Folate Deficiency is associated with a Three-Fold Increased Risk of Dementia

Among elderly people, lower levels of folate can be associated with a three-fold increase in risk for dementia, claims a study published in the Journal of Neurology, Neurosurgery, and Psychiatry, part of the British Medical Journal Specialist Journals, on February 5, 2008.

Folate, vitamin B12, and the protein homocysteine are involved in reactions that are needed to produce several chemicals, including some neurotransmitters, lipids, and nucleotides. Previously, studies have shown a link between deficiencies in these chemicals and the prevalence of dementia, however, the results have been controversial because of the physical changes dementia often creates. High levels of homocysteine have also been associated with cardiovascular disease.

In this study, the researchers followed 518 people over 2 years (2001-2003), tracking the development of dementia within the population. All participants were more than 65 years old and lived in one rural or one urban area in the south of the country. To do this, at the beginning and the end of the two year period, validated tests were run to test for any dementing illness. Additionally, blood tests were taken to assess folate, vitamin B12

Similarly, blood tests were taken to assess levels of folate, vitamin B12, and homocysteine levels, and the changes with time were observed. At the beginning of the period, almost one in five participants showed high levels of homocysteine, almost the same had low levels of vitamin B12, and 3.5% were deficient in folate. Higher levels of folate were associated with higher vitamin B12 levels and lower homocysteine.

At the end of the study, 45 of the participants had developed dementia. Of these, 34 had been diagnosed with Alzheimer's disease, seven with vascular dementia, and four with "other" types of dementia. Dementia showed more prevalence in older patients, in the relatively uneducated, the inactive, and those with deposits of the protein ApoE.

Dementia onset was more likely in those who were older, relatively poorly educated, inactive, and had deposits of ApoE, a protein associated with the breakdown of lipids. It was also much more likely in those whose folate levels fell further over the two years while homocysteine levels increased. Individuals with folate deficiency at the start of the study were at risk for dementia almost 3.5 times more than others.

This suggests, according to the authors, that changes in micronutrients such as folate could be linked with the other typical signs that lead up to dementia, such as weight loss and low blood pressure. Weight loss could indicate a dietary change in quality or quantity of food intake, but it is unlikely to itself change the levels of micronutrients in the blood.

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