Category: umami hypothesis

Psychophysics of Flavor Complexity

Seth Roberts15 Comments

If I need evidence that we like complex flavors, I will quote this passage from The New Yorker:

“This sauce is really good,” she said. “It’s so Jean-Georges. He does this French-and-Asian thing.” She warned me that she would need a few seconds to figure out its precise ingredients. (She refused to divulge them, on the ground that Vongerichten would consider the recipe “a trade secret.” I later learned from one of the waiters that the ingredients include powdered English mustard and soy sauce.) “It’s so complex,” she said. “It makes me smile.”

The soy sauce is fermented. As any regular reader of this blog knows, I believe we evolved to like complex flavors so that we would eat more bacteria-rich food. So we have something in our brain that measures complexity of smell/flavor and translates that into pleasure: the more complexity, the more pleasure.

My experience of cooking is that it isn’t easy to produce a lot of complexity using spices and stuff like garlic and ginger. It’s possible but not easy. Ordinary recipes, such as in Saveur, aim for a low level, with 5-8 spices. Chinese Five Spice has 5 spices; spice mixtures might have 8; curry powders might have 10. At Whole Foods, the ready-to-eat soups have twenty-odd ingredients. Apparently their soup designers don’t find it easy, either.

Then I discovered that miso by itself produced sufficient complexity. Miso soup doesn’t feel “under-complex”. Finally I understood why wine is such a powerful flavoring agent; wine, like miso, is fermented. It makes sense that foods that our complexity detector evolved to make us eat do a better job of setting off that detector than other foods.

Now consider how that detector works. Suppose you have two sources of sodium — two different salts, for example. You get the same saltiness from 2 g of Salt A as you do from 1 g of Salt A and 1 g of Salt B. I think complexity is quite different. I suspect that 2 g of Source A (e.g., miso) will produce a lot less complexity than 1 g of Source A and 1 g of Source B (e.g., wine).

I tried adding two fermented flavoring agents (miso and tsukudani) to soup. It worked! The result tasted clearly better than miso alone. Now I do this routinely. It’s very easy. The results have a level of deliciousness I can’t remember encountering before. Everything else I can eat (such as restaurant food) now seems less delicious. I think that three sources works better than two; whether four is noticeably better than three I don’t know.

The basic idea is there are strong sources of complexity (fermented foods) and weak ones (all other flavoring agents). One strong source = 10-20 weak sources. You get the best results by using several strong sources of complexity, perhaps three or more. Once you know this you no longer: 1. Obsess over recipe details (as in the New Yorker quote) because all complexity is alike and easily produced, just as no one worries about the source of saltiness. 2. Think traditional, time-honored recipes are better than what you can make yourself (e.g., Saveur). As far as I can tell food professionals (with one big exception) don’t understand this. I really enjoyed Top Chef Masters (a competition between 12 of the best chefs in America) but there was an almost total absence of fermented foods. Perhaps one chef used soy sauce. The winner, Rick Bayless, made a mole sauce. Mole sauces, which combine 20-odd weak sources of complexity, take hours. I think they produce less complexity than three fermented sources put together, which takes about a minute.

James Michener Anticipates Me

Seth Roberts9 Comments

In James Michener’s Poland (1983), a Polish peasant in a concentration camp tries to survive by thinking about food (p. 532 of the paperback):

He then transferred his imagination to a supper served at the wedding of a well-to-do farmer, where huge platters of sauerkraut, sausage, boiled pork and pickles had been provided, one to each of six tables, and he had helped himself piggishly, moving from one to the other so as not to reveal his gluttony. Â He recalled this particular feast for two reasons: as a peasant, he knew that the acid bite of the pickled kraut was good for him, all peasants knew that and it was one reason why they survived so long; and he could see in the rich fat of the meats the strength that came from them.

Later he thinks about animal fat:

He imagined himself luxuriating with platters of butter, or grease, or pork drippings, or oil that rich people bought from Spain, or the golden globules at the edge of a roast, or plain lard.

According to Wikipedia, Poland was based on “extensive study of Poland’s history and culture.” Thanks to Nadav Manham.

Sometimes Black Really Is White

Seth Roberts6 Comments

Jenny Holzer, the artist, says, “ I get up about four times a night and go back to sleep, or not.” I suspect she’s not eating enough animal fat. At my local Beijing supermarket yesterday, I asked a butcher to cut the meat off a piece of pork fat. Reverse trimming. At the moment, I think about 180 g of animal fat/day is a good dose. I’m much less concerned about amount of meat. Another instance, I thought to myself, where I want the opposite of everyone else. But that’s far more true in America than here. In China but not America, I can buy pork belly at any supermarket; in China but not America, there is vast selection of pickles and yogurt at any supermarket.

MSG and Nightmares

Seth Roberts11 Comments

At a dinner for foreign teachers at Tsinghua, I met a Canadian woman who teaches English literature. Soon after she moved to China, she started having nightmares every night. For dreams, they were unusually linear and realistic. They were nightmares in the sense that they felt “sinister”. This hadn’t happened to her before. It was especially puzzling because she was having a good time.

On a forum for foreigners in Beijing, she asked what might be causing the problem. MSG, she was told. All Chinese restaurants use MSG. She started cooking her own food. The problem went away. Whenever she ate a restaurant meal, the problem returned. The time between meal and sleep made a difference. The dreams would be more vivid if she slept soon after the meal.

Here is a discussion of the MSG/nightmare link with many stories about it. I believe we like the taste of MSG because glutamate is created when proteins are digested by bacteria. We like glutamate because we need to eat bacteria to be healthy. Bacteria are too big and varied to detect directly; it’s much easier to evolve a glutamate detector. The problem is that now you can have glutamate in your food without bacteria. Apparently cooked tomatoes and garlic are other sources.

With PubMed I found two relevant articles. One reported an experiment where hyperactive boys got better when additives, including MSG, were removed from their food. The other is a review article about the effects of MSG that mentions sleep.

I’m sure from the personal stories that MSG causes nightmares — and therefore probably also causes other problems. (That glutamate is a neurotransmitter makes the MSG-nightmare link even more likely.) Here are researchers from the Scripps Clinic in San Diego saying MSG is safe:

Since the first description of the ‘Monosodium glutamate symptom complex’, originally described in 1968 as the ‘Chinese restaurant syndrome’, a number of anecdotal reports and small clinical studies of variable quality have attributed a variety of symptoms to the dietary ingestion of MSG. . . . Despite concerns raised by early reports, decades of research [this review was published in 2009] have failed to demonstrate a clear and consistent relationship between MSG ingestion and the development of these conditions..

What the woman I met did in a week or so (establish that MSG has bad effects), medical researchers — at least, judging by this review — have failed to do in 41 years (“decades of research”). Just as dermatologists have been unable to figure out that acne is caused by diet.

More about the dangers of MSG.

The Most Promising Solutions to the Allergy Epidemic

Seth Roberts7 Comments

At a charity dinner in New York City to benefit the Food Allergy Institute, the president of the Institute told the guests that

Several promising treatments [were] in the works, including a Chinese herbal therapy being developed by the prominent allergist Dr. Hugh Sampson of Mt. Sinai (ready as soon as 2011) and a parasite “similar to those found in the stomachs of most citizens in developing countries,” which could someday be introduced into imperiled Upper East Side intestines, the theory being that “in the developed world, we live in too clean of an environment, so our immune system has nothing familiar to attack.”

Gatekeeper syndrome. How dare they not read this blog!

The Hygiene Hypothesis, Pro and Con

Seth Roberts5 Comments

According to BBC News, recent research supports the hygiene hypothesis:

Normal bacteria living on the skin trigger a pathway that helps prevent inflammation when we get hurt, the US team discovered. The bugs dampen down overactive immune responses that can cause cuts and grazes to swell, they say.

And other recent research says it’s wrong:

The decades-old “hygiene hypothesis” holds that early exposure to microbes somehow challenges the immune system and strengthens it against allergies. Studies have shown children exposed to bugs by older siblings or attending nursery cut their future allergy risk.

But new work published by the American Thoracic Society casts doubt on this.

The study by Dutch investigators at the Erasmus University found although children in day care got more colds and other infections, they were just as likely as other children to go on to develop asthma or another allergy by the age of eight. The children who went to nursery and who had older siblings had more than quadruple the risk of frequent chest infections and double the risk of wheezing in early life, with no obvious pay off in terms of later protection from allergy.

The original hygiene hypothesis said that exposure to harmful germs (e.g., that cause colds) cuts down on allergy risk. But it’s now clear it’s the exposure to harmless germs (e.g., in dirt) that’s helpful.

Allergies in the UK have tripled in the last 10 years. I believe this is due to greater consumption of food that is germ-free, such as factory food and restaurant food. Shelf-life considerations and food-safety laws, in other words.

Advice given by Allergy UK:

The best advice we can currently give to parents is not to smoke around their children and make sure they have a balanced diet and get plenty of exercise.

Not even close to what I think. My advice is: Feed your kids plenty of fermented food, such as yogurt. I’d bet a lot of money that my advice is better.
Thanks to Mark Griffith.

Benefits of Kefir: N=1

Seth Roberts8 Comments

A year and a half ago, Charles Richardson was given antibiotics for an ulcer. He writes:

When they put me on the course of antibiotics for the ulcer, my digestion absolutely went south. Stools became runny and smelly and irregularly timed. Even though I took a lot of supposedly high-end probiotic capsules, that went on for months after the antibiotics.

Six months ago — a year after the antibiotics — he started drinking kefir because of this blog. “After about a month [of kefir], I was back to normal,” he writes. He got the starter culture from kefirlady.com (where they cost $20 cash).

More recently he has seen further improvements:

I had a number of food allergies, particularly wheat. If I ate any wheat, I’d get hemorrhoids immediately, and sometimes what looked like a herpes outbreak.

I’ve had that for 30 years or so, but it appears to have gone away in the last month. I had to eat some pasta at a formal dinner, and was expecting a reaction, but had none. I was shocked. I also have a similar reaction to chicken, and had the some non-experience with some of that recently.

I don’t know to what I can attribute that change. The kefir could have helped,and possibly the Vitamin D [about 4000 units/day]. I also started take an amino acid dipeptide of L-glutamine/L-alanine. https://www.kyowa-usa.com/brands/sustamine.html) [about 10 g/day]

This is informative for several reasons.

First, the bad effects of the antibiotics lasted a really long time (a year). This indicates how bacteria-poor a normal American diet is. Richardson probably ate healthier than normal given that he once owned a health-food store.

Second, expensive probiotics didn’t help. This is why I make kombucha and yogurt, to have more quality control. And yogurt is surely closer to what our ancient ancestors ate to get bacteria than probiotic capsules.

Third, the kefir took about a month to solve the problem. This gives an idea of the time it takes to repopulate your intestine with bacteria. And thus how long you should try this or that solution before giving up.

Acid Reflux is Immune Problem, Says Rat Study

Seth Roberts8 Comments

A study using a rat model of acid reflux found that the problem is inflammation caused by the immune system, not stomach acid damaging tissue, as had previously been thought.

[The] study in rats showed that gastroesophageal reflux causes tissue in the esophagus to release immune chemicals called cytokines, which attract inflammatory cells. These cause the heartburn and chest pain that make GERD [gastroesophageal reflux disease] so distressing.

“Currently, we treat GERD by giving medications to prevent the stomach from making acid,” said Dr. Rhonda Souza, who led the study published in the November issue of Gastroenterology.

“But if GERD is really an immune-mediated injury, maybe we should create medications that would prevent these cytokines from attracting inflammatory cells to the esophagus and starting the injury in the first place.

Months ago I posted about a friend of mine whose acid reflux was cured by drinking kombucha. The implication of that case and the rat study is that acid reflux is caused by an over-active immune system. Perhaps stomach acid often gets into the esophagus. Only if your immune system is under-stimulated does this cause trouble.

Acid reflux is very common. According to the article, 20% of Americans “have it regularly”. All this supports my view that we need plenty of bacteria in our diet to be healthy, that few Americans get enough bacteria in their diet, and that the deficiency causes all sorts of digestive and immune problems.