Fermented milk has been suggested to have a blood pressure lowering effect through increased content of proteins and peptides produced during the bacterial fermentation. Hypertension is one of the major risk factors for cardiovascular disease world wide and new blood pressure reducing lifestyle interventions, such as fermented milk, would be of great importance. To investigate whether fermented milk or similar products produced by lactobacilli fermentation of milk proteins has any blood pressure lowering effect in humans when compared to no treatment or placebo. The Cochrane Central Register of Controlled Trials (CENTRAL), English language databases, including MEDLINE (1966-2011), EMBASE (1974-2011), Cochrane Complementary Medicine Trials Register, Allied and Complementary Medicine (AMED) (1985-2011), Food science and technology abstracts (1969-2011). Randomised controlled trials; cross over and parallel studies evaluating the effect on blood pressure of fermented milk in humans with an intervention period of 4 weeks or longer. Data was extracted individually by two authors, afterwards agreement had to be obtained before imputation in the review. A modest overall effect of fermented milk on SBP was found (MD -2.45; 95% CI -4.30 to -0.60), no effect was evident on DBP (MD -0.67; 95% CI -1.48, 0.14). The review does not support an effect of fermented milk on blood pressure. Despite the positive effect on SBP the authors conclude, for several reasons, that fermented milk has no effect on blood pressure. The effect found was very modest and only on SBP, the included studies were very heterogeneous and several with weak methodology. Finally, sensitivity and subgroup analyses could not reproduce the antihypertensive effect. The results do not give notion to the use of fermented milk as treatment for hypertension or as a lifestyle intervention for pre-hypertension nor would it influence population blood pressure.
Usinger, L., Reimer, C., & Ibsen, H. (2012). Fermented milk for hypertension. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.cd008118.pub2