Flaxseed

Flax is a slender annual plant, 60 to 120 cm tall, with narrow leaves and delicate five-petaled flowers that are usually blue, though white and pink forms exist. After flowering it forms round capsules about the size of a pea, each holding up to ten seeds. The seeds are flat, oval and pointed at one end, around 4 to 6 mm long, with a smooth shiny coat that is brown or golden depending on variety. They taste mild and nutty, and when wet they form a thick mucilaginous gel. Flaxseed is sold whole, ground (called flax meal), cold-pressed as oil, and as a flour. The whole seed often passes through the body undigested, so grinding is recommended.

Flax is among the oldest cultivated crops. Domestication likely began in the Fertile Crescent, from the wild species Linum bienne, some 8,000 to 10,000 years ago, and seeds and fibers have been found at prehistoric sites in the Near East and Europe. It was first grown both for its fiber, which makes linen, and for its oil-rich seed. The English word flax goes back to Old English fleax and a Germanic root related to plaiting or weaving. The species name usitatissimum is Latin for most useful, reflecting the plant's many roles.

Linen made from flax fiber is among the oldest textiles known. Spun flax fibers from a cave in Georgia date back more than 30,000 years, and ancient Egyptians wrapped mummies in linen and valued it as a sign of purity. Flaxseed was eaten and pressed for oil across Mesopotamia, Egypt and Europe. Roman writers mention flax as a food and remedy, and Charlemagne reportedly ordered his subjects to eat it for health.

Linseed oil became important for paints, varnishes, and later for linoleum, whose name derives from the Latin words for flax and oil. In North America, flax spread with settlers and became a major crop on the Canadian prairies, where Canada is now one of the largest producers and exporters of seed. Other main producers include Russia, Kazakhstan, China and India.

In India, roasted flaxseed is eaten as a savory powder and chutney in Maharashtra and other regions. In the twentieth century, interest rose in whole food nutrition, and flax became popular in health food circles as a source of plant omega-3 fatty acids. Today ground flax is used in bread, granola, smoothies and as an egg replacer in vegan baking, while fiber flax still supplies linen.

Ground flaxseed is stirred into oatmeal, yogurt, smoothies, pancakes, muffins and bread. Mixed with water, one tablespoon of meal in three tablespoons of water makes a gel used as an egg substitute in vegan baking. Whole seeds are sprinkled on bread and crackers. Flaxseed oil is used cold, as in salad dressings, and should not be heated to high temperatures. In traditional practice, the seed has been used for constipation and as a soothing poultice. Industrially, linseed oil is used in wood finishes, paints, putty and oilcloth, and flax fiber is woven into linen.

Flaxseed is one of the richest plant sources of alpha-linolenic acid, an omega-3 fat, and it supplies soluble and insoluble fiber and lignans. Studies suggest regular intake of ground flaxseed may modestly reduce LDL cholesterol and blood pressure and ease constipation. The conversion of plant omega-3 to the longer-chain forms found in fish oil is limited, so flax is not an equal replacement for fish. Evidence for effects on menopausal symptoms and cancer risk is mixed and inconclusive.