A problematic report on the 'dangers' of soy

Update: February 2011 - There's a nicely balanced article on this subject over on Calorie Count [1], which is part of About.com.

There was a report in yesterday's Guardian [2] about the supposed dangers of soy products. I am rather dubious about the claims, simply because some of the 'facts' stated about the use of soy beans in Asian cuisine, or Japanese cuisine in particular, are just plain wrong. The implication made in the article is that all soy products are fermented for a long time in Japanese cuisines, but this is simply not true. Only miso and soy sauce and like products - which are only consumed in very small quantities, since they are quite salty - fit that description.

Here is the ways that, as far as I know that soy has commonly been consumed in Japan for hundreds of years, and how I grew up eating them in a Japanese household (and I do mean a Japanese one, in Japan, not hyphenated-Japanese).

• As tofu. The way that tofu is made is not described correctly at all in this report:

After the long, slow boiling of soya beans in water to eliminate toxins, a curdling agent was added to the liquid to separate it. The curds would then be pressed to make tofu and the whey, in which the antinutrients were concentrated, would be thrown away.

If soy beans were cooked for a long time, they turn into the consistency that any cooked dried beans turn into - mealy and starchy - thus making it impossible to express soy milk from. As far as I know soy milk for tofu is made the way I described it in my how to make tofu series [3], by soaking the beans then grinding them up before cooking the resulting pulp for a relatively short time (less than 30 minutes) to produce soy milk. The whey is usually thrown away, simply because nigari, the coagulant, has a bitter taste. However, some Japanese households used to save the whey for making the next batch of tofu.

• As various tofu-based products: aburaage, atsuage, yuba, etc. Also various foods made from tofu such as ganmodoki.
• As natto [4], which are boiled and fermented soy beans. They are not, however, fermented for "a very long time" as the article at one point states all soy bean products are, but only for a day. (My grandmother used to make natto at home, fermenting the beans in the warm kotatsu, a heated covered table.) Tempeh is also only fermented for a day or so.
• As cooked whole dried beans, often together with hijiki (a type of seaweed), or mixed with steamed rice (daizu gohan, or soy bean rice). This goes against the quote from one of the interviewees, who produces soy sauce - "I never saw soy beans on the table in Japan - they're indigestible." Raw soy beans are indigestible for sure...so are all raw dried beans. I have to think he was misquoted somehow, if he really did live in Japan for 18 years and has a Japanese wife. Of course I guess it's likely she is from the Kansai region where they don't eat natto... This is the danger really of relying on anecdotal evidence.
• As green immature soy beans, boiled - edamame. Since I wrote this back in 2006, edamame have become almost ubiquitous in many American cities. In Japan, edamame are eaten as beer snacks and such all the time, especially in summer.
• Finally, as miso (and miso-like bean pastes) and soy sauce; both of these items are fermented for a long period - a minimum of 6 months in most cases, or longer. So, these products are the only ones that actually fit the definition of 'safe' soy products, according to these alleged researchers.

Missing from the list is soy milk, which is called to-nyuu in Japan. Traditionally people didn't drink soy milk in Japan, though I believe it has been consumed for a long time in other Asian countries. In Japan at least, it's just in the last two or three decades that it's been touted as a healthy alternative to milk. When I was going to school in Japan, our school lunches always had a bottle or carton of milk. Most people still drink milk rather than soy milk. I would even guess that proportionately more Americans now drink soy milk than Japanese people.

It's quite possible that industrially produced, highly processed soy products are not necessarily good for you. In my opinion, it's always a good idea to question just how good manufactured and engineered food products are for you. f you are eating soy products that have been consumed for hundreds, if not thousands, of years, or the whole soy bean such as edamame and cooked dried beans, you're probably fine. Anyone who over-relies on heavily processed foods of any type to excess is playing fast and loose with their health anyway! However, the items listed as facts in the report really aren't do make me skeptical about the veracity of the whole piece. And is soy milk, which is cooked, bad for you? I'm skeptical about that too.

Although Japanese use of soy was used as the primary examples, the article also made a blanket statement about all Asian cuisines. If you're Asian, what did you grow up eating? What about soy milk, which seems to be the primary focus of criticism?

Technorati Tags: tofu [5], soy bean [6], soy [7], guardian [8], nutrition [9], japanese food [10], asian food [11]