The brains of people with cognitive decline do better with higher levels of vitamin D, research shows.
The study appears in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
“This research reinforces the importance of studying how foods and nutrients build resilience to protect the aging brain against diseases such as Alzheimer’s disease and other related dementias,” says senior and corresponding author Sarah Booth. , director of the Jean Mayer USDA Center for Human Nutrition Research. Aging (HNRCA) at Tufts and Principal Scientist of HNRCA’s Vitamin K Team.
Vitamin D supports many functions in the body, including immune responses and maintaining bone health. Food sources include fatty fish and fortified beverages (such as milk or orange juice); brief sun exposure also provides a dose of vitamin D.
“Many studies have implicated dietary or nutritional factors in performance or cognitive function in older adults, including many vitamin D studies, but all are based on dietary intakes or blood measurements of vitamin D” , says lead author Kyla Shea, a scientist on the Vitamin K team and associate professor at the Friedman School of Nutrition Science and Policy at Tufts. “We wanted to know if vitamin D is even present in the brain, and if so, how these concentrations relate to cognitive decline.”
Booth, Shea and their team examined brain tissue samples from 209 participants in the Rush Memory and Aging Project, a long-term study of Alzheimer’s disease that began in 1997. Rush University researchers assessed the participants’ cognitive function, older people with no signs of cognitive impairment, as they aged, and analyzed irregularities in their brain tissue after death.
In the study, the researchers looked for vitamin D in four regions of the brain: two associated with changes linked to Alzheimer’s disease, one associated with blood circulation-related forms of dementia, and one region with no known association. with cognitive decline linked to Alzheimer’s disease. or vascular disease. They found that vitamin D was indeed present in brain tissue and that high levels of vitamin D in all four brain regions were correlated with better cognitive function.
However, vitamin D levels in the brain were not associated with any of the physiological markers associated with Alzheimer’s disease in the brain studied, including amyloid plaque accumulation, Lewy body disease, or evidence of Alzheimer’s disease. chronic or microscopic cerebrovascular accidents. This means that it is still unclear exactly how vitamin D might affect brain function.
“Dementia is multifactorial, and many disease mechanisms underlying it have not been well characterized,” Shea says. “Vitamin D may be linked to outcomes that we have not yet examined, but plan to investigate in the future.”
Vitamin D is also known to vary between racial and ethnic populations, and most participants in the original Rush cohort were white. The researchers plan follow-up studies using a more diverse group of subjects to examine other brain changes associated with cognitive decline. They hope their work will lead to a better understanding of the role that vitamin D can play in the fight against dementia.
However, experts warn people not to use high doses of vitamin D supplements as a preventive measure. The recommended dose of vitamin D is 600 IU for people aged 1 to 70 and 800 IU for older people – excessive amounts can cause harm and have been linked to the risk of falling.
“We now know that vitamin D is present in reasonable amounts in the human brain, and it appears to be correlated with less decline in cognitive function,” Shea says. “But we need to do more research to identify the neuropathology to which vitamin D is linked in the brain before we start designing future interventions.”
Support for the work came from the National Institute on Aging of the National Institutes of Health, as well as the Agricultural Research Service of the United States Department of Agriculture. Full information on authors, funders and conflicts of interest is available in the published article. The content is the sole responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the US Department of Agriculture.
Source: Tufts University
Original study DOI: 10.1002/alz.12836
This article is republished from Futurity under the Attribution 4.0 International License. Read the original article.
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