Junkfood Science: Caring for people's health

August 11, 2008

Caring for people's health

Weight bias has become so deeply ingrained in popular culture, that we often can’t even see it anymore. The belief that fat itself is unhealthy has been so heavily promoted, that when disparities in health outcomes are seen associated with the heaviest people, it’s automatically assumed that their fatness is the cause.

When an epidemiological study finds that women are associated with a three-fold higher risk of dying with coronary artery bypass surgery compared to men, even though their heart disease is less extensive, cardiologists want to find out the reasons for the poorer outcomes — such as inappropriate equipment, procedures or medications. Doctors want to research how medical care can be improved to better care for them. It would be unthinkable to blame the patients for being female and dismiss it as a health risk of being a woman or to propose changing women through sex change operations!

Yet, when an epidemiological study, for example, reports that, at a certain medical center, obese women with breast cancer have poorer survival rates compared to women of ‘normal’ weight, fat prejudice is so ingrained in our consciousnesses, that the correlation is instantly assumed to be caused by fat. It is viewed in popular discourse as another reason why being fat is unhealthy and why “fat can kill.” And it becomes another excuse to condemn fat people.

When it comes to fat people, any disparity in health risk factors or health outcomes associated them, is added to the pile of reasons used to justify weight loss interventions — precisely what’s being sold by stakeholders in the war on obesity. And, all too often, the research ends there. Fat people don’t receive the same caring concern for their health and research devoted to finding the reasons when poorer outcomes are reported among them. It’s believed they should just lose weight — never mind that there is no known way to safely and permanently make obese people thin.

There are countless cases [here, here, here, etc.] of ‘obese’ people having serious medical conditions left untreated while their symptoms are blamed on their fat. If they “just lost weight,” they’re often told, then they wouldn’t have those health problems — ignored are the facts that the same conditions are often found in thin people or that unusual weight gain can be a symptom of a medical condition, not the cause. When the British Saving Mother’s Lives study reported that most (64%) maternal deaths from 2003-2005 were among women who’d received substandard care, it was the fattest women who’d most received substandard care.

Discrimination in healthcare has been well-documented in the medical and sociological literature. But it goes far beyond differences in the attentiveness of the care they receive, or even access to healthcare... to the quality of care they receive and if it’s the best, most effective and safest for them.

The obesity-related medical research that gets most grant funding is that which supports the war on obesity — and that is very different from caring about fat people and supporting research devoted to improving medical care and health outcomes for the obese.

Looking closer at obesity research- who is it helping?

Vast sums of pharmaceutical obesity research dollars, for example, are devoted to weight loss pills and treating ‘obesity’ as a disease, but nearly none to researching the pharmacokinetics of drugs in the care of fat people — from chemotherapy, anti-inflammatories, anesthesia, to even antibiotics. Yet, even something as simple as the most appropriate dosages for medications to treat infections in fat people is poorly understood. In the journal Pharmacotherapy, concerned pharmacy researchers reported that little research has been done to know the appropriate doses; how drugs distributed through tissues are affected by body composition, blood circulation, drug lipophilicity and plasma protein binding; variables of drug clearance eliminated through the kidneys, since kidneys in the obese have higher glomerular planar surface areas; and hepatic metabolism.

“Obese patients may be incorrectly dosed with the use of fixed (underdosed) or total bodyweight-based dosing (overdosed) when the contribution of pharmacokinetic alterations in obesity are unrecognized,” they concluded.

At the 6th European Breast Cancer Conference on April 16th, oncologists from the Jules Bordet Institute in Brussels, Belgium, said that research reports have shown that obese women are generally under-treated with chemotherapy, which could contribute to their poorer outcomes. Dr. Elisabetta Rapiti, of the Geneva Cancer Registry in Geneva, Switzerland, said their research had found that obese patients more often had advanced disease by the time they were diagnosed and referred to them for treatment and surgery.* The fattest patients were also less likely to have had ultrasounds or MRI exams. Perhaps fat women are more reluctant to undergo physical examinations or visit doctors who are more judgmental towards obese patients, she said, or that our current diagnostic equipment and treatment techniques for breast cancers are less effective among fat women.

Yet, the public rarely hears that there may be reasons when health disparities are reported among fat people, except for their fat.

When oncologists are determining the best course of treatment for breast cancer patients, for example, one of the techniques used by surgeons is to determine if breast cancer cells are in the lymph nodes in the axilla. In the past, women underwent mastectomies to remove their breasts, along with painful axillary dissections to remove the lymph nodes. Lymph node dissection can lead to tough side effects, such as lymphedema, nerve damage, neuromas, chronic pain and increased risk for infections. Today, doctors can conservatively treat breast cancers and preserve the breast by just removing the cancer cells, followed by radiation of the remaining breast tissue. They then identify if there are cancer cells in the axilla, because these women will have better survival rates if they receive chemotherapy or hormone therapy and additional treatments.

So, to avoid surgical invasive axillary dissections, doctors perform a sentinel node biopsy to help determine the degree of cancer in the lymph nodes. To briefly describe it, since the sentinel node is the first lymph node to receive lymphatic flow from the tumor, if it’s positive for cancer, there can be other positive lymph nodes upstream. To detect the sentinel nodes, surgeons inject tiny amounts of radioactive tracer and/or a blue dye around the tumor. The blue dye improves the accuracy of the procedure and reduces the rates of false positives.

The injection method for the radiotracers (as well as amount of tracer, timing and massage of it into the surrounding tissue) is another factor that can affect successful sentinel node identification, especially for obese women, but the optimal technique and when to perform axillary node dissection continue to be debated. Doctors at Memorial Sloan-Kettering Cancer Center have repeatedly reported better results using intradermal injections, compared to intraparenchymal, as have oncology surgeons at Baylor University Medical Center in Dallas, with a 2% false negative rate, and at Ohio State University.

The problem is, as doctors at Memorial Sloan-Kettering Cancer Center reported in 2003, the sentinel node technique fails most often in the fattest women and in those who are older. Specifically, the blue dye procedure fails in obese women more often, meaning these women more often need further surgery for axillary dissections, and are more likely to have false negatives — leaving the sentinel nodes with cancer to go unidentified and untreated. So, how much might less effective diagnostic and treatments play a role in faster recurrences among the fattest women?

If improving clinical outcomes for obese women was a priority, research would be prioritized into finding the most effective diagnostics and medical interventions for them. Yet, fat people don't have advocates calling for such obesity research. They do have plenty of people telling them to eat fruits and vegetables. This is just one brief illustration that much of obesity research today — epidemiological papers trying to find more things to link to evil fat and support the war on obesity, or studies to support weight loss interventions to eradicate obesity — is not the same as clinical research working to improve care and clinical outcomes for fat people.

Fat linked to more aggressive, deadly cancer?

Of course, many of the health problems we hear linked to fatness far exceed the evidence. We continue to hear the news uncritically report that obesity is linked to poorer survival among women with breast cancer, such as the study from the University of Texas M.D. Anderson Cancer Center, published in Clinical Cancer Research this spring. This retrospective analysis had examined the correlation between BMI and advanced breast cancer among 602 of 909 patients seen at their center between 1974 and 2000. [They said that the 307 patients not included hadn’t had heights and weights recorded, even though at their center body surface area was always calculated for dosing of chemotherapy.]

Most media took its lead from an American Association for Cancer Research press release and reported the correlation of obesity and breast cancer survival as being due to fat causing “more aggressive” cancer. One of the researchers was widely quoted as suggesting that weight loss might even lower the incidence of breast cancers.

To its credit ScoutNews sought an independent viewpoint and reported Dr. Harold J. Burstein, from Harvard Medical School and the Dana-Farber Cancer Institute in Boston, as cautioning that the evidence suggesting a link between obesity and poor breast cancer outcomes is “less than overwhelming.” To women tormenting themselves about their weight at diagnosis or weight gain afterwards, fearing they could be jeopardizing their outcomes, he said: “the honest assessment is that we don't really understand yet whether there is a relationship between obesity and breast cancer outcomes, or how strong the relationship is.”

Reading the published study finds that, once again, what we most hear isn’t always what the study’s data really found. This study had actually reported: “The interaction between BMI and breast cancer type was not statistically significant. The interaction between BMI and menopausal status was not statistically significant for both overall survival and recurrence-free survival.”

The M.D. Anderson researchers found no statistical difference in overall survival between the inflammatory and noninflammatory types of advanced cancers, but saw an untenable 40% relative risk of poorer overall survival among obese compared to ‘normal’ weight women. However: “Visually, it is not obvious that an interaction between BMI and locally advanced breast cancer subgroups exists; furthermore, in the multivariable model, the interaction term was not statistically significant. This may indicate a similar prognostic effect of BMI between the two subgroups.” Based on that untenable correlation, however, in their conclusion they suggested higher BMIs among patients with advanced cancers was associated with poorer outcomes.

Their conclusions, they admitted, were in “sharp contrast” to the National Surgical Adjuvant Breast and Bowel Project trial of 3,385 women which had found that “obesity was not associated with increased risk of recurrence or increased breast cancer mortality.” This large trial had included women at all stages of cancer at diagnosis.

Lose weight to improve survival?

Over recent weeks, we’ve heard in the news that another new study had found “strong evidence that high BMI and a recent pregnancy were linked to a poorer breast cancer prognosis.” Lead author, Dr. Gillian C. Barnett from the Oncology Centre at Addenbrooke’s Hospital in Cambridge, UK, told Reuters Health: “Our study suggests that advice on weight loss should be given to all obese patients with breast cancer.”

This study, published in the Journal of Clinical Oncology, had culled through self-reported data from 4,560 women in the UK with invasive breast cancer who’d participated in the Studies of Epidemiology and Risk Factors in Cancer Heredity (SEARCH) study, looking for risk factors associated with survival, over an average of 6.8 years of follow-up.

Their computer modeling had actually found no tenable associations with smoking, BMI [adjusted HR = 1.16], use of hormone replacement therapy or oral contraceptives, age at menarche or menopause, age at first pregnancy, or alcohol [adjusted HR = 0.75]. The strongest associations with poor prognosis was tumor stage, with a significant 19.6-fold higher hazard ratio associated with stage IV tumors compared to stage I.

This study added nothing to what’s been known for years. This study brought doctors no further towards having more effective treatments or diagnostics for breast cancer in fat women. It wasn’t designed to try, because it wasn’t a clinical trial to test the safety or effectiveness of an intervention.

Like all epidemiological studies looking for correlations, it can never provide credible evidence of a causation. More importantly, a correlation offers no rational support for a clinical treatment. So, just as there’s no evidence that going braless will prevent breast cancers, despite the fact that wearing a bra is associated with a 12,500-fold higher risk of breast cancer, there’s even less evidence that losing weight will improve breast cancer survival.

We need no greater evidence that the war on obesity isn’t really about caring about the health and well-being of fat people than to look at the research that’s most being funded and the research that isn’t. Efforts to eradicate the 'problem' of the obese is far different from caring for them.

© 2008 Sandy Szwarc

* A cautionary note: Being diagnosed later in the progression of the disease can also give a false impression of lower survival, compared to women who are diagnosed earlier or who are diagnosed during screening with preclinical tumors and appear to live longer. In other words, their survival with the disease may actually be very similar.

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