Background

    Elevated homocysteine is associated with higher rates of neurodegenerative diseases, and neurodegenerative diseases are expected to become increasingly more prevalent due to aging populations. The B vitamins are known to lower homocysteine levels, so could B vitamins be used to lower the rates of neurodegenerative diseases?

    The study

    This meta-analysis included 21 randomized controlled trials with a total of 7,571 participants. The mean age of the participants ranged from 60 to 83 years, and the treatment duration ranged from 1 month to 3.4 years, with roughly half of the studies shorter than 12 months and the other half longer than 12 months. The participants usually had high baseline homocysteine levels. The trials most commonly used vitamin B9 (folate), vitamin B12, or a combination treatment.

    The results

    B-vitamin supplementation increased global cognition scores but did not affect cognition subdomains such as information processing speed, episodic memory, or executive function. The results remained consistent after removing low-quality studies. The authors recommend that B vitamins should be seriously considered as an intervention to prevent or slow cognitive decline.

    This Study Summary was published on August 3, 2021.