People with low levels of B12 or folate may have a higher risk of developing Alzheimer’s disease, according to a study in the May 8 issue of Neurology, the scientific journal of the American Academy of Neurology.
The long-range Swedish study of persons 75-years-old and older found that more than half (46 out of 78) of those diagnosed with dementia had both low levels of vitamin B12 or folate and Alzheimer’s type dementia.
Study authors theorized that vitamin B12 or folate deficiencies affect Alzheimer’s disease by influencing neurotransmitters or the levels of the amino acid homocysteine in the body. Either vitamin B12 or folate deficiency can increase homocysteine levels. Homocysteine has a neurotoxic effect that could lead to cell death or neurological conditions such as Alzheimer’s disease.
“In our study, we found that low levels of either of these two vitamins were related to an increased Alzheimer’s disease risk,” said study co-author Hui-Xin Wang. “Monitoring B12 and folate levels is important in order to avoid unfavorable conditions, even for those elderly people who are quite healthy in terms of cognition.”
For more than thirty years, researchers have observed low vitamin B12 and folate levels in elderly people, according to Wang. It had also been previously theorized that this vitamin deficiency might be tied to neurological or psychiatric disorders. This study breaks new ground by connecting these deficiencies with Alzheimer’s disease.
Vitamins B12 and folate (a form of water-soluble vitamin B) are found in common foods. Vitamin B12 is naturally found in animal foods including fish, milk and milk products, eggs, meat, and poultry. Leafy greens such as spinach and turnip greens, dry beans and peas, fortified cereals and grain products, and some fruits and vegetables are rich food sources of folate.
Study data were pulled from a population-based longitudinal study in Sweden called the Kungsholmen Project. A random sample of 370 non-demented persons, age 75 and older, and not treated with B12 or folate dietary supplements, was followed for three years to detect cases of Alzheimer’s disease. Within the timeframe of the study, 78 people developed some form of dementia.