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Soy 101, please

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Can someone please educate me on the good, the bad, and the ugly about soy. I stopped eating tofu a while back because I thought it wasn't good for a North American's diet. But now I'm reading about the benefits of miso and tofu.

What is fermented soy? Is it tofu or not? If so, what is UNfermented soy?

I did a CH search, but all I get is how to cook with tofu. I'm just confused.
Can someone please spell it out for an idiot!

Thank you in advance for your thoughts.

Many thanks in advance.

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  1. I have heard that fresh soy is not good for women. I don't eat tofu or edamame but do eat soy sauce and miso in moderation...

    1 Reply
    1. Here is a good place to start
      Your question is too broad for any sort succinct answer.

      1. There are as many articles on the evils of soy as there are about the benefits. The truth is somewhere in between. Soy doesn't provide all the promised benefits of the everything-soy fad of years ago nor has it been demonstrated to be a health risk.

        Here's a recent article that addresses soy in a non-alarmist manner:


        1. I mostly eat only fermented soy. My thinking on it is this:

          If you have hormone issues (male or female) or have some cancers, you need to be careful about phytoestrogens.

          Tofu is a highly processed food and I don't eat much processed foods.

          With all the soy products now available in high concentrations, it is not a "natural diet" to eat so much of one thing ( tofu, soy milk, edamame, soy sauce/paste/nuts, etc) you can easily get ALOT of soy without trying too hard.

          Unless you are really carefully reading labels, much of the soy in processed foods or soy products are GMO's or full of pesticide residues and additives.

          Those are the reasons I limit the soy in my diet. I love fermented soys though- especially miso and soy sauce and I read labels carefully.

          1. Well, there are a lot of potential goods and bads of soy products. For example, soy has the ability to lower blood pressure as well as LDL cholesterol. For example, soy also may slow down thyroid function. In term of real impact, one don't need to look any further than Japanese and Chinese. An average Japanese and Chinese consume more soy products than an average American.

            1. Soy products can be good for you. They also may be bad for you. There's not a simple answer.

              Starting with the easy:

              1) Avoid soy supplements (soy isoflavanes), e.g. pills and extracts. If you are eating a diet with soy, you do not need supplements. Supplements may or may not isolate flavanes in a way that is beneficial to your body and excess of flavanes may have negative effects.

              2) In the same vein, avoid soy protein powders, and products with soy protein isolate, many are chemically processed.

              The main concerns about soy are regarding it's phyto-estrogenic properties, phytates and trypsin inhibitors.

              Regarding phyto-estrogenic properties, you need not worry if you are avoiding supplements. Your mouth will fail and you body will tire of soy before you grow breasts from eating tofu.

              Phytate and trypsin inhibition are properties of unprocessed soy products. Cooking soy (boiling) for 15 minutes reduces both properties by approximately 80%. Long fermentation of soy reduces both properties by >80% making soy safer to eat. Examples of fermented soy are soy sauce, tempeh, fermented tofu, fermented black beans, natto, miso. Many of these products have a high sodium content because the sodium inhibits unwanted mold that would interfere with fermentation and taste of the final product. In that sense, you would want to avoid ingesting too much soy product to avoid excess sodium intake.

              Tofu (or the soy milk that was used to make the tofu) that has been cooked at high heat for a duration of 15 minutes or more, will largely but not totally negate some of the negative properties of raw soy. Taken in total, natural tofu (meaning tofu made from soy milk that hasn't been chemically processed/constituted) is a healthy part of your diet with no cholesterol and healthful antioxidants. Tofu does have a significant fat content though.

              Tempeh (fermented soy beans that form a "cake") which is similar to tofu is even healthier. The fermentation makes nutrients in soy more digestible, accessible and eliminates most of the negative effects of raw soy. Similarly, fermented tofu is also very healthy. Tzo dofu is a popular example of this genre.

              Soy sauce and miso also fermented, are healthful in the same fashion. The contain a high sodium content and should be consumed in moderation.

              Diferent soy products are fermented with different strains of beneficial bacteria and mold spores. Unfermented soy is simply soy that has not been subjected to bacteria or mold processing (think cheese and wine vs. milk and grapes).

              The take away is this, stick to natural soy products, that have been cooked, preferably soy products that have been fermented. Avoid raw soy, and eat lightly cooked soy sparingly unless it has been fermented. Do not subsist on unfermented tofu. Following these steps you will make soy products a healthful addition to your diet. 100's of millions of people consume natural soy (vs. powders/chemical extracts) in a healthful way, vegetable based proteins have an anti-inflammatory effect vs. animal protein and many diseases are caused by successive and cumulative inflammation.

              3 Replies
              1. re: Pookipichu

                After eating tofu for nearly 20yrs now i have yet to see one with significant fat content..... The average seems to be 3-5grams per serving....

                1. re: Ttrockwood

                  I'm pointing out the fat content of tofu because some people forget our don't know that it has fat. I say significant because it gets 50% of its calories from fat vs. 20% for chicken breast. If tofu is your main source of protein, the fat content is something that someone should be aware of. A serving size with 3-5 g of fat would not have very much protein.

                  But in the scheme of things, you're right, it's less fat (not to mention healthier in other ways) than eating a ground chuck burger or pork roast :)

                  1. re: Pookipichu

                    Ok, gotcha.
                    Either way i'm in the pro-fu camp :)

              2. Soy protein isolate is what i am most wary of. Soy protein powders, faux meats, and processed foods are usually where you see this.

                Unprocessed soy like edamame, fresh tofu (some japanese restaurants make their own), and temeph are "healthier" soy products.

                As already mentioned fermented soy foods like miso and tempeh are actually very high in nutrients and both contain significant probiotics as well.

                I limit more processed soy like soy milk, soy creamers, and anything with soy protein isolate.

                That said, i would prefer to eat a veggie burger full of soy protein isolate than any kind of factory farmed meat or poultry.

                Generally speaking adding edamame, tempeh, tofu, and miso to your diet is a great way to vary your protein sources - and its delicious!

                1. I have had very good luck eating Natto, which is Japanese fermented soybeans. Apparently, the soy is very digestible and I love that cheese-like flavor.

                  1. Thank you all. I guess tofu will be out, and we don't like tempeh, but perhaps we'll get some miso and make soup.

                    Thank you for the two article links, as well.

                    We don't eat beef or pork products, so we were trying to get more protein in our diet. We eat a lot of legumes and whole grains, chicken once in a while, quinoa. Nothing really processed, except maybe Better than Bouillon base, but I'll check that label anyway.

                    Thanks again everyone.

                    2 Replies
                    1. re: nemo

                      Just a heads up: Better Than Boullion's regular chicken and beef bases have hydrolyzed soy protein, but the low-sodium and organic versions do not.

                      1. re: Scrofula

                        Thanks, Scrofula. I just read the label. I know my store doesn't carry the organic, but I will look for the low sodium which I would prefer anyway and scout around for the organic.

                    2. The soybean is a type of legume. It can be cooked and eaten as you would peas, and the immature seed pods are a popular snack in Japan (boiled, salted, and you squeeze out the beans) aka edamame.

                      Soy beans can be pressed to produce a milky product liquid - this is soy milk. Soy milk can be heated and coagulated to produce tofu (the process is similar to cheese making, but with a different coagulating agent). That tofu can be eaten as is (silken, or soft tofu), or pressed to squeeze out liquid to make firmer varieties.

                      As the soy milk heats, you can remove the skin that forms on the top (like when you heat milk). This can be hung in sheets and dried - this can be the basis of some fake meat products.

                      Then you've got your fermented soy products - soy sauce, miso, tempeh, natto, doenjang, stinky tofu, etc.

                      Soy naturally contains an estrogen-like substance, which in excess can cause health problems. I don't think having soy as a normal, moderate part of the diet is a problem, but if you're a vegetarian, and you swap all your dairy and meat consumption for soy based substitutes, that's a *lot* more soy than your average East Asian eats as part of their diet. (veggie burgers, vegetarian chicken, fake meat products, soy milk, soy cheese, soy yoghurt, textured vegetable protein, etc).

                      3 Replies
                      1. re: tastesgoodwhatisit

                        Thank you for your response. We're not swapping out all dairy and fowl for soy but thought about adding a little tofu into the mix. Based on all the posts, we'll probably stay away from tofu but look into miso. I'll have to look up doenjang. Thanks for the lead.

                        1. re: nemo

                          Just for perspective, some of the alarm regarding soy products is justified due to heavy pesticide use in the industry. But if you are eating organic tofu, I would not avoid it or remove it from your diet.

                          if you like tofu, I wouldn't avoid eating it. If you don't like tofu, then don't eat it. There are many foods with healthful and deleterious qualities. Many cruciferous vegetables are high in oxalates, which bind to nutrients and inhibit absorption. Caffeine in coffee beans is a toxin. Yuca is delicious but also has enough cyanide to make you seriously ill if not prepared properly. Whole wheat and bran is high in phytates similar to raw soy.

                          It's important to take food wholistically and eat a varied diet. Unfermented tofu is consumed daily by many millions of people in Asia and tofu has fiber, minerals, antioxidants that are a beneficial part of one's diet.

                          1. re: Pookipichu

                            Thanks, Pookipichu

                            We like tofu but certainly can avoid it. Or at least eat it only on occasion.

                            We don't drink coffee or tea nor eat yucca. We try to eat varied. Veggies, fruits, chicken and seafood occasionally. We like quinoa. brown rice, and kasha as grains, and while we will check out the phytate levels, I don't think that's an issue. But points well taken. Thank you for your thoughts.