Is soy sauce bad for acid reflux?

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Soy sauce is a popular food but often triggers symptoms for acid reflux sufferers. However, since it stimulates digestion, it might also act as a reflux remedy for some.

What is soy sauce?

Soy sauce is a fermented liquid condiment native to China.

Traditional soy sauce is made from:

  • fermented soybean paste
  • roasted wheat
  • brine (a high concentration of salt in water)
  • fungus (either Aspergillus oryzae or Aspergillus sojae)

Today, soy sauce has become a very popular ingredient used in many cuisines around the world. Due to high demand, industrial processing is now done with acid hydrolysis. Its deep umami flavor, is unique, imparting desirable flavor and tastes to many foods.

Health benefits of soy

The Myths Of Soy As A Health Food – Dr. Berg
A nice video about the risks and benefits of fermented (like soy sauce) and unfermented soy. Duration: 4:00.

Soybean (Glycine max) is a very rich source of protein, minerals, vitamins, and bioactive compounds that account for the numerous health benefits of both soybean and products made from it.

The following are some health benefits of soybean:

Promotes the growth of body tissues

Soybean is rich in protein (36.5g/100g), and it is the only vegetable with a complete protein: soybean’s protein has all the nine amino acids that are essential for optimal human nutrition.

Proteins play a crucial role in the growth, development, and repair of body tissues like the skin, hair, bones, cartilages, and teeth.

Reduces blood lipid concentrations

Soybean is cholesterol-free and contains predominantly polyunsaturated fats including omega-3 and omega-6 fatty acids that enhance heart health.

It is also rich in fiber (9%) which binds to cholesterol and prevents its uptake into the bloodstream.

Consuming soybean or soy products decreases concentrations of low-density lipoprotein (LDL) “bad” cholesterol levels and increases high-density lipoprotein (HDL) levels in the blood. A high level of blood cholesterol is a risk factor for the development of cardiovascular heart disease.

Reduces blood sugar levels

Soybean contains compounds called isoflavones that have been demonstrated to initiate the dropping of glucose levels in the blood. It also enhances the body’s tolerance for sugar by increasing insulin sensitivity.

Promotes gut health

Soybean is rich in fiber, which is not digested by the human enzymes, as such it ends up in the large intestines where it serves as food for healthy bacteria, increasing their population.

A large population of healthy bacteria phases out disease-causing bacteria, which boosts the overall immunity of the body.

Is soy sauce acidic or alkaline?

Like every other fermented food, soy sauce is acidic with a pH range of between 4.8 to 5.

Though some of the ingredients used in preparing it are alkaline in nature, the final product is acid-forming when ingested. Its tart taste is associated with its acidity.

Is soy sauce bad for acid reflux?

Soy sauce is a condiment reputed for triggering and worsening acid reflux in sensitive people. This is because acidic foods tend to irritate the lining of their damaged esophagus walls.

Soy sauce might worsen heartburn and acid reflux symptoms for several reasons:

  • increases the secretion of digestive juices
  • contains gluten, which might worsen reflux in sensitive people

Increased gastric acid secretion

In a study carried out in Japan, the consumption of soup containing the Japanese soy sauce, shoyu, was reported to increase gastric juice secretion in participants.

While an increase in gastric juice secretion is desirable for facilitating digestion in the non-sensitive population, it is rather a detrimental thing for people suffering from acid reflux.

Moreso, soy sauce contains some bitter components, and a bitter taste increases the production of gastric acids in the stomach which increases the risk of occurrence of acid reflux episodes. For example, caffeine has been shown to induce gastric acid secretion due to its bitter taste.

Gluten content

Soy sauce contains wheat which contains gluten, a protein that some people might be intolerant to.

Several research studies have reported an association between heartburn and the consumption of gluten-containing foods in certain persons with gluten intolerance. Some studies have also reported a significant improvement in acid reflux symptoms with the consumption of a diet free of gluten in people with severe acid reflux.

Can soy sauce help acid reflux?

As mentioned above, soy sauce promotes digestion by stimulating gastric acid secretion. This might improve the acid reflux symptoms for some people.

Those who have low stomach acid levels and whose heartburn is caused by slow digestion and gastric emptying might experience improvement in their symptoms.

Heartburn-friendly soy sauce

Soy beans

There are a couple of ways to make soy sauce more heartburn friendly for sensitive people who might want to enjoy meals made with it:

Add baking soda

The acidity of soy sauce can be decreased by adding baking soda (sodium bicarbonate) to your soy sauce meal.

Baking soda has an alkaline pH which helps to neutralize stomach acidity and gives temporary relief from acid reflux.

As a matter of fact, many over-the-counter acid reflux prescriptions contain sodium bicarbonate and experts prescribe it as a temporary relief for acid reflux.

Add other alkaline foods to decrease acidity

Adding soy sauce to high-acid foods, such as tomatoes, onions, and other citrus fruits, would aggravate acid reflux in sensitive people.

Instead, adding alkaline foods like green leafy vegetables, and non-citrus fruits like pears, avocados, and melons may reduce acidity and be more soothing.

Also use soy sauce with lean meats, and seafood instead of fatty meats like pork, bacon, and sausages, which are well-known trigger foods.

Avoid cooking the meal to dry off the liquid

Avoid allowing the water in the meal to dry up too much when cooking with soy sauce.

A dried-up sauce would have a higher concentration of acid, which is more likely to trigger reflux episodes and severity than a sauce that has more water and whose acid is more diluted.

Side effects of soy foods

As beneficial as soy foods may be, consuming too much may come with some negative health effects:

Sodium content

Soy foods are very high in sodium or salt content. Consuming too much salt increases one’s risk of developing hypertension. Salt is also a risk factor for acid reflux.

This is because more salt draws more water into the bloodstream, thus increasing the volume of blood flowing through the arteries, and consequently the pressure of the blood flow increases.

High blood pressure is a risk factor for the development of heart disease.

Allergic reactions

Amines like histamine and tyramine are present in significant quantities in soy sauce. These amines are naturally present in some plants, and their concentrations have been found to be higher in aged foods like cheeses and condiments.

Consumption of too much amines can cause allergic reactions like skin rashes, itching, dizziness, sweating headaches, stomach problems, and fluctuations in blood pressure.

Histamine is reported to be responsible for the allergic reactions experienced by people who are sensitive to soybean.


Chemically produced soy sauce results in the production of certain toxic compounds called chloropropanols.

A typical example like 3-MCPD, has been reported to cause damage to the kidneys, cause cancers, and decrease fertility.

Final thoughts

Soy sauce is an acidic food condiment that does not cause acid reflux but can trigger and worsen acid reflux episodes and intensity in sensitive people.

Though trigger foods differ from person to person, experts generally advise that all sensitive people should generally reduce or cut off completely all fermented condiments, including soy sauce.

This article has been written by:

Meggy Jones

Expert Nutritionist and Food Scientist,
M.Sc. – Nutrition, ugent, Belgium