MONDAY, Oct. 18, 2010 (HealthDay News) -- People who eat a diet rich in vitamin B12 may be protecting themselves from Alzheimer's disease, a small, preliminary study suggests.
The findings add to the debate about whether vitamins can reduce the risk of developing Alzheimer's disease. While this new study appears to support the role of vitamins, other studies have yielded mixed results, the researchers said.
"Previous studies have reported that vitamin B12 deficiency is a common condition in the elderly," said lead researcher Dr. Babak Hooshmand, a research assistant with the Aging Research Center at the Karolinska Institute in Stockholm, Sweden.
"Our results indicate that vitamin B12 and related metabolites may have a role in Alzheimer's disease, 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," he added.
The report is published in the Oct. 19 issue of Neurology.
For the study, Hooshmand's group looked at homocysteine levels in the blood of 271 Finns 65 to 79 who did not have dementia at the beginning of the study.
The team looked at homocysteine because high levels of this protein have been linked to stroke. The researchers also looked at levels of holotranscobalamin, which is the active protein of vitamin B12 and lowers blood levels of homocysteine, the researchers said.
During seven years of follow-up, 17 people developed Alzheimer's. The researchers found that for each small increase of homocysteine, called a micromolar, the risk of Alzheimer's disease rose 16 percent. However, with each small increase in vitamin B12, called a picomolar, the risk of Alzheimer's dropped 2 percent.
The results remained constant after the researchers compensated for other factors, such as age, sex, education, smoking, blood pressure and weight.
Vitamin B12 is found in eggs, fish, poultry and other meats. A balanced diet -- not supplements -- is the best way to get the vitamin B12 you need, Hooshmand said.
Alzheimer's expert Greg M. Cole, a professor of medicine and neurology at the University of California, Los Angeles, said "this new study is too small to say that it adds a lot to the association of Alzheimer's disease and dementia with high homocysteine."
"But it is interesting that higher B12 appears protective given the recently published report that B vitamin supplements appeared to reduce brain shrinkage," he said.
William Thies, chief medical and scientific officer at the Alzheimer's Association, added that "while we're always excited to learn of study findings, similar results have been found in the past."
The concept of using a dietary supplement with vitamins to make an effective treatment is an ongoing area of interest and research, he said.
For more on Alzheimer's disease, visit the Alzheimer's Association.