May 20/Journal of Technology & Science -- "Natto is a popular traditional Japanese food made by fermenting steamed soybeans with Bacillus subtilis natto. It has long been thought that natto is effective in preventing hypertension," researchers in Tsukuba, Japan, report.

"But there have not been any reports demonstrating in vivo antihypertensive effects of natto. In this study, we demonstrate for the first time the antihypertensive activity of natto in vivo. We determined optimal conditions for producing natto with the highest angiotensin I converting enzyme (ACE) inhibitory activity. An ACE inhibitor partially purified from natto was orally administered as a single dose (1mg, 10mg and 100mg/kg body weight) in spontaneously hypertensive rats, and then their blood pressure was measured five times every hour after administration. The administration of the inhibitor, even at the lowest dose, resulted in a significant decrease in blood pressure," wrote S. Ibe and colleagues, University of Tsukuba.

The researchers concluded, "Thus, the ACE inhibitor from natto appears to moderately reduce blood pressure relative to increases in dosage."

Ibe and colleagues published their study in Food Science and Technology Research ("Antihypertensive Effects of Natto, a Traditional Japanese Fermented Food, in Spontaneously Hypertensive Rats." Food Science and Technology Research, 2009;15(2):199-202).

For additional information, contact S. Ibe, University of Tsukuba, Graduate School Life & Environmental Science, 3-1-1 Kannondai, Tsukuba, Ibaraki 3058666, Japan.

From the June 8, 2009, Prepared Foods E-dition