Category: self-experimentation

Ancient Non-Nutritional Wisdom: Morning Dance

Seth Roberts4 Comments

From the latest episode of The Amazing Race:

[PHIL:] In this detour, teams have to choose between two ways that the people of Guilin [China] express themselves artistically. The choice: choreography or calligraphy. In choreography, teams must join in a popular exercise in Guilin: dancing. They’ll make their way to the central island, join a group of locals performing their morning dance routine, and learn the dance.

Emphasis added. The dancing, done in pairs, provides plenty of morning face-to-face contact, just what I think everyone needs for good mood regulation.

On the Tsinghua campus, I saw morning groups practicing aikido, which doesn’t provide as much face-to-face contact. The Guilin dancing is perfect. Also good is that it’s done outside. The sunlight will give the light-sensitive circadian oscillator a big push. Faces push a face-sensitive circadian oscillator.

There is one region of China whose residents are known for being laid back and happy. I wonder: Is it Guilin?

Steve Levitt and John List Teach Experimentation to MBA Students

Seth Roberts2 Comments

From the Financial Times:

“The level of experimentation [at big businesses such as United Airlines] is abysmal,” says Prof List. “These firms do not take full advantage of feedback opportunities they’re presented with. After seeing example after example, we sat down and said, ‘We have to try to do something to stop this.’ One change we could make is to teach 75 to 100 of the best MBA students in the world how to think about feedback opportunities and how to think about designing their own field experiments to learn something that can make their company better.”

The two economists decided to team up to develop a course for [University of Chicago] Booth [Business School] students on “Using Experiments in Firms” – the first time either had taught at the business school.

This is an interesting middle ground between conventional science (done by professors) and what I have done a lot of (self-experimentation to solve my own problems — e.g., sleep better). I’m (a) trying to solve my own problems and (b) it’s not a job. Conventional scientists are (a) trying to solve other people’s problems and (b) it is a job. The MBA students will be taught experimentation that involves their own problems — well, their own company’s problems — and it is a job.

One important effect of this course, if the whole idea catches on, could be a cultural shift: A growing belief that experimentation is good and that failure to experiment is bad. Some of my first self-experiments involved acne. I was a grad student. When I told my dermatologist what I’d done — my results showed that a medicine he’d prescribed didn’t work — he looked unhappy. “Why did you do that?” he asked.

The Levitt/List course has a Martin-Luther-esque ring to it. Science: Not just for other people.

Thanks to Nadav Manham.

What about Multivitamins?

Seth Roberts5 Comments

A recent large study concluded:

After a median follow-up of 8.0 and 7.9 years in the clinical trial and observational study cohorts, respectively, the Women’s Health Initiative study provided convincing evidence that multivitamin use has little or no influence on the risk of common cancers, CVD, or total mortality in postmenopausal women.

I think this supports what I’ve been saying. In this blog I’ve emphasized two deficiencies in the American diet:

  • Not enough omega-3
  • Not enough fermented food

Neither is reduced by a multivitamin pill. As far as I can tell, when either one is fixed with something resembling an optimal dose, there are easy-to-notice benefits. Before I started making these points, there were plenty of reasons to think these are major deficiencies. For example, the Aquatic Ape Hypothesis suggested that we might need more omega-3 than we usually get. The Umami Hypothesis suggested we need a lot more fermented food than we usually eat. In contrast, I can’t think of a single reason to think that Americans suffer from major vitamin deficiencies. I take a multivitamin pill but I’d stop long before I’d give up flaxseed oil or fermented foods.

Sitting is Bad, New Research Suggests

Seth Roberts4 Comments

From a new study:

We prospectively examined sitting time and mortality in a representative sample of 17,013 Canadians 18-90 yr of age. [They were divided into five groups based on] daily amount of sitting time (almost none of the time, one fourth of the time, half of the time, three fourths of the time, almost all of the time . . . Participants were followed prospectively for an average of 12.0 yr for the ascertainment of mortality status. RESULTS:: There were 1832 deaths (759 of cardiovascular disease (CVD) and 547 of cancer) during 204,732 person-yr of follow-up. After adjustment for potential confounders, there was a progressively higher risk of mortality across higher levels of sitting time from all causes (hazard ratios (HR): 1.00, 1.00, 1.11, 1.36, 1.54; P for trend <0.0001) and CVD (HR:1.00, 1.01, 1.22, 1.47, 1.54; P for trend <0.0001) but not cancer.

I am pleased to see no problem with sitting one-fourth of the time. The CVD/cancer difference suggests the two diseases have different causes — which is consistent with cancer being due to environmental chemicals (e.g., cigarette smoke) and age (cancer risk goes up as the fourth power of age).

Related research from the same lab. My self-experimentation about standing. My one-legged standing (which I still do and am still studying).

Thanks to Dave Lull.

Principles of Experimental Design

Seth Roberts7 Comments

In this 10-minute talk I discuss what I think are the two main principles of experimental design:

  1. Something is better than nothing. You learn more from doing something than from thinking about what to do.
  2. When you do something, do the smallest easiest thing that will help, that will tell you something you don’t know.

Grad students often fail to understand Principle 1: They worry too much about what to do. Early in grad school, that was my big mistake. Professors often fail to understand Principle 2: They do something more complex than necessary. Failure is much more likely than they realize. My previous post was about such a failure (using genes to predict disease). When I was an assistant professor, I often made this mistake.

Brainwashing in High Places: Genes and Disease

Seth Roberts4 Comments

From an article by Nicholas Wade in the NY Times:

Since the human genome was decoded in 2003, researchers have been developing a powerful method for comparing the genomes of patients and healthy people, with the hope of pinpointing the DNA changes responsible for common diseases.

This method, called a genomewide association study, . . . has been disappointing in that the kind of genetic variation it detects has turned out to explain surprisingly little of the genetic links to most diseases.

Wade means the genetic variation is surprisingly poor at distinguishing healthy people and sick people. That is the empirical result.

Unlike the rare diseases caused by a change affecting only one gene, common diseases like cancer and diabetes are caused by a set of several genetic variations in each person.

This is the faith-based statement. Wade knows this how? What about the possibility that cancer and diabetes are caused by environmental differences? That there are consistent environmental differences (e.g., dietary differences) between those who get cancer and those who don’t?

I know of no evidence that common diseases like cancer and diabetes are caused by several genetic variations in each person. I know of a lot of evidence that they are caused by the wrong environment — lung cancer caused by smoking, for example.

Preachers say: If you do X, you will go to heaven. In other words, do something that helps me (the preacher) now and you will benefit later. It has been an effective argument. This is what the geneticists have been doing. They say to granting agencies — who believe what they read in the NY Times — if you give us money now we will find the genetic basis of Disease X. Just as there was no clear reason to believe the preachers’ claims, there was no clear reason to believe the geneticists’ predictions. Which unfortunately for them can be shown to be wrong.

The success of my self-experimentation at solving common problems led me to think the environment is more powerful than NY Times readers, or at least NY Times reporters, had been led to believe. Good news for people with problems but bad news for scientists who want large grants. My research was essentially free.

The Hygiene Hypothesis

Seth Roberts3 Comments

Here is a nice review of the hygiene hypothesis, proposed in 1989 by David Strachan. The hygiene hypothesis is that the increases in childhood allergies and asthma in rich countries were due to decreases in “infection in early childhood, transmitted by contact with unhygenic older siblings or acquired prenatally.” It was inspired by the observation that allergies and asthma were less common in larger families.

In the original, it was infections that were the crucial thing you got from older siblings. This idea ran into trouble when actual measurements of number infections did not show the expected inverse correlation:

When a composite index of exposure was generated by combining histories of illness due to measles, mumps, rubella, varicella, and pertussis, the tendency was for a slightly higher risk of allergic disease in children with multiple infections.

Also bad for the infection idea is that vaccination for measles didn’t protect against hay fever or eczema.

It looks to my perhaps-biassed eyes that it is dirt (= harmless foreign proteins and bacteria) exposure that matters, not exposure to human infectious agents. Living on a farm helps. Plainly you get dirty living on a farm and exposed to animal viruses and bacteria — but that you get human infectious agents from pigs and cows is unlikely. (In technical terms, they aren’t vectors.) Older brothers are more protective than older sisters. Boys are dirtier than girls; it isn’t obvious they are more infectious. Dogs are more protective than cats. Again, dogs are obviously dirtier than cats but the notion that they are more infectious — few infectious agents cross the species barrier — is less obvious.

An emphasis on dirt rather than human-infectious agents is more compatible with my belief in the vast importance of ingesting bacteria-laden food.

Scary Effect of Food Irradiation

Seth Roberts2 Comments

Continuing the theme that wiping out bacteria — as antibiotics do — might be a bad thing, here is a mysterious development:

The new study arose from a mysterious affliction of pregnant cats. A company testing the effects on growth and development in cats using diets that had been irradiated reported that some cats developed severe neurological dysfunction, including movement disorders, vision loss and paralysis. Taken off the diet, the cats recovered slowly, but eventually all lost functions were restored.

“After being on the diet for three to four months, the pregnant cats started to develop progressive neurological disease,” says Duncan, a professor of medical sciences at the UW-Madison School of Veterinary Medicine and an authority on demyelinating diseases. “Cats put back on a normal diet recovered. It’s a very puzzling demyelinating disease.”

Do Americans have bacteriophobia? I believe we need to eat plenty of bacteria-rich food for best health (the umami hypothesis). If so, then irradiating food is like taking all the vitamins out of it. Of course, food irradiation is big business. From a list of FAQs:

4. Does eating irradiated food present long-term health risks?

No. Federal government and other scientists reviewed several hundred studies on the effects of food irradiation before reaching conclusions about the general safety of the treatment. In order to make recommendations specifically about poultry irradiation, U.S. Food and Drug Administration scientists reviewed findings from additional relevant studies.

Independent scientific committees in Denmark, Sweden, United Kingdom and Canada also have reaffirmed the safety of food irradiation. In addition, food irradiation has received official international endorsement from the World Health Organizations and the International Atomic Energy Agency.

The International Atomic Energy Agency. It’s an interesting methodological question: Is Diet X (irradiated food) “safe” because it is no worse than Diet Y (ordinary food)? What if Diet Y isn’t safe?

Duncan, the researcher quoted above, said this:

“We think it is extremely unlikely that [irradiated food] could become a human health problem,” Duncan explains. ”We think [what happened to the cats] is species specific.”

Hmm. If you don’t understand what causes the effect, how can you make strong claims about it? I think food with too-few bacteria is already a human health problem.

Thanks to Peter Spero.

Nobel-Prize Cluelessness (stomach ulcers)

Seth Roberts14 Comments

Wherein the Nobel Prize is given for discoveries that are misleading. From a New Scientist article about medical self-experimentation:

Junior doctor Barry Marshall was sure the medical establishment was wrong about the cause of stomach ulcers. The received wisdom was that they were caused primarily by lifestyle factors, but Marshall and pathologist Robin Warren were sure that the bacterium Helicobacter pylori was to blame.

It turned out that Helicobacter pylori was present in half the stomachs in the world — only a tiny fraction of which developed ulcers. So much for causation. Marshall and Warren did not consider that lifestyle factors might cause immune efficiency to go down, leading to increased growth of the bacterium. In a famous example of self-experimentation, Marshall ingested a giant amount of the supposedly dangerous bacterium — but, uh-oh, didn’t get an ulcer.

Thanks to JR Minkel.