Miso

Studies in people

• Benefit

  Risk of death³

  A Japanese study found that people who ate more fermented soybean foods like miso were less likely to die.

• Benefit

  Muscle loss in women⁴

  Women with type 2 diabetes who regularly ate miso soup were less likely to have weak, low muscle.

• No harm found

  Blood pressure⁵

  In Japanese adults, eating more miso was not linked to higher blood pressure.

• Benefit

  Blood sugar control in women⁶

  In women with type 2 diabetes, habitual miso soup intake was linked to steadier blood sugar, but not in men.

• Benefit

  Heart rate and blood pressure⁷

  In middle-aged and older Japanese people, eating miso soup often was linked to a slower heart rate, but not to blood pressure.

• Open question

  Daily salt intake⁸

  People who ate miso soup more often tended to take in more salt each day.

• Concern

  Mineral uptake from meals¹⁰

  In people, miso soup cut how much zinc the body absorbed from a supplement by about a third.

• Benefit

  Nighttime blood pressure¹¹

  In people with slightly high blood pressure, eating miso for 8 weeks lowered nighttime blood pressure but not daytime blood pressure.

• Benefit

  Fatty liver disease risk¹²

  Eating miso soup as part of a traditional Japanese diet was linked to lower fatty liver scores in people.

• Benefit

  Obesity and salt intake¹³

  In 300 people, those with high urine salt who often ate miso were less often obese.

• Benefit

  Heartburn and indigestion¹⁴

  People who ate miso soup daily reported fewer heartburn and indigestion symptoms than those who ate it rarely.

Animal and lab studies only

• Benefit

  Blood pressure in rats²¹

  In animal studies, long-term miso soup slowed the rise in blood pressure caused by salty water.

Study type not stated

• Open question

  Fermented food microbes¹⁵

  Miso is a fermented food, and little is known about how its microbes work.

• Benefit

  Health effects of fermented food¹⁶

  Miso may help fight cancer, germs and obesity, but more research is needed.

• No harm found

  Blood pressure and salt¹⁷

  Miso soup seems not to raise blood pressure the way the same amount of salt does.

• Benefit

  Soybean allergy¹⁸

  Miso contains far fewer soybean allergens than raw soybean, and dark, long-fermented miso has the least.

How it’s made and used

• How the body absorbs soya nutrients⁹

  In women, miso soup and soya milk led to similar amounts of soya plant compounds in urine.

• Hormone-like activity in food¹⁹

  In lab studies, isoflavones in miso acted like the hormone estrogen in yeast cells.

• How the body handles medicines²⁰

  In animal studies, miso made the body clear a test medicine faster by boosting a pump that removes it.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.