B Vitamins May Reduce Brain Shrinkage by Up to 90 Percent
High levels of the amino acid homocysteine are linked to brain shrinkage and an increased risk of Alzheimer’s. B vitamins are known to suppress homocysteine. In a 2010 study, participants received relatively high doses of B vitamins, including:
- 800 micrograms (mcg) folic acid — US RDA is 400 mcg/day
- 500 mcg B12 (cyanocobalamin) – US RDA is only 2.4 mcg/day
- 20 mg B6 (pyridoxine hydrochloride) — US RDA 1.3-1.5 mg/day
The study was based on the presumption that by controlling the levels of homocysteine, you might be able to reduce the amount of brain shrinkage, which tends to precipitate Alzheimer’s.
Indeed, after two years those who had received the vitamin-B regimen suffered significantly less brain shrinkage compared to those who had received a placebo. In those who had the highest levels of homocysteine at the start of the trial, their brains shrank at half the rate of those taking a placebo.
The latest study takes this research a step further, showing not only that B group vitamins may slow brain shrinkage but that it may specifically slow shrinkage by as much as seven-fold in brain regions specifically known to be most impacted by Alzheimer’s disease.
Among participants taking high doses of folic acid and vitamins B6 and B12, blood levels of homocysteine were lowered as was the associated brain shrinkage – by up to 90 percent. The researchers noted:
” … B vitamins lower homocysteine, which directly leads to a decrease in GM [gray matter] atrophy, thereby slowing cognitive decline. Our results show that B-vitamin supplementation can slow the atrophy of specific brain regions that are a key component of the AD [Alzheimer’s disease] process and that are associated with cognitive decline.”