It's known that dietary substitution of soy protein for casein decreases LDL- and increases HDL-cholesterol levels. Danish researchers have now discovered, however, that soy protein appears to increase lipoprotein (a) levels, which suggests that use of soy protein might not be advisable in antiatherogenic diets.
Am J Clin Nutr March 1999;69:419-425
Dr. Mercola's Comment:
Elevated Lp(a) levels are a very strong risk factor for heart disease. It is well established yet very few physicians ever check for it in their patients. I routinely screen for this in all of my heart disease patients. This is an interesting study that provides us with further evidence that soy is not all it is cracked up to be.
Most of the positive studies on soy were funded by the edible oil industry which has strongly vested multi billion dollar incentives to promote soy. There are only several forms of soy I would recommend. Tempeh and miso are fine for most people. One half teaspoon twice a day of tofu would also benefit women with breast cancer as the soy has powerful lectin binders (not isoflavones) that bind to the breast cancer cells and remove them from the body.