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Folic acid plus vitamin B12 may improve brain functioning in older people

December 23, 2011

A new Australian study reports that long-term supplementation of folic acid and vitamin B12 may reduce cognitive decline in older people with high levels of psychological distress.

In the randomized controlled trial, 900 adults aged 60–74 years with depressive symptoms were assigned to receive 400 micrograms of folic acid plus 100 micrograms of vitamin B12 or a placebo every day for two years (1). Change in cognitive functioning was measured at 12 and 24 months. The study results showed that participants who received supplementation had better cognitive functioning after 24 months than the placebo group, particularly in immediate and delayed memory performance. No significant changes were evident in orientation, attention, semantic memory, processing speed, or informant reports.

The researchers concluded that long-term supplementation of folic acid and vitamin B12 may promote improvement in cognitive functioning in older adults with depressive symptoms. There is evidence to suggest that both B vitamins play important roles in healthy brain aging, since many studies suggest that low levels of these micronutrients can lead to more rapid deteriorations in cognitive functions. Such declines in functionality are often warning signs of dementia and its most common type, Alzheimer's disease.

Long-term deficiencies in B vitamins, such as vitamin B12, folate, and niacin, are known to have effects on brain degeneration, which has led to the hypothesis that such vitamins may play a role in the development of dementia. It is thought that interventions via folic acid and vitamin B12 supplementation may prevent cognitive impairment and dementia by lowering homocysteine concentrations (2, 3) or reducing vascular and other metabolic risk factors (4).

References

  1. Walker J. G. et al. Oral folic acid and vitamin B-12 supplementation to prevent cognitive decline in community-dwelling older adults with depressive symptoms – the Beyond Ageing Project: a randomized controlled trial. Am J Clin Nutr. Published online December 2011.
  2. Dufouil C. et al. Homocysteine, white matter hyperintensities, and cognition in healthy elderly people. Ann Neurol. 2003; 53:214–221.
  3. Balk E. M. et al. Vitamin B6, B12 and folic acid supplementation and cognitive function: a systematic review of randomized trials. Arch Intern Med. 2007; 167:21–30.
  4. Seshadri S. et al. Plasma homocysteine as a risk factor for dementia and Alzheimer’s disease. N Engl J Med. 2002; 346:476–483.