Causes of Parkinson’s disease remain unknown however a relationship between genetics and environmental elements has long been suspected. One such environmental aspect has been that many people with Parkinson’s exhibit low levels of iron in their blood compared to normal controls. In addition, higher iron levels are found in their brains… The value of these findings makes it difficult to interpret if there is a causal relationship between blood levels of iron and accumulations of iron in the brain. Can iron be identified as a possible environmental risk that can be modified to possibly prevent the development of Parkinson’s?
A group of international researchers performed an analysis of studies that had been done previously. They employed a novel epidemiological study design, mendelian randomization, which uses genotype-disease associations. They analyzed results of studies that included 22,000 people from Europe and Australia for the genetic effect on iron levels and then analyzed studies of the genetic effect on the risk of Parkinson’s disease that included 20,809 people with Parkinson’s and 88,892 controls from Europe and the United States. They then performed more analyses based on three polymorphism in two genes to determine the effect of iron on Parkinson’s.
They found that high levels of iron in the blood are likely to be protective against developing Parkinson’s although it is not clearly understood how that happens. Also, accumulations of iron in the brain may be the result of genetic abnormalities. They stress that there may be other factors involved that might influence this analysis. While higher levels of iron in the blood may confer some protection, it is not necessary to begin taking iron supplements until it is understood why iron accumulates in Parkinson’s brains.
This is an important first study for researchers working on the prevention of Parkinson’s. Further studies on the mechanism of action will also be necessary before any recommendations for specific treatments can be made.
Citation: Pichler I, Del Greco M. F, Gögele M, Lill CM, Bertram L, et al. (2013) Serum Iron Levels and the Risk of Parkinson Disease: A Mendelian Randomization Study. PLoS Med 10(6): e1001462. doi:10.1371/journal.pmed.1001462