Heartwire
Probiotics Benefit Blood Pressure in Meta-Analysis
Michael O’Riordan
July 21, 2014
QUEENSLAND, NEW ZEALAND – Consumption of probiotics—the live bacteria found in yogurt, kefir, miso soup, and sauerkraut, among other foods—can lower blood pressure to a modest degree, according to the results of a new meta-analysis [1].
The reductions in systolic and diastolic blood pressure were approximately 3.5 and 2.4 mmHg, respectively, although investigators observed larger reductions among individuals with elevated blood pressure at baseline and those who consumed multiple probiotic species.
“However, even a small reduction of blood pressure may have important public health benefits and cardiovascular consequences,” states Dr Saman Khalesi (Griffith University, Australia) in the article published July 21 in Hypertension.
Researchers point out that the Heart Outcomes Prevention Evaluation (HOPE) study showed a 3.3 mmHg reduction in systolic blood pressure, along with a 1.4 mmHg reduction in diastolic blood pressure, which were associated with a 22% relative reduction in risk of cardiovascular mortality, MI, or stroke.
The current meta-analysis included nine clinical trials with 543 participants. Probiotic species varied among the trials; four studies used yogurt as the source of probiotic bacteria, two used fermented and sour milk, one used probiotic supplements in capsule form, one used probiotic rosehip drinks, and one used probiotic cheese. The studies lasted three to nine weeks, and the total daily dose of probiotics ranged from 109 to 1012 colony-forming units.
In addition to the mean systolic blood pressure reduction of 3.5 mmHg, investigators note that five studies reported a significant reduction of over 5 mmHg in systolic blood pressure after participants consumed probiotics. The 2.4 mmHg overall reduction in diastolic blood pressure was significant but appears to be driven by one study in which an 8 mmHg reduction in diastolic blood pressure was observed.
For those who ate more than one probiotic species, the reduction in systolic blood pressure was 5.8 mmHg. Those who consumed probiotics for more than eight weeks had a 4.9 mmHg reduction in systolic blood pressure.
“These findings, along with results from [another] meta-analysis on the beneficial effect of probiotics on the lipid profile, suggest that probiotics may be used as a potential supplement for future interventions to prevent hypertension or improve blood pressure control,” conclude Khalesi et al. Future studies are needed, however, to clarify the effects of different products with different probiotic species on blood pressure. Mechanistic studies are also needed to determine how probiotics reduce blood pressure, they write.
References
Khalesi S, Sun J, Buys N, Jayasinghe R. Effect of probiotics on blood pressure: a systematic review and meta-analysis of randomized, controlled trials. Hypertension 2014; DOI:10.161/hypertensionaha.114.03469. Abstract