The Nutrition Lesson Hidden in a Bowl of Miso Soup

Tyler Cowen is the only person I know who talks about the great value of travel. Schools should teach it, he says. I agree. If you’ve read The Shangri-La Diet, you may remember the turning point was a visit to Paris when I inexplicably lost my appetite. You don’t know that my belief in fermented food — to be healthy, we need to eat lots of fermented food — also began with foreign travel: A trip to Japan.

When I got back to Berkeley from Beijing a few months ago, I looked around my kitchen: What should I make? I came up blank. Huh? I couldn’t understand why I couldn’t think of anything. (In Beijing I had never cooked.) The first few days back in Berkeley I made grilled fish. The Aquatic Ape Hypothesis. Then I went to the Fancy Food Show in San Francisco. At a Japanese food booth, including miso soup packets, I suddenly remembered: For my last nine months in Berkeley, after a trip to Japan in January 2008, I’d been eating a lot of miso soup. Every day. Which I’d never done before. Nine months was long enough to block out what I’d cooked before January 2008 yet short enough to be forgotten after three months in China.

Why did I start eating so much miso soup? In a Tokyo supermarket I had noticed they sold a lot of miso paste. Maybe there were ten types for sale. When I got home from Japan, that experience inspired me to buy a tub of miso paste. I’d add one or two tablespoons to a few cups of water, along with vegetables and thinly-sliced meat (plus vinegar and hot sauce). It was so delicious and easy that I started making miso soup every day. I went through five or six tubs of miso.

The miracle was how easy it was — that one ingredient (miso) should so easily produce such a delicious result. No one spice will do that. Garlic alone won’t do that. Ginger alone won’t do that. One ingredient was so compelling, pulled me so far from my previous cooking that I completely forgot about it after a three-month absence. During those nine months, while I was eating all that miso soup, I didn’t wonder why miso made such a difference. But when I finally thought of the umami hypothesis — we like umami, sour, and complex flavors so that we will eat more bacteria-laden food; bacteria tend to produce those flavors — all of sudden it made sense. Miso was so tasty because it was fermented. It was so tasty because it was so missing.

10 thoughts on “The Nutrition Lesson Hidden in a Bowl of Miso Soup

  1. Seth, I’ve been following your posts on your belief that eating more fermented food is healthy. It may be, but IMO you’re overgeneralizing about bacteria and the immune system. If umami has anything to do with bacteria, what about the repugnance we feel toward feces? Most biologists will tell you that we evolved that repugnance because feces is nearly 2/3 bacteria by weight; it’s filled with chemicals produced by microbes that have quite descriptive names, like putrescine.

    Also, the immune system: is there really any evidence that it needs to be stimulated constantly? The gut’s immune system secretes IgA, the purpose of which is to keep bacteria away from the gut lining and out of the body. Overactive immune systems are the source of problems, not health, e.g. autism appears to be a case of that, so does depression, lupus, etc.

    I’ve seen some of your commenters mention keeping eggs at room temperature; ordinarily, the inside of an egg should be sterile, so it’s hard to see what aging will do, and the outside can contain pathogenic bacteria, like Salmonella spp.

    In short, it doesn’t appear to me that you have made a case for your theory. You need to distinguish between pathogenic and beneficial bacteria, that umami has anything to do with bacteria, and you need to show that stimulating the immune system in general is a good thing.

  2. Thanks, Dennis. Re feces: the bacteria we need to be afraid of (and avoid) are those that can grow inside us. The bacteria of feces obviously fit that description — thus our repugnance makes perfect sense. The bacteria we don’t need to be afraid of are those that can’t grow inside us. With few exceptions, the bacteria that grow on plants and dead meat fit this description. Optimized for those conditions, they cannot handle the much different conditions inside the body.

    Re why stimulating the immune system is a good thing. Lots of studies show that various probiotics improve health. Here are 3 observations that made me see the broad generalization: 1. A woman who started eating yogurt everyday had her overall health greatly improve a the same time. 2. A friend was unable to get rid of a skin infection until he started taking Chinese herbs. 3. The beneficial effect of tapeworms on hay fever and asthma. In each case, introduction of (harmless) foreign substances likely to stimulate the immune system apparently improved its function. The evidence for the hygiene hypothesis is another sort of evidence that supports this point.

  3. Regarding over reactive immune systems, I’ve heard it theorized that they’re a weak immune systems way of overcompensating. Since it is slow to mobilize and has less chance to fight off infections, it can’t afford to take as many risks and responds to more false positives, and does so with greater damage and inflammation. This can contribute to allergies and autoimmune disorders.

    The sad thing is that since the weak immune system is too slow to respond, most viruses can reproduce to critical mass where they divide faster than the weak immune system can suppress them, so the overreaction is often in vain. A strong immune system on the other hand is confident enough in it’s ability to quickly kill off real threats before they hit critical mass, so it doesn’t need to overreact to every potential threat.

  4. I have a question about the Shangri-La Diet.

    I’m taking the sugar water once a day (1 T in a teacup of hot water). Is it ok to exercise right before I take it? As long as I’m drinking sugar water, I figure I can at least multi-task and let it restore my glycogen after a hard workout. Do you foresee any negative effects?

    Thank you very much!! :)

  5. Caroline, yes, okay to exercise before you take it.

    Caleb, yes, I agree. I think slow response and overresponse go together, which explains why the same treatment could make the immune system (a) better at fighting off ordinary bugs and (b) less likely to overrespond (allergies).

  6. Your experience of miso is very facinating, but I found the discussion on bacteria even more so. I understand our repugnance towards feces but never understood exactly why – now it all makes sense.
    I will be shopping for some miso myself later this week – it’s something I really want to try now.
    Kym

Leave a Reply

Your email address will not be published. Required fields are marked *