Multivitamins increase the risk of Alzheimer’s Disease.
There is no definitive proof that multivitamins increase the risk of Alzheimer’s Disease.
Online interest in the relationship between multivitamins and Alzheimer’s Disease was sparked by a paper published in 2009 by Dr George Brewer from University of Chicago (1). Dr Brewer believes that copper (in unfiltered water and multivitamins) plays a key role in the development of Alzheimer’s Disease.
There are no randomised controlled trials or clinical studies to definitively establish a relationship between copper containing multivitamins and Alzheimer’s Disease. Dr Brewer has developed a hypothesis connecting Alzheimer’s Disease and copper and he has then supported the hypothesis with relevant studies where he can.
Dr Brewer believes that demographic data supports his hypothesis that Alzheimer’s is a disease of the twentieth century in the developed world (2). Not everyone agrees with Dr Brewer on this point and this issue has been debated over and back in the medical literature (3, 4). Disbelievers say that Alzheimer’s Disease is a disease of ageing and that life-expectancy increased in the twentieth century which explains the apparent increase in Alzheimer’s Disease. Dr Brewer disagrees.
Dr Brewer is convinced that a new environmental toxin/toxins must have emerged in the twentieth century to cause this increase in Alzheimer’s Disease. Dr Brewer has noticed a correlation between the timing of the introduction of copper plumbing and the increase in Alzheimer’s Disease (5). He also is convinced that the amount of copper that leaching from piping is enough to cause Alzheimer’s Disease (5).
Dr Brewer further develops his hypothesis quoting animal studies that showed that copper ingestion from drinking water in Alzheimer Disease animal models greatly enhanced the Alzheimer’s like disease in rabbits (6). Additionally, humans studies showed that individuals with free copper levels higher than 1.6 μmol/L (the upper value of the normal reference range) were more frequent among people with Alzheimer’s Disease as compared to matched controls (p < 0.001) (7).
Dr Brewer advocates dietary modification, avoidance of copper containing multivitamins and filtering water to reduce intake of copper in order to avoid Alzheimer’s Disease (8).
Two small clinical studies looked at the effects of copper supplementation on cognitive function and cerebrospinal fluid in patients with Alzheimer’s Disease (9, 10). The authors of this study believed that dysregulation of copper metabolism rather than copper toxicity may relate to Alzheimer’s Disease. Copper supplementation had no impact on cognitive function but was associated with a significant decrease in Abeta42 which is a marker for Alzheimer’s Disease. This is completely at odds with the Brewer model.
In summary, there is no scientific evidence to support the claim that multivitamins cause Alzheimer’s Disease. Dr Brewer’s hypothesis is biologically plausible but unproven theoretical model.