A new study shows that vitamin B12 may protect against Alzheimer’s disease (AD).
Researchers took blood samples from 271 Finnish people, aged 65 to 79, who did not have dementia at the start of the study.
Blood samples were tested for levels for homocysteine and holotranscobalamin (the active portion of the vitamin B12). Too much homocysteine in the blood has been linked to negative effects on the brain, such as stroke. However, higher levels of vitamin B12 lower homocysteine.
At 7-year follow-up, 17 subjects had developed AD.
Results revealed that for each micromolar increase in the concentration of homocysteine, the risk of AD increased by 16%, whereas each picomolar increase in concentration of the active form of vitamin B12 reduced risk by 2%. The results remained after adjusting for other factors of AD, such as age, gender, education, smoking status, blood pressure and body mass index. The addition of folate did not appear to raise or lower the risk of AD.
“Low levels of vitamin B12 are surprisingly common in the elderly. However, the few studies that have investigated the usefulness of vitamin B12 supplements to reduce the risk of memory loss have had mixed results,” notes study author Babak Hooshmand, MD, MSc.
Neurology – October 19, 2010;75:1408-14.