Official estimates indicate that 55 million people worldwide have dementia, a number that is expected to rise as the world’s population ages. To find treatments that can slow or stop the disease, scientists need to better understand the factors that can cause dementia, according to Neuroscience News.
Researchers at Tufts University have completed the first study to examine vitamin D levels in brain tissue, specifically in adults who have experienced varying rates of cognitive decline.
“It was found that the older group with higher levels of vitamin D in their brains had better cognitive function,” said lead researcher Sarah Booth, director of the Jan Meyer Center for Human Nutrition Research, affiliated with the USDA.
Fish, milk and orange
Also, the study, which was published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, states that 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); A short exposure to sunlight also provides a dose of vitamin D.
“Many studies have implicated dietary factors in cognitive performance or function in older adults, including many studies on vitamin D, but all of them are based on dietary intake or specific blood measures,” said lead researcher Kayla Shea, professor of nutritional sciences at Tufts University. with vitamin D,” indicating that the team of researchers wanted to know “whether vitamin D is present in the brain, and how vitamin D concentrations relate to cognitive decline.”
Orange and its juice
Brain tissue samples
Booth, Chia, and their team examined brain tissue samples from 209 participants in the Rush Memory and Aging Research Project, a long-term study of Alzheimer’s disease that began in 1997.
The researchers in the Rush project assessed the cognitive function of the participants, older adults with no signs of cognitive impairment, as they got older, and analyzed the residues in brain tissue after death.
In the Tufts University study, the researchers focused on vitamin D levels in four regions of the brain, two of which are associated with changes related to Alzheimer’s disease, one associated with forms of dementia related to blood flow, and a fourth region that has no known association with cognitive decline associated with Alzheimer’s disease or any other disease. of vascular diseases.
The researchers found that vitamin D was already present in brain tissue, and that higher vitamin D levels in all four brain regions were associated with better cognitive function.
It was also shown that 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 the buildup of amyloid plaques, or evidence of chronic or microstroke strokes, meaning it remains unclear exactly how vitamin D can It affects brain functions.
“Dementia is multifactorial, and many of the underlying pathological mechanisms have not been well-characterised,” says Professor Xia. “It could be that vitamin D is associated with an outcome that has not yet been seen, but which the team of researchers plans to study in the future.”
Meanwhile, experts warn against using large doses of vitamin D supplements as a precaution, as the recommended dose of vitamin D is 600 IU for people between the ages of 1 and 70, and 800 IU for those who are older, as excess amounts are harmful. They can cause harm and possibly poison a person.