The casein peptide, called C12, reduced systolic pressure in the 10 participants by an average of 9 points, while diastolic pressure fell an average of 6 points, write the researchers in the November issue of the American Journal of Hypertension (17(11 Pt 1):1056-8),
"These preliminary data are encouraging and deserve testing in a larger and longer treatment trial," writes Dr Raymond Townsend of the University of Pennsylvania in Philadelphia and colleagues.
Findings from the small study are set to be confirmed in a larger trial on 50 people being carried out by the same team over an eight-week period.
The DMV peptide is already used in supplements, including a product developed by the TwinLab brand, while Japanese food firm Kanebo has created a little bottle drink containing the active ingredient.
Foods that can help control blood pressure present a significant opportunity for industry. About two thirds of strokes and half the incidence of heart disease are attributable to raised blood pressure, according to the World Health Organisation.
Worldwide, high blood pressure is estimated to cause 7.1 million deaths, about 13 per cent of the total and about 4.4 per cent of the total chronic disease burden.
C12 was shortlisted for an award at this year's Health Ingredients Europe show.