Subj: Re: [healthfraud] MSM/Sulfur Date: 11/5/2001 2:08:25 PM Eastern Standard Time From: <A HREF="mailto:[email protected]";>[email protected]</A> To: <A HREF="mailto:[email protected]";>[email protected]</A> Sent from the Internet (Details)
Thomas J. Wheeler, Ph.D. [email protected] Associate Professor of Biochemistry & Molecular Biology University of Louisville School of Medicine Alternative medicine reading list: http://www.louisville.edu/medschool/biochemistry/grad/alternative_med/Syllabus .htm NEW! Weekly updates Oct.-Dec. 2001 >>> Licia Kuenning <[email protected]> 10/29/01 08:12PM >>> Thomas Wheeler writes, > the claim that MSM can be a dietary source of sulfur, which I > believe is false. I'm curious as to why MSM (in those who can tolerate it, which I can't) wouldn't be a source of sulfur. Or is there a distinction I'm unfamiliar with between "dietary source" and "source"? >>>>>>>>>>>>>>>>>>>>>> Just because something contains sulfur doesn't mean that it can be converted to something the body can use (or, even if it can, whether the body needs it). In the case of MSM, there appears to be little or no capacity for the body to take it up and metabolize it to a useful form. Here is the relevant section from the Quackwatch article http://www.quackwatch.com/01QuackeryRelatedTopics/DSH/msm.html "The claim that MSM is an important source of dietary sulfur is unsupported by published research. One study that involved feeding MSM to guinea pigs found that the sulfur from MSM was absorbed rapidly into the blood stream and was incorporated into methionine and cysteine of serum proteins. However, most of the sulfur appeared in the urine; less than 1% was incorporated into serum proteins. Increasing the dosage of MSM 100-fold increased the incorporation into serum proteins only 3-fold, indicating that the capacity to use MSM in this pathway is limited [12]. Thus, while MSM is naturally present in small amounts in a variety of foods, its contribution to sulfur metabolism in humans is likely to be negligible." The important dietary sources of sulfur are the amino acids cysteine and methionine. Inorganic sulfate (the precursor of various sulfated molecules) is formed from cysteine oxidation, so there appears to be no need to obtain additional sulfate in the diet. There is also sulfur in the vitamins biotin and pantothenic acid, but since these are required as vitamins and not synthesized in the body we need no additional sulfur for them. Again referring to the Quackwatch article, "Although sulfur is considered to be an essential mineral, no dietary requirement for inorganic sulfur has been found and no Recommended Dietary Allowance or Estimated Safe and Adequate Daily Dietary Intake has been established for it. In fact, the 10th edition of Recommended Dietary Allowances does not discuss it."
