Fat substitutes of the future may do more than reduce your fat intake, thanks to University of Georgia research.

Casimir Akoh, a food science professor with the UGA College of Agricultural and Environmental Sciences, is developing fat substitutes designed with added health benefits.

"People are asking, 'What's in this oil for me?' and that's the question I'm trying to answer," he said. "I'm working on fats that are beneficial, but don't make you too fat."

To do this, Akoh modifies the fat to enhance the way our bodies absorb it. He is also creating new fats with nutritional benefits.

Lower Cholesterol, Improve Brain Development

"When these new fats are absorbed, they will help boost your immune system," Akoh said. "When added to food products, they help improve food properties and can help hospital patients recover quicker, help lower cholesterol, and even improve brain development."

Akoh is fashioning a variety of healthy, digestible low-calorie fat substitutes, called structured lipids, by exchanging properties of one fatty acid for those of another. One of his fat substitutes was created from medium- and long-chain fatty acids from fish oil.

To create the new fat substitutes, Akoh uses enzymes to blend long-chain fatty acids, like those in vegetable and fish oils, with short- or medium-chain fatty acids. The long-chain fatty acids provide nutritional qualities, while the short- and medium-chain fatty acids metabolize faster and provide quick energy.

"The combination of fatty acids is important," he said, "because they each deliver benefits via two different physiological pathways: the long chains through the lymph system, and the short and medium chains through the circulatory system."

It Has to Taste Good

"Consumers want foods with minimal to no fat or calories, but they also want foods that taste good," he said. "Because several foods containing fat replacers don't compare favorably with their full-fat counterparts, it's difficult for some people to maintain a reduced-fat diet regime."

A perfect example is the fat replacer Olestra, which was developed by Proctor & Gamble. Olestra is used as a fat substitute in such snack products as fat-free Pringles potato chips.

"Our bodies don't absorb or metabolize Olestra," said Akoh. "This causes Olestra to have side effects like abdominal cramping and loose stools."

Despite the possible side effects, Akoh said consumers do get health benefits from Olestra as a replacement for conventional fat.

Unlike Olestra, which is marketed to people on reduced-fat diets, Akoh's new oils would be targeted to more specific consumers.

Helping Targeted Groups

"We're trying to develop these oils for specific groups, like people with cystic fibrosis or AIDS patients," he said. "The oil would be created especially for their health needs."

In lab tests, Akoh's fish-oil structured lipid (fat substitute) has been shown to reduce cholesterol by 49 percent and boost the immune system by increasing thymus cells 19 percent. The thymus is a ductless gland composed mainly of lymphoid cells. It plays a part in the body's immune system.

"This could be of benefit to AIDS patients who have low T-cell counts," he said.

These new fats could be used in salad dressings, beverages, infant formulas and medical intravenous solutions. So far, though, they haven't made it into the commercial market.

"Right now, there's no single, ideal fat replacer that can recreate all the functional and sensory attributes of fat," Akoh said.

"Consumers just have to remember that there's no 'magic bullet' to achieving dietary goals," he said. "You should combine proper nutrition, dietary variety, a healthy lifestyle and regular exercise, and reduce your total dietary fat by choosing foods formulated with fat replacers."

(Jane Sanders contributed to this article.)