Through some relevant researches, the experts believe that, peanut oil and corn oil contain a strong carcinogen called as aflatoxin. And cottonseed oil contains the toxic substance called as gossypol, which may easily cause chronic poisoning to people. What's more, the erucic acid contained in rapeseed oil is very detrimental for the health of the patients who suffer from hypertension and heart disease. As a result, the experts suggest that people should change the habit of long-term consumption of vegetable oil. When they cook the food, they can try to appropriately increase the use of animal fats, so as to reduce the harms brought by vegetable oil.