Sunday, May 31, 2009

Bigotry Begets Bloat? So claims a new study--but the evidence is thin


Taranto dissects the illogic and assumptions behind the nonsense below quite well. One thing he misses is however perhaps the most basic: Lack of a control group. Because of affirmative action, a lot of whites feel discriminated against too. Surely their feelings should have been surveyed and their weight gain measured. It would have been interesting at least and would have given (or not) at least some grounds for generalizations. So, if anything, I would interpret the results as showing that neurotic black women tend to eat more and therefore gain weight more

"Perceptions of racism--from being treated with suspicion in a store to unfairness in employment or housing--can heighten stress levels and affect health, research has shown," reports the Boston Globe:
A new study from Boston University links these smoldering signs of racism to weight gain in black women, suggesting a possible explanation for the their higher obesity rates compared to white women.

Yvette Cozier, an epidemiologist at the Slone Epidemiology Center at BU, led a survey of more than 43,000 women enrolled in the long-running Black Women's Health Study. Writing in the June issue of Annals of Epidemiology, she and her co-authors describe participants' reports on their weight, body mass index, and perceptions of racism.

At the beginning of the eight-year study, the women were asked if they sometimes felt they were treated poorly in a restaurant or store, whether they thought people considered them dishonest or less intelligent, and if they had felt unfairness on the job, in housing, or from police. The women, 21 to 69 years old at the study's outset, were placed in four groups based on how frequently they said they experienced these signs of racism. Their weight was recorded every two years from 1997 through 2005. Their waist circumference was measured at the beginning and end.

At the end of the trial, all the women had gained weight. But the women who said they felt higher levels of racism gained more weight and had bigger waist-size increases compared to the women who felt the least racism. That held true after accounting for factors such as education, geographic region, and beginning body mass index.

"Racism is real and it has real effects," Cozier said in an interview. "It can result in real changes in the body."

In fact, Cozier's study--available here at the low, low price of $31.50--offers no support whatever for this statement.

To begin with, nothing in the study addresses the hypothesis that "racism is real," unless one defines racism solely as a phenomenon within the mind of the putative victim. The study purports to measure the prevalence of perceived racism. It does not test the accuracy of its subjects' perceptions.

Further, it appears that for part of the study, even the perception of racism was imputed by the researchers rather than reported by the subjects themselves. Here is how the study describes the questions:
Five questions asked about the frequency in daily life (everyday racism) of the following experiences: "you receive poorer service than other people in restaurants or stores," "people act as if they think you are not intelligent," "people act as if they are afraid of you," "people act as if they think you are dishonest," and "people act as if they are better than you." Response options were "never," "a few times a year," "once a month," "once a week," "almost every day." Three questions asked about lifetime experience of being "treated unfairly due to your race" on the job, in housing, and by the police (lifetime racism). Response categories were "yes" and "no."

The "everyday racism" questions are not about race! The researchers merely assume that if a black woman encounters someone who acts as if he is better than she, it must be because she is black, not because, say, he's a stuck-up jerk--or because she is oversensitive. The "lifetime racism" questions do measure perceived (though not necessarily actual) racism, but the "everyday racism" questions measure only perceived slights.

Cozier's assertion that what she baselessly calls racism "has real effects" is equally unwarranted. The study shows a correlation between what it characterizes as "perceived racism" before 1997 and weight gain in the ensuing eight years; it does not establish that the former caused the latter. To our mind it seems much more plausible to posit that the tendency to see oneself as a victim of racism (or to be perturbed by perceived slights, whether racially motivated or not) and the tendency to gain weight arise from a common cause, which one might describe as an attitude of powerlessness or a lack of self-confidence.

Relatedly, Cozier's study found that "normal-weight women were more likely to use confrontive coping ('tried to change the situation'), while overweight and obese women were more likely to use evasive coping ('put off facing the problem')." But how one copes with a problem is a separate question from one's threshold for perceiving a problem in the first place.

The study concludes by asserting that its findings "underscore the public health importance of continuing antidiscrimination efforts in this country and worldwide." Now there's a brave position! Yet it doesn't follow from the study either. To be sure, antidiscrimination efforts are worthwhile inasmuch as they prevent discrimination. But is there a shred of evidence that they reduce the level of perceived discrimination?


Green tea extract reported to show promise against leukemia

No control group and tiny sample size! Spare us! But it's only a pilot study so nobody should get excited one way or the other. Journal abstract here

Scientists are reporting positive results in early leukemia clinical trials using the chemical epigallocatechin gallate, a substance in green tea. "The majority of individuals who entered the study with enlarged lymph nodes saw a 50 percent or greater decline in their lymph node size," said Tait Shanafelt, a hematologist at the Mayo Clinic in Rochester, Minn., and lead author of the study. Moreover, "patients tolerated the green tea extract at very high doses."

The findings appeared online May 26 in the Journal of Clinical Oncology. The findings tested the chemical's effect on patients with chronic lymphocytic leukemia, the most common type of leukemia in the United States. Currently it has no cure. The illness starts with a mutation in a single blood cell called a lymphocyte. Over time, the altered cells multiply and replace normal lymphocytes in the bone marrow and lymph nodes, organs that are found all over the body and act as filters or traps for foreign particles. The lymph nodes become enlarged as a result.

About half of patients with early stage diseases have an aggressive form of the disease that leads to early death, researchers said. They hope the green tea extract can stabilize early-stage patients or perhaps work in combination with other therapies to improve their effectiveness.

Green tea is made with the leaves of Camellia sinesis, a shrub native to Asia. In the trial, 33 patients received variations of eight different oral doses of Polyphenon E, a proprietary compound whose primary active ingredient is epigallocatechin gallate. Doses ranged from 400 to 2,000 milligrams twice a day. Researchers determined that they had not reached a maximum tolerated dose, even at 2,000 mg twice per day.

The research has moved to the second phase of clinical testing in a followup trial, already fully enrolled, involving roughly the same number of patients. All will receive the highest dose administered from the previous trial. The studies are part of a multiyear project that began with tests of the green tea extract on cancer cells in the laboratory of Mayo hematologist Neil Kay, a coauthor of the study. After the research showed dramatic effectiveness in killing leukemia cells, scientists said, the findings were applied to studies on animal tissues and then on human cells in the lab.


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