The not-soy-good results

Soy protein and isoflavones haven't held up well in clinical trials, but there's still a place for soy in our diets.

Once the belle of the health-food ball, soy is looking a little forlorn these days. Claims that soy protein would protect us from heart disease now seem a little inflated. Studies have shown its effect on "bad" LDL cholesterol is pretty small, averaging less than a 5% decrease in most studies. Large amounts of soy protein — 50 grams a day, which is about half the amount of protein that Americans typically eat in a day — have had the same modest effect as smaller amounts.