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102 posts from April 2005

April 27, 2005

More on Flegal and obesity

Ampersand responds to my earlier post on Flegal's JAMA study. Read Amp's essay first and then check out my replies.

Amp thinks I'm not being fair to the Center for Consumer Freedom, the group behind the ad onslaught against the Centers for Disease Control. (Cf. US Ad Blitz Dismisses Obesity as Hype [Reuters]).

The Center for Consumer Freedom is launching an all out attack on the CDC. The lobby group isn't content to congratulate the Centers for publishing new and better research. It wants to punish the CDC and its scientists for their previous findings. The CCF's main strategy is to impugn the motives of the CDC. They imply that the agency knowingly disseminated bad research to scare the public.

The CCF claims that the earlier study was a flawed piece of propaganda, but they don’t offer any evidence to support that allegation. The press release simply reports that some scientists were critical of the study's methodology. The fact that someone, somewhere criticized some scientific methodology isn't a case. We can't decide whether the study was done well unless we hear their arguments and those of the study's defenders.

Maybe some of our epidemiologically savvy readers would like to weigh in on the merits of the earlier CDC study.

The general consensus seems to be that the Flegal study is better than its predecessor. But that’s how science works. It's a learning process. Findings are published, the scientific community reacts, and new research tries to overcome the shortcomings of earlier work.

Amp writes:

“There’s nothing wrong with skepticism, of course. But I can’t help but notice that, when it comes to the harms of obesity, suddenly Majikthise’s skepticism vanishes, and alternative ideas aren’t even mentioned:
…There is no doubt that obesity increases the risk of death and ill-health. […] this study suggests that if obesity rates increase, excess deaths will increase as well.
In fact, Majikthise sounds more certain about the obesity/death association than the JAMA authors themselves do.”

No one doubts that there are some excess deaths attributable to obesity, least of all the authors of this study. If obesity becomes more common, then there will be more excess deaths attributable to it. That’s just arithmetic.

Amp wonders why the authors of the study felt compelled to point out that their research didn't address the impact of overweight on other non-lethal health problems. I think their disclaimer is an important caveat. The CCF spin is that overweight is harmless or beneficial. In fact, we’re getting better at compensating for some of the chronic diseases it causes or exacerbates. The authors argue that overweight and obesity are less dangerous today because of better treatments for high blood pressure, high cholesterol, and diabetes. This is good news, but it's not license for complacency. Preventing chronic disease is as important as reducing excess mortality.

I may have given the misleading impression that I support reducing diets as a pillar of public health policy. That wasn't my intent. In the long run the most effective public health interventions will be measures that benefit people of all body types: PhysEd in public schools, community bike trails, tax credits for worksites with exercise facilities, better prenatal care (to ensure healthy weight gains during pregnancy and prevent gestational diabetes), increased support for breast feeding (because breast fed babies are less likely to become obese), zoning and tax incentives to lure fresh food stores to the inner city, an end to the corn syrup subsidy, and so on.

Update: What does this study mean for parents? Maternal and Child Health lays it on the line.

Revere the epidemiologist at Effect Measure gives Flegal's methodology a first-glance thumbs up and offers a backgrounder on the shady Center for Consumer Freedom.

The Constitution in exile

Fafnir scores an exclusive interview with our exiled Constitution.

April 26, 2005

Rorschach for Democrats

Steve Brady applies the wisdom of Alan Moore to Democratic filibuster strategy:

Nevercompromise

High praise

John Rogers of KungFu Monkey says of Orac:

I enjoy the way he crotch-kicks modern medievalism with reason and science, while he seems to be amused at the way I just mercilessly mock it into submission. Despite our differing approaches, go hang with the smart guy.

Hear, hear!

Speaking of Orac, he's got a great post about the Taran Francis tragedy unfolding at Montefiore Medical Center in the Bronx.

This case sums up so much of what's wrong with our health care system.

Evidently, the 13-year-old Francis was turned away from his root canal appointment at Bronx-Lebanon Hospital because he wasn't accompanied by a legal guardian. I didn't know New York as parental notification for root canals. Over the next few days, Francis's untreated infection spread from the tooth to his brain and killed him.

Thanks to the tactlessness of the Montefiore medical center, Francis's body is still on life support:

When a doctor appeared, the two women asked, "Should we be worried about anything?" Douglas said.

"The doctor said, 'Yes. He's literally brain dead.' " Soon after, they were approached by a hospital social worker, who told them, "We're going to give you time to mourn. You have 24 hours," said Douglas.

Asked what that meant, the social worker explained, "Legally, in New York state, the hospital has the right to take a person off life support when he's brain dead," Douglas said.

That's when Marcerlyn called a lawyer.

Douglas noted, "We pleaded with the doctors, 'This child needs time, for Christ's sake. Give him time.' "

In a chilling response, she said, the social worker told them that the only reason the hospital was giving Taran medical attention at that point was "to keep his organs functioning in case you want to donate them." [New York Post]

None of this would have happened to a white middle class family with good insurance. First off, the tooth would have been taken care of. What kind of hospital just sends a kid home with a severe infection without following up with his parents?

I bet the medical staff would have been much more solicitous towards a socially prominent family with a brain dead child. If Frances were a senator's son, a social worker wouldn't have just barged in and dictated a 24-hour mourning deadline. (Not that brain dead people don't need to come off life support, and not that organ donation isn't a wonderful option to discuss with families, of course.)

I should add that Orac's post is one of the many fine pieces of medical blogging on display at Grand Rounds XXXI, chez Dr. Tony.

Brooks: "Just quit when you need elastic waistbands"

When it comes to obesity, David Brooks, John Tierney, and the Center for Consumer Freedom remind me of the of the kid in this joke:

A kid is in his bedroom, near ecstasy as he masturbates ever more vigorously. In walks his father.

"You'd better stop that, son," says the dad. "Otherwise, you're liable to go blind."

The boy dutifully affirms that he will stop immediately.

A week later, the dad once again walks in on the boy as he is masturbating.

"I thought we had an agreement," dad sputters angrily.

"Well," says the kid, "I figured I'd just quit when I need glasses."

As Scott Lemieux notes, the fast food industry and the anti-public health crowd want the public to mentally cordon off obesity as a discrete disease. The industry is fostering the self-delusion that bad diet isn't harmful unless it's causing obesity. That way, it's easier to ignore the fact that the same bad habits that cause obesity in the minority are also hurting everyone else who partakes (i.e., most of us, to some extent):

But, in a sense, Tierney and Brooks are reacting to the focus on obesity rather than health more broadly; when evidence emerges that weight per se is less important than is generally asserted, well then go ahead and eat that second Double Quarter Pounder. But, of course, eating fast food regularly is unhealthy, as is being sedentary, and this is true whether it makes you obese or not (and in many cases, especially among young people, it doesn't.) Focusing on preventing obesity as an end in itself, I think, is not helpful in making this point (and Brooks is certainly correct in implying that aesthetic and health concerns, which should be kept distinct, are obviously being conflated.) We should focus on encouraging people to exercise regularly and heating a healthy diet rather than on what their bodies look like. This will, of course, reduce obesity as well, but that's a side effect; that shouldn't be the primary goal, and defining the goal in these terms I think ultimately plays into the hands of the fast food lobby. [Emphasis added.]

See more of Scott's writing on obesity, policy, and culture here, and here.

Happy birthday, dear TB

Coturnix invites you to join the fun at Tangled Bank:

The Tangled Bank is a blog carnival that collects, once every two weeks, best blog posts about science, nature, medicine, environment and the interface between science and society. The First Anniversary Edition has just been posted, but digging through the archives is great fun, too, as well as a good way to find some wonderful blogs.

Futures and options

Death business booms in Baghdad
Mon Apr 25,11:16 AM ET
BAGHDAD (AFP) - Hussein Mohammed never dreamt that roadside bombs and suicide attacks in Baghdad would make him a fortune.With every victim that falls to an explosion and suicide attack, the demand for coffins increases and my work flourishes," said the coffin-maker in his tiny shop in the heart of the war-torn capital.

Several people have been killed on the doorsteps of Mohammed's shop on the notorious Haifa Street, now an eerie no-go zone where a few nervous motorists speed past, only too aware that the insurgents' favoured tactics include roadside bombs. American snipers keep watch from the rooftops.

"During the days of Saddam (Hussein), I used to make one coffin a day. Now, I make scores of them and the demand increases with every suicide car bomb that explodes," said the 67-year-old Baghdadi.

With a daily fare of bombs and shootings up and down the country, it is rare that a day passes in the capital with no one falling victim to violence. [...]

Ironically the accompanying image is archived among the Lifestyle Photos.

The funeral home around the corner is accumulating yellow ribbons--about five identical yellow corsages now adorn the outside walk. Word is that a several of New Yorkers who have died in Iraq have been laid out there. I take comfort in the thought that at least the Democratic funeral home is getting all the business. Not a single yellow ribbon is on display in front of the Republican funeral parlor down the street.

Yes, our neighborhood has Democratic and Republican memorial homes.

[Via Flint.]

Fat is the new climate change

Have you heard the great news? According to the latest data from the Centers for Disease Control, obesity probably only kills about 112,000 Americans every year. John Tierney and David Brooks can hardly contain themselves.

Tierney opines:

[The new research has] taken away the favorite cudgel of the scolds who used the "obesity epidemic" as an excuse to attack the flabby. The supposedly deadly consequences of fat provided the scientific rationale for the last politically correct form of prejudice.

The fatophobes are fighting on, disputing the new study and arguing that it still shows the fatal dangers of being seriously obese. But they have lost the scientific high ground. Not only do people of "normal" weight die younger than the moderately overweight, the study shows, but thin people die even younger than those of normal weight.

Not coincidentally, the food and restaurant lobby is also helping itself to the latest CDC data. Last week the industry-sponsored Center for Consumer Freedom issued a press release berating the CDC for releasing "flawed" research earlier this year (namely, the study that estimated the excess deaths at 400,000 per annum).

The Center for Consumer Freedom is a parasitic form of think tank life. Instead of producing its own trumped-up studies like the anti-global warming groups, the CCF prefers to hijack other people's work.

In the press release, the Center for Consumer Freedom basically accuses the CDC and the authors of the earlier study of propagandizing the public, if not of outright scientific malpractice. The data were there in the Center's computers all along, they press release claims. Well, yes. Of course data sets used by Flegal and her colleagues have been around for awhile. They're the three National Health and Nutrition Examination Surveys (NHANES) compiled by the Department of Health and Human Services and used for countless studies over the years. But that doesn't mean that it should have occurred to the scientists who made the earlier estimates of obesity-related mortality to use the same statistical methods as the Flegal team. There is such a thing as scientific progress. We expect later research to supersede earlier work by capitalizing on its insights and overcoming its limitations. In their article Flegal and colleagues describe how they adapted a statistical technique designed to estimate breast cancer risks to the study of obesity. I get the impression that this approach is an original contribution and not a standard technique that their CDC colleagues should have anticipated.

Sorry, guys, the but size-16 print giveth, and the size-2 print taketh away...

Flegal KM, Graubard BI, Williamson D, et al. Excess deaths associated with underweight, overweight, and obesity. JAMA.2005;293:1861-1867.

These researchers argue that earlier studies may have overestimated the impact of obesity per se because their statistics didn't fully control for the subtly confounding effects age, gender, smoking, and drinking. Flegal and her colleagues tried to overcome the limitations of previous studies by using newer survey data and more sophisticated statistical methods.

The study itself looks pretty solid to me. It's the secondary spin that's insidious. Third parties are trying to give the public a false sense of security about the obesity crisis. Being overweight is good for you, the flacks insist. Well, not exactly... (Being overweight is probably healthier than yo-yo dieting, eating disorders, or extreme bariatric surgery, but this study doesn't bear on those important issues.)

Here's the first of several catches:

The new study attributes 111,909 deaths to obesity, but then subtracts the benefits of being modestly overweight, and arrives at the 25,814 figure. [CNN]

The Center for Consumer choice has arbitrarily seized upon the 25,814 figure because it's a good stick to beat the authors of the 400,000 estimate. But why subtract the number of lives "saved" by mere overweight from the number of deaths attributable to obesity? (Flegal compared recorded-deaths-in-2000 to a what the death rate would have been in an otherwise identical parallel universe where everyone was at a "normal" weight.) It's likely that the current standards for "normal" weight are too narrow. They may even be too low for the average American. In which case we should reckon excess deaths by comparing the real world to one in which everyone is either "normal" or "slightly overweight." Even so, it wouldn't follow that obesity (as currently defined) is less common or less dangerous than we thought.

Obesity apologists are equivocating about the difference between overweight and obesity. The effects of being overweight are uncertain, but there is no doubt that obesity increases the risk of death and ill-health. Furthermore, the number of excess deaths per year is a function of the prevalence of obesity, and no one disputes that the condition is becoming increasingly common.

But does being slightly overweight actually improve health? Or is this finding some kind of artifact? The intuitive explanation is that our current height-weight tables are wrong (either for the entire population or for certain sub-groups). Maybe it's healthier to have a little extra body fat, especially late in life. Besides, some heavier people may be at lower risk because they are leaner, fitter, and more muscular than many of their lighter counterparts.

Obesity may be a big problem without necessarily being responsible for as many excess deaths as we thought. The authors found that excess risk is highest for younger obese people. But most deaths occur after age 70. So, even obesity is associated withe a large relative increase in mortality for younger people, this increase won't necessarily translate into a large absolute number of excess deaths. Whereas if weight causes even small changes in the death rate of older people, these will produce large absolute numbers of excess deaths (or lives saved). But it's also worth noting that the preventable death of a younger person probably "costs" its victim more years of life. (As Amp suggests, no death is preventable. So-called "preventable" deaths are just the ones we can postpone. Many early obesity-related deaths are eminently postponable.)

Of the 111,909 estimated excess deaths associated with obesity (BMI>30), the majority, 84,145 excess deaths, occurred in individuals younger than 70 years. In contrast, of the 33,746 estimated excess deaths associated with underweight, the majority, 26, 666 excess deaths, occurred in individuals aged 70 years and older. (Flegal K, et al., 2005)

Maybe the latest results mean that doctors should encourage older people to bulk up--but not necessarily. A "normal" weight in a person over 70 may be a sign of a more serious health problem. After a certain age, people tend to get lighter for reasons that are more sinister than simple fat loss. Weight loss in the elderly is more likely to be associated with muscle wasting, bone loss, protein/calorie malnutrition, and a host of other serious health problems that directly increase a person's risk of dying, more or less irrespective of their body fat levels. It certainly doesn't follow that it's better to be overweight throughout one's life, rather than just during the critical years. (It should be emphasized that the current study doesn't claim to establish any cause and effect relationships. It is merely a sophisticated accounting of correlations between selected variables. Controlled trails and longitudinal studies will be needed to determine the precise causal relationship between weight and mortality.)

Brooks, Tierney, and the restauranteurs also overlook the fact that being overweight is itself a risk factor for future obesity. The more people who are overweight today, the more are likely to become obese in the future. So, even if overweight isn't associated with ill health, we should still be concerned about the potential for large numbers of overweight people to become obese. And this study suggests that if obesity rates increase, excess deaths will increase as well. The more fat someone has already, the smaller their "safety margin." People tend to gain weight with age until relatively late in life. Given that so many of the Baby Boomers are already overweight, many more will surely cross the line into obesity in the next few years. Besides, there is overwhelming evidence that excess fat actually causes even more weight gain through the vicious cycle known as metabolic syndrome.

The latest data don't take into account the fact that people are getting fat much earlier in life, nor that overweight and obesity are becoming more common every year.

Children and teenagers are the fastest-growing group of obese Americans. The effects of the childhood obesity boom are already manifesting themselves in historically unprecedented rates of type 2 diabetes and high cholesterol in childhood. The current study doesn't reflect the most recent trends. The study only includes people who were at least 25 when they participated in one of the three NHANES surveys (between 1971 and 1994), so it can't give us even a cross-sectional glimpse of the effects of early obesity.

Today's obese adults are more likely to have been overweight or obese since childhood than were obese people of previous generations. We don't know what the long-term effects of earlier onset will be, but we can only assume they will be worse. How could more years of high blood pressure, high cholesterol, and diabetes be a good thing?

Even if obesity "only" kills 100,000-odd people per year, that's still a lot of preventable death. Moreover, the researchers hypothesize that excess weight is less dangerous than it used to be primarily because of better treatments for high blood pressure, high cholesterol, and other illnesses caused or exacerbated by excess body fat. All things being equal, it would be better to prevent these diseases than to maintain people on expensive and potentially dangerous drugs for life. The study didn't even attempt to measure the detrimental effects of excess weight on general health or quality of life.

Tierney and others imply that if mere overweight is good for people, then our public health programs must be misguided. But if being overweight really extends people's lives, then we should redouble our public health efforts to stop millions of overweight Americans from drifting into obesity. For these people, even a small weight gain could have dire consequences. Maybe relatively modest weight loss will also turn out to be a huge benefit for people who are already obese. Even preventing further weight gain in obese people might save many lives. If so, perhaps obesity interventions are even more cost-effective than we thought. (Strategies to reduce the health impact of obesity should include efforts to fight size discrimination, which probably has a lot to do with the negative health outcomes associated with the condition.)

Pundits and interest groups are exploiting the Flegal study as an excuse to sneer at public health iniatives, malign the CDC, and to downplay the seriousness of the obesity epidemic.

Update: I notice that Brian Leiter is as big a Tierney fan as I am.

More interesting blog-based discussion of the Flegal from Alas, a Blog, Left Oblique, and Kevin Drum, and Jay Sennett.

April 25, 2005

Blog Sheroes triumphant

Thanks to Liza and Nichelle for organizing a terrific evening of networking, strategizing, drinking, and general conviviality. Read Nichelle's report on the inaugural meeting. I'll post links to the pictures when they go up.

Blogsheroes will be reconvening monthly at venues to be determined. Check the official Blogsheroes website for details.

Red Harvest hosts the Carnival of the Un-Captialists

From the guy who brought you Truong v. American Bible Society...

The Op presents an excellent lineup for Carnival of the Un-Capitalists IV.

A reminder...

Remember, Un-Capitalist comrades, this Sunday is May Day. Red Harvest will have a special musical post for the occassion. So, get your red flags out and brush up on the lyrics to Bandiera Rossa. Also, next week's Carnival, hosted by Meat-Eating Leftist, will be a special May Day edition, with a focus on worker's rights, unions, and international solidarity movements. Send your submissions to uncapitalist@gmail.com.