The formulation delivered 432 mg of fatty acids per cup. The U.S. Department of Agriculture suggests daily consumption of 250 mg per day in healthy adults.
The fortified product passed consumer panel testing, according to the researchers. Twenty-five volunteers evaluated 1-oz cups of standard 2% milk alongside samples of skim milk containing 78 parts butter oil to 22 parts fish oil in institutionally approved study conditions.
“We couldn’t find any aroma differences,” said Susan E. Duncan, a professor of food science and technology in the College of Agriculture and Life Sciences. “We were concerned the fish oil would undergo a chemical process called oxidation, which would shorten the milk’s shelf life, or the milk would acquire a cardboard or paint flavor by reacting with the fish oil. It appears we have a product that is stable, with no chemical taste or smell issues.
“I think the dairy industry can look at our study and determine whether it is plausible to modify its products. I would like to help people who love milk, yogurt, and dairy, which have intrinsic nutritional value, address an additional need in their diets, especially if they don’t like to eat fish or can’t afford it. One of these dairy servings a day apparently is enough to sustain enough continuous omega-3 to benefit heart health.”
If such a product catches on with consumers, Ms. Duncan said the next step for researchers is to follow groups of volunteers in an epidemiological study of whether the food improves health outcomes.
“Milk was first fortified with vitamin D as a way to fight rickets — a disease that leads to soft or weak bones,” said Kerry E. Kaylegian, a dairy foods research and extension associate with Penn State’s College of Agricultural Sciences, who was not involved in the research. “It was a good approach to address a dietary deficiency disease, because so many people drink milk, which is already loaded with nutrients.
“This study describes fortification of milk with omega-3 fatty acids EPA and DHA. We can’t say lack of those compounds definitively causes cardiac disease, but there is evidence that they protect us and contribute to heart and brain health. Milk would be a good delivery vehicle for those nutrients.”