HEALTH NEWS

Study Title:

B12 Status and Brain Atrophy

Study Abstract

Objectives: To investigate the relationship between markers of vitamin B12 status and brain volume loss per year over a 5-year period in an elderly population.

Methods: A prospective study of 107 community-dwelling volunteers aged 61 to 87 years without cognitive impairment at enrollment. Volunteers were assessed yearly by clinical examination, MRI scans, and cognitive tests. Blood was collected at baseline for measurement of plasma vitamin B12, transcobalamin (TC), holotranscobalamin (holoTC), methylmalonic acid (MMA), total homocysteine (tHcy), and serum folate.

Results: The decrease in brain volume was greater among those with lower vitamin B12 and holoTC levels and higher plasma tHcy and MMA levels at baseline. Linear regression analysis showed that associations with vitamin B12 and holoTC remained significant after adjustment for age, sex, creatinine, education, initial brain volume, cognitive test scores, systolic blood pressure, ApoE 4 status, tHcy, and folate. Using the upper (for the vitamins) or lower tertile (for the metabolites) as reference in logistic regression analysis and adjusting for the above covariates, vitamin B12 in the bottom tertile (<308 pmol/L) was associated with increased rate of brain volume loss (odds ratio 6.17, 95% CI 1.25–30.47). The association was similar for low levels of holoTC (<54 pmol/L) (odds ratio 5.99, 95% CI 1.21–29.81) and for low TC saturation. High levels of MMA or tHcy or low levels of folate were not associated with brain volume loss.

Conclusion: Low vitamin B12 status should be further investigated as a modifiable cause of brain atrophy and of likely subsequent cognitive impairment in the elderly.

From press release:

Vitamin B12 may protect the brain in old age
ST. PAUL, Minn. – Vitamin B12, a nutrient found in meat, fish and milk, may protect against brain volume loss in older people, according to a study published in the September 9, 2008, issue of Neurology®, the medical journal of the American Academy of Neurology.

For the study, 107 people between the ages of 61 and 87 underwent brain scans, memory testing and physical exams. Researchers also collected blood samples to check vitamin B12 levels. Brain scans and memory tests were also performed again five years later.

The study found that people who had higher vitamin B12 levels were six times less likely to experience brain shrinkage compared with those who had lower levels of the vitamin in their blood. None of the people in the study had vitamin B12 deficiency.

"Many factors that affect brain health are thought to be out of our control, but this study suggests that simply adjusting our diets to consume more vitamin B12 through eating meat, fish, fortified cereals or milk may be something we can easily adjust to prevent brain shrinkage and so perhaps save our memory," said study author Anna Vogiatzoglou, MSc, with the University of Oxford in the United Kingdom. "Research shows that vitamin B12 deficiency is a public health problem, especially among the elderly, so more vitamin B12 intake could help reverse this problem. Without carrying out a clinical trial, we acknowledge that it is still not known whether B12 supplementation would actually make a difference in elderly persons at risk for brain shrinkage."

"Previous research on the vitamin has had mixed results and few studies have been done specifically with brain scans in elderly populations. We tested for vitamin B12 levels in a unique, more accurate way by looking at two certain markers for it in the blood," said Vogiatzoglou.

Vogiatzoglou says the study did not look at whether taking vitamin B12 supplements would have the same effect on memory.


###

The study was supported by the UK Alzheimer's Research Trust, the Medical Research Council, the Charles Wolfson Charitable Trust, the Norwegian Foundation for Health and Rehabilitation through the Norwegian Health Association, Axis-Shield plc and the Johan Throne Holst Foundation for Nutrition Research. The research was part of the program of the Oxford Project to Investigate Memory and Aging at the University of Oxford.

Study Information

A. Vogiatzoglou, MSc, H. Refsum, MD, PhD, C. Johnston, S. M. Smith, DPhil, K. M. Bradley, FRCR, FRCP, C. de Jager, PhD, M. M. Budge, MD and A. D. Smith, DPhil, FMedSci
Vitamin B12 status and rate of brain volume loss in community-dwelling elderly.
Neurology
2008 September
University of Oxford