Articles related to COGNITIVE HEALTH/MEMORY

The presence of vitamin D in the brain and its link to improved cognitive performance in aged subjects was originally discovered by a Tufts University study. Higher vitamin D concentrations were linked to a 25% to 33% decreased risk of dementia or mild cognitive impairment in four different brain areas. Authors did note, however, that the observational nature of the study and the lack of a diverse subject population were two of its drawbacks, and there may be further explanations for the results.

Lecanemab is a humanized IgG1 monoclonal antibody that binds to some forms of amyloid. In this study approximately 1,800 participants age 50-90 with dementia and imaging evidence of amyloid deposits were randomized to biweekly IV lecanemab or placebo. After 18 months, the lecanemab group showed reductions in brain amyloid and moderately less decline on measures of cognition and function.

Prior research showed that higher flavonol consumption was associated with lower Alzheimer’s risk. This longitudinal study demonstrated that increased flavonol consumption yielded slower declines in global cognition and in episodic, semantic, and working memory, independent of other health and lifestyle factors.

Gantenerumab treatment generated a slowing of clinical decline from baseline score on the Clinical Dementia Rating-Sum of Boxes (CDR-SB), but at levels that did not reach statistical significance. The relative reduction in clinical decline was 8% in GRADUATE I and 6% in GRADUATE II compared with placebo.

The findings of this study are similar to results from in small human post-mortem study and could provide a pathological explanation for the subjective complaint of long-COVID “brain fog.” Using a mouse model to explore how mild respiratory infections with COVID could lead to neuroinflammation and subsequent brain damage, investigators found signs of central neuroinflammation after clearance of the virus. There is an accompanying case presentation.

At the time of this study, in 2016, dementia was seen in 10% of those over age 65 in the US, and mild cognitive impairment (MCI) in 20%, with increased risk for every 5 year advance in age. Risk was 80% higher for non-Hispanic Black individuals and approximately 40% higher in Hispanic persons, compared with White individuals. Dementia and MCI were inversely correlated with years of education, though.