This systematic review compared the impact of plant and animal protein on the conditions that constitute metabolic syndrome in humans. The researchers found that soy protein intake with isoflavones led to a 3 percent greater decrease in both total and LDL cholesterol compared with animal protein ingestion; these results were especially prevalent in individuals with high fasting cholesterol concentrations. The researchers did not find this effect in soy protein without isoflavones or other plant proteins such as pea, lupine, or wheat gluten. When included in a mixed meal, plant protein (wheat gluten, soy protein) produced a lower insulin response after the meal than did whey protein (from dairy). This systematic review supports previous evidence that soy protein with isoflavones may prevent the onset of risk factors associated with metabolic syndrome (i.e., hypercholesterolemia and hyperglycemia), in humans.