Key vitamin levels needed to avoid brain shrinkage

Elderly  people with low levels of vitamin B12 may be at increased risk of having brain atrophy, or shrinkage associated with Alzheimer’s disease and impaired cognitive function.

A study published in the journal Neurology says that people who were more vulnerable to B12 deficiency, including elderly, vegetarians, and pregnant women, should take steps to maintain a proper B12 level through eating a balanced and varied diet, including meat, fish, milk, and fortified cereals.

The study involved 107 volunteers aged 61 to 87, who were cognitively normal at the start and who underwent annual clinical exams, MRI scans, cognitive tests, and had blood samples taken.

Those with lower vitamin B12 levels at the start had a greater decrease in brain volume, while those with the lowest B12 levels had a sixfold greater rate of brain volume loss, compared with those who had highest B12 levels.

Dr Jonathon Friedman, of the Texas A&M Health Science Centre College of Medicine, said that the participants “all had normal B12 levels, yet there was a difference between the higher levels and the lower levels in terms of brain shrinkage, which is new information which could potentially change what we recommend to people in terms of diet”.

Another B12 study is currently being carried out at Oxford and due to be completed in 2009.

A co-author of the first study, Anna Vogiatzoglou, of Oxford University, said “we are doing a clinical trial in which we are giving B vitamins, including B12 to elderly people with memory impairment.

“We are doing MRI scans at the start and the end, and so will be able to find out if taking B vitamins really does slow down the shrinking of the brain.”