In this video, Dr. Cousens says that the brain ..
“shrink about 1% a year after about 45 or 50 something like that. B12 is really important to keep the brains from shrinking.”
That may be the case for the population at large, but LiveScience.com reports that if only look at healthy brains and exclude “all of the people with so-called “preclinical” cognitive diseases”, then “age did not have a significant effect on brain size”.
To me that just implies that brain shrinkage means brain deterioration. And if vitamin B12 can help reduce the risk of brain shrinkage, then it might help reduce the risk of brain deterioration. Of course, it is also possible that there is brain deterioration with brain shrinkage.
Dr. Michael Greger in this video …
talks about vegetarian/vegan have twice the risk of dying from neuro degenerative diseases than meat eaters.
He believes that this is due to low omega-3 and B12 in the plant kingdom, and supplementation of these may be necessary for vegetarians and vegans.