I love soy sauce, but I'm trying to minimize my consumption of phytochemicals.

Is there any difference between "brewed" and "regular" soy sauce as far as their phytochemical content?

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  • 1
    Hi MaxB, health effects of food are strictly off topic here. It is OK to ask about "phytochemicals" when that's a well-defined category that can be measured in the food, but without references to potential health effects, or inviting answers to comment on which kind of soy sauce is likely to have that effect.
    – rumtscho
    Commented Apr 11, 2019 at 9:59

2 Answers 2


AFAIK, "brewed" is the term used for naturally fermented soy sauce compare to faster fermentation using chemicals; remember that using chemicals is not automatically bad.


As for the phytochemicals (stuff in plants) I don't have a clue.


Phytochemicals are found in any food sourced from plants, including any fresh vegetables you eat. For most people it would be nearly impossible to eliminate them from their diet, and would have significant deleterious effects on health to not consume vegetables.

Based on a quick google search and some biochemistry knowledge it would seem that fermented soy sauce contains active forms of a some isoflavone compounds (see section on "fermented staple crop foods: soy and rice"), which are inactive if you eat the beans themselves (or non-fermented forms of the beans). There are also a number of other biologically relevant compounds too, that would make this a very long post if I went into them all. Not all these compounds will be affected by acid-hydrolysis to the same extent, so take this with a word of caution, and read the literature I have linked, even if you don't understand it all (I don't, and I'm a virologist with a fairly extensive background in cancer research, biochemistry and molecular biology).

I'll use the isoflavones as a typical answer:

The component levels in the different soys are difficult to find as most people study the fermented soy sauce, but it seems around 0.1% - 0.3% isoflavonoids is pretty common for the fermented sauce, and that there are no isoflavonoids in acid-hydrolysed sauce. Isoflavonoids are often considered to be the more biologically relevant forms of the phytochemicals in soy, and have been extensively studied in terms of cancer prevention (they are considered anti-cancer for example) and similar things.

Cancer rates being lower in Asiatic countries has been attributed to the soy consumption (see section and is also implicated in lower levels of things like osteoporosis, obesity and cardiovascular diseases too (sections - As a word of caution here, the tests done on these sorts of things generally use purified version that are much much more concentrated than you would find in any soy sauce, so the effects are magnified.

This protective effect is probably not strictly down to isoflavones, but taken as a whole it seems that consuming soy products, whether fermented or not, is generally considered a good thing.

  • *"it seems that consuming soy products, whether fermented or not, is generally considered a good thing." -- my Q was censored. See the unedited version and also this: ncbi.nlm.nih.gov/pubmed/18558591
    – user18825
    Commented Apr 12, 2019 at 4:00
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    I am aware that your question was edited and I did see the original version. With regards the pubmed article: Did you see that he was consuming 3 quarts (2.8 liters) of soy milk a day! and also This is a very unusual case of gynecomastia related to ingestion of soy products. That's the sort of level of intake associated with identifiable complications. If you are consuming a comparable level of soy sauce you will have bigger problems from the salt intake than you would from the phytochemical components.
    – bob1
    Commented Apr 12, 2019 at 13:53
  • Look at the original Q. You are missing the point.
    – user18825
    Commented Apr 16, 2019 at 10:26
  • I don't think I did miss the point - the subtle effects are things like lower cancer rates, less obesity, etc in my answer. To see these things you need population size studies incorporating 100's, if not 1000's of people. There are currently no ways to measure even more subtle effects (I'm talking scientifically here). In terms of negative effects - well, there don't seem to be any, unless you consume massive amounts.
    – bob1
    Commented Apr 16, 2019 at 13:50

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