Methylsulfonylmethane, also called vitamin U, is a metabolite from the well-known solvent that also has anti-inflammatory and analgesic properties, dimethylsulfoxide (DMSO). The theory of the use of MSM is that it is able to supply the body with sulfur, which is involved in a number of metabolic pathways, notably those involved in skin, hair, nail, tendon, and cartilage health. When MSM is used as a dietary supplement, it is thought to improve arthritis and joint health and pain because it is supplying much-needed sulfur in connective tissues. Increases in serum sulfur have been attributed to some of the therapeutic effects of MSM as well as DMSO and glucosamine sulfate (Gessler et al., 1991; Parcell, 2002; Robb-Nicholson, 2002).
Other dietary sources of sulfur are usually high in protein, because sulfur is a component of protein. Good sources include eggs, meat, and fish, as well as sulfur-containing amino acids, such as methionine and cysteine (Parcell, 2002).
Although MSM is widely used for joint health, most often in combination with glucosamine sulfate, glucosamine hydrochloride, and/or chondroitin sulfate, little clinical support exists for its efficacy. For people who suspect they are low in sulfur, consuming more foods containing sulfur may be as effective, and certainly cheaper.
An investigational study was conducted on common mechanisms of action of aspirin and MSM in cancer prevention. To investigate this, the inhibition of cyclooxygenase (COX) and prostaglandin production was examined under differential ion-inducing conditions in mouse eryihro leukemia cells. Both MSM and aspirin were found to induce differentiation by a COX-independent mechanism, and the authors suggested that another mechanism common to both agents may activate gene functions leading to differentiation (Ebisuzaki, 2003).
Seasonal Allergic Rhinitis
A clinical study was conducted to investigate whether MSM could help in the treatment of seasonal allergic rhinitis. The main outcome parameters tested were symptoms associated with seasonal allergic rhinitis (such as respiratory symptoms and energy levels) tested by a questionnaire and by inflammatory reactions measured by plasma C-reactive protein, and histamine. Additionally, the study investigated possible adverse reactions and tried to discover MSM's mechanism of action. The 55 participants were given 2,600 mg of MSM daily for 30 days. The stud; found that by day 7, upper respiratory symptoms were significantly improved from baseline; by day 14, energy levels were increased significantly; and by day 21, lower respiratory symptoms were significant!
All improvements were sustained until the end of the study. The authors concluded that the results of the study suggest that MSM may be helpful for improving seasonal allergic rhinitis symptoms but that a larger well-designed study is needed to determine its use. MSM was found to be very safe, and few side effects were found with supplementation (Barrager et al., 2002).
MSM is typically used in the range of 2-5 g/day for the beginning or loading dose and 50-200 mg/day for maintenance. MSM is considered safe for use as a dietary supplement, and studies in animals have found that toxicity only occurs in extremely high doses (Horvath et al., 2002).