Cottonseed oil is a vegetable oil extracted from the seeds of the cotton plant after the cotton lint has been removed. It must be refined to remove gossypol, a naturally occurring toxin that protects the cotton plant from insect damage. Unrefined cottonseed oil is therefore sometimes used as a pesticide. In its natural unhydrogenated state cottonseed oil, like all vegetable oils, has no cholesterol. It also contains no trans fatty acids. However, it does contain over 50% Omega-6 fatty acids and only trace amounts of Omega-3 fatty acids, and the imbalance is considered unhealthy if not used in moderation or balanced elsewhere in the diet. Further, these polyunsaturated fats can potentially go rancid during the extraction process.
Some consumers are wary of cottonseed oil because cotton crops are one of the most chemically-intensive crops grown in the U.S. Many chemicals approved for use on cotton are not approved for use on food-based crops. Cotton field leftovers, or gin trash, is frequently fed to cattle.
Cottonseed oil is rich in palmitic acid (22-26%), oleic acid (15-20%), linoleic acid (49-58%) and 10% mixture of arachidic acid, behenic acid and lignoceric acid. It also contains about 1% sterculic acids and malvalic acids in the crude oil. The cyclopropene acids are undesirable components, but they are largely removed during refining, particularly deodorization, and also during hydrogenation. They are not considered to present any health hazard in cottonseed oil.
Cottonseed oil is commonly used in manufacturing potato chips and other snack foods. Along with soybean oil, it is very often partially or fully hydrogenated. The growing consensus is that in hydrogenated (trans fat) form these oils are very unhealthy. Cottonseed oil was the first oil to be hydrogenated in mass production, originally intended for candle production, and soon also as a food (as Crisco). In part because regulations apply differently to non-food crops, it has also been suggested that cottonseed oil may be highly contaminated with pesticide residues, but insufficient testing has been done.