Last week, a patient with a strong family history of colon cancer told me that one of her sisters spends $2,000 a month on organic food and still had a pre-cancerous polyp on a recent colonoscopy. I have never seen data showing that organically farmed food lowers cancer risks. But given the common perception that organic foods offer more health and safety benefits than conventionally farmed foods, I was not surprised by the comment.
In my search for answers on this topic, I came across an article published in the September 2012 issue of Annals of Internal Medicine, Are Organic Foods Safer or Healthier Than Conventional Alternatives?: A Systematic Review. To my delight, I discovered the lead author was a local colleague and friend. I read the paper carefully and then called Dr. Dena Bravata to discuss. What I learned from our conversation went beyond the published data and was disturbing on many levels.
This comprehensive “meta analysis” — conducted by Standford University researchers without funding from any outside industry source, meaning without conflicts of interest — reviewed all of the available evidence comparing the health effects of organic and conventional foods. The details can be found in the paper, and the appendices are available online for anyone who wants to recalculate the data. But here is the bottom line:
In summary, our comprehensive review of the published literature on the comparative health outcomes, nutrition, and safety of organic and conventional foods identified limited evidence for the superiority of organic foods. The evidence does not suggest marked health benefits from consuming organic versus conventional foods, although organic produce may reduce exposure to pesticide residues and organic chicken and pork may reduce exposure to antibiotic-resistant bacteria.
Translation: Leading researchers at Stanford University’s Center for Health Policy/Center for Primary Care and Outcomes Research were unable to produce evidence that organic food is healthier or safer.
Americans spend more than $25 billion a year on organic foods, which often cost twice as much as conventionally farmed foods, because they believe they are healthier. But this new evidence shows that we can get the same health benefits from a balanced diet of conventionally farmed foods at a fraction of the price. That’s great news, right? Not so fast.
Since the article’s publication, Dr. Bravata and her colleagues have appeared on dozens of talk radio and television news programs, including the Today Show, CNN and the BBC. And they’ve been besieged by unbelievable amounts of hate mail — including letters beginning with such phrases as “how dare you?” and “you call yourself a doctor” — from organic food advocates who have responded to the research with the fervor of religious zealots. The hatred has been so vehement that authorities at Stanford University told her that she should be careful getting into her car.
This isn’t the first time scientific investigation has challenged strongly held beliefs.
When Galileo advanced his theories about planetary movement and heliocentricity, the Catholic Church placed him under house arrest for committing heresy. Copernicus even refrained from publishing his own data on the subject out of fear of ridicule from his colleagues. Eventually, however, the scientific method proved the Earth revolved around the sun, and Galileo was vindicated.
Joseph Lister, a professor of surgery at Glasgow University in the late 1800s who was influenced by Louis Pasteur’s work on rotting and fermentation and their relationship to microorganisms, pioneered antiseptic surgery with a method of sterilizing surgical instruments and cleaning wounds that made surgery safer for patients. Although American surgeons initially scoffed at his advancements, his work ultimately transformed surgical practices throughout the world.
I am not placing Dr. Bravata’s research in the same category as Galileo’s or Lister’s. But when scientific researchers are threatened and intimidated by individuals whose belief systems are challenged by the results of scientific inquiry, progress is hindered and we all lose.
Here’s my take on organic foods: If you want to support local organic farmers, have environmental concerns, or prefer the taste and are not on a strict budget, by all means, pay more for your fresh fruits and vegetables. But don’t do it believing that you are preventing cancer or getting more nutrition from those organically farmed foods because there is currently no evidence to support that. The same goes for meats: Costly organic choices provide no health advantages over conventionally farmed sources if you cook them well and wash your hands.