Monday, August 09, 2010


For a long time, large population studies carried out in many communities seemed to suggest that high levels of homocysteine in the blood seem to be a cardiac risk factor. That people with high blood homocysteine levels have additional risk factors of heart attacks and strokes. Homocysteine is an amino acid formed in the body from one of the important protein building blocks, methionine. However, when we lowered the blood homocysteine level, we did not seem to lower our CV risk. It made no difference. We were puzzled. This is quite unlike blood cholesterol levels, where increase levels was an important risk factor and lowering cholesterol reduces the risk.
In the 4th August issue of Lancet Neurology, is another study concluding the same. Dr Graeme Hankey and colleagues of Melbourne Australia, carried out the VITATOPS ( Vitamins to prevent strokes ) study, in 8164 patients across 20 countries. This was a double blind, placebo controlled trial ( one half on placebo and the other half on Multi-vit B ). After a median followup of 3.4 years, they found no difference in stroke and heart attack rates. It may be that 3.4 years follow-up may not be long enough to show any difference, and the numbers may be too small. The homocysteine levels, which were raised at start of the study, did come down significantly.
Be that as it may, for all those out there who are taking all sorts of multi-vitamins ( and there are many of my patients who are taking all sorts of vitamin supplements ), please know that the multi-vits may not help the heart.
We are still puzzled by the role of homocysteine, in atherosclerosis. Although there is enough epidermiological evidence, there is limited understanding of the patho-physiological mechanism. Obviously much more work needs to be done. Many of us feel that homocysteine is a minor risk factor that maybe important in addition to other risk factors like cigarette smoking. Whatever it is, vitamin supplements are very popular and has spun a whole OTC pharma industry, stronger that the "statins " industry.
My advice is be aware. Take drugs only when you have too, with medical evidence. We do not wish to have a " Calcium supplement and Heart trouble issue " years later.