Quality Over Quantity Matters for Fatty Acids
With the recently issued U.S. Food and Drug Administration (FDA) rule removing partially hydrogenated oil (trans fats) from the generally recognized as safe (GRAS) list, there has been a renewed focus on the role of fats in the diet. In session 011, “Outlook on Healthy Oils,” which took place Sunday morning, three industry experts examined the latest science on fatty acids and put the data into the context of the 2015 Dietary Guidelines Advisory Committee (DGAC) recommendations.*
Penny Kris-Etherton, distinguished professor of nutrition at The Pennsylvania State University, kicked off the session by summarizing some of the key DGAC recommendations regarding fats and taking an in-depth look at current scientific studies. The 2010 Dietary Guidelines for Americans recommended that saturated fats be replaced by unsaturated fats. The same is true for the 2015 DGAC recommendations, except that the new recommendations emphasize the replacement of saturated fats with polyunsaturated fats, and not monounsaturated fats. In addition, the big difference in the 2015 DGAC recommendations is that they focus on optimizing types of dietary fat and not reducing total fat. The low-fat trend is out and instead the focus is on the quality and types of fat.
As Kris-Etherton explains, this move to focus on reducing and replacing saturated fats with polyunsaturated fats is backed up by current research. Multiple studies show that replacing saturated fatty acids (SFAs) with polyunsaturated fatty acids (PUFAs) significantly reduces total and LDL cholesterol and the risk of cardiovascular disease (CVD). She notes, however, that this is not to say monounsaturated fats aren’t good for you—it’s just that there is not enough research to provide a robust evidence base. There is some growing evidence that monounsaturated fatty acids beneficially affect cardiometabolic risk and decrease visceral adiposity.
The second speaker, Cyril W. C. Kendall, research associate in the Department of Nutritional Sciences, Faculty of Medicine at the University of Toronto, discussed fatty acids in the context of healthy dietary patterns. As he explained, because the traditional African diet was high in fiber and low in fat, the population had very low rates of chronic disease. When this investigation started around 50 years ago, it launched—to some extent—the low-fat trend that would really take off in the 1970s. According to Kendall, that’s the decade when people really started to reduce their total amount of fat (the low-fat trend) and the amount of carbohydrates consumed began to increase dramatically. However, as obesity and diabetes rates increased, it finally become apparent in the early 2000s that the low-fat diet wasn’t working.
Kendall went on to showcase some studies that demonstrate that there is an increased risk for chronic disease with high glycemic index diets and Western dietary patterns. On the other hand, there is a decreased risk with the DASH (Dietary Approaches to Stop Hypertension), low glycemic index, and vegetarian diets. In addition, studies have shown that the Mediterranean diet—high in olive oil and produce and low in milk, meats, and simple sugars—reduces blood pressure and CVD events while improving the lipid profile. Kendall concluded his presentation by emphasizing an increase in the consumption of plant proteins, fiber, and whole grains, while looking at the quality of fat and carbs in the diet.
The final speaker, David Dzislak, North American commercial leader for grains and oils at Dow AgroSciences, examined the impact of the changing opinion of fats on the oils industry. In 2004, 65% of all vegetable oils used in the United States were hydrogenated. It was at that time that the trans fat labeling came into effect and drove a huge conversion across the food industry. However, Dzislak pointed out that the industry still has about 2 billion pounds of partially hydrogenated oils to transition from, which the GRAS status removal has accelerated. Today, canola oil is the second largest oil used by the U.S. food industry due to its scalability, stability, and applicability. In addition to canola, the industry is developing new profiles of palm, sunflower, and soybean oil to meet the growing demand for healthy oils.
*Note: These are just the recommendations by the Advisory Committee and do not necessarily reflect the final 2015 Dietary Guidelines for Americans that have yet to be released.