Family time

Tuesday, September 4, 2012

Eat your poison

The headline blurts out "Organic food no better for you than the average fodder"... or some similar dissembling. Here's the headline at Business Insider; New Study Shows It's A Myth That Organic Foods Are Healthier. Or this one from U.S. News and World Report," Organic Foods Not Healthier or More Nutritious, Study Says.

When you start looking at what the study actually says, of course the information and message is quite different. You also have to wonder about the scientific discipline and methodology currently practiced at Stanford.

Dr. Crystal Smith Spangler, a researcher at Stanford, published this study titled Are Organic Foods Safer or Healthier Than Conventional Alternatives?: A Systematic Review in today's issue of Annals of Internal Medicine.

She and her team reviewed evidence comparing the health effects of organic and conventional foods.They analyzed 17 studies in humans and 223 studies of nutrient and contaminant levels in foods.

Her conclusion; The published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods. Consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.

Now I am of course not a scientist, I only play one on the internet. Neither am I a champion of organic food, necessarily. But I am a skeptical person who prefers to read the study for himself and not let stupid news organizations tell me what something says.

I am also a person who fought cancer for many years, losing an organ and a few assorted body parts in my struggle, who made the decision to forego pesticides in my environment many years ago.

Let's look a little deeper at her data synthesis:

Only 3 of the human studies examined clinical outcomes, finding no significant differences between populations by food type for allergic outcomes (eczema, wheeze, atopic sensitization) or symptomatic Campylobacter infection. Two studies reported significantly lower urinary pesticide levels among children consuming organic versus conventional diets, but studies of biomarker and nutrient levels in serum, urine, breast milk, and semen in adults did not identify clinically meaningful differences. All estimates of differences in nutrient and contaminant levels in foods were highly heterogeneous except for the estimate for phosphorus; phosphorus levels were significantly higher than in conventional produce, although this difference is not clinically significant. The risk for contamination with detectable pesticide residues was lower among organic than conventional produce (risk difference, 30% [CI, −37% to −23%]), but differences in risk for exceeding maximum allowed limits were small. Escherichia coli contamination risk did not differ between organic and conventional produce. Bacterial contamination of retail chicken and pork was common but unrelated to farming method. However, the risk for isolating bacteria resistant to 3 or more antibiotics was higher in conventional than in organic chicken and pork (risk difference, 33% [CI, 21% to 45%]).

And the limitation: Studies were heterogeneous and limited in number, and publication bias may be present.

So, what do we know? We know that the study doesn't say that it is a myth that organic foods are healthier. Because even this limited study shows lower pesticide contamination.  It shows that organic produce is 30 percent less likely to be contaminated with pesticides than conventional fruits and vegetables. That sounds pretty good to me. Or are pesticides now supposedly good for you? Or horrors, could the scientists be way off on what denotes a maximum or critical exposure?

Two studies found that children who ate conventional produce had higher levels of pesticide residues in their urine, and the levels fell when the children switched to organic foods. But,the authors suggest that it's not clear whether there would be clinical consequences to the residues. Perhaps they should experiment on their own families and get back to us, especially after this loud "all clear."

We know that conventional food has more bacteria resistance to antibiotics. Isn't that a broad indicator that could be labeled as an indices relating to health as well?

"I think different people will make different decisions based on our findings," said study author Dr. Crystal Smith-Spangler, an instructor at Stanford University School of Medicine and a physician-investigator at the VA Palo Alto Health Care System, in California. "We thought we'd find more significant differences, but there are many reasons why someone might consume organic foods. Health is one, but they may be concerned about the environment, animal welfare practices or taste, and we weren't evaluating that."

I don't see anywhere in the study where the authors make the claim that eating pesticide laden food is as safe as eating food free from contaminates. Did I miss something? Pesticides have been linked to many childhood diseases and disorders including attention deficit disorder, cancer, infertility and birth defects.

While I suppose a case could be made for the relative nutritional merits of the organic versus conventional debate; very similar except for higher phosphorus in the organic, I think that this study is a scattershot cobble of anecdotal evidence without even a clear baseline definition of what organic means, nor a reasonable amount of clinical research evaluated related to humans.

I was looking at a paper today by Harvard Doctor Chensheng Lu, a critic of Ms. Spangler's study,  published in 2005, titled Organic Diets Significantly Lower Children’s Dietary Exposure to Organophosphorus Pesticides.

It reports the following:

The National Research Council (NRC) report Pesticides in the Diets of Infants and Children () concluded that dietary intake represents the major source of pesticide exposure for infants and children, and this exposure may account for the increased pesticide-related health risks in children compared with adults. However, direct quantitative assessment of dietary pesticide exposure in children to support this conclusion is no simple task: Several studies (; ; ; ) have analyzed pesticides in representative samples of children’s food, and only two have used biologic monitoring to specifically examine dietary exposures (; ). The paucity of exposure data renders the debate over pesticide-related health risks in children controversial (; ; ). Nevertheless, those studies have provided valuable information on dietary pesticide exposure among children and have prompted the needs to improve research methods in order to better assess children’s exposure to pesticides through dietary intake.

Dr. Lu told Reuters that the conclusion that organic food isn't healthier is "premature." He said people should still consider the differences when grocery shopping.

    "If I was a smart consumer, I would choose food that has no pesticides," Lu said. "I think that's the best way to protect your health."

Hey, maybe Spangler is on to something? Maybe poison is good for you. I think that she does us no favors with this haphazard study.

"May 2, 2012 — Prenatal exposure to a pesticide used on many crops may be linked with abnormal changes in a child's developing brain, scientists report.
Compared to children with low prenatal exposure, those with high exposure to the pesticide chlorpyrifos had abnormalities in the cortex (the outer area of the brain), says Virginia Rauh, ScD, professor and deputy director of the Columbia Center for Children's Environmental Health at the Mailman School of Public Health at Columbia University.
The cortex helps govern intelligence, personality, muscle movement, and other tasks.
"In areas of the cortex, we detected both enlarged and reduced volumes that were significantly different from the normal brain," she tells WebMD. "This suggests the process of normal brain development has been disturbed in some way."
The study is published in Proceedings of the National Academy of Sciences' Early Edition.
In 2001, the U.S. EPA banned the residential use of chlorpyrifos. It still allows it on crops. It can also be sprayed in public places such as golf courses.
Some environmental advocates have petitioned the EPA to ban agricultural use.
Rauh's team selected 40 children from a larger group of 369 children, followed from birth.
All had been born between 1998 and 2001, before the household-use ban. Rauh had sent their umbilical cord blood samples to the CDC to analyze pesticide levels.
For this study, she selected 20 children with high prenatal exposure and 20 with low prenatal exposure. She took MRIs of their brains when they were about 6 to 11 years old.
Overall brain size did not differ much between the two groups. However, the high-exposure group had enlargements in many areas and reduced volumes in other areas.
The findings reflect those from animal studies, Rauh says.
In other studies, Rauh has found higher exposure to the pesticide is linked with lower IQs and a decline in working memory in children.
The pesticide works by blocking an enzyme needed by pests -- and people -- for proper nerve functioning. It belongs to a class known as organophosphates.

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