Vitamin B12 may reduce risk of Alzheimer's disease

[NEWS, 19 October 2010] A new study from Karolinska Institutet shows that vitamin B12 may protect against Alzheimer's disease (AD). The findings, which are presented in the medical journal Neurology, add more evidence to the scientific debate about whether the vitamin is effective in reducing the risk of memory loss.

Vitamin B12 can be found in fish, poultry and other meat products. According to the researchers the current study show the need for further research on the role of vitamin B12 as a marker for identifying people who are at increased risk of AD.

"Low levels of vitamin B12 are surprisingly common in the elderly", says MD, MSc Babak Hooshmand, Doctoral Student at the Department of Neurobiology, Care Sciences and Society. "However, the few studies that have investigated the usefulness of vitamin B12 supplements to reduce the risk of memory loss have had mixed results."

For the seven-year study, researchers took blood samples from 271 Finnish people age 65 to 79, who did not have dementia at the start of the study. During that time, 17 people developed AD. Blood samples were tested for levels for homocysteine, an amino acid associated with vitamin B12, and for levels of the active portion of the vitamin, called holotranscobalamin. Too much homocysteine in the blood has been linked to negative effects on the brain, such as stroke. However, higher levels of vitamin B12 can lower homocysteine.

The study showed that an increase of homocysteine in the blood also increased the risk of AD, while the presence of holotranscobalamin reduced risk. The results stayed the same after taking into account other factors, such as age, gender, education, smoking status, blood pressure and body mass.

The study was supported by the Swedish Research Council, the European Commission Seventh Framework Programme, the Academy of Finland, the Ragnhild and Einar Lundströms Minne Lindhés Foundation, the Stohnes Foundation, the Gamla Tjanarinnor Foundation and the Dementia Foundation of Sweden.

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