The safety and efficacy of soy protein appear to depend on how much you consume; less than a certain amount provides little benefit, and more than a certain amount may be harmful. Here are some guidelines for daily intake (each gram of soy protein provides about two milligrams of isoflavones):
25 Grams of Soy Protein
Minimum amount necessary to lower total blood cholesterol and "bad" (LDL) cholesterol (the effect is more noticeable in those with previously elevated levels of cholesterol).
50 Grams of Soy Protein
Studies show a greater reduction of blood cholesterol at this level.
More than 50 Grams
Uncharted territory, and possibly dangerous. Some laboratory and animal studies show harmful effects at these higher levels, and no human population has consumed this much on a regular basis.
Return to Weighing the Health Benefits of Soy.