Archive for the ‘Health’ Category

Mindless Eating

Monday, April 30th, 2007

Book review: Mindless Eating: Why We Eat More Than We Think by Brian Wansink.
This well-written book might help a few people lose a significant amount of weight, and many to lose a tiny bit.
Some of his advice seems to demand as much willpower for me as a typical diet (e.g. eat slowly), but he gives many small suggestions and advises us to pick and choose the most appropriate ones. There’s enough variety and novelty among his suggestions that most people are likely to find at least one feasible method to lose a few pounds.
A large fraction of his suggestions require none of the willpower that a typical diet requires, but will be rejected by most people because their ego will cause them to insist that only people less rational than them are making the kind of mistakes that the book’s suggestions will fix.
Most of the book’s claims seem to be backed up by careful research. But I couldn’t find any research to back up the claim that approaches which cause people to eat 100 calories per day less for days will cause people to lose 10 pounds in ten months. He presents evidence that such a diet doesn’t need to make people feel deprived over the short time periods they’ve been studied. But there’s been speculation among critics of diet books that our bodies have a natural “set point” weight, and diets which work for a while have no long-term effect because lower body weights cause increased desire to return to the set point. This book offers only weak anecdotal evidence against that possibility.
But even if it fails as a diet book, it may help you understand how the taste of your food is affected by factors other than the food itself.

Salt

Tuesday, April 24th, 2007

I had been skeptical of reports that low sodium diets produce health benefits (suspecting they were fighting the symptoms of high blood pressure rather than an underlying cause), but a new study has provided strong enough evidence to change my diet.
It’s time to switch from regular to low sodium soy sauce, and I’m going to reduce my seafood consumption (since I’ve started taking Omega-3 fish oil capsules and am eating more walnuts, my reasons for eating seafood have diminished).

Caffeine and the CYP1A2 gene

Monday, February 5th, 2007

I recently took a simple genetic test to determine whether I have genes for fast or slow caffeine metabolism. The result says that I’m a fast metabolizer, which indicates that caffeine use reduces my risk of heart attacks rather than increasing it.
This kind of testing is just becoming affordable, and it seems like many more tests of this nature should become common soon.

Money buys happiness?

Wednesday, January 31st, 2007

There has been a fair amount of research suggesting that beyond some low threshold, additional money does little to increase a person’s happiness.
Here’s a research report (see also here) indicating that the effect of money has sometimes been underestimated because researchers use income as a measure of money, when wealth has a higher correlation with happiness.
There’s probably more than one reason for this. Wealth produces a sense of security that isn’t achieved by having a high income but spending that income quickly. Also, it’s possible that people with high savings rates tend to be those who are easily satisfied with their status, whereas those who don’t save when they have high incomes are those who have a strong need to show off their incomes in order to compete for status (and since competition for status is in some ways a zero sum game, many of them will fail).

Last Well Person

Wednesday, June 28th, 2006

Book Review: The Last Well Person: How to Stay Well Despite the Health-care System by Nortin M. Hadler
There appears to be a large discrepancy between how effective most people think modern medical practices are and the evidence that experts have presented suggesting that it does very little to extend life. This book gives the impression of describing a pattern of ineffective or harmful practices that might be offsetting the benefits of the practices that are known to work. But there are enough flaws in his argument that I can’t decide how much of his conclusions I should accept.
He starts by saying he’s a Popperian, but often acts like he’s following some other, more dogmatic, philosophy. I’m particularly annoyed at his certain feelings of inevitability that we will die by about age 85:

I am aware of no data to support the premise that we can alter the date of death. … When high-functioning octogenarians decline, it is because their time is approaching.

He starts by making a plausible claim that many people get cardiovascular surgery when there’s no evidence that it will benefit them (and is likely to create some risks).
But starting in the next chapter it becomes easy to find flaws in his arguments. He raises some plausible doubts about the evidence for statins, but then tries to imply that if the imperfect evidence that’s available shows that less than 2% of people who are prescribed statins will benefit, then we should doubt that those people ought to take statins.
He presents evidence that prostate cancer treatments save fewer lives than is commonly thought. It appears that sometimes the treatment merely changes the cause of death to something else. Yet he concludes that the treatment is useless, when the data he presents indicate nontrivial benefits. He hints that the evidence doesn’t meet the usual standard of statistical significance, but feels comfortable concluding (without even saying how close it is to being statistically significant) that the lack of proof is strong evidence of ineffectiveness.
He has a somewhat interesting proposal that the final phase of drug testing be done by the FDA rather than by drug companies. If the FDA were run by angels, that would solve a number of problems with the existing regulatory incentives, but with an FDA run by humans it would replace them with new problems. For instance, the choice of which drugs to test is something that only a few special interest voters (i.e. mainly those working for large drug companies) would understand, so their interests would be likely to influence those choices to the benefit of those companies.

Unusual Bodies

Wednesday, June 21st, 2006

Book Review: One of Us : Conjoined Twins and the Future of Normal by Alice Domurat Dreger
This book raises questions about peoples’ reactions to conjoined twins that may have important implications for many other unusual traits. It eloquently questions common assumptions about the desire to seem normal. It has led me to wonder about the extent to which healthcare is used to make people more normal at the cost of making them less healthy.
The book presents strong evidence that conjoined twins who remain conjoined are at least as well off as those who are separated, and some evidence that separations reduce the twins’ life expectancy, possibly by a significant amount.
Remarkably, of the twins who remained conjoined to adulthood, only one pair requested separation (they didn’t survive it), and among those whose refused separation are a number whose twin had just died (which meant that separation appeared to offer the only chance for the remaining twin to survive).
This doesn’t mean conjoined twins are better off that way (those who have been separated seem equally satisfied with their status), but it strongly suggests that decisions to perform separations are motivated by something other than concern over the twins wellbeing. And it suggests that people who claim things like “The proposed operation would give these children’s bodies the integrity that nature denied them” are imposing their values on others in ways which would be considered unacceptable if the victims had a little political power.
The book reports a fair number of statements by doctors (and occasionally parents) which suggest they consider a normal appearance worth risking health to achieve. The book also theorizes that having a normal child is an important enough part of parents’ identity to override their interest in their children’s’ wellbeing. The book also reports some indications that surgeons are biased toward surgery for unusual problems by the fame if can bring them.
Unfortunately, there isn’t as much evidence as there ought to be about the health effects of separations. The book claims (plausibly, but without supporting references), that “most medicine is not yet evidence-based”, with most surgical decisions being based on storytelling rather than careful studies.
The book raises some important questions about cases where doctors think the only way to save one twin is to kill the other. The author points out some strong similarities between the medical killing that is done in some of these cases and a hypothetical case where a heart is taken from a live singleton (i.e. not conjoined) donor to save another (which all would agree is wrong). One difference that she fails to consider is that if you consider the heart property, it looks like jointly owned property in one case and individually owned property in the other, and we should expect some differences to result from that (although doctors may still be more willing to kill one twin than that perspective would justify).
One interesting example that the book provides of medicalizing a difference is the attempt to get doctors to recognize Drapetomania, a “disease” which causes slaves to run away.
How widespread is the practice of impairing health to make people more normal? Surgeries on intersex children probably create modest health risks. Commonly used medicines to deal with ordinary colds suppress annoying symptoms that are tools the body uses to fight the disease, and tend to make the disease last longer (see the book Why We Get Sick : The New Science of Darwinian Medicine by Randolph Nesse). A child with 3 arms makes doctors want to chop it off, presumably at some risk.
Are these part of a wider pattern that would help explain why increased healthcare spending doesn’t seem to make us healthier?
On a loosely related note, I just ran across an unsettling complaint that Prozac seems to help too many people:

“There’s nobody nonsyndromal. You can give Prozac to anyone you want.”

Which is anathema to what medical science is supposed to be about. “We try to convince people there’s some specificity to what we do,” says Millman. “But this is embarrassing.”

Is this an indication that people don’t want drugs to do anything other than treat abnormal conditions (i.e. that they consider it wrong to improve on normal conditions)? Or does it reflect concern that there will be less demand for doctors’ skills if no diagnosis is relevant to the decision to use it? (This seems less likely given that they can still play a role in monitoring side effects).

I was inspired to read this book by a brief comment from Robin Zebrowski at the recent Human Enhancement Conference.

Human Enhancement Conference

Friday, June 2nd, 2006

The conference on Human Enhancement Technologies and Human Rights this past weekend had many boring parts and a few interesting tidbits.
Many of the speakers were left-wing ideologues who seemed to be directing their speeches only to others from the same small set of left-wing academics. There were fewer libertarians at the conference than I expected, but still enough that it was strange how much of a disconnect there was between the ideology shown in the speeches and the ideology I knew from elsewhere that many people held but were being quiet about.
There was plenty of concern about whether increased control over one’s body would decrease diversity, but I heard little that enlightened me on that subject. There have clearly been many technologies that increased diversity, such as tattoos. There are some that have decreased diversity because there is a substantial consensus about what’s best (e.g. eyesight – it’s unclear why we should be concerned about a shortage of people who can’t see well enough to drive). Then there are a few traits such as degree of autism where there’s some uncertainty whether reduced diversity would be good. There are some pontificators (I didn’t hear anyone this focused at the conference) who think they know better than the masses what the right amount of diversity is, and that their opinions should be imposed on the masses. But the evidence for the pontificators’ expertise and the masses propensity to make mistakes is generally underwhelming, so I can’t find much reason to be as concerned about the effects of enhancement technology as I am about the desire to impose expert opinion on those who don’t want it.
Hank Greely pointed out that the letter of the law authorizes the FDA to regulate anything that could be considered a body enhancement, including clothing. So only the FDA’s interest in obeying the spirit of the law will deter them from regulating external enhancements.
One amusing report of unwanted side effects of an enhancement technology is the increase in sexually transmitted diseases in seniors following the introduction of Viagra.
Aubrey de Grey made an interesting argument that the most effective approach to convincing people to support a cure for aging is to persuade them that they are being logically inconsistent when they fail to do so. He has a point, but it’s weaker than he thinks. He gave several examples of problems that were allegedly solved by persuading society to be more logically consistent, but I generally doubt that’s what happened. One example was tolerance of homosexuality. I see few signs that logical arguments had much effect on that. I think the biggest change came from peer pressure, which became increasingly popular as gays became able to migrate to places where there were enough gays to safely start exerting peer pressure. Another factor was the shift away from the belief that the main purpose of sex should be reproduction. That initially happened due to changing circumstances (reduced reliance on children to support elderly parents). I’d say that has generally produced beliefs that are more inconsistent as people abandon the least convenient symptoms of the belief (e.g. contraception) but are much slower to abandon symptoms that are remote from their experience. I think similar theories could be made about some other examples he gave (slavery becoming more expensive to enforce when railroads made it easier for slaves to escape to a non-slave state).

Diet and the Environment

Friday, April 21st, 2006

A recent report says that switching from a meat-heavy diet to a vegetarian diet is as valuable for reducing greenhouse-gas emissions as switching to driving the right car. And that if you eat fish, switching from large fish to things like sardines and anchovies makes a big difference.
I’m unsure whether to believe the magnitudes of the differences, but the general idea appears right.

Fantastic Voyage

Wednesday, March 15th, 2006

Book Review: Fantastic Voyage : Live Long Enough to Live Forever by Ray Kurzweil, Terry Grossman
This book provides a lot of interesting ideas for improving your health, but it is a bit too ambitious and I’m often left wondering whether they researched a particular idea well even that I should respect their opinion. They often seem to be more interested in showing off how many different topics they know something about than they are on focusing on the most important steps that a typical reader should be taking.
They are somewhat biased toward technological solutions, but occasionally surprise me with other approaches, such as pointing out some clear evidence that some kinds of meditation improve longevity.
I’m fairly suspicious of their advice about aluminum. It’s unclear why we should consider aluminum dangerous enough to be worth worrying about, but if it is then choosing the right baking powder and antacids are at least as important as the aluminum sources the book mentions (minor gripe: the index doesn’t have entries for aluminum or metals). Parts of the book leaves me wondering whether a close examination would reveal similar questionable aspects to their advice.

You are what you eat

Tuesday, November 29th, 2005

Here are some interesting claims about how easy it is to reduce crime through better nutrition (found via the Freakonomics blog). Probably exaggerated, but plausible.