Submitted to: Prostaglandins Leukotrienes and Essential Fatty Acids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 5, 1995
Publication Date: N/A
Interpretive Summary: Coronary heart disease (CHD) is responsible for more than 550,000 deaths in the United States each year. It has been estimated that the associated costs exceed $70 billion a year in direct and indirect costs. The reduction in cardiovascular mortality observed in the United States during the last 25 years is attributed in part to changes in dietary habits by the epublic, as prescribed by nutritionists and dietitians. The last 15 years of research has demonstrated that consumption of fat from marine fishes results in significant improvements in biochemical markers and clinical variables associated with the atherothrombotic process. This effect has been attributed to changes in the way the body utilizes certain fatty acids. There is a need for the development of dietary alternatives for the great number of Americans who do not eat fish in any significant amount. In this pilot study the authors demonstrated the biochemical similarity, if fnot equivalency, of alpha-linolenic acid found in vegetable oils and fatty acids typically found in fish with regard to their influence in the conversion of essential fatty acids into powerful vasoactive substances called eicosanoids. This means that alpha-linolenic acid-rich vegetable oils (e.g., flaxseed oil, soybean oil and canola oil), if used in proper amounts, can be effective substitutes for marine lipids in modulating eicosanoid production thereby reducing blood's clotting tendency. The results of this research make available to the consumers an alternative option to pursue more healthful dietary habits.
Technical Abstract: Two decades of research conclusively demonstrated the antithrombotic properties of the long-chain n-3 polyunsaturated fatty acids (PUFA) present in lipids from marine fishes. Most American consumers, however, given their preference for meat, will not realize the benefits of a fish-rich diet. Could alpha-linolenic acid (18:3n-3) be similarly effective via modulation of the synthesis of vasoactive eicosanoids, i.e., thromboxane and prostacyclin? The present pilot study is a contribution toward answering this question. We determined that the excretion of 11-dehydrothromboxane B2 declined by 34% from baseline level seven weeks after the n-6/n-3 ratio of dietary PUFA was reduced from 28 to 1. The excretion of 2,3-dinor-6-oxo-prostaglandin F1alpha was similarly affected, although in a less conspicuous manner. The dietary adjustment was brought about by substituting measured amounts of canola and flaxseed oils (3:1) for measured amounts of olive and corn oils (3:1) in an otherwise fat-free basal diet.