An important study appeared in JAMA Psychiatry in June 2016, providing additional evidence that high blood levels of vitamin B can slow the shrinking of the brain that commonly occurs after age 60. Previous studies have shown that vitamin B12 and other B vitamins, (folic acid and vitamin B6) can slow the rate of brain atrophy in older subjects with mild cognitive impairment and decrease the risk of progression to Alzheimer’s disease.
Overall, the emerging scientific evidence suggests if you can slow or prevent the shrinking of the brain, which is common after age 60, you may decrease your risk of dementia and Alzheimer’s disease quite substantially.
The latest study presented data from the Swedish National Study on Aging and Care. The study followed 501 subjects, ages 60 and older, from 2001-2009. All subjects were free of dementia at the beginning of the study. MRI imaging of their brains was conducted in 299 of the subjects routinely during the six-year follow-up period. Results showed individuals with higher blood levels of vitamin B12 showed a significant decrease in the rate of total brain tissue volume loss compared to individuals with lower blood levels of B12.
Vitamin B12 is required to make a number of brain neurotransmitters and has been shown to have neuroprotective effects, which may directly slow brain shrinking. It also lowers a chemical in the blood called homocysteine. High homocysteine is know to be extremely damaging to the brain and cerebrovascular blood vessels, and high blood levels of homocysteine are strongly correlated with brain atrophy and risk of Alzheimer’s disease in many studies.
What’s more, study participants with lower vitamin B12 levels and/or high homocysteine levels also showed increased white matter hyper-intensity, (WMI) on their MRI scans, which is strongly tied to increased risk for cognitive decline and other mental health disorders.
The overall evidence suggests slowing brain atrophy is an important feature of maintaining cognitive function with aging. Thus far, only B-vitamin supplementation has been able to show this effect in human clinical intervention studies. No drugs have been able to do this, at least not this dramatically.
I think preventing total brain atrophy as we age is a fascinating area that is strongly linked to a patient’s healthy life expectancy and quality of life, so I believe it is a topic to discuss with all patients 60 years and older.