Researchers in Japan report that a novel fermented milk product containing gamma-aminobutyric acid (known as GABA) may lower blood pressure in people with mild hypertension.
The team from the Tokyo Metropolitan Police Hospital and the Yakult Central Institute for Microbiological Research in Tokyo carried out a randomised, placebo-controlled, trial on a small number of adults with slightly raised blood pressure.
The group of 39 patients (16 women and 23 men) aged around 51 on average, took either the milk product with added amino acid or a placebo everyday for 12 weeks, followed by two weeks of no intake.
The researchers measured the peripheral blood pressure and heart rate of seated patients at weeks 0, 2, 4, 8, 12 and 14. Routine blood study and urinalysis were performed before and after the intake. The study is reported in the European Journal of Clinical Nutrition.
The results show a significant decrease of blood pressure within two or four weeks, which remained decreased throughout the 12-week intake period. For the GABA recipients, both systolic blood pressure and diastolic blood pressure decreased statistically from baseline levels.
In the group taking the GABA milk product, systolic blood pressure decreased significantly more than the placebo group. Heart rate, body weight, and urine analysis did not vary between groups throughout the study.
The authors conclude that a fermented milk product containing gamma-aminobutyric acid could be used to help lower blood pressure in people with slightly raised levels.