Abstract
Shortly after the discovery that linoleic acid was an essential fatty acid in 1930, α-linolenic acid also was reported to prevent the fatty acid deficiency syndrome in animals. However, several prominent laboratories could not confirm the findings with α-linolenic acid, and as a result there was a loss of interest in omega-3 fatty acids in lipid research. Even the findings that a prostaglandin can be synthesized from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is necessary for optimum retinal function generated only limited interest in omega-3 fatty acids. The breakthrough came in the 1970s when Dyerberg and Bang reported that the low incidence of atherosclerotic coronary disease in Greenland Eskimos was due to the high marine lipid content of their diet. They subsequently found that EPA, which was increased in Eskimo plasma, inhibited platelet aggregation, and they concluded that the low incidence of coronary artery disease was due to the anti-thrombotic effect of EPA. This stimulated widespread interest and research in EPA and DHA, leading to the present view that, like their omega-6 counterparts, omega-3 fatty acids have important physiological functions and are essential fatty acids.
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Key Points
This paper provides a very short overview of the history of the discovery of the omega 3 essential fatty acids. The Burrs predicted in their 1930 paper that like linoleic acid, other unsaturated fatty acids cannot be synthesized in adequate amounts by animals. This prediction was confirmed for linolenic acid by Wesson and Burr, leading to the question of whether linolenic acid also was functionally essential. Burr, Burr and Miller tested this in 1932 by supplementing the fat-free diet with methyl linolenate and found that it was effective in curing the fatty acid deficiency syndrome in the rat. They concluded that linolenic acid was about as potent as linoleic acid, but this result could not be confirmed by other prominent laboratories. However, the conclusion that linolenic acid is not an essential fatty acid was generally accepted, resulting in a lack of interest in omega-3 fatty acids that persisted until the late 1970s.
In 1982, Holman and colleagues stated that … linolenic acid is a required dietary nutrient for humans…the essentiality of linolenic acid resides in the polyunsaturated fatty acids formed from it. The consensus opinion today is that omega-3 fatty acids, like their omega-6 counterparts, have important physiological functions and are essential fatty acids. Understanding the mistakes and distractions that led to the long delay in recognizing the essentiality of omega-3 fatty acids should help avoid similar pitfalls in dealing with new findings and thereby allow more benefit from advances in lipid research.