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CORVALLIS, Ore. - A research program at Oregon State University has built a better egg.

About 15 years of research by an OSU poultry scientist has created systems to produce chicken eggs that are enriched in omega-3 fatty acids, and studies are continuing in an effort to incorporate conjugated linoleic acids, or CLAs.

When perfected, eggs may be available with significant amounts of both these types of fatty acids, providing valuable protection against heart disease and cancer while aiding the immune system.

Researchers say this accomplishment could create some new and attractive dietary options for health-conscious consumers, who increasingly get fewer and fewer of these nutrients because people are often eating less of their traditional sources, meat and dairy products. The research could also provide a boost to both the fresh egg and processed egg industries.

"These are some advances that so far have just barely begun to catch the attention of consumers," said Gita Cherian, a pioneer in this field of research, leader of this program in OSU's Agricultural Experiment Station and the Walther H. Ott Professor of Poultry Science at OSU.

"But in fact, the work to put omega-3 fatty acids into eggs is already well along, and you can find eggs with this feature in many supermarkets," Cherian said. "A high dietary level of omega-3 fatty acids has been shown by good scientific studies to have value for cardiovascular health."

Less far along and facing larger obstacles of cost, efficacy and taste testing is the work with CLAs, Cherian said. The conjugated linoleic acids, she said, may have value in cancer prevention and tumor suppression. Eggs that could feature both omega-3 and CLAs would have a powerful consumer appeal and might also find demand in processed foods that used lots of eggs, such as salad dressing, pasta, mayonnaise or other products.

The fortified eggs, Cherian said, can be produced by feeding chickens certain additives containing CLA oils and fish oil or flaxseed.

According to Cherian, animal studies show that 3.0 grams per day of CLAs may be needed for beneficial health effects. These fatty acids are not produced by the human body and can only be obtained from certain foods.

"Most of us don't get anywhere near that much of these fatty acids," she said. "The average dietary intake is less than one gram per day, not three. But we've been able to put about 400 milligrams of CLAs into the egg yolk lipids of a single egg.

"If these products were incorporated into a routine healthy diet," Cherian added, "it could have a substantial health benefit."

The OSU researcher said work still needs to be done to find less expensive feed sources for CLAs, and to explore the effect they have on fortified egg yolks, which appear to become a little more hard and "rubbery" than yolks from conventional eggs. Other taste and consumer testing is also needed, she said.

Use of these feed additives with chickens does not appear to affect the health of laying hens or their egg production, researchers have found.

According to Cherian, part of the overall concern about adequate dietary levels of fatty acids has been due to the increasing emphasis on low fat diets.

"Animal products contribute about 70 percent of the total fatty acids in a typical western diet," Cherian said. "And the proper concern in recent decades about the health risks of a high fat diet has caused many people to significantly cut back on their intake of many animal products, to the point that most people do not consume the levels of fatty acids that are associated with health benefits."

Research also suggests that these fatty acids are incorporated and retained better by tissues when their consumption is associated with a food, as opposed to dietary supplements.

The consumption of eggs has also fallen for almost 50 years, although some surveys suggest it began to rise again in the mid-1990s. Contradictory reports circulated about whether the cholesterol in eggs was a health risk. More recent research suggesting that egg consumption did not have a pronounced effect on blood cholesterol may have helped stem the decline in consumer preference for eggs, which otherwise are rich in a variety of nutrients.

Published studies done by Cherian's research group in the past two years have found that incorporation of CLA into chicken eggs produces a lipid-stabilizing antioxidant effect and reduction in the content of volatiles. And feeding CLA-rich eggs to rats resulted in significant increases in CLA in the rat tissues.