Inadequate levels of vitamin B12 and high levels of homocysteine, an amino acid and one of the building blocks of all proteins in the body, are common in the elderly, and experts have hypothesized that this combination may have an effect on brain structure. Now a new study shows that this combination is associated with accelerated brain aging in older adults.
The 501 participants in the Swedish study were at least 60 years old (mean age 71) and were free of dementia when the study began.
They underwent a structural magnetic resonance imaging (MRI) scan of the brain to determine total gray matter and white matter as well as cerebrospinal fluid and intracranial volumes.
Investigators also took blood samples for analysis. During the following six years, the MRI was repeated either once or twice, depending on the age of the participant.
Analysis of the resulting data indicated that both vitamin B12 and homocysteine concentrations are related to accelerated aging of the brain, with higher blood levels of vitamin B12 and lower homocysteine levels associated with slower rates of volume loss of total brain tissue.
Do those results mean you should start taking vitamin B12 supplements to protect your brain? Not yet. More clinical trials are needed to uncover the practical implications of this research.
JAMA Psychiatry, June 2016