Millions of us eat soy sauce regularly. Is it bad for you?

Few foods are as versatile as soy sauce. While it's especially popular in Chinese and Japanese dishes like rice, noodles and sushi, soy sauce is also commonly added as an ingredient to American, Spanish, Mediterranean and Italian dishes. It's also used in marinades, dressings, and as a tabletop condiment, dip, braising liquid or salt substitute. 

The global soy sauce market is so popular that it's valued at 48.1 billion in 2022 - a valuation that may nearly double by 2032, according to one estimate. "Soy sauce offers salt, umami and a hint of sweetness that plays nicely with many foods," says Caroline Susie, a registered dietician and national spokesperson for the Academy of Nutrition and Dietetics.

What is soy sauce? 

Originating in China more than 2,300 years ago, soy sauce is a liquid condiment that is "made from fermented soybeans, wheat, yeast and salt," says Tara Schmidt, lead registered dietitian for the Mayo Clinic Diet. It was first used to add flavor and preserve foods, and offers similar benefits today. 

It's traditionally made by combining cooked wheat grains and soybeans into a paste, then adding in salt, water, and a fermenting agent like yeast or a culturing mold like Aspergillus. From there it spends several months in a fermenting tank where enzymes break down the soy and wheat proteins into amino acids. The starches are then converted to simple sugars, which completes the aging process. The final stage is pasteurizing the liquid to eliminate any bacteria. 

There's also a chemically-produced type of soy sauce that requires the addition of artificial coloring and flavoring. Chemically-produced soy sauce isn't as healthy though and may contain carcinogenic substances. It usually has the word “hydrolyzed" on the label, so consumers can identify the difference.

There are many other varieties of soy sauce that have been adapted in various regions of the world, and many different types of soy sauce exist. These include light, dark, seasoned, double fermented, tamari, sweetened and low sodium. 

Is soy sauce bad for you? 

As for health benefits, soy sauce has some advantages and disadvantages. On the plus side, it's high in dietary antioxidants and it has some antimicrobial properties, says Schmidt. "At high levels of consumption, soy sauce can also have an anti-inflammatory effect," she adds.

But such nutritional value is minimal, so soy sauce should primarily be enjoyed for taste or as a salt substitute. "While a variety of soy foods provide us with some health benefits, the concerning part of soy sauce is its high sodium concentrations," says Schmidt. Indeed, Susie points out that a single tablespoon of soy sauce "contains 40% of the daily recommended 2,300 mg sodium per day." Too much salt in one's diet can lead to high blood pressure, heart disease, and stroke. 

Is soy sauce healthier than salt?  

Despite soy sauce being high in sodium - about 870 mg per tablespoon - it's still substantially less than the 6,976 mg of sodium in a tablespoon of salt, which is why some people use soy sauce as a salt substitute. "Soy sauce can be a great alternative to salt for those with high blood pressure who need to reduce sodium intake," says Josh Redd, NMD, the founder of RedRiver Health and Wellness and author of "The Truth About Low Thyroid." Sodium levels can be improved further still by opting for a low sodium version of soy sauce, "which still provides excellent flavor," says Susie. In addition to containing about half as much sodium, she says, "low sodium soy sauce may even be preferred by some who find regular soy sauce to be overpowering." 

At the same time, those with autoimmune or chronic health conditions need to be especially careful when consuming large amounts of soy sauce because of its wheat content. "We have found most of our autoimmune patients have a gluten intolerance," Redd says. Because of this, such people should "opt for gluten-free or soy sauce alternatives," says Susie. Histamine intolerance is another common hurdle for some people to overcome when considering eating soy sauce. "Fermented foods like soy sauce can be high in histamines," says Redd. Such foods "may trigger symptoms for those sensitive to histamine." He advises these individuals to choose small amounts of salt over soy sauce. 

Aside from these groups, most people can enjoy the flavor and variety of eating soy sauce so long as they keep quantities in check. "Soy sauce can be enjoyed in moderation and can be a part of an overall healthy diet," says Susie.

More:Half the people on the planet eat rice regularly. But is it healthy?