Past research has associated antioxidants, namely vitamin E and selenium, with protection against dementia, but a study published in JAMA Neurology has called this association into question. The study found vitamin E and selenium may have no effect on dementia risk—at least in men. The research looked at data from the Prevention of Alzheimer’s Disease by Vitamin E and Selenium (PREADViSE) trial, a double-blind randomized clinical trial that was conducted from 2002 to 2009 and included 7,540 men without dementia, age 60 or older. Participants received one of four treatments: vitamin E (400 IU per day), selenium (200 µg per day), vitamin E plus selenium, or a placebo. After the trial ended, 3,786 of the men were followed for nearly six more years. Cognitive screening tests were used in both phases of the study to identify men needing further testing, and medical records were analyzed to confirm cases of dementia. Researchers found that 325 of 7,338 men (4.4%) developed dementia, and that neither of the supplements, nor the combination of both, was linked to reduced dementia risk.
While this study found that vitamin E and selenium didn’t affect dementia risk, it’s important to understand the study’s weaknesses. Since the study only included men, we don’t know if the findings would be the same in women. In addition, some participants who were identified through screening tests as needing further evaluation opted not to undergo additional testing, making it difficult to establish dementia cases accurately. The bottom line is that we still don’t know for sure how these nutrients affect dementia risk. If you have questions about supplements or other treatments for dementia, you should talk to your healthcare provider to find a regimen that makes sense for you.
Source: JAMA Neurology