Berg‡ and Wouter H. J. Vaes J. Agric. Food Chem., 2008, 56 (22), pp 10505-10509 Publication Date (Web): October 24, 2008 (Article) DOI: 10.1021/jf801989e

(NaturalNews) Levels of the beneficial, cancer-fighting compound sulforaphane in broccoli are reduced by 90 percent when the vegetable is cooked, according to a study conducted by researchers from TNO Quality of Life in the Netherlands, and published in the Journal of Agricultural and Food Chemistry. "Consumption of raw broccoli resulted in faster absorption, higher bioavailability, and higher peak plasma amounts of sulforaphane, compared to cooked broccoli," the researchers wrote.

Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7.\nSchurgers LJ, Teunissen KJ, Hamulyák K, Knapen MH, Vik H, Vermeer C.\nBlood. 2007 Apr 15;109(8):3279-83. Epub 2006 Dec 7.\nPMID: 17158229 \nDOI 10.1182/blood-2006-08-040709\n

A popular vitamin supplement is being advertised with claims that are demonstrably untrue, as revealed by research published in the open access journal BMC Pharmacology. Benfotiamine is a synthetic derivative of thiamine (vitamin B1). It is marketed heavily as a dietary supplement using a selection of unsubstantiated, 'not-quite-medical' claims that tend to characterize this field. A large part of this campaign has been built around the belief that benfotiamine is lipid-soluble and, therefore, more physiologically active. Scientific research led by Dr Lucien Bettendorff of the Center for Cellular and Molecular Neurobiology at the University of Liège, Belgium, has entirely disproved these claims.

Benfotiamine, a synthetic S-acyl thiamine derivative, has different mechanisms of action and a different pharmacological profile than lipid-soluble thiamine disulfide derivatives. Volvert ML, Seyen S, Piette M, Evrard B, Gangolf M, Plumier JC, Bettendorff L. BMC Pharmacol. 2008 Jun 12;8:10. PMID: 18549472 doi:10.1186/1471-2210-8-10 Conclusion Our results show that, though benfotiamine strongly increases thiamine levels in blood and liver, it has no significant effect in the brain. This would explain why beneficial effects of benfotiamine have only been observed in peripheral tissues, while sulbutiamine, a lipid-soluble thiamine disulfide derivative, that increases thiamine derivatives in the brain as well as in cultured cells, acts as a central nervous system drug. We propose that benfotiamine only penetrates the cells after dephosphorylation by intestinal alkaline phosphatases. It then enters the bloodstream as S-benzoylthiamine that is converted to thiamine in erythrocytes and in the liver. Benfotiamine, an S-acyl derivative practically insoluble in organic solvents, should therefore be differentiated from truly lipid-soluble thiamine disulfide derivatives (allithiamine and the synthetic sulbutiamine and fursultiamine) with a different mechanism of absorption and different pharmacological properties.