Severe Gastric Distress

• Raw soybeans cause different symptoms in people. Most of the symptoms are related to the stomach and intestines. Diarrhea is very common with raw soybeans. Some people experience stomach aches or pain instead, which can be accompanied by nausea or vomiting.
  
  

Dizziness

• Some people experience dizziness when they eat raw soybeans. It is not clear whether the dizziness is a lone symptom, or if it is accompanied by nausea, vomiting or diarrhea.
  
  

Enzyme Inhibitors

• Soybeans naturally contain protease inhibitors that keep the digestive enzymes from working. The digestive enzymes break down food so it can be digested. If these enzymes are kept from working, the food -- in this case, soybeans -- cannot be digested. That is why raw soybeans cause such symptoms of gastric distress. Cooking destroys the protease inhibitors in soybeans so they can be digested.
  
  

Phytic Acid Blocks Nutrients

• Soybeans are high in phytic acid, which keeps nutrients from being absorbed by the body. Cooking destroys the phytic acid so the nutrients that soybeans can provide are easily absorbed.
  
  

Other Toxic Raw Vegetables

• Soybeans are not the only vegetables that should not be eaten raw. Most beans cause some toxicity if eaten raw. Whether they cause mild stomach aches or more serious toxicity depends upon the individuals and how much of the raw bean they ate. Lima beans release a cyanide compound when their shells are opened, but cooking destroys the compound. Red kidney beans are among the most toxic of beans. They are very high in lectin, which can cause toxicity if only a few raw beans are eaten, or if they are undercooked, which can occur in some crockpots when dried beans are used.