Category: fallibility of experts

Are Low-Carb Diets Dangerous?

Seth Roberts15 Comments

A link from dearieme led me to a recent study that found low-carb high-protein diets — presumably used to lose weight — associated with heart disease. The heart disease increase was substantial — as much as 60% in those with the most extreme diets. (A critic of the study, Dr. Yoni Freedhoff, called the increase in risk “ incredibly small“.) Four other studies of the same question have produced results consistent with this association. No study — at least, no study mentioned in the report — has produced results in the opposite direction (low-carb high-protein diets associated with a decrease in heart disease).

I find this interesting for several reasons.

1. I learned about the study from a Guardian article titled “What doctors won’t do”. A doctor named Tom Smith said, “I would never go on a low-carbohydrate, high-protein diet like Atkins, Dukan or Cambridge.” Fine. He didn’t say what he would do to lose weight. The psychological costs of obesity are huge. The popularity of low-carb diets probably has a lot — or everything — to do with the failure of researchers to find something better. I have never seen people who criticize low-carb diets appear aware of this. I disagree with a lot of Good Calories Bad Calories but I completely agree with its criticism of researchers.

2. There has never been a good explanation of the success of low-carb high-protein diets (why they cause weight loss), although this has been well-known for more than a century. (A good explanation would be a theory that made predictions that turned out to be true.) Such diets require a big change in what you eat. A big change is likely to have big health consequences in addition to the weight loss, and those side effects could be either good or bad. It now appears bad is more likely. With a good theory of weight control, you should be able to find a much smaller change that produces the same amount of weight loss as a low-carb high-protein diet. Because the change is much smaller, it should have much smaller side effects. Much smaller side effects (unknown whether they are good or bad) are much less likely, if bad, to outweigh the benefits of the weight loss. I have never come across a low-carb advocate who seemed to understand this (that we don’t know why they work and it would be a very good idea to find out).

3. The Japanese are remarkably healthy (live very long), slim, and have very little heart disease, yet eat lots of rice. Which makes absurd the notion that all high-carb diets are unhealthy or fattening.

4. The comments on the low-carb study are mostly critical and the criticisms are terrible. For example, Dr. Yoni Friedhoff, who blogs about weight control, says, “The paper’s basing all of its 15 years worth of conclusions off of a single, solitary, and clearly inaccurate, baseline food frequency questionnaire”. The authors of the study correctly reply that inaccuracy would reduce the associations.

5. Until nutrition scientists do better research, our best source of nutritional guidance may be what we like to eat. Evolution shaped us to like foods that are good for us, at least under ancient conditions. We like carbs and we don’t like foods high in protein (lean meat is barely edible) so a low-carb high-protein diet is on its face a bad idea. This is why I find it plausible that the low-carb high-protein association with heart disease reflects cause and effect (low-carb high-protein causes heart disease) and that in particular a high-protein diet causes heart disease. (Too little of the right fats?) We very much like fat. Under ancient conditions, the fat people ate was mostly animal fat and, before that, if you believe in aquatic apes, fish oil. It is quite plausible that lactose tolerance spread so quickly throughout the world because at the time everybody was starved of animal fat — high-fat mammals had been hunted to extinction — and dairy products were a good source of it.

 

 

What Should Your Cholesterol Be?

Seth Roberts9 Comments

According to the Mayo Clinic website, lower levels of cholesterol are better. For total cholesterol, says the Mayo Clinic, below 5.2 mmol/L (= 200 mg/dL) is “desirable”. A level from 5.2 to 6.2 mmol/L is “borderline high”, and above 6.2 mmol/L (= 240 mg/dL) is “high”.

A 2011 study from Norway, based on 500,000 person-years of observation, found drastically different results. For both men and women, the lowest levels of total cholesterol (below 5.0 mmol/L) were associated with the most death. For men, the best level was intermediate — what the Mayo Clinic calls “borderline high”. For women, the safest levels were the highest.

If high cholesterol causes heart disease, as we are so often told, the pattern for women makes no sense. For a long time, experts have told us to limit egg consumption because eggs are high in cholesterol. However, a new study shows that egg consumption has no association with heart disease risk.

Via Malcolm Kendrick. I also like his post about whether statins cause muscle pain.

Hard to Say Whether Medicine Does More Good Than Harm

Seth Roberts6 Comments

A draft article by Spyros Makridakis about blood pressure and iatrogenics takes issue with the statement that “The treatment of hypertension has been one of medicine’s major successes of the past half-century.” Over the last half-century, the article says, the death rate for people with high blood pressure decreased by almost exactly the same amount as the death rate for people without high blood pressure. Apparently “one of medicine’s major successes” is a case where the health benefit no more than equaled the health cost — leaving aside what the treatment cost in time and money.

Because very high blood pressure (systolic > 180 mm Hg) is quite dangerous and blood pressure drugs really work, this is a surprising outcome. Makridakis points out that doctors start treating high blood pressure when it rises above systolic = 140 mm Hg, a point when there is little or no increase in death rate. This article tells doctors to immediately prescribe drugs when systolic blood pressure is above 160. Yet death rate clearly increases only when systolic blood pressure is above 180. Makridakis concludes (as do I) that blood pressure drugs have significant health costs as well as benefits. The drugs are so often prescribed when they do no good and the costs are so high that the overall health costs of blood pressure treatment have managed to be as high as the overall benefits. Even when handed a relatively easy-to-measure problem (high blood pressure) and a relatively simple solution (blood pressure drugs), our health care system managed to achieve no clear gain. If this is “one of medicine’s major successes”, medicine is in bad shape.

The last paragraph of Makridakis’s article makes a surprising statement: “We strongly believe that medicine is extremely useful.” It does not explain this belief, which is contradicted by the rest of the article. I was puzzled. I wrote to the author:

I recently read your paper on “High blood pressure and iatrogenics”. The main part makes good sense. Then it ends with something quite puzzling: “We strongly believe that medicine is extremely useful.” No doubt a few areas of medicine are extremely useful. For large chunks of medicine, it is hard to tell whether they do more good than harm, because so many drugs and other treatments have undisclosed or unnoticed bad effects.

For example, tonsillectomies — for a long time the most common operation — is associated with a 50% increase in mortality in one study. The notion that cutting off part of the immune system is a good idea makes as much sense as the idea that cutting out part of the brain is a good idea. Another example is sleeping pills. They are associated with a three-fold increase in death rate soon after they begin to be taken. I am not saying that medicine overall does more harm than good. I am saying that a strong belief about the outcome of such an assessment (does medicine overall do more good than harm?) doesn’t make sense.

Makridakis replied:

Thank you for your email. The paper you mention is a draft posted for comments. I agree with you that my statement is wrong. It should have read: : “We strongly believe that medicine can be extremely useful”. For instance, this could be the case in treating heart attacks, strokes, traumas from car accidents or bullet shots. But in most other cases the harm from treatment can be greater than the benefits. In addition, the harm from preventive medicine can exceed its value. Thank you for pointing out this mistake to me.

Puzzle resolved.

Rent-Seeking Experts

Seth Roberts18 Comments

Two thought-provoking paragraphs from Matt Ridley:

From ancient Egypt to modern North Korea, always and everywhere, economic planning and control have caused stagnation; from ancient Phoenicia to modern Vietnam, economic liberation has caused prosperity. In the 1960s, Sir John Cowperthwaite, the financial secretary of Hong Kong, refused all instruction from his LSE-schooled masters in London to plan, regulate and manage the economy of his poor and refugee-overwhelmed island. Set merchants free to do what merchants can, was his philosophy. Today Hong Kong has higher per capita income than Britain.

In July 1948 Ludwig Erhard, director of West Germany’s economic council, abolished food rationing and ended all price controls on his own initiative. General Lucius Clay, military governor of the US zone, called him and said: “My advisers tell me what you have done is a terrible mistake. What do you say to that?” Erhard replied: “Herr General, pay no attention to them! My advisers tell me the same thing.” The German economic miracle was born that day; Britain kept rationing for six more years.

This is standard libertarianism. I like the stories but I don’t agree with the interpretation. I don’t think it is “economic planning and control” that causes stagnation in these examples. I believe it is expertise — more precisely, rent-seeking experts who know too little and extract too much rent. There are libertarian experts, too. They too are capable of doing immense damage (e.g., Alan Greenspan), contradicting Ridley’s view that “economic liberation” always causes prosperity. In both of Ridley’s examples, the experts give advice that empowers the experts. In the first example, Cowperthwaite is told by “LSE-schooled” economists to “plan, regulate and manage the economy.” All that planning, regulation and management require expertise, in particular expertise similar to that of the experts who advised it. Which you cannot buy — you have to rent it. You must pay the experts year after year after year to plan, regulate, and manage. Because the advice must empower the experts, there is a strong bias away from truth. That is the fundamental problem.

Freud is the classic rent-seeking expert. You are sick because of X, Y, and Z — and if you pay me for my time week after week, I will cure you, said Freud. Curiously no treatment that did not involve paying people like Freud would work. Curiously psychoanalytic patients never got better. Therapy lasted forever. You might think this is transparently ridiculous, but professors at esteemed universities such as Berkeley still take Freud seriously. Millions of people pay for psychotherapy. The latest psychotherapeutic fad is cognitive-behavioral therapy — which again requires paying experts to get better, week after week. Berkeley professors take that seriously, too.

Evidence-based medicine advocates are among the newest rent-seeking experts. Like Freud, they focus on process (you must follow a certain process) rather than results. (What they call process in other contexts is called ritual. Rituals always empower experts.) Rather than trying to learn from all the evidence — which might seem like a good idea, and a simple one — evidence-based medicine advocates preach that only a tiny fraction of the evidence (which you need a Cochrane expert to select and analyze) can actually tell us anything. Again, this might seem transparently ridiculous, but many people take it seriously. Evidence-based medicine has an amusing twist which is that its advocates tell the rest of us how stupid we are (for example, “correlation does not equal causation”).

The workhorses of the rent-seeking expert ecology — the ones that extract the most rent — are doctors. They are incapable of giving inexpensive advice. However they propose to help you, it always involves expensive treatment. This might seem like a recipe for crummy solutions, but again many people take a doctor’s advice seriously (by failing to do their own research). My introduction to the world of rent-seeking solutions was the dermatologist who told me I should take antibiotics for my acne. I was to take the antibiotics week after week — and because I was taking a dangerous drug, I should also see my doctor regularly. During these regular visits, the doctor never figured out that the antibiotic did nothing to cure my acne. I learned that by self-experimentation.

Like anthropologists who fail to notice their own weird beliefs (a recently-deceased Berkeley professor of anthropology took Freud seriously, for example), the profession that came up with the rent-seeking concept has failed to notice that many of them do exactly that.

One clue that you are dealing with a rent-seeking expert is that they literally ask for something like rent. Religious experts tell you to attend church week after week. Psychotherapists want you to attend therapy week after week. Psychiatrists tell you to take an anti-depressant daily for the rest of your life. My dermatologist told me to take an antibiotic daily (and to renew the prescription I needed to see him). And so on. As these examples suggest, rent-seeking experts thrive in areas of knowledge where our understanding is poor. Which includes economics.

“Rent-seeking experts” in education.

More What I call “standard libertarianism” Tyler Cowen calls “crude libertarianism”. Maybe I should have called it “off-the-shelf libertarianism”. In addition to what Tyler says, which I agree with, I would say that governments and their “central planners” have sponsored innovation (e.g., the Internet, the greenback, basic scientific discoveries) much better than Ridley seems to give them credit for. Innovation is a huge part of economic development.

False Confidence About What Caused the Newtown Massacre

Seth Roberts3 Comments

New York magazine commenters are usually smart and well-informed. Which is why this comment, on an article about “the forgotten victim”, Nancy Lanza, the shooter’s mother, stands out:

They say money cannot buy happiness [Adam’s father is apparently rich], but when dealing with someone with a mental illness, it can go a long way toward paying to fix unhappiness — it can pay for good doctors, proper medication [emphasis added], care-givers/guardians, all the tools required to secure a property and keep the “patient” safe, AND giving the mentally ill person his ideal living situation, limiting the snits and tantrums that can lead to real anger, which, in turn can lead to acting out.

No doubt this particular commenter is smart and well-informed. Which makes the fact that he or she is perfectly sure that “proper medication” exists so scary, at least if this person had any control over me or anyone who mattered to me. It reminds me of people who think that if you’re fat all you have to do is eat less.

No More Antixoxidants

Seth Roberts8 Comments

This fascinating blog post by Josh Mittledorf points out that antioxidants, once believed to reduce aging by reducing oxidative damage, have turned out to have the opposite effect. By reducing a hormetic effect, they make things worse. I’m a friend of Bruce Ames, one of main proponents of the free radical theory of aging. I’ve heard him talk about it a dozen times. The turning point — the beginning of the realization that this might be wrong — was this 1994 study, which found that beta-carotene, a potent antioxidant, increased mortality. Bruce did not have a good explanation for the counter-theoretical result. However, Mittledorf doesn’t mention an important fact which doesn’t fit his picture. Selenium, a potent antioxidant, also powerfully reduces cancer. Don’t stop taking selenium.

I also like this theoretical paper by Mittledorf about why aging evolved (turning off certain genes reduces aging) and how its evolution — not easily explained by conventional evolutionary ideas — is part of a range of phenomena that the conventional ideas cannot explain. One reason, maybe the main reason, that aging is adaptive is very Jane Jacobsian: it makes the community more flexible. Less likely to repeat old ways of doing things.

Thanks to Ashish Mukarji.

 

 

Bacteria are Neither Good nor Bad

Seth Roberts15 Comments

Health experts call bacteria “good” and “bad”. Bad bacteria make us sick. Good bacteria help us digest food, and a few other things. Let me propose another view. Any bacteria (i.e., bacterial species) will make us sick if it becomes too numerous — so all bacteria are “bad”. All bacteria protect us against other bacteria — so all bacteria are “good”. The terms “good” and “bad” are misleading. It is like saying a person is inherently rich or poor. Anyone, given a lot of money, becomes rich. Anyone whose money is taken away becomes poor. Low bacterial diversity or reduction of diversity makes it more likely that one bacterial species can overwhelm its competitors, producing sickness. When this happens, to say that the species (e.g., H. pylori) that became numerous “caused” the sickness (e.g., ulcers) is to seriously misunderstand what happened and how to prevent it from happening. We are taught that our immune system protects us from infection. We should be taught that bacterial diversity does the same thing.

The following story, from a reader of this blog, suggested these ideas:

My wife had a lot of problems, visceral fat that wouldn’t go away being one of the most obvious symptoms. Every time I convinced her to try a ketogenic (= very low carb) diet, she would get sick. I went to NYC to see Paul Jaminet speak. He suggested that she likely had some type of gut infection or dysbiosis. Not a bad theory, as she’d undergone prophylactic antibiotic treatment to clear up an H. pylori infection. (Yes, I know, but at the time it seemed like the thing to do.)

She started putting on weight after that, which is typical.

Finally she gave VLC [very low carb] one last try. She wound up getting inflamed lymph nodes in her thighs. Our doctor was wondering if she might have bovine tuberculosis or the bubonic plague, either of which would explain her symptoms. (The nodes were inflamed, black-and-blue, and sensitive. This is a typical symptom of bovine tuberculosis, and the disease spreads from the gut to the body through the bowel. As we consume raw milk, this wasn’t a crazy theory, but there have been no recorded outbreaks in Connecticut for years and years.) All the tests he did for an infection came back negative, but her symptoms clearly suggested she had one.

Finally she went to see a new OB-GYN. His nurse/dietician reaffirmed everything I’d been telling her, and she finally decided to go fully ketogenic. Once again, she got sick, but this time she decided to tough it out. Sure enough, after many weeks she started feeling better, and more importantly, the weight started coming off, and the visceral fat started reducing.

She did a stool test, and (I haven’t seen the results yet) we were told that she had the obesigenic gut biota. So she started an intensive probiotic regimen. This helped her one negative from the ketogenic diet: constipation.

She’s thrilled with the progress she’s seeing, and her few lingering issues after going primal 2.5 years ago seem to be resolving. The constant yeast infections have abated, and she’s planning a new wardrobe, heaven help me.

There are several interesting things here: 1. A very-low-carb diet made her sick. 2. This happened after antibiotic treatment. 3. Tests for infection were negative. 4. If she waited long enough, the low-carb-induced illness abated. 5. Probiotics helped. 6. Fermented foods didn’t help. At the time of Paul Jaminet’s diagnosis, says the reader, they were already eating plenty of fermented food: “Sauerkraut, yogurt, home-made kefir, the whole drill. No effect.”

How can these observations be explained?

With some general ideas. Each bacterial species keeps similar species in check by competing for the same resources (food and location). No two species need exactly the same things but there is plenty of overlap. For example, Species 1 needs Resources A and B, Species 2 needs Resources A and C. They keep each other in check by reducing the supply of A. Suppose C = carbohydrate. By reducing C, a very-low-carb diet reduces the number of Species 2, making more A available. This allows Species 1 to greatly expand. Maybe this expansion kills off Species 2. Armed with vast amounts of A, Species 1 out-competes other competitors. Its numbers greatly increase, causing sickness.

The notion that some bacteria are good and others are bad is absurd because all are safe in small amounts and all will cause sickness in large amounts. If any one person was replicated in millions or billions of copies it would cause enormous damage, waste and disruption, no matter who it was. Suppose I was genetically replicated so that there were hundreds of millions of me. I only like a few singers, such as Michelle Shocked and Cat Power. There would be a huge undersupply of records by those singers and a huge oversupply of other music. The music industry would collapse. I am a certain size. There would be a huge shortage of clothes of my size and a huge oversupply of clothing of other sizes.

The bacterial ecosystem is not self-correcting. It is the opposite: disruptions tend to spread. Suppose you eat too little carbohydrate. This reduces Species 2 (which needs A and C = carbohydrate). This means there is more Resource A for Species 1 (which needs Resources A and B). Species 1 increases. By virtue of increased numbers, it pushes down its competitors for Resource B. These weakened competitors, which also need D, E, and F, begin to lose battles for those resources against other bacteria that need D, E, and F. They decline in number. No longer with substantial competition for what it needs (A and B), Species 1 multiplies unchecked and causes damage until A and B run out. (Which may be why the reader’s wife, after a long illness, got better.) Fever fights infection because bacteria that grow best at one temperature (normal body temperature) do less well against competitors at a higher temperature.

The tests for infection failed to come up positive because they looked for too few bacteria. According to this view, there are thousands of bacteria inside us that can run out of control. You can test for only a tiny fraction of them. Fermented foods failed to help because they did not provide enough diversity.

We have a huge preference for diversity in what we eat. We much prefer a meal with three foods than one food, for example. The usual view is that this preference evolved because we need many nutrients (e.g., many vitamins) to be healthy. Now I wonder. Maybe the protective effect of bacterial diversity was the main reason. If so, taking a multi-vitamin pill is not going do much good, which is what research suggests.

These ideas are obviously supported by evidence that fermented foods improve health and antibiotics harm health, which I’ve covered many times. They are also supported by two recent studies with a different emphasis. One of them found that teenagers who had more biodiversity near home had more bacterial diversity on their skin. (Maybe there are other important drivers of diversity besides fermented foods.) The other found that people with sinusitis had less bacterial diversity in their nose than people without sinusitis and that increasing diversity tended to prevent sinusitis. Someday the 2005 Nobel Prize for “showing” that ulcers are “caused” by H. pylori will seem as medieval as the 1949 Nobel Prize for prefrontal lobotomies.

The practical consequences of this view include: 1. Antibiotics should be a very last resort. When given, they should be followed by treatments that restore bacterial diversity. The reader’s story suggests restoration of diversity may not be easy. Plainly diversity should be tracked after antibiotics. 2. Epidemiological studies should not just ask how did the germs spread? They should also ask why were they allowed to do harm? Why didn’t natural defenses – the immune system and other bacteria – suppress them to harmless levels? To the epidemiological neglect of immune function we can add neglect of this line of defense. 3. There should be convenient ways to measure one’s bacterial diversity so each of us can learn where we are and what makes it go up and down. 4. Researchers should study what makes bacterial diversity go up and down. Here is a recent study about this: old people living in an old-age home, who ate a restricted diet, had less bacterial diversity than people the same age who lived independently and ate more varied foods.. 5. Researchers should learn the correlates of high and low diversity. Take a group of people, measure their bacterial diversity, track their health for six months.

 

 

 

The Personal Scientist Who Knew Too Much

Seth Roberts3 Comments

The San Jose Mercury News recently ran a story by Lisa Krieger about a father (Hugh Rienhoff) who found a single-amino-acid mutation that he believes causes his daughter’s growth difficulties.

Born with small, weak muscles, long feet and curled fingers, Beatrice confounded all the experts.

No one else in her family had such a syndrome. In fact, apparently no one else in the world did either.

Rienhoff — a biotech consultant trained in math, medicine and genetics at Harvard, Johns Hopkins and the Fred Hutchinson Cancer Research Center in Seattle — launched a search.

He combed the publicly available medical literature, researching diseases, while jotting down each new clue or theory. Because her ailment is so rare, he knew no big labs or advocacy groups would be interested.

He did some of his own lab work in his San Carlos home, borrowing tools or buying them used online.

A few commercial labs, like the San Diego-based biotech Illumina, offered him help for free. And a wide array of pediatricians, geneticists and neurologists volunteered their opinions.

Over time, he zeroed in on a stretch of genes that control a growth hormone responsible for muscle cell size and number. And he knew he could further target his search — saving time and money by not sequencing Bea’s entire genome, but only the exomes, which are the genes that code for proteins.

This is not a simple upbeat story. The father is a genetic researcher and doctor. I agree, he has made considerable progress in understanding the cause of his daughter’s problem. Not addressed are two questions: 1. Why is he sure he has the right mutation? Perhaps his daughter has other mutations. I’m sure the father understands this, the journalist may not. 2. What about environmental causes? As Aaron Blaisdell’s story shows — Aaron has/had a single-gene genetic disease that vanished when he changed his diet — single-gene diseases may respond to environmental changes. Early work with bacteria emphasized this. If Rienhoff had spent equal effort in trying to find environmental changes that help, he might be further along in discovering them. An obvious place to start would be testing different diets. There is no sign he has done that. His knowledge of genetics, plus the brainwashing that doctors undergo (they are told genes are incredibly important), may have led him to waste a lot of time. Someone with less understanding of genetics may realize better than Rienhoff that knowing what genes have changed may be very little help in finding helpful environmental changes.

Thanks to Allan Jackson.

 

Big Diet and Exercise Study Fails to Find Benefit

Seth Roberts34 Comments

Persons with Type 2 diabetes have an increased risk of heart disease and stroke. They are usually overweight. A study of about 5000 persons with Type 2 diabetes who were overweight or worse asked if eating less and exercise — causing weight loss — would reduce the risk. of heart disease and stroke. The difficult treatment caused a small amount of weight loss (5%), which was enough to reduce risk factors. The study ended earlier than planned because eating less and exercise didn’t help: “11 years after the study began, researchers concluded it was futile to continue — the two groups had nearly identical rates of heart attacks, strokes and cardiovascular deaths.”

Heart disease and stroke are major causes of death and disability. Failure of such an expensive study ($20 million?) to produce a clearly helpful result is an indication that mainstream health researchers don’t understand what causes heart disease and stroke. Another indication is that the treatment being studied (eating less and exercise) was popular in the 1950s. Mainstream thinking about weight control is stuck in the 1950s. It is entirely possible that greater weight loss — which mainstream thinking is unable to achieve — would have reduced heart disease and stroke. If you understand what causes heart disease and stroke, your understanding may lead you to lines of reasoning less obvious than people with diabetes are overweight –> weight loss treatments).

One of the study organizers – Rena Wing, a Brown University professor who studies weight control — told a journalist “you do a study because you don’t know the answer.” She failed to add, I’m sure, that wise people do not give a super-expensive car to someone who can’t drive. You should learn to drive with a cheap car. Allowing ignorant researchers to do a super-expensive study was a mistake. To learn something, do the cheapest easiest study that will help. (As I have said many times.) You should not simply do “a study”. This principle was the most helpful thing I learned during my first ten years as a scientist. In this particular case, I doubt that a $20 million study was the cheapest easiest way to learn how to reduce heart disease and stroke.

I made progress on weight control, sleep, and other things partly because studying myself allowed me to learn quickly and cheaply. If researchers understood what causes major health problems, they would be able to invent treatments with big benefits. That the Nobel Prize in Physiology or Medicine is given year after year to work that makes no progress on major health problems is another sign of the lack of understanding reflected in the failure of this study. I have never seen this lack of understanding — which has great everyday consequences — pointed out by any science blogger or science columnist or science journalist, many of whom describe themselves as “skeptical” and complain about “bad science.”

 

 

The Fallibility of Epidemiologists: Neglect of the Immune System

Seth Roberts12 Comments

Anne Weiss recently repointed me to an interview with the epidemiologist Tom Jefferson about swine flu. Jefferson, let me stress, is a good epidemiologist. In the interview he makes a point I make on this blog, that research is heavily shaped by two questions: 1. what will make money? 2. what will be good for my career? (How curious that economists — with the exception of Veblen and Robin Hanson — spend so much more time on #1 than #2.) For example:

Interviewer Why aren’t researchers interested in [other viruses]?

Jefferson: It’s easy: They can’t make money with [them]. With rhinoviruses, RSV and the majority of the other viruses, it’s hard to make a lot of money or a career out of it. Against influenza, though, there are vaccines, and there are drugs you can sell. And that’s where the big money from the pharmaceuticals industry is. It makes sure that research on influenza is published in the good journals. And that’s why you have more attention being paid there, and the entire research field becomes interesting for ambitious scientists.

Because Jefferson is willing to tell the truth about virology, it is interesting what he doesn’t say.

The big glaring gap is that in a discussion about how to avoid getting sick he says nothing about improving immune function. Not one word. He isn’t a doctor. He doesn’t work for a drug company. There is no obvious reason he fails to discuss this. He is reflecting the blindness of his whole field, I believe. It isn’t a mystery how to improve immune function: Sleep better and eat more fermented food. I have blogged before (here, here, and here, for example) about how widely this supremely important question — how to improve immune function — is ignored.

The other gap in the interview is more subtle. Jefferson recommends hand-washing as a great way to avoid getting sick. He says:

I wash my hands very often — and it’s not all because of swine flu. That’s probably the most effective precaution there is against all respiratory viruses, and the majority of gastrointestinal viruses and germs as well.

Later he says:

One study done in Pakistan has shown that hand washing can even save children’s lives. Someone should get a Nobel Prize for that!

In contrast, I believe that touching other people (and thereby picking up their germs on your hands) is part of a self-vaccination system whose goal is to protect us against the dangerous microbes nearby by exposing us to them in small amounts. Part of the system is an enjoyment of touching others and being touched. Another part is whatever causes us to constantly touch ourselves around the mouth. A third part is the tonsils, perfectly placed to pick up a tiny fraction of the germs around our mouths.

This theory of mine, which is supported by several lines of evidence, suggests that hand washing has a serious downside: It interferes with the self-vaccination system. Jefferson says nothing about any downside of hand washing. I’m not saying that Jefferson should have known of this theory of mine, of course not. (For one thing, the interview was before I thought of it.) My point is that — for reasons having nothing to do with money or career — he is too certain about what he knows. Maybe hand washing is only helpful when persons have weak immune systems or in places with large amounts of germs, such as hospitals. With strong immune systems in normal places, maybe it does more harm than good.

I became aware of the big gap in research after I improved my sleep and stopped getting colds. Before that, I had gotten the usual number of colds. No one had said that could happen — had said there was so much room for improvement in immune function. Anne Weiss became aware of the gap in research when she visited her doctor:

[More than 10] years ago I was seeing a family medicine doc who also taught epidemiology at [Famous Canadian University]. At one of my appointments I asked her how I could strengthen my immune system. She laughed in my face and told me that just was not possible.

Weiss says she was treated “as if I had asked about the existence of fairies or unicorns.” (She added that attitudes seem to be changing and one Canadian hospital now uses probiotics to prevent and treat C. difficile infection.)

Epidemiologists could easily study environmental control of immune function. They could ask questions like how many colds do you get in a typical year?, when you get a cold, how long does it usually take before the symptoms disappear? and during the last year, how many days did your longest cold last? As far as I know, they haven’t done so.