Soy Sauce: How It's Made and How It Can Affect Your Health

Soy sauce is a popular condiment used in Asian cuisine. Per a September 2020 article published in the Journal of Agricultural and Food Chemistry, soy sauce usually has a salty, savory, umami taste; it is also used when preparing cooked and uncooked foods.

Though the sauce might not be healthy in all aspects of nutrition, it has been linked to some health benefits. Learn how soy sauce is made, how the condiment can affect your health, and some soy sauce alternatives you can use.

Nutritional Values of Soy Sauce

The U.S. Department of Agriculture (USDA) says that a tablespoon of soy sauce (made from soy and wheat) contains:

• Calories: 8.48 calories
• Fat: <1 gram
• Cholesterol: 0 milligrams
• Sodium: 878 milligrams
• Carbohydrates: <1 gram
• Fiber: <1 gram
• Protein: 1.30 grams

How Soy Sauce Is Made

When you think of soy sauce, a dark-colored sauce usually comes to mind. However, several types of soy sauce exist, including:

• Light soy sauce
• Dark soy sauce
• Tamari soy sauce
• White soy sauce
• Sweet soy sauce
• Non-fermented soy sauce

Each type of soy sauce varies due to "fermentation times, temperatures, and ratios of ingredients," according to the Journal of Agricultural and Food Chemistry study, and comes with different flavors. The same article noted that the method of choice for producing soy sauce also varies according to the country of origin. Still, it's traditionally prepared with soybeans, wheat, salt, water, and fermenting agents (mold or yeast). The mixture is left to ferment for eight months or more; then, it is pasteurized before it's bottled.

Quicker, cheaper methods of making soy sauce—which may be labeled as hydrolyzed soy protein—are generally more chemical-driven. Manufacturers may use additives to enhance color and flavor. Furthermore, some soy sauce products have been found to contain unwanted compounds, including known carcinogens.

According to a 2014 article published in Comprehensive Reviews in Food Science and Food Safety, some of these quicker methods can lead to the production of a chemical called 3-MCPD. This chemical has been tied to tumors, infertility, and kidney damage in animal studies, but there is little evidence about its effects on humans.

The Salt in Soy Sauce

Though having enough salt in your diet is important, eating too much of it can lead to health conditions like high blood pressure. While traditional soy sauce is low in calories and carbs (with less than 10 calories and 1 gram of carbs per tablespoon), it has very high levels of sodium. A single tablespoon contains over 900 milligrams. That is more than a third of the recommended daily limit for healthy adults (2300 milligrams, according to the USDA and U.S. Department of Health and Human Services).

If your body is sensitive to sodium, a sodium spike may trigger water retention, which can result in bloating or slight swelling around the hands and feet. You might notice indentations in your skin after you remove your socks or that your rings or watch fit a little snugger. And over time, having too much sodium can increase your risk for heart disease, according to the Centers for Disease Control and Prevention (CDC).

The Health Benefits

Despite having a lot of salt, soy sauce could also help protect your health. According to a 2019 Biotechnology Advances review, soy sauce can reduce immune responses, helping people who suffer from seasonal allergies. Soy sauce may also be able to reduce the instance of IL-6, which is an inflammatory cytokine (a protein that can be produced by cells related to or beyond the immune system), per an August 2022 study published in Microorganisms. Other studies also showed that dark soy sauce could be an antioxidant.

Besides soy sauce, other fermented soy products have also been linked to health benefits. For example, a 2019 Nutrients study found that tempeh could be linked to healthier gut microbiomes. Meanwhile, natto may be able to help prevent blood clots and high blood pressure. Overall, a 2019 article published in Food Chemistry found that fermented soy products showed promise in preventing inflammation, diabetes, and cancer. However, more research is needed.

Other Health Considerations

Soy sauce, like other fermented foods, also contains significant amounts of histamine. Your body releases histamines to aid in digestion. It's also released in response to injury or allergies to increase inflammation, which can aggravate conditions like rosacea. Too much histamine can also trigger symptoms such as headaches, dizziness, itching, rashes, and digestive problems in those with histamine intolerance. Furthermore, if you're sensitive or allergic to gluten, wheat, or soy, then you may want to avoid soy sauce.

Soy Sauce and Soy Sauce Alternatives

If you enjoy soy sauce and can tolerate it well, make sure to use naturally-brewed varieties, according to nutritionist Cynthia Sass, MPH. She recommended Kikoman's Organic Soy Sauce. However, keep in mind that lite, reduced sodium, or less-sodium sauces can still be high in salt. Most still provide about 600 milligrams of sodium per tablespoon.

But if you are allergic to soy sauce or want a lower sodium alternative, you can also try coconut aminos. Sass recommended Bragg's Coconut Liquid Amch is made with organic coconut blossom nectar, distilled organic apple cider vinegar, and sea salt. It's both gluten- and soy-free. And, though the flavor is less intense than soy sauce, one tablespoon portion provides just 140 milligrams of sodium (6% of the recommended daily limit).

Coconut aminos can be used as a one-to-one substitute in any recipe or as a condiment, Sass said. One of the ways she recommended using coconut aminos is in a simple stir-fry sauce. To make the sauce, mix the aminos with some fresh-squeezed tangerine juice, freshly grated ginger root, minced garlic, and crushed red pepper. Then, sauté with a generous portion of veggies. Serve your stir-fry with a lean protein over a small scoop of brown or wild rice, and top with chopped nuts or pumpkin seeds.