The Nation's Health

Homocysteine: Homocysteine and coronary plaque

If you’ve watched the news over the past year, you know that doubt has been cast over the idea that reducing homocysteine blood levels with high doses of B vitamins (B6, B12, and folic acid, or B9) results in reduced risk for heart attack.

Is the homocysteine concept dead? Shall we empty our bottles of costly B vitamins into the trash and move on?

I don’t think so. As detailed in one of our Track Your Plaque Special Reports from a few months ago, I think the homocysteine issue still deserves lots of respect and further investigation. After all, hundreds of clinical studies have connected higher homocysteine levels with greater risk for heart disease, stroke, and aneurysm. Numerous studies, for example, have repeatedly and consistently demonstrated a tripling of heart attack risk when homocysteine levels exceed 14 mol/l. Can we dismiss this association because several more recent studies—NORVIT, HOPE, and VISP—suggested that, when starting homocysteine levels are 12.5, that B vitamin supplementation does not reduce heart attack risk?

I think there’s lots more to know about the homocysteine connection. That said, I have never seen a patient who I thought had heart disease strictly because homocysteine was increased.

I believe that we can at least use homocysteine as an index of lifestyle : the higher the homocysteine, the poorer the diet, or the less effective the absorption of B vitamins (especially vitamins B12 and folic acid). Homocysteine levels of <9 micromol/l suggest both adequate intake and absorption of these B vitamins.

If homocysteine is tightly connected with risk for heart disease, yet supplementation of B vitamins fails to reduce risk, might there be another means of connection? Or, could both homocysteine and heart disease be connected in some way that has nothing to do with B vitamins?

Don’t close the book on homocysteine. Just because conventional experience fails to draw connection does not necessarily mean that none exists. If it’s any consolation, taking B vitamins has been correlated with better memory, concentration, and other health benefits, even if no reduction in heart disease develops.