Are all fats created equal? Not when it comes to their impact on health.
Among the three types of fat, the monounsaturated and polyunsaturated fats found in oils are generally considered better for your heart than the saturated fats found in lard. But there are important differences even among the polyunsaturated fats. The human body can make all but two fatty acids – linoleic and alpha-linolenic acid. Both of these fatty acids are essential for cell structure, body function and immune response, and must be provided through foods. Because of differences in chemical structure, linoleic acid is classified into the omega-6 fatty acid family and alpha-linolenic acid, or ALA, into the omega-3 fatty acid family.
The entire group of omega-3 fatty acids has been the subject of much research in recent years for their role in helping to prevent a myriad of issues from pre-term labor among pregnant women to heart disease in adults. In addition to ALA, much attention has been placed on docosahexaenoic acid (DHA), docosapentaenoic acid (DPA) and eicosapentaenoic acid (EPA). Of these, only ALA is considered essential, meaning that the body can’t make it from other fats and therefore must obtain it through foods. While the other three fatty acids can be synthesized from ALA, the conversion process is very slow, so direct consumption of these fatty acids through foods is recommended.
DHA is considered particularly important to the optimal development of an infant’s brain and eyes, both during pregnancy and after birth. In addition, DHA may help prevent preterm labor and may help protect against postpartum depression. During pregnancy, the fetus receives DHA from its mother through the placenta. Transfer of DHA from the mother to the fetus is greatest during the third trimester, a period of rapid development for the brain and nervous system. After birth, breast-fed infants continue to receive DHA through their mother’s milk.
Pregnant and breast-feeding mothers are encouraged to pay special attention to their diets to ensure an adequate consumption of foods rich in DHA. Cold-water fish, such as salmon, herring, mackerel and whitefish, and DHA-enriched eggs are our best dietary sources of DHA. Long-lived larger fish, specifically shark, swordfish, king mackerel and tilefish, are also good sources of DHA, but not recommended during pregnancy because they tend to be contaminated with high levels of methylmercury.
The latest information on omega-3 fatty acids and health will be focus of day two of this year’s Lillian Fountain Smith Conference for Nutrition Educators scheduled for June 9 and 10 at the Marriott Hotel in Fort Collins, Colo. Dr. Jay Whelan with the University of Tennessee will open the Friday session with a discussion of which omega-3 fatty acids benefit health. Next, Dr. Mary Harris from Colorado State University will present new research related to omega-3 fatty acids and pregnancy outcomes. Finally, Dr. Kate Claycombe from Michigan State University will discuss the role of omega-3 fatty acids in obesity-aggravated heart disease.
The two-day Smith Conference is sponsored by the Department of Food Science and Human Nutrition at Colorado State University and is open to the public. Registration is $95 for both days; $50 for one day. For more information, contact Pam Blue at (970) 491-7435 or check out the conference Web site at www.cahs.colostate.edu/fshn/LFSC/.
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by Pat Kendall, Ph.D., R.D., Food Science and Human Nutrition Specialist, Colorado State University, Cooperative Extension