'Immune' milk yields hearty benefits.

Though calcium can lower cholesterol in the blood, this does not appear to explain all of the anticholesterol effects attributable to milk -- at least not to "immune" milk. Researchers in New Zealand have shown that the antibody-rich skim milk from cows vaccinated against particular strains of 16 species of human-gut bacteria lowers cholesterol more than skim milk with equivalent calcium from nonimmunized cows.

No one was more surprised by the data than nutritionist Susan J. Sharpe, who led the study at the University of Auckland School of Medicine. Though unpublished data from studies on animals and at least one published human trial in Switzerland had hinted at immune milk's cholesterol-lowering properties, her team remained unconvinced. But then the milk's developer approached them with the idea of putting its product to the test. "We thought [our patients] could not come to any harm by taking extra milk," Sharpe recalls, and the study would give the university's cardiology clinic a chance to monitor how well participants -- all with moderately high cholesterol concentrations (209 to 360 milligrams per deciliter) -- adhered to a newly prescribed low-fat diet. So they agreed.

In the April AMERICAN JOURNAL OF CLINICAL NUTRITION, Sharpe and her colleagues report on cholesterol data collected at 2-week intervals. After observing 17 men and 13 women for more than 2 months, researchers assigned them at random to groups drinking two glasses of reconstituted powdered skim milk daily from either normal or hyperimmunized cows. After 10 weeks, participants stopped the supplementation and continued to eat normally for 4 weeks. Then each began an additional 10-week course of drinking the other type of milk.

The drinks, which tasted identical and had comparable amounts of nutrients, added the equivalent of 1 liter of milk to each participant's daily diet.

Compared to when they drank regular skim milk, participants experienced an average 5 percent drop in cholesterol concentrations while drinking the immune milk and a 7 percent lowering of low-density lipoprotein (LDL) cholesterol--the so-called bad cholesterol. Moreover, the Auckland team observed a novel and apparently unrelated trend toward lower blood pressure with both milks -- though only the immune milk lowered both systolic and diastolic blood pressure.

Stolle Research and Development Corp. of Cincinnati patented immune milk in 1988 for treating rheumatoid arthritis. Though marketed only in Taiwan today, the milk is undergoing federally approved human trials to document its antiarthritis and anticholesterol effects. Moreover, notes Stolle's Daniel Gingerich, basic research within the company is exploring mechanisms for the milk's apparent benefits because these effects remain "surprising and, at this point, unexplained."