Many plant foods are perfectly safe to eat raw, but soybeans aren't among them. Some of the components found in raw soybeans can cause short term digestive problems, as well as possible long-term health issues. Cooking or fermentation neutralizes some of the negative side effects raw soybeans could have on your health.

Lectin Effects

Soybeans contain lectins, glycoproteins that bind to carbohydrates in cells. This can damage the cells or lead to cell death in the gastrointestinal tract. Lectins may bind to the intestinal walls, damaging the cells and affecting nutrient absorption as well as causing short-term gastrointestinal side effects. Unlike most proteins, lectins aren't broken down by enzymes in the intestine, so the body can't use them. Lectins can affect the normal balance of bacteria in the intestine and the immune system in the digestive tract.

Saponins in Soybeans

Saponins, another component found in soybeans, can cause side effects if you eat soybeans raw or cooked, because cooking doesn't break down this toxin like it does lectins. Enzymes used in fermentation, however, can break down saponins. Like lectin, saponins can damage the cells of the intestines if eaten in large amounts. Saponins also impart a bitter taste to raw soybeans. Cooking methods can leach some of the saponins out of the soybeans, removing the bitter taste.

Protease Inhibitors

Raw soybeans contain proteins called protease inhibitors, which block the actions of certain enzymes. Eating raw soybeans can block the pancreatic enzyme elastin, which breaks down proteins in meat for digestion. Since protease inhibitors are heat-sensitive, boiling soybeans at 212 degrees F for 15 to 30 minutes improves their nutritional value, according to the textbook "Food Safety and Toxicity."

Potential Side Effects