Study under review: Effects of vitamin D supplementation on cognitive function and blood Aβ-related biomarkers in older adults with Alzheimer's disease: a randomised, double-blind, placebo-controlled trial.
Dementia defines a broad range of neurological diseases that are characterized by cognitive dysfunction, including memory loss. It impacts about 14% of individuals over the age of 71 and about 38% of people over the age of 90. Alzheimer’s disease is the leading form of dementia, with more than half of all cases of dementia being attributed to Alzheimer’s.
As shown in Figure 1, one of the hallmark features of Alzheimer’s is the accumulation of amyloid plaques in the brain, mostly composed of a protein known as amyloid beta (Aβ). The Aβ protein is believed to play a role in the progression of the disease through oxidative stress, inflammation, and neurotoxicity.
There is some evidence in cell culture and animal models that vitamin D may help clear these Aβ peptide-based plaques from the brain, and therefore slow or reduce disease progression. Additionally, a recent Mendelian randomization study found that genetic variations in vitamin D may play a causal role in the development of Alzheimer’s disease in humans. As such, vitamin D supplementation may be a potential therapeutic intervention for Alzheimer’s. The present study was a randomized, double-blind, controlled trial that tested the efficacy of vitamin D on improving cognitive function and reducing Aβ peptide levels in people with Alzheimer’s disease.
Cognitive diseases impact about 14% of all people over the age of 71. Currently, Alzheimer’s is responsible for more than half of all cognitive disease in elderly people. The Aβ peptide is one of the hallmark features of Alzheimer’s and contributes to disease progression. Vitamin D has been shown to lower the burden of Aβ peptide-based plaques in cell culture and animal models. The present study was a randomized, double-blind, controlled trial that tested the efficacy of vitamin D on improving cognitive function and markers of Aβ peptide accumulation.
Other Articles in Issue #60 (October 2019)
Mini: Is vitamin D supplementation useful for pregnant women?
We've previously covered evidence suggesting that pregnant women supplementing with vitamin D have a lower risk of giving birth to babies with low birthweight. This Cochrane review suggests vitamin D may have other benefits as well.
Can vitamin D impact mortality?
This meta-analysis suggests that if it does, the effect size on all-cause mortality is pretty darn small. However, supplementation may reduce the risk of dying from cancer.
The surprisingly satiating effects of fasted cardio
Skipping breakfast before morning cardio cuts out some calories early in the day, but are those calories just consumed later on?
Does plate size matter?
Previous research looking at whether shrinking one's plate actually shrinks one's food intake has been equivocal. This well-designed study sheds some stronger light on the issue.
Supplementing spirulina for metabolic maladies
This meta-analysis synthesizes the latest evidence concerning spirulina's ability to make a dent in the metabolic syndrome.
Red flags in study design cast doubt on soy supplementation study results
Want to know some reasons why we don't usually cover studies looking at proprietary supplement blends? Then read on.
Interview: Suzanne Robotti, Founder of MedShadow
In this interview we chat with the founder of MedShadow, a nonprofit whose mission is to provide the information needed to weigh the risks and benefits of healthcare treatments.