April 29, 2011
by Jeff Gelski
The search for healthier, more functional fats and oils potentially may benefit from two acids — stearic and stearidonic — that may sound similar but have different characteristics. The body converts stearidonic acid into eicosapentaenoic acid (EPA), a type of omega-3 fatty acid. Stearic acid is converted into oleic acid, another ally in the creation of healthier fats and oils.
Both stearidonic and stearic acids were discussed March 24 in Chicago at Wellness 11, an event sponsored by the Institute of Food Technologists.
Robert Collette, president of the Institute of Shortening and Edible Oils, explained the characteristics of Soymega, a soybean oil with stearidonic acid developed through a collaboration between The Solae Co. and Monsanto, both based in St. Louis. The soybeans used to make Soymega soybean oil are 20% stearidonic acid, compared to 0% for commodity soybeans, Mr. Collette said. Soymega readily converts to EPA, an omega-3 fatty acid found in fish oil, and offers more stability than other omega-3 fatty acid oils, he said.
Soymega may be added to a range of food products, including beverages, baked foods, dairy products, snack foods, prepared foods and oil-based foods, Mr. Collette added.
Stearic acid, meanwhile, is a saturated fat, but studies have suggested that, unlike other saturated fats, it has little effect on blood cholesterol levels, according to the Dallas-based American Heart Association. Stearic acid is mainly found in animal products, and it is also in some other foods like chocolate, according to the A.H.A.
The 2010 Dietary Guidelines Advisory Committee concluded the potential impact of changes in stearic acid intake on cardiovascular disease risk remains unclear, said Roger Clemens, a member of the committee, who spoke at Wellness 11.
The committee concluded moderate evidence from a systematic review indicates that when stearic acid is substituted for other saturated fatty acids or trans-fatty acids, plasma L.D.L. (bad) cholesterol levels are decreased, said Dr. Clemens, a professor in the University of Southern California’s School of Pharmacy. When substituted for monounsaturated fatty acids or polyunsaturated fatty acids, L.D.L. cholesterol levels are increased.
According to the A.H.A., it is believed stearic acid has little effect on cholesterol because a high proportion of it is converted into oleic acid.
High-oleic oils, which offer stability benefits, have served as another source of innovation in creating healthier fats and oils. In 1995 members of the National Sunflower Association made the commitment to change the fatty acid structure of sunflower oil. Now, NuSun oil with oleic levels over 80% is available commercially.
Omega-9 fatty acid oils from canola and sunflowerseed are on the market due to the research and development efforts of Dow AgroSciences, Indianapolis. The company developed Nexera canola and sunflower seeds that have high-oleic content to create the oils. Dow AgroSciences increased the oleic acid content of canola to 75% from 62%. It decreased linolenic acid, which is unstable, to 2% from 10%.
The U.S. Department of Agriculture in 2010 approved the Plenish high-oleic soybean trait from Pioneer Hi-Bred, a DuPont business, for cultivation in the United States. The oil from Plenish soybeans contains oleic acid content of more than 75% and has 20% less saturated fat than commodity soybean oil. Plenish high-oleic soybeans may be grown under contract in the United States in 2011 with commercialization anticipated in 2012.
At Wellness 11, Mr. Collette also spoke about Vistive Gold low-saturate/high-oleic/low-linolenic soybeans, which are in a developmental phase. When they enter the market, they should offer the nutritional benefits of 0 grams of trans fat and the lowest saturated fat levels of soybean oils. Vistive Gold should be useful in frying, spray for crackers/snacks and baking blends.
The Food and Drug Administration already has said it has no problems with a Generally Recognized As Safe (GRAS) status for the use of Vistive Gold soybean oil under the intended conditions of use, including as a fry oil and as a spray oil for crackers and snacks. Monsanto is taking regulatory steps to allow for a full commercial introduction of Vistive Gold soybeans.
“We are currently engaged in an aggressive demand creation, educating food companies on the potential benefits of forthcoming oils,” said Philippe Ballet, food business development director for Monsanto. “The food and agriculture industries must work together to commercialize these types of oils as a viable way to nutritionally improve the food supply in the U.S. There is a critical need to bridge supply and demand, and that requires suppliers, processors and the food industry in general to work together.”
Sources of stearic acid among U.S. population
(18 food sources of stearic acid represent 76.7% of total intake)
Grain-based desserts 8.3%
Regular cheese 6.1%
Sausage, franks, bacon, ribs 6.0%
Chicken and chicken mixed 5.7%
Beef and beef mixed 4.8%
Mexican mixed dishes 4.4%
Dairy desserts 4.3%
Pasta and pasta dishes 3.3%
Fried white potatoes 3.2%
Eggs and egg mixed 3.2%
Reduced fat milk 3.0%
Whole milk 2.6%
Yeast bread 2.5%
Cold cuts 2.2%
Source: 2005-06 NHANES (National Health and
Nutrition Examination Survey)
Dietary changes may reduce triglycerides
Dietary and lifestyle changes, such as substituting healthy, unsaturated dietary fats for saturated ones, engaging in physical activity and losing weight may decrease triglycerides by 20% to 50%, according to a new scientific statement from the American Heart Association, Dallas. Triglycerides are the chemical form in which most fats exist in food as well as in the body, according to the A.H.A. They are associated with heart, blood vessel and other diseases.
The statement, which was published in Circulation: Journal of the American Heart Association, examined research from more than 500 international studies during the past 30 years.
“The good news is that high triglycerides can, in large part, be reduced through major lifestyle changes,” said Michael Miller, M.D., chair of the statement committee and professor of medicine in epidemiology and public health and director of the Center for Preventive Cardiology at the University of Maryland School of Medicine in Baltimore. “In contrast to cholesterol, where lifestyle measures are important but may not be the solution, high triglycerides are often quite responsive to lifestyle measures that include weight loss if overweight, changes in diet and regular physical activity.”
In its scientific statement, the A.H.A. recommended several dietary changes for individuals outside the normal range of triglycerides, including limiting added sugar to less than 5% to 10% of calories consumed, cutting fructose from both processed foods and naturally occurring foods to less than 50 to 100 grams per day, limiting saturated foods to less than 7% of total calories, reducing trans fat to less than 1% of total calories, and reducing alcohol, especially if triglyceride levels are higher or greater than 500 mg/dL.
The A.H.A. also encouraged individuals with triglyceride levels in the borderline to high range (150 to 199 mg/dL) to incorporate physical activities of at least moderate intensity for at least 150 minutes per week. These activities, such as brisk walking, may contribute an additional 20% to 30% triglyceride-lowering effect, the A.H.A. said.
“Triglycerides are an important barometer of metabolic health,” said Neil J. Stone, M.D., co-chair of the statement and professor of medicine in the Feinberg School of Medicine at Northwestern University in Chicago. “When the clinician sees an elevated triglyceride level, there needs to be an important conversation about risk factors and the need to eat less, eat smarter, and to move more on a daily basis to improve triglycerides and the metabolic profile.”
Nearly one-third of adults have elevated triglyceride levels in the United States, the A.H.A. said. People with high triglycerides should replace saturated fats with monounsaturated fats and polyunsaturated fats such as those found in canola oil, olive oil or liquid margarine, according to the A.H.A.
According to Stepan Food & Health Specialties, Maywood, N.J., not all triglycerides are the same. The company’s Neobee medium chain triglycerides (MCTs) are metabolized in a unique way. Unlike typical long chain fats, Neobee MCTs are transported directly to the liver where they are burned for energy. Neobee MCTs have little effect on cholesterol levels under normal circumstances and provide fewer calories per gram than long chain fats, according to Stepan. The low viscosity liquids have oxidative stability and organoleptic properties that allow them to work as flavor solvents or coatings.