What we eat can certainly have an impact on the way our brains function. Previously I have written about the importance of a healthy diet for brain function and also the links between the Mediterranean style diet and the brain.
In both of these posts I write about how important oily fish seem to be for the efficient functioning of the brain (mental function is often referred to as cognition). Previously I have concentrated on the fact that oily fish provide omega 3 fatty acids which are vital for the structure and function of the brain. However, oily fish also provides a dietary source of Vitamin D. This is important, since food sources of vitamin D are limited. Oily fish such as mackerel, salmon, sardines and trout are the primary food source. Egg yolks contain some vitamin D and some foods are fortified with this ‘sunshine’ vitamin. Our main source of vitamin D is the manufacture in the body via the exposure of our skin to sunlight. Recently, however, there has been a lot of concern that UV exposure in the UK may be insufficient to keep vitamin D levels high enough for optimal for health with many individuals in the UK are falling short of recommended levels. More can be read on the importance of vitamin D in previous blog posts.
A very recently published study (1) has found a link between vitamin D levels in the body and brain function (cognitive performance). Previous studies have found that an inadequacy in vitamin D could be linked to problems with brain function but so far results have been inconsistent. This study (1), which was conducted by University of Manchester scientists, was set up in order to examine the association between blood serum vitamin D levels and cognitive performance in middle-aged and older men. 3,133 Eurpoean men aged 40-79 years were included in the research. Cognitive (brain) function was tested via a number of different validated tests. Blood serum vitamin D levels were measured as was physical activity, functional performance and mood/depression.
Higher levels of vitamin D were significantly associated with better cognitive function as measured by one of the tests, the Digit Symbol Substitution test (DSST). This test is an internationally-recognised test that assesses an individual’s memory, recognition capabilities and speed of information processing. Reduced cognitive function was most pronounced in individuals with the lowest vitamin D levels. This research provides valuable information, however further research is warranted to determine whether health vitamin D levels, or vitamin D supplementation, can play a role in preserving cognitive function in older adults (1).
Although the study is only an association study it has some key strengths: it was based on a large population sample and took into account potential confounding influences, such as depression and levels of physical activity. Interestingly the association between increased vitamin D and faster information processing was more significant in men aged over 60 years, although the biological reasons for this remain unclear and requires further investigation.
The positive effects vitamin D appears to have on the brain need to be explored further but certainly raise questions about its potential benefit for those with or susceptible to dementia. Dr Susanna Sorensen, Head of Research at The Alzheimer’s Society made a comment (2) on the research via the charity website:
“One in three people over 65 will die with dementia making research into this area vital. This study, including over 3,000 men from a number of European locations, shows that maintaining vitamin D levels could play a role in reducing the decline of brain function.
However, further research is needed to determine whether or not vitamin D can help preserve brain function in older people or reduce risk of dementia. As vitamin D is readily available to most people, through exposure to sunshine or eating oily fish, it will be interesting to see the results of future studies.
In the meantime, current evidence tells us that a healthy lifestyle, including a balanced diet and exercise, is the best way of reducing your risk of dementia.”
Alzheimer’s Society is the UK’s leading care and research charity for people with dementia and those who care for them. There are 700,000 people with dementia in the UK with numbers set to rise to one million by 2025. Alzheimer’s Society is a membership organisation, which works to improve the quality of life of people affected by dementia in England, Wales and Northern Ireland. Please visit their website for more information. You may also like to read the two posts I mentioned at the start of this piece which are about brain function.
If you rarely get out into the sunlight you may wish to consider taking a vitamin D supplement which provides around 12mcg of the nutrient per day (around 500iu). Vitamin D supplements may be particularly useful during the autumn and winter months and for individuals who have darker skins or who don’t go outside regularly.
(1) Lee DM et al. 2009. Association between 25-hydroxyvitamin D levels and cognitive performance in middle-aged and older European men. J Neurol Neurosurg Psychiatry. Published Online First: 21 May 2009. doi:10.1136/jnnp.2008.165720
(2)Alzheimer’s Society comment on research into impact of vitamin D on brain performance
Published Wednesday 20th May 2009 in Research news http://www.alzheimers.org.uk/site/scripts/news_article.php?newsID=469
Written by Ani Kowal
Related posts:
- More evidence links vitamin D to brain function
- Can low vitamin B12 levels lead to brain shrinkage?
- Exercise found to protect and even improve the aging brain
- High vegetable and fruit intake may be linked to better brain function
- Feed your brain – Can what we eat have an impact on the function of the brain?
