Even the savviest shoppers can be confused by the complicated impact of different fats in the diet. A registered dietitian/nutritionist explains these fatty obfuscations in a way consumer can understand.
Cheryl Winter, M.S., R.D., R.N., explains why not all fats are bad and reviews the three major categories of dietary fats: saturated fats, monounsaturated fats and polyunsaturated fats. Saturated fats elevate low-density lipoprotein (LDL) cholesterol and should be limited in the diet; however, diets higher in monounsaturated and polyunsaturated fats are known to decrease the 'bad' LDL-cholesterol, without lowering the 'good' high-density lipoprotein (HDL) cholesterol.
She then goes on to explain the two subclasses of essential fatty acids (EFAs) within the polyunsaturated fats category, omega-6 and omega-3 EFAs. The principle omega-3 fatty acid is alpha linolenic acid (ALA), which is converted into docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in a healthy person. She noted when EPA and DHA are consumed from fish and fish oils, the body does not have to convert them.
Linoleic acid is the principal omega-6 fatty acid, and it is abundant in most cooking oils, including sunflower, safflower, soybean and corn oil, as well as processed foods, she wrote. A healthy person will convert linoleic acid into gamma linolenic acid (GLA), which is then synthesized with EPA into eicosanoids. Eicosanoids are hormone-like compounds that aid in many body functions, and promote heart health by preventing blood platelets from clotting and sticking to the artery walls. Eicosanoids also play a role in the reduction of inflammation.GLA is also metabolized to arachidonic acid, which has been shown to have properties of increased inflammation and increased clotting. However, these potentially negative effects can be avoided if a person eats the correct ratio of omega-6s to omega-3s. She recommended a ratio of 1-2:1, but said the current American diet is closer to 10:1. She suggests intakes of 1.5 g/d of each of the EFAs
She wrote that not only do Americans need to increase their intakes of omega-3 EFAs, they should also reduce the amount of omega-6 EFAs because too much omega-6 fatty acids will inhibit the conversion of plant-based ALA to EPA, thereby reducing the full benefits of the omega-3s.
A statement at the end of the article said this article is available for reprint and provides contact information for Winter. This may be a valuable print-out to hand to omega-3-interested shoppers, or it could make a nice addition to a store newsletter.