Soy sauce helps provide foods with that great umami flavor, but it may not be the most healthy aspect of your diet.
For example, a review of cancer causing aspects of diet published in the journal Carcinogenesis suggests that soybeans and soy sauce may contain nitrosamines that are associated with genetic mutation in lab animal studies.
On the other hand, other research has suggested that dark soy sauce contains antioxidants, and there’s been some progress in isolating the active compounds in dark soy that provide the antioxidant activity. Antioxidants are important for preventing cellular damage associated with the oxidative stress processes within the body.
The sodium content of soy sauce is a concern for those with high blood pressure. There are variations in sodium content for different brands of soy sauce. This Chowhound article has some reports of sodium levels for different brands. Here are some of the results that the author, lastZZ reported:
- Kikkoman Regular—- 920mg
- Kikkoman Low Sodium—575mg
- Trader Joe’s—– 460mg
- Japanese made brand bought in an Asian store—- 740mg (no preservatives listed)
And, there are more results listed by readers in the comments of that article.
Note, low-sodium versions of soy sauce are readily available in most markets. While there hasn’t been much in terms of studying the health impacts of changing to low-sodium soy sauce specifically, the one study that has looked at this was conducted on very small cohort of 64 persons in Japan. While not all of their findings were statistically significant because of the low numbers of people in their study, they found some beneficial effects on lowering blood pressure in older persons:
“… in those aged 40 years and older, 6.4 mmHg net reduction in diastolic BP with no significant change in systolic BP was noted in the low-sodium group.”
Moreover, the study found that participants in the study generally liked the taste of low-sodium soy sauce. Thus, they conclude:
“Replacing soy sauce and miso of the common type with the low-sodium alternative is feasible in the general population and could be the basis for a salt reduction strategy in the Japanese diet.”