The study focused on 107 volunteers whose average age was 73 years, ranging from 61 to 87 years old. All participants were required to undergo a physical examination, brain MRI and CT scans. Only people in good physical and mental health were included in this study.
For this study, blood samples were also taken of the volunteers. Tests were done to measure vitamin B12 plasma levels, in addition to levels of homocysteine, folate and methylmalonic acid (MMA). These measurements were taken once a year over the duration of five years.
For all the volunteers, the B12 plasma levels fell within the range of normal.
At the end of the five-year period, the volunteers were again subject to brain scans and memory tests. Subjects who had the most brain loss also had lower concentrations of B12. No correlation was made between brain loss and levels of homocysteine, folate or MMA.
The results of this study demonstrated that those people with lower B12 plasma levels were six times more likely to have a loss of brain volume and a decrease in brain size than those with higher levels. Therefore, the authors of this study have concluded that by increasing the consumption of of vitamin B12 among the elderly can reverse brain shrinkage, and possibly prevent memory loss as well. It is hoped that future clinical trials will determine the affects of vitamin B12 supplementation on brain shrinkage.
In the meantime, the authors of this study would advise the geriatric population to increase their intake of vitamin B12 through meat, fish, milk and fortified cereals.