Maybe the assumption that natural substances can do no harm has again been shown to be wrong. Are these margarines good or bad for you?

A case published in BMJ Case Reports this week raises an interesting question about plant sterol-enriched margarines and cardiovascular risk. They reduce LDL cholesterol but do not seem to reduce cardiovascular risk. In this report a lady developed xanthelasma 18 months into a programme of cholesterol reduction with plant sterols.

Vergès B, Athias A, Petit JM, Brindisi MC. Extravascular lipid deposit (xanthelasma) induced by a plant sterol-enriched margarine. BMJ Case Reports 2009 [doi:10.1136/bcr.10.2008.1108]

The authors point out that elevated campesterol, a plant phytosterol and the cause of the xanthelasma in this case, may promote atherosclerosis. They go on to say that their observation raises concern about potential cardiovascular risk after long-term consumption of these margarines.