High levels of homocysteine are associated with faster brain shrinkage and Alzheimer's disease.

BBC: Vitamin B 'puts off Alzheimer's'

The study authors believe it was the B vitamins' effect on levels of homocysteine that helped slow the rate of brain shrinkage.

BBC: Vitamin B 'puts off Alzheimer's'

They know that heart disease, for example, tends to occur in patients with an overabundance of any of these things: low-density lipoprotein, triglycerides, C-reactive protein or homocysteine.

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