Cold-pressed peanut oil contains many healthy fats, vitamin E, and antioxidants. However, peanut oil is rich in polyunsaturated fats, which can become unstable when heated and form harmful compounds called free radicals. Merely exposing this oil to light, heat, or moisture can start this process of oxidation and drastically reduce nutrient content. Since it is rich in omega-6 polyunsaturated fat (linolenic acid), it can contribute to a higher ratio than desired of omega-6: omega-3 fatty acid intake that is common in the standard American diet and which can contribute to inflammation. Additionally, some peanut oil can contain allergens that can cause allergic reactions in some people. Some peanut oils may also contain aflatoxins, a type of mold that develops in peanut seeds which can be harmful to health.