August 18, 2015

Homocysteine, Memory Loss And Dementia - A Strong Association

How Strong Is The Link Between Homocysteine, Memory Loss And Dementia?

In an earlier post we discussed Bradford Hill's criteria for causality.  The first of these was 'strength' - i.e., just how strong is the association between high blood homocysteine levels and dementia?

In biology, 'strength' is expressed as a 'population attributable risk.' Put simply - how many population 'events' can be attributed to the feature in question.  A recent study looked at homocysteine in relation to ‘cognitive function’ and ‘cognitive decline’.  Overall, 28 of 33 studies confirmed an association between high homocysteine and impaired cognition.

What About Alzheimer's Disease?

Considering Alzheimer's Disease, the 'population attributable risk' for high versus low homocysteine was a staggering 21.7%!!

This agrees with an earlier report, estimating that potential risk reduction with high dose folic acid and B12, as used in Betrinac, is 22% for a 3 µmol/L decrease in homocysteine!

Think about this just for a moment... current evidence suggests that about 1 in 5 cases of dementia 'might' be preventable, simply by high dose B vitamin supplements!!

What About Other Risk Factors?

In comparing other risk factors for Alzheimer's including physical activity, smoking, and education, the strongest associations are seen for low education and high homocysteine.

In short, the strengths of the associations between high homocysteine and cognitive decline, and between high homocysteine and incident dementia including AD, are substantial.


In Our Next Blog Update We Will Look At The "Consistency" Between Homocysteine And Cognition 

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