Duke-NUS Medical School (Duke-NUS) and Duke University scientists have found that vitamin D levels give an indication of risk of brain decline in Chinese elderly. Low levels correlate with an increased chance of cognitive decline and impairment.
Produced naturally in the skin when exposed to sunlight, as well as found in food such as fish oils and eggs, vitamin D helps maintain healthy bones and muscles. Research has shown that it also plays a key part in brain function. Low levels of the organic compound are associated with greater risk of cardiovascular and neurodegenerative diseases, while Western studies linked low levels with future cognitive decline.
This recent work is the first large-scale prospective study in Asia to uncover the association between vitamin D status and risk of brain function in the Chinese elderly. The 1,202 participants of 60 years or older from the Chinese Longitudinal Health Longevity Survey had their baseline vitamin D levels measured at the start of the study, and their cognitive abilities assessed over two years. Regardless of gender and age, subjects with lower vitamin D levels at the start of the research were approximately twice as likely to demonstrate significant cognitive decline over time. Furthermore, low vitamin D levels at baseline also raised the danger of future cognitive impairment by up to threefold.
“Although this study was conducted on subjects from China, the results are applicable to regions in Asia where a large proportion of the elderly are ethnically Chinese, like Singapore,” said Professor David Matchar, first author of the study and Director of the Health Services and Systems Research Programme at Duke-NUS. The Singapore team designed and performed the analysis, as well as contributed to the survey instruments.
These findings verify the hypothesis that vitamin D has a protective role against neurone damage and loss. The knowledge provides the fundamentals for more focused investigations into the effects of vitamin D supplements on cognitive decline, whereby understanding of the protective mechanism may help identify effective interventions to stem the growing prevalence of cognitive decline in ageing populations.
Published on 12 July 2016 in The Journals of Gerontology, Series A: Medical Sciences, this project is supported by the National Research Foundation Singapore under its Singapore Translational Research Investigator Award.
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