Elevated levels of homocysteine (Hcy) in the blood have been associated with an increased risk of cardiovascular disease and Alzheimer’s disease (AD). Low levels of vitamins B-6, B-12, and folate can contribute to elevated levels of Hcy leading to hopes that supplements of these 3 B- vitamins might reduce the risk heart disease and senility. Unfortunately, several double-blind controlled clinical trials found that while supplements of these B-vitamins did lower serum Hcy levels they failed to reduce the risk of cardiovascular events. However, to date there is only limited data on whether or not supplements of these 3 B-vitamins might protect the brain from damage leading to senility. Two earlier trials did provide some evidence supplements of B-vitamins might slow the loss of cognitive function particularly in those with elevated Hcy levels but neither study looked at whether or not brain atrophy was impacted. Pharmaceutical agents have proven of little value in slowing the atrophy of brain tissue or doing much to slow the loss of cognitive function over time. Nearly one in five Americans over the age of 70 shows at least mild cognitive impairment (MCI) and about half of those with MCI will develop Alzheimer’s disease.
Dr. David Smith at Oxford University and colleagues examined the impact taking either a placebo or a B-vitamin supplement (folic acid 800mcg; pyridoxine 20mg; and vitamin B-12 500mcg per day) in a group of 266 older subjects with mild cognitive impairment. Cognitive function and brain atrophy were assessed before and after two years of taking the placebo or B-vitamin supplements. The primary outcome was the amount of atrophy seen in their brains using before and after treatment MRIs. A total of 168 subjects completed the study. The rate of brain atrophy in the B-vitamin group was slowed by about 30% compared to the placebo group. In subjects whose initial Hcy level were in the top 25% (>13) the slowdown in brain atrophy was even more dramatic (53% less than the controls). The authors of this trial conclude: “The accelerated rate of brain atrophy in elderly with mild cognitive impairment can be slowed by treatment with homocysteine-lowering B-vitamins.” 1
By James Kenney, PhD, RD, FACN
1. PLoS ONE5(9):e12244.doi:101371/ journal.pone.0012244
Stephanie Ronco has been editing for Food and Health Communications since 2011. She graduated from Colorado College magna cum laude with distinction in Comparative Literature. She was elected a member of Phi Beta Kappa in 2008.