Improving the health image of saturated fats appears formidable. The American Heart Association lists both trans-fatty acids and saturated fats as "The Bad Fat Brothers" while the Dietary Guidelines for Americans also puts a limit on intake of these saturated fats. Yet some people in the food processing industry, especially proponents of stearic acid and palm oil, have taken on the challenge, although with different arguments.
Stearic acid, a saturated fat, should be viewed as a "neutral fat" that may replace trans fat, a "bad fat," in food products, said speakers at the presentation "Scientific literature review of dietary stearic acid health effects and safety" given at the Institute of Food Technologists 2008 Annual Meeting and Food Expo in New Orleans. Stearic acid, the speakers said, is a "neutral fat" because it has little effect on cholesterol, either high-density lipoprotein (H.D.L. or "good" cholesterol) or low-density lipoprotein (L.D.L. or"bad" cholesterol). Trans fat increases L.D.L. and decreases H.D.L.
Other kinds of saturated fat beside stearic acid raise both H.D.L. and L.D.L. The report "Recent Developments in Saturated Fat Nutrition" from Loders Croklaan, Channahon, Ill., wants research and heart health guidelines to focus more on the ratio of total cholesterol to H.D.L. than on just total cholesterol.
"The new paradigm is that saturated fats don’t really do anything," said Dr. Gerald P. McNeill, Ph.D., director of R.&D. and marketing for Loders Croklaan, about heart disease. "They are the same as carbs and the same as protein. They have no effect one way or another."
The ‘neutral’ fat
Dr. Penny Kris-Etherton, Ph.D., a professor in the Department of Nutritional Sciences at Penn State University, spoke at the I.F.T. presentation. She has reviewed scientific studies in which stearic acid was substituted for trans fats. The studies revealed a decrease in L.D.L.
The I.F.T. presentation also said controlled trials consistently found stearic acid to have neutral effects on plasma lipids, lipoprotein and most hemostatic factors compared to other long-chain saturated fatty acids, trans-fatty acids and carbohydrates.
According to the A.H.A., a percentage of stearic acid in the body is converted to oleic acid, a monounsaturated or healthy fat.
"Even though stearic acid is a saturated fat, studies have suggested that it has little effect on blood cholesterol levels, because such a high proportion is converted to oleic acid," the A.H.A. said.
The A.H.A. recommends people limit intake of saturated fat to less than 7% of their overall energy intake and trans fat to less than 1%. The 2005 Dietary Guidelines for Americans recommends people consume less than 10% of calories from saturated fatty acids. It does not give a percentage for trans fat.
The Food and Drug Administration should consider separating out stearic acid underneath the saturated fat listing on the Nutrition Facts Panel, such as it does for sugars and fiber under the carbohydrate listing, said Robert Earl, senior director of nutritional policy for the Grocery Manufacturers Association, Washington.
Such a move may benefit the health image of chocolate. Cocoa butter is 60% saturated fat, but more than 50% of that saturated fat is stearic acid, said Alison Bodor, vice-president of regulatory and scientific affairs for the National Confectioners
Association, Vienna, Va. She gave an example of a dark chocolate product that had 7 grams of saturated fat, which included 4 grams of stearic acid.
Stearic acid is mainly found in animal products, and it’s also in some plant foods like chocolate, according to the A.H.A. New soybeans are in the pipeline that will have increased levels (about 25%) of stearic acid, according to the United Soybean Board. The soybeans may be on the market in the next four to six years.
The health aspects of H.D.L.
The Loders Croklaan report, "Recent Developments in Saturated Fat Nutrition," said stearic acid is not a healthier alternative when compared to other kinds of saturated fat. While the report admits other kinds of saturated fat raise total cholesterol, which stearic acid does not, the report also said other kinds of saturated fat raise H.D.L. or "good" cholesterol, which stearic acid does not.
"Stearic acid is certainly better than trans fat, but so are (other) saturated fats," said Dr. McNeill.
The report pointed to a Harvard School of Public Health study that appeared in 2005 in the American Journal of Epidemiology. A graph in the study showed increasing intake of saturated fat had no effect on heart disease, neither increasing nor decreasing risk, according to the Loders Croklaan report.
The Harvard researchers said, "Intakes of saturated fat and monounsaturated fat were not statistically significant predictors of C.H.D. (coronary heart disease) when adjusted for non-dietary and dietary risk factors. However, the ratio of polyunsaturated fat to saturated fat was inversely associated with risk of C.H.D."
Dr. McNeill, whose Ph.D. is in biochemistry, said he has reviewed scientific literature on fats and cholesterol.
"I can read these papers from cover to cover," he said. "Saturated fat in general raises H.D.L. a lot. Saturated fat raises good cholesterol more than anything we can eat."
He added many tests, up until 2004, lumped trans fats in with saturated fats, thus skewing results.
"In the 1970s trans-fat intake increased dramatically, but it was hidden from consumers and hidden from nutrition researchers," he said.
The health image of saturated fat has an impact on palm oil since it is about 50% saturated fat. Palmitic acid, the main saturated fat in palm oil, increases H.D.L. and L.D.L. by similar amounts, Dr. McNeil said.
The A.H.A. commended H.D.L. levels in a July 1 release on a memory loss study.
"H.D.L. cholesterol, which at high levels decreases the risk of heart attacks, serves several vital biological functions," the A.H.A. said. "It helps clear excess cholesterol from the blood; assists nerve-cell synapses to mature; and helps control the formation of beta-amyloid, the major component of the protein plaques found in the brain of Alzheimer’s patients."
Yet the A.H.A. criticized saturated fats in the same release.
"To raise H.D.L. and lower L.D.L. cholesterol, the American Heart Association recommends exercising regularly; eliminating trans fats from the diet; reducing the intake of all fats, especially saturated fats; and consuming monounsaturated fats, such as olive, canola and peanut oils," the A.H.A. said.
Consumers view trans fats, saturated fats negatively
Consumers viewed both saturated fats and trans-fatty acids as unhealthy in two recent surveys.
The International Food Information Council’s "2008 Food & Health Survey" showed 91% of respondents in 2008 said they were aware of trans fats, up from 87% in 2007. Awareness of saturated fat came in at 90% in 2008, up from 88% in 2007. Eighty per cent of consumers viewed saturated fat as not healthful in 2008 while 79% thought the same about trans fats.
The web-based survey conducted by Cogent Research, Inc., Cambridge, Mass., involved 1,000 respondents.
In the United Soybean Board’s "Consumer Attitudes About Nutrition" survey, 6% viewed saturated fats as very or somewhat healthy while 9% viewed trans fats as very or somewhat healthy. The survey also asked consumers to choose which was healthier, saturated fat or trans fat. In 2008, 36% selected saturated fat and 17% selected trans fat, which compared with 2007 results of 42% for saturated fat and 16% for trans fat.
"The narrowing gulf between trans and saturated fat perception suggests the need for food companies to develop products low in both of these harmful types of fat," the United Soybean Board said.
An independent research firm conducted the study in February. It included 1,000 random surveys.
This article can also be found in the digital edition of Food Business News, October 14, 2008, starting on Page 1. Click