Miso and soy sauce portions linked to blood pressure in Japan
What it found
In a survey of 25,738 Japanese adults, the amount of miso or soy sauce eaten per dish was not linked to blood pressure or to how many people had high blood pressure.
Early links seen in women disappeared after accounting for age and other diet and lifestyle factors.
What they found
Studies in people
Blood pressure levels
After adjusting for age, body weight, alcohol, steps, vegetables and fruit, the amount of soy sauce or miso per dish was not linked to systolic or diastolic blood pressure in men or women.
High blood pressure rates
A total of 7,279 people had high blood pressure. In the simple analysis, women using more soy sauce or miso were more likely to have high blood pressure, but this link disappeared after adjusting for age and other factors.
Other diet factors
People who used larger amounts of soy sauce or miso also ate more vegetables, fruit, fish and soy products, and took in more potassium. The authors suggest this may offset any effect of the seasonings on blood pressure.
Other findings
Typical portion sizes
The median amount per dish was about one teaspoon of soy sauce and about two teaspoons of miso. These amounts contain 228 mg of sodium for soy sauce and 441 mg for miso.
What the authors conclude
“Our findings suggest that larger portion sizes of soy sauce or miso alone may not be risk factors for elevated BP.”
Also in their conclusions
- They conclude that the portion sizes of soy sauce and miso were not associated with blood pressure levels or the prevalence of hypertension among Japanese adults.
- They suggest that larger portion sizes of soy sauce or miso alone may not be risk factors for elevated blood pressure.
- They say that traditional diets using soy sauce or miso as seasonings may produce health benefits, through the higher intakes of vegetables and soy products.
How it was done
Soy sauce and miso are major sources of salt in Japan, and high salt intake is known to raise blood pressure. The authors wanted to see whether the amount used per dish, rather than total salt, mattered for blood pressure.
They used data from 25,738 Japanese men and women aged 20 and over who took part in the National Health and Nutrition Survey between 2012 and 2016. Food records from one day were used to work out the amount of soy sauce or miso per dish, and this was compared with blood pressure measured at a health check.
What it can’t tell you
- This was a cross-sectional study, so it can show links but cannot prove that eating more or less miso or soy sauce changes blood pressure over time.
- The study cannot rule out that people with higher blood pressure might have changed their seasoning use, even though those on blood pressure drugs were excluded.
- The diet was recorded on a single weekday, which may not reflect usual habits.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- National Institute of Biomedical Innovation, Japan; Ministry of Health, Japan
The paper
- Title
- Association between the Portion Sizes of Traditional Japanese Seasonings-Soy Sauce and Miso-and Blood Pressure: Cross-Sectional Study Using National Health and Nutrition Survey, 2012⁻2016 Data
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Okada E, Saito A, Takimoto H (2018). Association between the Portion Sizes of Traditional Japanese Seasonings-Soy Sauce and Miso-and Blood Pressure: Cross-Sectional Study Using National Health and Nutrition Survey, 2012⁻2016 Data. Nutrients. doi:10.3390/nu10121865Free full textPubMed 30513805DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error