Should I take vitamin B supplements for mild memory problems?

Oxford scientists investigated the effects of vitamin B on brain atropy ( the loss of neurones and their connections) in people with mild memory problems. Studies have found that high levels of homocysteine (tHcy), an amino acid in the blood, affect the rate of brain atropy and that raised levels of tHcy increase the risk of Alzheimer's disease.

168 elderly people with mild cognitive impairment but not taking anti-dementia drugs were recruited in the Oxford area. Both the volunteers and researchers were unaware of the treatment received, either high dose of vitamin B tablets ( a combination of folic acid, B12 and B6) or placebo pills for a 2 year period.

The researchers found that taking B vitamins for 24 months led to brain shrinkage and the rate of shrinkage in the treatment group was 30% less than the placebo group. They concluded that a simple and safe treatment can slow down the rate of brain atropy in people with mild cognitive impairment. The study was published in PLoS One, a peer-reviewed journal. A study published in 2008 in JAMA showed conflicting results.

Critics say that this is well-conducted randomised controlled trial with promising results. However the evidence did not show brain shinkage may lead to improvement in symptoms or that the B vitamins can prevent Alzheimer's disease, but warrant more research.

Source: David Smith A, Smith SM, de Jager CA et al. Homocysteine-Lowering by B Vitamins Slows the Rate of Accelerated Brain Atrophy in Mild Cognitive Impairment: A Randomized Controlled Trial. PLoS One 5(9): e12244

Folic acid and B vitamins do not affect cancer risk

Folic acid and B vitamins are thought to have an important role in cancer prevention, but a study published in JAMA found that these supplements had no significant effects on overall cancer risk.

More than 5000 women health professionals, aged 42 or older, enrolled in a RCT designed to evaluate the effects of folic acid and B vitamins on cancer risk in women with high risk cardiovascular disease. They were randomly assigned to receive a daily combination of folic acid and B vitamin or a placebo for 7.3 years.

Researchers found that the supplement group had similar risk of developing cancer or death and there was a significant reduced risk of cancer in women aged 65 or older at study entry. The authors said "if the findings is real and substantiated, the results may have public health signficance because the incidence rates of cancer are high in elderly perosns...."

Source: Effect of Combined Folic Acid, Vitamin B6, and Vitamin B12 on Cancer Risk in Women. JAMA, 2008; 300 (17): 2012-2021 ( f/t via Athens)

Vitamin B supplement does not slow Alzheimer's disease

Reserachers thought that vitamin B may slow Alzheimer's disease because it can lower the levels of homocysteine, an amino acid linked to brain cell damage. A new research published in JAMA has demonstrated that vitamin B supplements made very little difference to the decline of mental functions, contrary to what previous studies have suggested

340 patients with mild to moderate Alzheimer's disease were randomised to receive either a combination of vitamin B supplements or a placebo for 18 months. Researchers found no significant difference in reduction of cognitive ability between the groups and concluded that this is not a useful treatment of Alzheimer's disease.

Source: Aisen PS, Schneider LS, Sano M et al. High-Dose B Vitamin Supplementation and Cognitive Decline in Alzheimer Disease: A Randomized Controlled Trial. JAMA 2008; 300(15): 1774-1783 ( f/t via Athens)