Here is a summary/directory of my posts about what I call the umami hypothesis — the idea that we must ingest plenty of microbes to be healthy. My Watts Towers. The easiest way to ingest plenty of microbes is to eat fermented foods.
Category: umami hypothesis
Assorted Links
- Probiotics reduce/prevent diarrhea caused by antibiotics. News article. The abstract says “The pooled evidence suggests that probiotics are associated with a reduction in AAD [antibiotic associated diarrhea].” It should say that the evidence suggests — very strongly, in fact — that probiotics cause a reduction in AAD (because there is no plausible alternative explanation of the association). This mistake is so elementary it is like saying 2 + 2 = 3. And JAMA is one of the world’s most prestigious medical journals.
- Living without money. The author was much healthier than when he lived with money. Among the many possible explanations is that dumpster food, old enough to allow microbes to grow on it, is healthier than fresher and therefore more sterile food.
- Not just farms. Children who grow up on farms have fewer allergies and less asthma than children who grow up in cities — important support for a modified version of the hygiene hypothesis (and my umami hypothesis). This study finds that living near other sorts of biodiversity provides similar benefits.
Thanks to Brody, Jazi Zilber and Mark Griffith.
Assorted Links
- Difficulties repeating priming effects
- Unexpected benefits of yogurt in mice. “The yogurt-eating mice were incredibly shiny. . . . These animals had 10 times the active follicle density of other mice.”
- A 13-year-0ld invents a cure for hiccups.
- A business that sells starter cultures for yogurt, kefir, kombucha, and so on — even natto. Here’s a little secret: you shouldn’t need to buy starter cultures. The store-bought product (e.g., bottle of kombucha), if not pasteurized, should function as starter culture for yogurt, kefir, or kombucha.
- Amish farm kids have fewer allergies than Swiss farm kids. Suggesting that something besides growing up on a farm can reduce allergies. Drinking microbe-rich raw milk?
Thanks to Hal Pashler and Bryan Castañeda.
Assorted Links
- The magic of mangoes. “In one double blind trial which included a low fat diet, the participants who took the mango supplements lost 5.3 per cent of their body weight while the control group lost only 1.3 per cent.” Which sounds impossible.
- Greek yogurt taste test
- Umami flavour as a means of regulating food intake and improving nutrition and health
- Babies fed breast milk have better intestinal microflora than babies fed formula. “Our findings suggest that human milk promotes the beneficial crosstalk between the immune system and microbe population in the gut, and maintains intestinal stability.”
Thanks to Melissa McEwen and Bryan Castañeda.
Fermented Foods Improve Irritable Bowel Syndrome
It’s hard to get scurvy. If you eat anything resembling an ordinary diet you won’t get it. The existence of scurvy, produced by extreme conditions, led to the discovery of Vitamin C. From the case of scurvy and Vitamin C we learned — well, most people learned — that some diseases are clues to what we need to eat to be healthy.
There is no lab test for irritable bowel syndrome (IBS). It is diagnosed if you have “abdominal pain or discomfort in association with frequent diarrhea or constipation,” says Wikipedia, and a dozen other things (colon cancer, lactose intolerance, celiac disease and so on) can be ruled out. It is common. In the United States, one study found that 14% of those surveyed had it. Surveys in other countries produce even higher values — the United States is not a hotspot. “It is one of the most common diseases diagnosed by doctors,” says an NIH webpage.
What is it telling us? According to the NIH webpage, “medications are an important part of relieving symptoms.” Those medications include anti-depressants. If you treat the problem with drugs, you completely ignore the possibility that a digestive problem is due to eating the wrong food. You might think that would be obvious — but no. Of course, people with IBS are less interested in taking medicine so they often believe they are “intolerant” to various foods. But they have a hard time figuring out what those foods are, and their problems persist. The Wikipedia section about causes is a monument either to the ignorance of medical school professors or Wikipedia contributors:
The cause of IBS is unknown, but several hypotheses have been proposed. The risk of developing IBS increases sixfold after acute gastrointestinal infection. Post-infection, further risk factors are young age, prolonged fever, anxiety, and depression.Publications suggesting the role of brain-gut “axis” appeared in the 1990s, such as the study “Brain-gut response to stress and cholinergic stimulation in IBS” published in the Journal of Clinical Gastroenterology in 1993. A 1997 study published in Gut magazine suggested that IBS was associated with a “derailing of the brain-gut axis.” Psychological factors may be important in the etiology of IBS.
That’s all. Nothing about eating the wrong food. And people wonder what to do about the cost of health care! My suggestion: get rid of everyone (especially medical school professors) too blind or biased to consider that a digestive problem may caused by the wrong food.
Fortunately not everyone is rushing to treat IBS sufferers with drugs. In an obscure journal called Molecular Medical Reports, an open-access article recently appeared about diet and IBS (“Diet and effects of diet management on quality of life and symptoms in patients with irritable bowel syndrome”). The authors are from Norway, which makes the sanity more understandable. The article looks at the effect of dietary advice on IBS symptoms. It compares three groups of patients (IBS patients given dietary advice, IBS patients not given dietary advice, and people without IBS). Patients with IBS eat quite differently than everyone else (for example, they eat less dairy, thinking they might be lactose intolerant), but they are still bad off.
The main point of the article is that the dietary advice was helpful. IBS patients given the advice two years before the study were better off than IBS patients not given the advice, although even those given the advice were considerably worse than normal. Looking at the difference between the diets of the two IBS groups, the better-off group ate a lot more probiotic dairy:
The guided IBS patients reported a consumption of sour milk products containing probiotics almost twice as often as the unguided IBS patients and one and a half times that of the controls. The products used were supplemented with Lactobacillus rhamnosus GG, Lactobacillus acidophilus La-5 and Bifidobacterium Bb-12. Patients with IBS were found to have fewer Lactobacillus spp. and Bifdobacterium spp. in their intestinal flora than healthy individuals (44). These bacteria have been shown to bind to epithelial cells and inhibit pathogen binding, and to enhance barrier function (46). Furthermore, these bacteria do not produce gas on fermenting carbohydrates, an effect which would be amplified as they also inhibit Clostridia spp. (46). A number of studies have shown an improvement in flatulence and abdominal distension with a reduction in the composite IBS symptom score, following probiotic intake (45,46) [emphasis added]
It is highly unlikely that we need to eat sour milk products containing probiotics to be healthy — such products are new in evolutionary history. But it is entirely possible that we need to eat plenty of microbe-laden (e.g., fermented) food to be healthy, as I have said countless times on this blog. The big improvement in IBS symptoms produced by probiotics supports my belief that we need to eat plenty of fermented foods to be healthy. (The Wikipedia entry about IBS mentions probiotics and yogurt, but not fermented foods.) Maybe IBS, like scurvy, is a clue to something really important.
Thanks to Melissa McEwen.
Flavour, a New Scientific Journal
A new online open-access journal called Flavour has just started publication. The first issue has three articles and an editorial.
The journal
encourages contributions not only from the academic community but also from the growing number of chefs and other food professionals who are introducing science into their kitchens. . . . often in collaboration with academic research groups.
The first set of articles has an example of a collaboration between chefs and professional scientists — how to get a strong umami flavor from Nordic seaweed. Then you add the flavor to ice cream. Which reminds me of dessert at a friend’s house where he poured expensive balsamic vinegar on vanilla ice cream.
Thanks to Melissa McEwen.
Why We Touch Our Mouths So Much: Forewarned is Forearmed
When I taught Introductory Psychology, I came across a study in which researchers put people in a room with food and watched them. They were looking for cycles in eating and drinking. They noticed that their subjects spent a lot of time touching the face near their mouth — what they called “the snout area”. After I read that, I noticed the same thing countless times. Right now I am at an airport waiting for a flight. Looking around, I see three of about 50 people touching their mouth or nearby.
Why do we do this? I propose an evolutionary explanation: To expose our immune system to all the germs near us in small amounts. Mouth-touching is part of a larger sampling process: 1. We touch many things constantly. In particular, we shake hands, hug, and otherwise touch people near us. Germs that have managed to live in or on other people are the most dangerous. 2. We lick our lips often, moving germs on our lips inside our mouths. 3. When you eat, food transfers bacteria from the inside of your mouth to your tonsils, which circle your throat. Tonsils are full of lymphocytes, the immune-system cells that detect germs. Once we have developed antibodies to a microbe, of course, we are much less vulnerable to it. The whole sampling process is a kind of self-vaccination.
We need conventional vaccination when self-vaccination fails. Polio vaccination was the first big vaccination program, and it worked: polio was nearly wiped out. Before around 1900, polio was not a big problem. It became a big problem at roughly the same time that public health measures and the replacement of horses by cars caused cities to become much cleaner places. Others have theorized that this is why polio became a big problem. As recently as 1951, thousands of children died from polio.
This is related to but different than my ideas about our need for fermented food. (I believe we need to eat plenty of fermented food, day after day, to be healthy.) When we eat fermented food, we ingest large amounts of bacteria that are familiar and safe. The amount is large because the food has been fermented. The bacteria are familiar because we eat the same food repeatedly. They are safe because the insides of our bodies are dramatically different than what we eat (e.g., different temperature). The sampling system I am proposing here exposes us to small amounts of unfamiliar dangerous bacteria. However, this sampling system and the factors that push us to eat fermented food (our liking for complex, sour, and umami flavors) both act to produce the best environment for our immune system. Fermented food resembles exercise and practice; the mouth-touching system resembles information.
A similar sampling system is our love of gossip. We love to hear it, we love to spread it. Gossip spreads information about the dangers around us. Again, forewarned is forearmed.
I am in Tokyo (for a few more minutes), an admirably clean city. Public rest rooms, for example, are convenient, clean, and free. (Unlike New York, Los Angeles, San Francisco, Beijing . . . ) The practical point of this idea isn’t that there is something wrong with public health measures, it is that they can go too far.
Kombucha For Bees, Man, and Woman
Dennis Murrell calls himself a “natural beekeeper”. This is one reason he sprayed kombucha on his bees:
In the early spring, I grade my hives strong, average, below average, weak. This year, I sprayed the below average hives with a slightly diluted, about 30%, solution of overly ripe kombucha. It was probably about 3 weeks old. The spraying was done incidentally, without any planning, etc., just to watch the first reaction of the bees. After spraying, the below average hives were left alone, without any more manipulation or observations. . . . Ten weeks later, I popped the covers off the below average hives and found they had a full super of honey, while all the others, even those with larger bee populations had none. I was quite surprised to say the least! And I’d had forgotten about the incidental kombucha spraying until looking at my notes a week later.
Wow. Does this presage a honey surplus? As other beekeepers follow his example? He sprayed kombucha on his bees partly because he himself had found it so beneficial:
I began drinking about a cup a day. . . . I’d been afflicted with a skin aliment since my youth [psoriasis?]. There’s no known cure. Modern medicine can relieve the symptoms. But the drugs used have more long term side effects that are worse than any benefits. Well, within 24 hours [of drinking kombucha], the itching associated with the irritated skin disappeared. Within three days, the slight swelling associated with the irritated skin also disappeared. Within a month, 99% of the irritated areas disappeared. During that time, I lost joint pain that had plagued me for a decade, commercial beekeeping is rough on the back and joints. I regained full movement in my right shoulder. And a sense of wellness replaced whatever biologically stressed out condition I thought was normal. Once you’re over 50, some of the things lost along the way become more apparent. Hair texture, intestinal fortitude, urinary function, energy level, and sexual prowess all decrease. And weight increases. Using kombucha, a probiotic, has reversed my losses to that of a man 10 to 15 years younger. And I’ve lost some weight. Before using it, I felt old. After using it, I feel alive. . . . My wife, a nurse, was more than skeptical, she thought I’d poison myself with that ugly looking concoction. But when she saw my results, she tried it. Within a month, her joint pain completely disappeared, allowing her to get up off her knees without help or pain. And her hair has returned to the luster and thickness it had when she was in her 30′s.
I gained a few pounds when I moved from Berkeley to Beijing in August. Until I read this, it hadn’t occurred to me that it might be due to kombucha deprivation. (It took three weeks to brew kombucha in Beijing. I have not seen it for sale in Beijing even in Western-style health food stores!) To me, the most interesting change he describes is better hair texture. Perhaps it reflects better digestion. I can’t see why better immune function would improve your hair.
Thanks to Steve Hansen.
Fermented Foods In Gladiator
From the movie Gladiator:
Slave Trader 1 These slaves are rotten.
Slave Trader 2 It all adds to the flavor.
A big reason I believe we need to eat fermented foods to be healthy is that they taste so good.
Acupuncture Critic Misses Big Points
Recently the Guardian ran an article by David Colquhoun, a professor of pharmacology at University College London, complaining about peer review. His complaints were innocuous; what was interesting was his example. How bad is peer review? he said . Look what gets published! He pointed to a study of the efficacy of acupuncture and included graphs of the results. “It’s obvious at a glance that acupuncture has at best a tiny and erratic effect on any of the outcomes that were measured,” he wrote.
Except it wasn’t. There were four graphs. Each had two lines — one labelled “acupuncture,” the other labelled “control”. You might think to assess the effect of acupuncture you compare the two lines. That wasn’t true. The labels were misleading. The “acupuncture” group got acupuncture early in the experiment; the “control” group got acupuncture late in the experiment. Better names would have been early treatment and late treatment. You could not allow for this “at a glance”. It was too complicated. With this design, if acupuncture were effective the difference between the two lines should be “erratic”.
The paper’s data analysis is poor. To judge the efficacy of acupuncture, their main comparison used only the data from the first 26 weeks. They could have used data from all 52 weeks. That is, they ignored half of their data when trying to answer their main question. Colquhoun could have criticized that, but he didn’t.
Colquhoun’s criticism was so harsh and shallow, apparently he is biased against acupuncture. But there are two big things few pharmacology professors appear to know. One is how to stimulate the immune system. This should be central in pharmacology, but it isn’t. Half of why I think fermented foods are so important is that I think they stimulate the immune system. (The other half is they improve digestion.) There are plenty of less common ways to do this. The phenomenon of hormesis suggests that small doses of all sorts of poisons, including radiation, stimulate repair systems. The evidence behind the hygiene hypothesis suggests that dirt improves the immune systems of children. Bee stings have been used to treat arthritis. And so on. In this context, sticking needles into someone, which puts a small amount of bacteria into their blood, is not absurd. Acupuncture also allowed patients to share their symptoms, the value of which Jon Cousins has emphasized.
The other big thing Colquhoun doesn’t seem to know is the absurdity of the chemical imbalance theory of depression. Speaking of ridiculous, that’s ridiculous. Which plays a larger role in modern medicine — antidepressants or acupuncture? If you want criticize peer review, criticize the chemical imbalance theory. It is as if peer reviewers have been saying, yes, the earth really is flat for fifty years. Perhaps this is ending. During a talk that Robert Whitaker gave at the Massachusetts General Hospital in January, he was told by doctors there that the chemical-imbalance theory was an “outdated model”.
Thanks to Dave Lull and Gary Wolf.