- The science of fermented sausage and cheese
- Fermented food in Australia. “There’s a yeasty funkiness to fermented foods that I find really interesting,”
- Bad medical journalism pushes down good medical journalism. Decline of TheHeart.org. In contrast, I don’t think The New Yorker got worse after it was bought by Conde Nast.
- Whole body vibration. Clearly helps some people in chronic pain (the pain goes away). In other cases, the benefit is less clear.
Author: Seth Roberts
Coffee Experiments: Suggestions for Improvement
Seth Brown, a “data scientist” with a Ph.D. in computational genomics, has done several experiments about the best way to make coffee. In one, he compared other people’s burr grinders to his blade grinder. There was no clear difference in taste. In another, an Aeropress apparently produced better-tasting coffee than drip extraction. He hasn’t found other factors that matter. If I drank coffee, I’d be happy to know these things.
If I were teaching how to do experiments, his work would be a good case study. I’d have my students read it and suggest improvements. The contrast between his data analysis (sophisticated) and experimental design (unsophisticated) is striking, maybe because he has no background in experimentation.
Here’s what I would have done differently:
1. Study my reactions, not the reactions of guests. He had house guests rate the coffee he made. Yet he brews coffee for himself much more often than for others — at least, he gives that impression. Since his main customer is himself, it wasn’t clear why other people’s opinions are more important than his opinion. Maybe he read somewhere that blinding is good and thought it would be easier to achieve if other people did the ratings. He could have rated coffee he made himself blinded. Put stickers on the bottom of identical cups, shuffle the cups. However, since he will usually make coffee unblinded (he will know how he made it), it isn’t clear that blinding is good.
2. No “control” experiments. In a “control” experiment, he asked guests which of two identically-made cups of coffee was better. He doesn’t say what he learned from this — apparently nothing.
3. Simultaneous presentation. He gave guests two cups of coffee made differently and asked which they preferred. Apparently he gave them one cup at a time. Simultaneous presentation, allowing them to go back and forth, would have allowed much better discrimination. Maybe the two types of grinder differed but his experiment was too noisy to detect this.
In a footnote he wrote:
Ideally, I would have liked to use better control conditions [he appears to realize that there was something wrong with his control experiment — SR], larger sample sizes, more thorough subject randomization [I have no idea what this means; his designs are within-subject. In within-subject experiments, subjects are not randomized — SR], and a more consistent testing environment.
All of these changes would have made his experiments more difficult. Maybe he has internalized the rule harder is better.
The beginning of wisdom about science is roughly the opposite: do the simplest easiest thing that will tell you something. We always know less than we think, so make as few assumptions and as little investment as possible. The easier your experiment, the less you will lose if you make a wrong assumption. The smaller your sample size, the more resources (time, money, subjects, energy) you will have left over for other experiments. Bunsen’s experiments would have been easier if he had studied himself. By studying others, he made an untested assumption that they resembled him.
I’ve done dozens of tea experiments in which I compared tea brewed two different ways. The main things I’ve learned, besides best brew times and best amounts of tea to use, are: 1. Rinse tea before brewing. It eliminates a kind of dirty taste. 2. Combine chocolate tea and black tea. The combination is better than either alone. 3. A little bit of salt helps.
Assorted Links
- blood levels of omega-3 correlated with children’s behavior. “Many, if not most UK children, probably aren’t getting enough of the long-chain Omega-3 we all need for a healthy brain, heart and immune system.”
- “Chemical brain drain”. See the comment about Dursban.
- The back pain of a friend of mine, which had lasted 20 years and was getting worse, went away when he followed this doctor‘s advice.
- Appreciation of Jane Jacobs
Thanks to Alex Chernavsky and Dave Lull.
Omega-3: More Evidence of Brain Benefit
In a study to be released Tuesday, participants with low levels of omega-3 fatty acids in their blood had slightly smaller brains and scored lower on memory and cognitive tests than people with higher blood levels of omega-3s. The changes [that is, the differences] in the brain were equivalent to about two years of normal brain aging, says the study’s lead author.
As this article recommends, I used to eat plenty of fish. But I still noticed a dramatic improvement in my balance and cognitive abilities when I started taking flaxseed oil. The best amount seemed to be 2-3 tablespoons/day. Fish wasn’t supplying close to the optimum amount of omega-3. One comment on the article was
The only proper response to this article should be, “Duh.”
I disagree. A better response is to ask How much room for improvement is there?
Why We Need Diverse Fermented Foods
I found this comment from Art Ayers deep in a discussion on his excellent blog Cooling Inflammation:
Probiotic fermenting bacteria only work in the upper part of the gut, not in the colon. The anaerobic bacteria that work in the colon must be slowly acquired by persistent eating of diverse veggies to provide diverse polysaccharides and uncooked veggies to provide the bacteria.
I agree and disagree. It’s an excellent point that the bacteria near the stomach are quite different from the bacteria deep in the colon. So you need different sources of each. I don’t know what “probiotic fermenting bacteria” are (I was under the impression that all bacteria “ferment”), but, yeah, bacteria that live on lactose (e.g., in yogurt) are going to be quite different than bacteria that live on more complex sugars that are digested more slowly than lactose and thus pass further into the intestine.
To me, this explains why I like vegetables. I have no trouble avoiding fruit, bread, rice, pasta, and so on, but I hate meals without vegetables. Why? This line of thought suggests it is because they supply complex polysaccharides needed for deep-colon health. As Ayers implies, you wouldn’t need a lot. This line of thought suggests how you or nutrition scientists can decide what fermented foods to eat (some for each part of the digestive system).
I disagree about raw vegetables. Like most people, I don’t like raw vegetables. I like the crunchiness but the taste is too weak. That most people are like me is suggested by the fact that raw vegetables are almost never eaten without dip or dressing (which add fat and flavor) or something done to make them more palatable (e.g., sugar and liquid from tomatoes). If raw vegetables were important, even necessary, for health, the fact that they are hard to eat would make no evolutionary sense.
I do like pickled/fermented vegetables of all sorts, such as kimchi and sauerkraut. I believe they are a far better source of the bacteria you need than raw vegetables (they have far more of the bacteria that grow on raw vegetables than ordinary raw vegetables).
A High School Teacher Learns About Teaching
While reading a blog post about teaching high school math, this caught my attention:
I tend to stay pretty focused on teaching; rarely do I give A Talk. Today . . . I made an exception.
[teacher] “What is it you think I want?” [student] “You want me to shut up.” . . . [teacher] “Why?” [student] “Because it’s your job!” [teacher] “Because I want everyone to pass this class.”The class’s sudden silence [made me realize] that my remark had [had] an impact. . . .
I adopt my students’ values and goals, rather than insist they adopt mine. [emphasis added. To be sure, this is an overstatement — the truth is teacher/student compromise — but you get the point.] The kids were shocked into silence [because] they realized that my most heartfelt goal was to pass everyone in the class. I learned a key lesson I still use every time I meet a new class [–] make it clear I want to help them achieve their goals, which usually involve surviving the class.
I was unclear what the “key lesson” was so — I have edited the quote to make it clearer — so I asked the teacher blogger, who replied
The key lesson is explicitly state that I adopt my students’ values and goals, rather than insist they adopt mine. My students’s awareness that I want to give them value as they define it is essential to creating the classroom environment I want.
When I began working full time as a public school teacher [after years doing test prep], I had much tougher kids [than in test prep], and my classes were not as comfortable as I was used to. It was the emptiness or worse, hostility, I got from enough of the students that bothered me. I enjoyed teaching. But I felt something missing around the edges that I’d always felt–expected–from my classrooms, and I couldn’t even really spell out what was lacking—not gone, just not universal. I didn’t know why.
So in that moment [when I told my students that my goal was to help them reach their goals] I realized that one of my greatest teaching strengths was completely under the radar [= not noticed] not only to the toughest of my public school students, but to *me*. Many of my toughest public school students, the ones that had tracking bracelets or a long history of suspensions or just three years of repeated failures—hell, not only didn’t they realize that I wanted them to achieve their academic goals, they didn’t realize they HAD academic goals, since no one had ever told them that just “passing the class” was an allowable goal. I’d never realized how essential that understanding was to the rapport and engagement I had with kids until I experienced teaching without it.
I’ve only rarely experienced that alienation or hostility since [I learned to be explicit about my priorities]. I still have to be tough and snarl and yell. But now my public school classes give me the same sense of affinity, of understanding, that my test-prep classes did.
All or almost all teachers want their kids to do well. But teachers usually define “doing well” by their own ruler, and set their goals higher than is realistic–and so are often disappointed. I think most people [including high school teachers] don’t understand the degree to which high school students feel their choices in school are completely out of their control. They can’t choose most classes, they are “helped” by giving them more of the classes they hate (double math periods for strugglers).
This supports my view that teaching is much easier when you try to help students reach their goals than when you try to get them to reach your goals. Few teachers I know have figured this out — at best, they get to different students learn differently and stop. I think it’s the beginning of wisdom about teaching. I eventually found, after years of experimentation, that (a) my students’s goals overlapped mine well enough to be acceptable to onlookers and (b) their innate desire to reach those goals was strong enough that there was no need to grade them.
Association of Sleep and Chronic Illness
A recent PatientsLikeMe survey found a strong correlation between chronic illness and poor sleep. Here are the most interesting results:
PatientsLikeMe survey respondents in the U.S. (n=3,284) . . . are almost nine times more likely to [have] insomnia than the general adult population. . . . PatientsLikeMe members with health conditions experience [each] of the four symptoms of insomnia [= trouble falling asleep, trouble staying asleep, early awakening, and waking up not rested] at twice the rate of the general adult population.
This supports my view that bad sleep causes illness. The correlations could have plausibly been the other way (better sleep among survey respondents). People sleep more when sick. Whatever makes sick people sleep more might also make them fall asleep faster and wake up less often.
If I slept poorly, I would move heaven and earth to sleep better. (But would never take sleeping pills.) I sleep well, actually, but I still track my sleep and do various experiments to see if I can improve it. For example, recently I was puzzled why I was sleeping less well in Berkeley than in Beijing. One possibility was that my Beijing bedroom was darker than my Berkeley bedroom, even though my Berkeley bedroom was quite dark (e.g., no light from a street lamp). I made my Berkeley bedroom even darker and found my sleep improved. It really was cause and effect. When I made my Berkeley bedroom lighter, my sleep got worse.
My enormous concern with sleep — nothing matters more for health — seems to put me in a tiny minority. Even sleep researchers don’t say bad sleep causes sickness. However, Robb Wolf agrees with me. He has said, “If someone sleeps poorly it is hard to keep them alive. If someone sleeps well, it is hard to kill them” — a good way of putting it. At the recent Ancestral Health Symposium in Atlanta, I asked him where he got this. He said it was based on his experience, meaning his experience working with other people.
My view is heavily based on my experience of my own health. Exactly when I greatly improved my sleep, I greatly improved my health. I stopped getting obvious colds. The people around me continued to get them. I hadn’t expected this. In the research literature I found plenty of support for the idea that better sleep causes better health. An example is that poorer health during the winter seems to be due to less light, not the cold. I am sure morning sunlight improves sleep. Vitamin D has been associated with dozens of measures of health (more Vitamin D, better health). This too may reflect the underlying causality better sleep –> better health because sunlight increases Vitamin D and improves sleep. That morning Vitamin D improves sleep (Tara Grant’s great discovery) be important here. Epidemiologists should always measure sleep the way they always measure smoking. Now they almost never do.
Thanks to Richard Sprague.
More “Even sleep researchers don’t say that bad sleep causes illness” — that’s wrong. Here’s an example:
Yet there’s strong evidence that lost sleep is a serious matter. The Sleep in America polls and several large studies have linked sleep deficits with poor work performance, driving accidents, relationship problems, and mood problems like anger and depression. A growing list of health risks has been documented in recent studies, too. Heart disease, diabetes, and obesity have all been linked with chronic sleep loss. ”People just don’t realize how important sleep is, and what the health consequences are of not getting a good night’s sleep on a regular basis,” Hunt tells WebMD. “Sleep is just as important for overall health as diet and exercise.”
I should have said sleep researchers don’t connect good sleep with good immune function, which this quote illustrates.
Assorted Links
- Fruit kimchi recipe
- Eight types of natto at all-you-can-eat natto restaurant in Tokyo. This calls for a trip to Tokyo!
- Yale University gives Nobel Prize to someone who didn’t win one. Oops.
- Michael Lewis on the last crisis. ”I don’t feel, oh, how sad that Lehman went down. I feel, how sad that Goldman Sachs and Morgan Stanley didn’t follow.”
Does Chicken Extract Improve Brain Function?
An article in the latest Nutrition Journal says that a “proprietary” extract of chicken meat, called CMI-168, improved brain function. From the abstract:
Normal, healthy subjects were supplemented with either placebo or CMI-168 for 6 weeks. The subjects were given a series of cognitive tests to examine their levels of cognitive functioning at the beginning and end of supplementation, as well as two weeks after termination of supplementation. The combination of these tests, namely Digit Span Backwards, Letter-Number Sequencing, and the Rey Auditory Verbal Learning Test (RAVLT), was used to assess the subjects’ attention and working memory. . . . Subjects supplemented with CMI-168 showed significantly (p < 0.01) better performance in all cognitive tests after 6 weeks’ supplementation compared to [placebo] and [their] superior performance was maintained even 2 weeks after termination of supplementation.
This is the first time I’ve heard that something in chicken improves brain function. The abstract understates the strength of the evidence; p < 0.001 (not 0.01) in almost all relevant comparisons.
However, several details make me question the claim.
1. Two of the five authors work for the company that sells the chicken extract.
2. The subject recruitment makes no sense. “A total of 46 healthy male and female subjects aged between 35 and 65 years were recruited either as walk-in or referred from their general practitioners for counseling for life-style related issues.” Walk-in? “Life-style related issues”? “Counseling”? I have never heard of such things in this context. Nothing is said about payment or the fraction of people who declined to participate.
3. Vague statistics. I cannot tell if pre-treatment scores were used to make the treatment scores more sensitive. Someone who does better than average before treatment is likely to do better than average after treatment — you want to adjust for that.
4. No apparent learning effect. Subjects in the placebo group did not clearly improve from test to test. There is usually a big learning effect with such tests. Nothing is said about learning effects.
5. Vague supporting evidence. “Anecdotal evidence has long associated EOC [essence of chicken] with improving cognitive performance, especially related to learning and memory, as well as executive function,” says the paper. It provides no documentation of this evidence.
6. Uniformly positive results. The paper emphasizes results from nine different tests of brain function. All showed significant improvement at the same p value (p < 0.001). When I used four different tests to measure the brain effects of flaxseed oil, different tests had widely different sensitivities.
I haven’t been able to find anything supporting the idea that chicken meat (or extract) improves memory other than what this company says. I asked a Chinese friend about this; she too had never heard this claim. The company behind this (Brand’s) is more than a hundred years old, and essence of chicken has been their main product. In spite of my doubts, however, I would still like to test the product to see what effect it has on my reaction-time measure of brain function.
Strangely enough, after writing this post weeks ago, I noticed by accident that duck seemed to improve my brain function. I was stunned — as I said, I had never heard such a thing. I’ll describe the data later.
The Emperor’s New Clothes and the New York Times Paywall
A few years ago I blogged about three books I called The Emperor’s New Clothes trilogy. Each book described a situation in which, from a certain point of view, powerful people — our supposed leaders — “walked around naked”, that is, did things absurd to the naked eye, like the Emperor in the story. As in the story, many people, including experts, said nothing.
After reading about the fate of the Washington Post, I thought of the New York Times paywall, which can be avoided (i.e., defeated) by using what Chrome calls “incognito mode”. (Firefox has a similar mode.) I didn’t know this until recently; some of my friends didn’t know it. One of them carefully rationed the Times articles she read. I wonder how the long the ignorance will last. The Times is an extremely important institution. In the many long discussions at the Times about the paywall, no one mentioned this?