Vinegar-based Japanese side dish linked to lower blood pressure in men over 40

New research has revealed that Japanese men over the age of 40 who eat sunomono, a Japanese side dish made with vinegar, is associated with having lower blood pressure.

The observational study led by Hiroaki Kanouchi, PhD, from Osaka Metropolitan University in Osaka, Japan was published in the journal, Heliyon.

According to the researchers, Sunomono is a traditional Japanese side dish made with sliced cucumber or seaweed in rice vinegar, often with seafood garnish. It is a normal food, regularly eaten by older generations in Japan, with individually prepackaged portions available for purchase in supermarkets, making it a common source of larger volumes of dietary vinegar.

While the authors pointed to previous studies that have shown subjects who drink 30 milliliters of vinegar a day had lower blood pressure, studying sunomono provided an opportunity to examine if vinegar consumption as part of a normal diet correlated to differences in blood pressure. To do this, the research team recruited 1,498 men and women over 40 years old who were screened for hypertension or other disqualifying health conditions. Of that cohort, 746 participants had their blood pressure tested and categorized based on the Japanese Society of Hypertension guidelines, then filled out a dietary survey, paying attention to sour vinegary food consumption, particularly sunomono.

“Men who did not habitually eat sunomono had significantly higher blood pressure, even though their weight and BMI were the same,” Kanouchi said in a statement. “We believe it could be promoting growth of good gut microbiota, but we would need more studies to confirm that.”

In addition, they found that eating sunomono – at least monthly – correlated with lower average blood pressure among men, even when adjusted for age, BMI, smoking history, intake of sodium, potassium, and alcohol, amongst other factors. This indicates that eating sunomono could already be having a positive impact on health, according to the researchers.

While the authors assessed both men and women, only men were found to have the lower average blood pressure results. They attribute this to several reasons including the population with non-intake habits for side dishes containing vinegar in women was lower than that in men; systolic blood pressure and diastolic blood pressure were lower in women than men; and the younger age of the non-intake habitual group in women.