Oz is a professor at the Columbia University College of Physicians and Surgeons who holds the surgery department's vice chairmanship; in their letter last week, the 10 doctors -- who are not affiliated with the school -- wrote that Oz's position at "a prestigious medical institution" is "unacceptable."
"Dr. Oz has repeatedly shown disdain for science and for evidence-based medicine, as well as baseless and relentless opposition to the genetic engineering of food crops," said the letter, sent via e-mail by Dr. Henry I. Miller of Stanford University's Hoover Institution. "Worst of all, he has manifested an egregious lack of integrity by promoting quack treatments and cures in the interest of personal financial gain."
On Thursday, Oz took aim at Miller and other signatories, questioning their backgrounds and ties to the tobacco industry and campaigns to defeat GMO labeling laws. "On paper, Miller looks impressive, but put him under the microscope and there's more to the story," Elisabeth Leamy, a reporter for "The Dr. Oz Show," said on Thursday's episode.
She went on to highlight Miller as a vocal proponent of an effort to defeat Proposition 37, a GMO labeling bill in California.
Miller declined to comment on Thursday.
"These doctors criticized me for promoting treatments and cures in interest of personal, financial gain, something I tell you every day on this program that I never do," Oz said on the show. "In addition, they cite my baseless and relentless opposition to genetically engineering food crops. Again, that's not true. I have never judged GMO foods, but just like 64 countries around the world, I support GMO food labeling so you can decide on the foods for your family."
Oz implied that his critics took aim at him because they want to prevent GMO labeling restrictions.
He also declared: "Public shaming and bullying is not how it should be done."
The as-seen-on-TV doctor had already begun to mount his counter-offensive earlier in the day. Writing in an essay for Time magazine, Oz said that some of the physicians who questioned his ethics are compromised by their own apparent ties to biotech and tobacco industries. One of the signatories of the scathing letter, Oz noted, "was found guilty after trial of 13 counts of fraud related to Medicaid."
"I know I have irritated some potential allies," Oz wrote in Time, an idea he repeated on his show. "No matter our disagreements, freedom of speech is the most fundamental right we have as Americans."
But, he added: "We will not be silenced. We’re not going anywhere."
In the Time piece -- which Oz said was "about my unwavering commitment to you, the viewer, through my show" -- he wrote:
I have spent my entire career searching for ways to lessen the suffering of my patients. The best and safest paths have generally been the traditions of conventional medicine. They are tried and true, well funded, and fast. But there are other routes to healing that offer wisdom as well, so I have been willing to explore alternative routes to healing and share any wisdom that can be gathered. I have done this throughout my career as a surgeon, professor, author and, of late, as a talk-show host. Despite being criticized, I want to continue exploring for myself and my audience.
While Oz emphasized on air that he has the support of his Columbia colleagues, eight of the medical school's faculty members wrote an op-ed in USA Today that highlighted a 2014 BMJ study, which found that less than half of the recommendations on his show were based on evidence.
"We are members of the Columbia faculty who recognize that the Dr. Oz Show performs a public service by bringing alternative therapies which are generally under-researched and under-regulated into the public forum," the faculty members wrote in the op-ed, which was published Thursday. "Many of us are spending a significant amount of our clinical time debunking Ozisms regarding metabolism game changers. Irrespective of the underlying motives, this unsubstantiated medicine sullies the reputation of Columbia University and undermines the trust that is essential to physician-patient relationships."
The faculty members did not call for Oz's resignation from Columbia, but suggested he add a disclaimer at the beginning of each episode of his show.
Writing in Time, Oz wrote:
I discovered problems in the promising research papers that supported some products; the products themselves were often poor quality; and scammers stole my image to promote fake pills. So I have not mentioned weight loss supplements for a year and have no plans to return to that neighborhood.
[This post has been updated.]