Dr. Mehmet Oz is responding to critics who say he lacks integrity and credibility as a physician and promotes "quack treatments" for financial gain. A group of 10 doctors sent a letter last week calling on Columbia University to remove America's favorite TV doctor from the school's faculty.
In a segment for "The Dr. Oz Show" taped on Tuesday, and scheduled to air in full on Thursday, Oz rebutted those attacks.
"This month we celebrate my one-thousandth show, and I know I've irritated some potential allies in our quest to make America healthy," Oz said in the video clip released to the press. "No matter our disagreements, freedom of speech is the most fundamental right we have as Americans, and these 10 doctors are trying to silence that right. So I vow to you right here, right now: We will not be silenced; we will not give in."
Columbia is standing behind Oz, saying in a statement that the university is "committed to the principle of academic freedom and to upholding faculty members' freedom of expression for statements they make in public discussion."
Oz has received public criticism before for controversial statements including endorsing a dietary supplement unregulated by the U.S. Food and Drug Administration whose weight-loss claims turned out to be based on fraudulent data. A study published last year in the journal BMJ found that fewer than half the recommendations Dr. Oz made on his show -- 46 percent -- were backed up by medical evidence.
The latest controversy flared up last week when group of doctors sent a letter to Dr. Lee Goldman, Columbia's Dean of the Faculties of Health Sciences and Medicine. They wrote:
"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. Worst of all, he has manifested an egregious lack of integrity by promoting quack treatments and cures in the interest of personal financial gain.
"Thus, Dr. Oz is guilty of either outrageous conflicts of interest or flawed judgements about what constitutes appropriate medical treatments, or both. Whatever the nature of his pathology, members of the public are being misled and endangered, which makes Dr. Oz's presence on the faculty of a prestigious medical institution unacceptable."
The author of the letter, Dr. Henry I. Miller of the Hoover Institution, a conservative think tank at Stanford University, told CBS News he felt compelled to speak out because of what he called Oz's "fear-mongering" on the issue of genetically modified foods, which Miller has written about in Slate and elsewhere.
Genetically modified organisms, or GMOs, have been a frequent topic of discussion on Oz's show. He has called for such foods to carry labels disclosing that they contain genetically engineered ingredients.
On Monday, Oz told CBS News, "In a sea of inaccurate sweeping complaints, we noticed one specific allegation - GMOs. Although they misrepresented our stance, we have supported GMO labeling."