Hemp seed contains 20%–30% edible (fixed) oil; 25%–30% protein, which includes eight of the daily essential amino acids recommended for humans; 20%–25% fiber; 20%–30% carbohydrates; and many essential nutrients and vitamins.
Humans have used hemp seed as food since ancient times. Grain or oilseed hemp products include hemp seed, seed flour, seed protein, seed powder, seed oil, and hemp meal. Nowadays, hemp grain is used in human health food because of the desirable ratio of omega-6 and omega-3 fatty acids in hemp oil, similar to those found in fish oil. It is not yet legal to feed hemp to animals in the U.S. but it is in South Africa.
Hemp seed oil is used in many cosmetics and as a substitute for other industrial oils. Hemp seed oil has a pleasant flavor and is used like olive oil as table oil and in salad dressing. Hemp seed oil should not be used for frying or baking; when heated at temperatures above 320°F (160°C), flavor declines, and it may produce toxic byproducts. Also, hemp seed and hemp seed oil do not have a long shelf life. Sterilization of hemp seed may foster rancidity of the oil within the seed.
Hemp seed should be stored in dark containers and refrigerated to extend the shelf life and preserve the quality. Most of the hemp grain imported in the U.S. comes from Canada, where industrial hemp has been legalized since 1998. Canada is one of the primary producers of oilseed hemp, and most of the Canadian hemp seed is exported to the U.S.