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

NOTES

NOTES ONE. WHAT’S FOR DINNER? P. 5 DHA is a quick-change artist Readers who know that the cis double bonds in polyunsaturated fatty acids are more rigid and have signi ficantly fewer degrees of freedom than the single bonds in saturated fatty acids, the result of repulsive forces between the hydrogen atoms on double-bonded carbons, may find the notion of DHA as a quick-change artist confusing. But a new and more accurate understanding of DHA has emerged very recently from studies using nuclear magnetic resonance and other techniques. To explain this flexibility, Klaus Gawrisch at the National Institute of Health’s Laboratory of Membrane Biochemistry and Biophysics points to the extremely low potential barriers to rotation about the carbon-carbon bonds between the double bonds: these permit DHA, and other polyunsaturated fatty acids, to rapidly change conformation without expending significant energy. William Stillwell and Stephen R. Wassall discuss the unusual properties of DHA in “Docosahexaenoic Acid: Membrane Properties of a Unique Fatty Acid,” Chemistry and Physics of Lipids 126 (2003): 1–27; see also D.C. Mitchell, K. Gawrisch, B. J. Litman, and N. Salem, Jr., “Why Is Docosahexaenoic Acid Essential for Nervous System Function?” Biochemical Society Transactions 26 (1998): 365–70. 169 P. 7 And this rarity I will not attempt to cite the many thousands of studies linking deficiency in omega-3s to a long and growing list of illnesses . For an overview of the field and a more complete list of references, see Andrew Stoll, The Omega Connection (New York: Simon and Schuster , 2001); William Lands, Fish and Human Health (Orlando, FL: Academic Press, 1986); or Artemis Simopoulos and Jo Robinson, The Omega Plan (New York: HarperCollins, 1998). Other excellent resources are William E. Connor’s “Importance of n-3 Fatty Acids in Health and Disease ,” American Journal of Clinical Nutrition 71 (2000): 171S–175S, and the Power-Pak program for pharmacists, physicians, nurses, and dieticians written by Doug Bibus and released August 1, 2001: Omega-3s: Implications in Human Health and Disease (for availability, contact PowerPak at www.powerpak.com). Also, I assert that there is a connection between an insufficiency of omega-3s and certain kinds of cancers even though a RAND Corporation study published in January 2006 in the Journal of the American Medical Association found no significant association between omega-3s and the incidence of any cancers. This study, like so many attempting to understand the role of specific fats in health and disease, failed to take into account the competitive interactions between different fats and to understand that no fat can be examined in a vacuum. It is for this reason that epidemiological studies and animal studies, many of which do show striking associations between a high percentage of omega-3s in the diet and low incidences of certain cancers, are so important. Epidemiological findings are a reflection of total dietary intake over long periods of time; the diets of experimental animals can be precisely controlled. Experimental studies are also revealing the actual mechanisms whereby omega-3 fatty acids reduce cancer growth, some of which are discussed in later chapters. (Catherine H. MacLean et al., “Effects of Omega-3 Fatty Acids on Cancer Risk,” Journal of the American Medical Association 295 [2006].) P. 9 But it’s time we learned that certain fats A. J. Hulbert, N. Turner, L.H. Storlien, and P. L. Else, “Dietary Fats and Membrane 170 NOTES Function: Implications for Metabolism and Disease,” Biological Reviews 80 (2005): 155–69. P. 10 The new strains Soybeans typically produce oil with about 7 percent alpha linolenic acid. A new variety created by researchers at Iowa State University produces oil with only 1 percent. A university spokesperson, while boasting that this oil, which was developed through conventional hybridization, will help reduce the amount of trans fats in the food supply, does not mention that it will also reduce the amount of omega-3s (Walter Fehr, “New Soybean Oil Eliminates Need for Hydrogenation and Cuts Trans Fats,” Ag Decision Maker Newsletter, November 2003,www.extension.iastate.edu/agdm/articles/others/FehrNov03 .htm [accessed January 7, 2005]). Varieties of rapeseed used to produce canola oil generally have 8 to 10 percent alpha linolenic acid, but one new variety has only 3 percent (R.K. Downey, “Canola: A Quality Brassica Oilseed,” in Advances in New Crops: Proceedings of the First National Symposium...