The Queen of Fats: Why Omega-3s Were Removed from the Western Diet and What We Can Do to Replace Them

TIME LINE: SOME IMPORTANT EVENTS IN THE LONG, UNFINISHED TALE OF OMEGA-3 RESEARCH

TIME LINE SOME IMPORTANT EVENTS IN THE LONG, UNFINISHED TALE OF OMEGA-3 RESEARCH 1792—Jean Senebier, a Swiss clergyman and scientist, observes that exposure to air causes oils to go white, lose their fluidity, and in time go rancid. Further investigation convinces him that rancidity involves oxidation. 1814—Michel Eugène Chevreul, a French scientist, shows that hog’s lard consists of two distinct oily bodies. One is a solid at room temperature and the other, a liquid. 1887—A fatty acid with three double bonds is described. It is called linolenic acid and first found in hempseed oil. 1897—The French chemist Paul Sabatier describes the hardening (hydrogenation) of fats in the presence of a metallic catalyst, a discovery for which he wins a Nobel Prize in 1912. 1900—V. D. Anderson in Cleveland, Ohio, manufactures the first continuous screw press—known as the “expeller”—for extracting oil from oil seeds. The expeller is much more efficient than earlier hydraulic presses, but it still leaves much of the oil in the meal and much room, therefore, for improvement. 1903—The German chemist Wilhelm Norman takes out a patent for the “conversion of unsaturated fatty acids . . . into saturated compounds ” by hydrogenation. 153 1911—Procter and Gamble introduce Crisco, a solid vegetable fat made by hydrogenating cottonseed oil, thus providing a lost-cost, vegetable-derived alternative to butter and lard. —The first commercial quantities of soybeans are imported into America from Manchuria and crushed for oil. 1929—George and Mildred Burr discover that certain fats are essential for the growth and survival of rats, causing scientists to rethink the idea that fats are necessary only as a source of calories and fat-soluble vitamins. 1930—Gynecologists working with artificial insemination report that extracts of seminal fluid cause uterine tissue to contract, an observation that leads to the discovery of the important cell messengers called prostaglandins. 1931—The Burrs identify the essential factor in fats required by rats: the unsaturated fat linoleic acid. Later they find that either linolenic acid or archidonic acid can replace linoleic acid. —Henry Ford plants 500 acres in Dearborn, Michigan, in soybeans . Before the Second World War, the United States imports about 40 percent of its edible oils and fats. After the war, and after soybean production takes off, the country is able to export edible oils. 1934—Archer Daniels Midland Company opens the first continuous countercurrent solvent extraction plant in the United States, using hexane as the solvent and a 100-tons-per-day Hildebrandt extractor from Germany. By the late 1940s, much of the oil seed–crushing industry moves from screw presses to far more efficient solvent extraction. 1938—The Burrs are unable to prove that linoleic acid is essential for humans and the question remains unresolved until the 1960s. 1950—Ralph Holman and a graduate student discover that linoleic acid is the precursor of arachidonic acid and that alpha linolenic acid is the precursor of DHA and eicosapentaenoic acid. 1951—Two English scientists, A. J. P. Martin and A. J. James, perfect the first gas-liquid chromatograph, a powerful analytical and purification tool that enables scientists to separate the many different fatty 154 TIME LINE acids in tissues and foods; for this work, they shared the Nobel Prize in 1952. —Herbert Dutton proves that linolenic acid is the cause of the off flavors and odors in soybean oil, leading to the expanded use of partial or selective hydrogenation to eliminate this fat. 1953—Ancel Keys publishes a chart that seems to show that the incidence of heart disease is directly correlated with the total fat intake of a population. 1955—Trans fatty acids are found to be naturally present in ruminants but not nonruminants. 1957—Sune Bergström isolates the first prostaglandins. 1960—Holman describes the presence of high amounts of Mead’s acid (20:3ω9) in animals deprived of essential fatty acids. 1962—Holman’s mother dies of a deficiency of linoleic acid, one of several cases leading to the recognition that linoleic acid, the parent omega-6 fat, is essential for humans. 1964—Holman proposes a new system for naming the different families of unsaturated fatty acids, the omega system, and hypothesizes that the different families compete for the same elongation and desaturation enzymes. —Bergström and David van Dorp demonstrate that prostaglandins are made from twenty-carbon fatty acids, such as arachidonic...