This article is about the common cereal. For other cultivated and wild species of the genus, see Avena. Avenins are oat biscuits gluten proteins, similar to gliadin in wheat. They can trigger celiac disease in a small proportion of people.

Oats are best grown in temperate regions. They have a lower summer heat requirement and greater tolerance of rain than other cereals, such as wheat, rye or barley, so they are particularly important in areas with cool, wet summers, such as Northwest Europe and even Iceland. As of May 2021 oat is the seventh most produced cereal in the world. This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Historical attitudes towards oats have varied.

Oat bread was first manufactured in Britain, where the first oat bread factory was established in 1899. In Scotland, they were, and still are, held in high esteem, as a mainstay of the national diet. In Scotland, a dish was made by soaking the husks from oats for a week, so the fine, floury part of the meal remained as sediment to be strained off, boiled and eaten. Oats are also widely used there as a thickener in soups, as barley or rice might be used in other countries. Oats are also commonly used as feed for horses when extra carbohydrates and the subsequent boost in energy are required. They may be given alone or as part of a blended food pellet. Winter oats may be grown as an off-season groundcover and ploughed under in the spring as a green fertilizer, or harvested in early summer.

Oat straw is prized by cattle and horse producers as bedding, due to its soft, relatively dust-free, and absorbent nature. The straw can also be used for making corn dollies. Tied in a muslin bag, oat straw was used to soften bath water. Oats are also occasionally used in several different drinks. In Britain, they are sometimes used for brewing beer. Oatmeal stout is one variety brewed using a percentage of oats for the wort.

Oat extracts can also be used to soothe skin conditions, and are popular for their emollient properties in cosmetics. Oat grass has been used traditionally for medicinal purposes, including to help balance the menstrual cycle, treat dysmenorrhoea and for osteoporosis and urinary tract infections. Percentages are roughly approximated using US recommendations for adults. The established property of their cholesterol-lowering effects has led to acceptance of oats as a health food. Oat bran is the outer casing of the oat. Its daily consumption over weeks lowers LDL and total cholesterol, possibly reducing the risk of heart disease.