Nutritional lipids are the fats which--along with polyunsaturated and monounsaturated counterparts--are recommended to enhance the quality of human life. They are rumored (and in some cases, proven) to combat cardiovascular disease, arthritis, diabetes, cancer, macular degenerative eye disease, attention deficit disorder and well...just about every condition under the sun.

“The science behind the effects of dietary fat on human health is so complex that there are no simple and straightforward answers to the questions in the field today,” says Nurhan Dunford, assistant professor and oil/oilseed chemist at Oklahoma State University (Stillwater, Okla.). For example, some manufacturers now see trans fatty acids (TFA) as a curse to be exorcised from their products. However, few recognize that one TFA, conjugated linoleic acid (CLA), a milk-fat product found in ruminant animals and their products, has been shown to fight cancer and arteriosclerosis in regulated, scientific studies. The most surprising characteristic of CLA is that it may also reduce body fat by preventing fat accumulation in fat cells.

“CLA has a rearrangement of linoleic acid's (LA) molecular structure, resulting in a unique fatty acid with proven clinical health benefits,” says David Lewis, North American business unit manager at a company that supplies manufacturers with nutritional lipids.

The Key to Weight Loss?

Weight management benefits are not all that CLA offers. It also is responsible for boosting the immune system. Although conjugated fatty acids in milk fat were identified 66 years ago1, it was not until the late 1970s when Michael W. Pariza and his research team at the University of Wisconsin (Madison, Wis.) isolated CLA from grilled ground beef. They found that CLA would inhibit the development of tumors in mice. “Pariza's discovery set off an explosion of research in this area,” says Lewis.

“Incorporation of CLA into prepared foods requires controlled processing conditions to minimize conversion of CLA to undesirable isomers,” says Dunford. Over 20 isomers of CLA have been identified. It is believed that cis-9, trans-11 and trans-10, cis-12 isomers of CLA are the most active forms.

CLA is mostly marketed as a dietary supplement often produced from safflower oil. “Licensed versions of a new, isomerized safflower oil have been shown to increase antibody production, stimulate the active immune system and help protect against colds and flus. The isomerized safflower oil version of CLA enhances immune health by increasing anti-inflammatory mediators and inhibiting infections and allergy-related antibodies,” says Lewis. Dosage recommendations of CLA for weight management benefits--such as reduction of body fat and increased lean muscle mass--can be between 2.5-3g daily. And dosages of the isomerized safflower oil for immune benefits can be seen at 2g daily.

“Dairy products, especially, are good, natural sources of CLA,” says Dunford, who suggests that CLA-enriched frozen dairy desserts have been considered. “The glyceride oil and powder form of CLA has a 'clean' taste, meaning that it will not affect the flavor profile of the end-product in food applications,” declares Lewis.

According to Dairy Management Inc. (Rosemont, Ill.), CLA will not be counted as a trans-fat, due to its many beneficial characteristics. Thereby, it will be exempt from the proposed USDA ruling requiring trans fat labeling. Even before CLA was recognized as self-affirmed GRAS by one company in August 2004, the dietary supplement community was spellbound with its “ne'er do wrong” image. Mintel's GNPD reports that 33 new international products touting CLA in the Mintel description were welcomed into the fold in 2004.

The Oleic Acid Connection

Oleic acid found in olive oil has carried this notion further than any other MUFA. In 2004, Mintel's GNPD reports that 1,743 new consumable product descriptions used the phrase “olive oil” or “oleic acid.” This represented a 28% increase from new products initiated with the same description in 2003 (see chart for search criteria).

Dunford references a study published in the American Journal of Clinical Nutrition2, which examines the changes in the ratio of omega-6 to omega-3 in the food supply over several decades. Between 1935 and 1955, the ratio increased from 8.4:1 to 10.3-12.4:1, but the ratio appeared to decrease from 1985 to 1994 (12.4:1 to 10.6:1). “This shift was attributed mainly to changes in vegetable oil consumption patterns, specifically the increase in canola oil consumption,” says Dunford.

She attributes this to canola oil's low ratio of omega-6 to omega-3 fatty acids. Next to olive oil, canola oil, also a MUFA, has more oleic acid than most other dietary oils. According to the GNPD, in 2004, manufacturers increased product launches with canola oil by 48% more in 2004 than they did in 2003. Nana's Cookie Bars (San Diego) represent one of several products in 2004 that have relinquished hydrogenated oils for canola oil.

Manufacturers do not seem inclined to look beyond olive oil's original placement as a complement ingredient in Mediterranean food products. The GNPD shows that less than 9% of U.S.-based products mentioning olive oil in their product descriptions are placed in the desserts and frozen dairy desserts, bakery, beverages, breakfast cereals and confectionery categories (in 2004). Comparatively, canola oil is found in 28% of the same product categories. Olive oil's stronger flavor may be the reason it is used less often in these applications.

PUFAs include not only linoleic acid (omega-6), but also alpha-linolenic acids (ALA or omega-3), arachidonic acid (ARA), eicosapentanoic acid (EPA) and docosahexanoic acid (DHA). “There are large gaps in present knowledge of lipid requirements in humans. We know that there are certain lipids that are required at different amounts or at different stages of growth,” explains Dunford. Omega-3 derivatives EPA and DHA are essential for infants and the prenatal, especially as it applies to brain and visual development. As such, they are heavily incorporated into infant formulas.

In the U.S., aside from pet food, the infant formula category is almost the sole carrier of DHA-containing products. According to Mintel's GNPD list, aside from dietary supplements, products such as biscuits, ice cream and butter were among the 28 U.S. products cataloged as containing EPA in 2003. In December 2004, Nestle (Glendale, Calif.) Good Start Supreme launched a soy-based infant formula with DHA and ARA. In adults, studies have demonstrated that EPA and DHA can improve blood flow, reduce high blood pressure and promote healthy blood triglycerides.

Many food products developed in the U.S. are highly refined to improve shelf stability. “Nutritionally beneficial, minor oil components are lost during the oil-refining process, especially during alkali refining which removes free fatty acids from the crude oil,” says Dunford.

Stability and extended shelflife, which are otherwise displayed in saturated and hydrogenated fats, is a quality found in high oleic safflower oil. Its shelflife stability contributes to its successful performance as a nutritional lipid. It has a nutritional makeup similar to olive oil and often is blended with olive oil. Hain-Celestial's (Uniondale, N.Y.) Terra Sweet Potato Chips combine safflower, canola and sunflower oils to produce a product without trans fats.

MCT, Not Mediocrity

Butterwick envisions that nutritional lipids with combination effects, such as those that promote weight loss and lower cholesterol, also will be highly sought after.

MCTs, made by esterifying C8 and C10 fatty acids with glycerin, were invented as an energy source for people who have problems metabolizing long-chain fats. MCTs contain no trans fatty acids, and are not promoted as a tool for weight reduction, says Butterwick. However, many food formulators hoping to replace TFAs are looking to MCTs as a potential solution.

“They are stable to oxidation because they are fully saturated. They can be tasteless and odorless, which allow them to act as carriers for flavor extracts,” explains Butterwick.

MCTs provide uniform opacity as a clouding agent in beverages, as plasticizers or softening agents for soft chew or candy confections and as spraying oils to reduce stickiness in dried fruit or raisins. Conversely, they are sprayed onto crackers so that salt and other flavors will stick to the cracker.

Nutritionally, they have been used in sports nutrition products because of their ability to rapidly metabolize and provide quick energy. “MCTs can metabolize in 1/8th the time of normal oil or fat,” says Butterwick. They also make similar health claims as diacylglycerides (DAG).

The metabolization of longer-chain triglycerides contribute to obesity and elevated cholesterol. Excess energy is stored as triacylglyceride (TAG) in adipose tissue. “There are reports indicating that consumption of DAG instead of TAG does not affect excess energy levels but produces metabolic effects, particularly increased fat oxidation, which may be associated with improved appetite control and energy balance,” Dunford affirms. MCTs and DAG oils are metabolized similarly to carbohydrates, and used as energy or calories. “Basically, they don't become fat in the body, so they are slightly less caloric than normal fats,” recognizes Butterwick.

“DAG oils are more likely to be incorporated as an ingredient because of the ease of production and, consequently, reasonable cost and stability,” says Dunford. Nevertheless, with zero U.S. mentions, DAG fell short on recorded 2004 Mintel GNPD product introductions.

That will not be the case in 2005. Enova, which claims to be the best-selling oil product in the Japanese market, soon will be on grocery shelves nationwide after a successful testing season in select U.S. cities. DAG is the major component of Enova, which is produced from soy and canola oils. NS

Much of the information in this article was derived from Mintel International's Global New Products Database, www.gnpd.com, 312-932-0400.

Sidebar1: On the Web: LIPIDS