Diets Rich in B12 May Protect Against Alzheimer’s Disease


B vitamins have recently been associated with preventing brain shrinkage in elderly people that could lead to cognitive impairment and potential Alzheimer’s disease. A new preliminary study has seemed to confirm those findings, especially as it relates to vitamin B12, or cobalamin.

B12 from Balanced Diet More Important than Supplements

Vitamin B12 is required for proper neurological function, red blood cell formation and DNA synthesis. Previous studies have found that B12 deficiency, defined as a blood level below 170-250 picomol per ml, is common in the elderly.

Lead researcher Dr. Babak Hooshmand with the Aging Research Center at the Karolinska Institute in Sweden evaluated the homocysteine levels in the blood of 271 Finnish people between the ages of 65 and 79 who did not have dementia. Homocysteine was the focus of the study because high levels of this protein are associated with both memory loss and stroke, and the active component of vitamin B12 (holotranscobalamin) is thought to lower blood levels, thereby reducing risk.

Read: B Vitamins May Help Prevent Alzheimer's


During the 7-year study period, for each micromolar increase in homocysteine, the risk of Alzheimer’s rose by 16 percent. When vitamin B12 was studied individually, for each picomolar increase, the risk of Alzheimer’s dropped by 2 percent. Folate, another factor in homocysteine formation, was not found to be linked with Alzheimer’s risk.

The results remained constant even after researchers compensated for other factors such as age, sex, smoking status and weight.

Read: Nutrient Combination May Improve Memory

"Our results indicate that vitamin B12 and related metabolites may have a role in Alzheimer's disease,” said Dr. Hooshmand, “but more research is needed before we can get conclusions on the role of vitamin B12 supplements on neurodegenerative diseases such as Alzheimer's disease."

Rich sources of vitamin B12 include animal foods such as meat, poultry, fish, and eggs. B12 is not generally present in plant foods, however vegetarian soy products and ready-to-eat breakfast cereals may be fortified with the vitamin. Hooshmand stresses that a balanced diet, and not dietary supplements, is the best way to get the vitamin B12 needed for health benefits.

Source Reference:
"Homocysteine and holotranscobalamin and the risk of Alzheimer disease - A longitudinal study"
B. Hooshmand, MD, MSc, A. Solomon, MD, PhD, I. Kåreholt, PhD, J. Leiviskä, MSc, M. Rusanen, MD, S. Ahtiluoto, MD, B. Winblad, MD, PhD, T. Laatikainen, MD, PhD, H. Soininen, MD, PhD and M. Kivipelto, MD, PhD
NEUROLOGY 2010;75:1408-1414