A study, conducted by Stanford University scientists and published in the Annals of Internal Medicine titled “Are Organic Foods Safer or Healthier Than Conventional Alternatives?” has generated quite a bit of heat in kitchens all across America. Enough so, in fact, that some folks have started a petition to have the article retracted.
The study was a statistical survey of 17 previous studies in the scientific literature dealing with the relative effects of organic and conventionally grown foods on human populations and 233 studies measuring the impact of organic foods on laboratory animals.
The study’s lead author, Dr. Crystal Smith-Spangler, said she undertook the study in response to a frequently asked question among her patients as to whether organic foods were worth the extra cost.
The study found that:
- there were no detectable differences in the rate of allergies such as eczema (in three human studies with controls for organic produce consumption)
- there was no strong evidence demonstrating that organic fruits and vegetables were more nutritious than their conventional counterparts, except for phosphorus, which was higher in the organic produce though not to a nutritionally significant degree
- organic foods were higher in phenols, which are plant-based anti-oxidants
- organic eggs and chickens were slightly higher in omega-3 fatty acids then conventionals
- organic foods were found to contain 30 percent less pesticide residue, though both were considered to contain safe levels
- there are lower levels of antibiotic resistant bacteria in organic chicken and pork, though both types of fruits and vegetables carried similar risk levels for conventional e-coli contamination
What was the authors’ conclusion? “There isn’t much difference between organic and conventional foods, if you’re an adult and making a decision based solely on your health,” said study senior author Dr. Dena Bravata.
Supporters of organic food were rather upset by this interpretation of the findings. In their petition to have the study retracted, which several thousand people have now signed, they called the study “fatally flawed” because “it failed to examine key food issues such as the use of GMOs, high-fructose corn syrup, mercury in the food supply, and countless other factors.” Furthermore they were upset by the involvement of Ingram Olkin, one of the study’s 12 authors, claiming that Olkin had used the “multivariate Logistic Risk Function,” to attack whistle blowers when working for the tobacco industry. Multivariate analysis is a commonly accepted statistical tool.
I think that while it’s clear the petitioners were upset, it seems that they are neither scientists nor statisticians and their basis for having the article withdrawn can not be considered scientifically rigorous.
They might have better off pointing out the fact that the studies upon which this meta-study depended did not use matched groups. This means that for the study to be entirely valid, the crops would have needed to be grown under identical conditions, which they were not. The studies generally monitored what people ate, not how the food was grown. When a carefully monitored, matched-group study was performed comparing organic and conventional strawberries, the organic strawberries had a higher nutritional content.
Alternatively, they could have pointed out that while no outside money was used to directly fund the study, the Stanford Center for Health Policy under whose auspices the study was performed, is funded by Cargill, Monsanto, McDonalds, Wal-Mart and other companies whose names are not exactly synonymous with organic food.
Then again, they could have also mentioned the fact that the study, pretty much missed the point of why so many people prefer organic food. It’s not necessarily the nutrition, per se, though careful studies do show an advantage. Far more important is the ecological footprint and the fact that conscience-driven people do not want to be supporting a chemical–based food system with their dollars. People want to avoid pesticides, not only for their health impacts, but also for the well-documented decline in pollinators and their role in bio-diversity loss. Massive monoculture plantings also contribute significantly to the loss of biodiversity, which reduces the resiliency of our food system. Other reasons people prefer organic foods include: because they taste better, they are safer for children and babies, their absence of irradiation, lack of GM ingredients, and a better quality of life for the animals raised on organic feed.
The petitioners could have also just carefully read the study’s own disclaimers that point out that:
- There have been no long-term studies done on the impact of organic foods which controlled for socioeconomic impact
- Their results should be interpreted with caution, and
- The study did find limited evidence for the superiority or organic foods
In fact, there was an interview with lead author Dr. Crystal Smith-Spangler in which she acknowledged that “it was beyond the scope of our article to review and be able to really answer” the larger questions pertaining to:
- The comparative environmental effects of organic and non-organic farming
- The health effects of agricultural chemicals leeching into groundwater
- The impact of pesticides on farm workers
- The risks of farm use of antibiotics as a breeding grounds for antibiotic-resistant bacteria
Smith-Spangler added, “A study that would examine the question, ‘Is the amount of pesticides in our food safe?’ would include a lot more data on dose response and maybe some animal data. And there are lots of experts out there who can weigh in on that issue.”
So perhaps this all turns out to be little more than a tempest in a tofu pot. The main thing is that people become informed about the way that food is produced in this country so that they can make intelligent buying decision at the grocery store. In a way, this whole controversy probably contributed to that effort in ways its authors never dreamed of.
[Image credit: Suzies’s Farm: Flickr Creative Commons]
RP Siegel, PE, is an inventor, consultant and author. He co-wrote the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water in an exciting and entertaining format. Now available on Kindle.
Follow RP Siegel on Twitter.