Zinc supplements have been suggested for treating MS since it was first defined as a disease in the 1880s. However, there is currently no clear evidence supporting zinc supplementation in MS.
There is some evidence that zinc may shorten the duration of the common cold. Although this evidence is not definitive, it is important because viral infections, like the common cold, may trigger MS attacks. Zinc is sometimes recommended due to its role in the polyunsaturated fatty acids pathway (see Diet and Fatty Acid Supplements page), but it is unclear whether supplements are required for this pathway to function normally.
Zinc has the potential to stimulate the immune system, activating T-cells and macrophages. Zinc supplements have also been shown to increase inflammation in EAE (an experimental animal model of MS), suggesting it may be harmful for people with MS. Furthermore, in a mouse model of lupus, another autoimmune disorder, one study found that decreasing zinc intake produced therapeutic results.
One report of a high incidence of MS in a zinc-related industry suggested a possible toxic effect of zinc. Additionally, high zinc intake may cause copper-deficiency myelopathy, a neurological disorder with symptoms similar to those of MS. The research concerning blood levels of zinc in people with MS has produced mixed results, with some suggesting too much zinc and others too little.
The effects of zinc supplements are not well understood. Due to possible harmful effects and the lack of proven therapeutic effect, it may be reasonable for those with MS to avoid zinc supplements. If supplements are taken, it is probably best to take low doses, such as 10 to 15mg or less daily.
References and Additional Reading
Bowling AC. Complementary and Alternative Medicine and Multiple Sclerosis. New York: Demos Medical Publishing, 2007.
Bowling AC, Stewart TS. Dietary Supplements and Multiple Sclerosis: A Health Professional’s Guide. New York: Demos Medical Publishing, 2004.
Jellin JM, Batz F, Hitchens K, et al. Natural Medicines Comprehensive Database. Stockton, CA: Therapeutic Research Faculty, 2009.
Ulbricht CE, Basch EM, eds. Natural Standard Herb and Supplement Reference: Evidence-Based Clinical Reviews. St. Louis: Elsevier-Mosby, 2005.