This is interesting. A sour Milk that the Japanese use has been shown to lower blood pressure.
In one other study I had it showed Calpis milk to lower blood pressure by up to 15 points.
I do not know of anywhere in the U.S. that sells this but if I am not mistaken buttermilk might be similar.
Sour milk reduces blood pressure
TOKYO, JAPAN. Calpis sour milk has been used traditionally in Japan for many years. It is prepared by fermenting skim milk with a starter culture containing Lactobacillus helveticus and Saccharomyces cerevisiae. The fermented milk contains about 0.7 billion L. helveticus and 2.5 million S. cerevisiae cells per milliliter. Researchers at the Kyorin University School of Medicine have discovered that Calpis sour milk is effective in lowering blood pressure in patients with hypertension. Their experiment involved 30 hypertensive patients, 26 of which were receiving antihypertensive medication such as calcium antagonists, beta- blockers, diuretics, and ACE inhibitors. Seventeen of the patients were fed 95 ml of Calpis sour milk daily for an eight-week period. The remaining 13 patients were given a placebo sour milk prepared by adding lactic acid to skim milk. At the end of the trial period the systolic blood pressure in the Calpis milk group had decreased by an average of 14.1 mm Hg and diastolic pressure by 6.9 mm Hg. No significant blood pressure changes were observed in the placebo group. The blood pressure decreases in the Calpis milk group remained four weeks after the end of treatment. The researchers conclude that daily supplementation with sour milk is a useful and practical way of reducing blood pressure in patients with hypertension. NOTE: This work was done in cooperation with Calpis Food Industry Co., the manufacturer of Calpis sour milk.
Hata, Yoshiya, et al. A placebo-controlled study of the effect of sour milk on blood pressure in hypertensive subjects. American Journal of Clinical Nutrition, Vol. 64, November 1996, pp. 767- 71