Milk protein may reduce high blood pressure

A section of a protein derived from milk appears to reduce blood pressure in people with hypertension, results from a small study suggest.

After taking the casein peptide, called C12, a group of ten people with high blood pressure experienced an average drop of 9 points in systolic pressure, the upper number in a blood pressure reading. Diastolic pressure, the lower number, fell by an average of 6 points.

Lead author Dr. Raymond R. Townsend of the University of Pennsylvania in Philadelphia stressed that with only ten people in the study, these findings cannot be used to make treatment recommendations.

"We're not going to stand up and say this is how you need to manage high blood pressure," he said. "It's not the be all and end all for blood pressure. But it's intriguing."

However, he noted that he and his team are continuing their research, now asking 50 people to take the milk protein fragment every day for 8 weeks.

Both studies are funded by DMV International, a Dutch company that sells ingredients to the food and pharmaceutical industries.

In an interview, Townsend told Reuters Health that this experiment came out of a long history of research. In the 1960s, for instance, investigators found they could help control high blood pressure using sour milk.

Previous studies in rodents and humans have suggested that the C12 section of casein may reduce blood pressure as well as conventional medicines called angiotensin-converting enzyme (ACE) inhibitors.

To investigate further, Townsend and his colleagues asked ten people with hypertension to take C12 either alone or combined with a seaweed extract called alginic acid, which research suggests may help the body excrete sodium in urine.

As part of the study, participants took an inactive placebo pill for 5 days and then one of five treatments: a placebo treatment, or high or low doses of C12 either alone or combined with alginic acid. Each participant repeated this five times, in order to try each treatment.

When people received the high dose of C12 along with alginic acid, their systolic pressure and diastolic pressure fell significantly more than after the placebo, Townsend and his team write in the American Journal of Hypertension.

No patients reported any side effects.

Townsend explained that people likely would not get the same benefits of C12 by drinking lots of milk. Dairy contains a lot of salt, which can be bad for blood pressure, he said, and people would have to consume an impossible amount.

"The amount of milk you would need to get this effect would be on the order of gallons," Townsend said.

SOURCE: American Journal of Hypertension, November 2004.