Last week, 10 physicians penned a letter to Columbia University's dean of health sciences and medicine calling for the university to oust Dr. Mehmet Oz, who is a professor in the surgery department.
The doctors accused Oz, named "America's doctor" by Oprah Winfrey in 2004, of "manifesting an egregious lack of integrity by promoting quack treatments and cures in the interest of personal financial gain." In particular, the doctors said Oz's critiques of genetically modified foods were fear-mongering and slammed him for peddling bogus weight-loss cures. The leader of the group, Henry Miller, a research fellow at the Hoover Institution, says Oz has been promoting "new age nonsense" on TV for years.
On Tuesday evening, Oz addressed his critics on air, saying he "will not be silenced" and "will not give in." Spokespeople for Oz have also pointed out that a number of the doctors criticizing him have ties to American Council on Science and Health, a group that advocates on behalf of companies producing genetically modified foods. He plans to address his detractors on a special episode of his show on Thursday.
But Oz is now under the microscope, and it might not be a very good diagnosis. Here are seven scientifically questionable cures Oz has touted.
1. Pure Green Coffee
In 2014, Congress took Dr. Oz to task for promoting ineffective supplements on his show.
Senator Claire McCaskill accused Oz of giving viewers "false hope" for easy weight loss by promoting supplements he knows are ineffective. Oz admitted that he used "flowery language" on the show in describing the weight-loss supplements, but stressed that he believe in the power of the products.
A small-scale study published in 2012 which found that an ingredient in green coffee beans, chloregenic acid, may indeed help people lose a significant amount of weight in 22 weeks. However, a different study in 2013 on the same ingredient found that it actually increased their insulin resistance and did nothing to cause weight loss. There have been no major, long-term studies on the green coffee bean or the efficacy of chloregenic acid for weight loss. Most of the studies conducted involve a small participant pool. Green coffee beans has also never been approved by the FDA as an effective and natural way to lose weight. The Federal Trade Commission filed a lawsuit against Pure Green Coffee for lying to customers about what the product can do. The suppliers agreed to a $9 million settlement with the FTC.
2. Garcinia Cambogia
"Thanks to brand new scientific research, I can tell you about a revolutionary fat buster," Dr. Oz said on air in November 2012. "It's called Garcinia Cambogia." Oz framed Garcinia Cambogia, a tropical fruit, as a miracle-worker, claiming that it allowed consumers to lose weight without modifying their diet or exercising.
But a 1998 study begs to differ. When compared with a placebo, Garcinia Cambogia did not notably help participants lose more weight. The study concluded: "Definitive conclusions that Garcinia/HCA supplements are efficient tools against various health problems especially obesity remain to be proven in larger-scale and longer-term clinical trials, despite substantial public interest in such supplements."
3. Raspberry Ketone Diet
Dr. Oz (in 2012): It's a "miracle fat burner in a bottle.”
Some doctors argue that there is not enough data on the pill's effectiveness, and even less on what happens after people stop taking the pills. Pharmacist Dr. Sarah G. Kahn told Everyday Health that the product is not safe for many people with certain conditions, such as diabetes, heart problems or high blood pressure. She said for people with COPD or asthma, the supplement can worsen their problems.
4. Conjugated Linoleic Acid (CLA)
Dr. Oz called consuming green tea and CLA the most powerful "1-2 punch" for shrinking fat cells.
While there have been studies to show the supplement helps in aiding weight loss, there have been few on the long-term effects, and most of the studies have only been done on animals.
Professor Michael W. Pariza, the man behind the discovery of conjugated linoleic acid, pointed out that there have been no conclusive studies on the effects of CLA on muscle growth. The supplement's effect on people with certain health conditions, such as diabetes, has also not been shown. Most important, while Oz touted it's benefits without any exercise or dieting, Pariza said that CLA is no magic pill, and cannot cancel out bad eating and lack of exercise.
“I think it’s something that can help [with weight loss], but certainly there are no miracles," he said.
5. Safflower oil
Dr. Oz: "There's a new supplement that will help you lose inches off your waist without diet and exercise."
Montel Williams appeared on Oz's show in 2012 to introduce safflower oil, which he claimed would help those who take it lose belly fat without diet or exercise. He told the audience that the supplement helped him lose an inch off his waist in just five days. When he stopped, the inch came back; when he started again, he lost the inch. Sounds like a miracle worker, right?
Dr. Oz called it "an ancient secret weapon against fat."
The supplement became hugely popular as a result of this episode. But in 2013, CLA experts came out strong against Safflower oil and denounced its efficacy. The CLA suppliers called out Williams for being a paid spokesperson for Safslim, a brand of safflower oil. The former talk-show host is no longer associated with SafSlim.
Safflower oil contains a minuscule amount of CLA (some .7 mg CLA/g fat), researchers say. Dr. Michael Pariza, the leader in CLA research, said that research only shows that safflower oil might "rearrange" body fat, not get rid of it. In other words, the fat might not be around your waist anymore, but it's just somewhere else on your body. Another CLA researcher, Dr. Mark Cook, backed up this point and added that his studies showed safflower oil did not reduce BMI.
6. Hot Pepper Jelly
Dr. Oz: "Burn away that belly and do it fast ... this stuff is a way to ignite your metabolism ... that's without doing anything else. I'm not telling you to go running or jogging or weight lift or anything else."
He said on air during the "Dr. Oz's 7 Effective Belly Blasters" special that hot pepper jelly has "worked for a lot of people," yet he gave no specific data or research. That's because there really hasn't been any significant research or studies on the effects.
While hot pepper jelly does have several health benefits and can increase metabolism, it does not speed it up nearly enough to accomplish what Oz claimed. Research on hot pepper by Dr. David Heber and his team at the University of California in Los Angeles found that the substance can help users burn an extra 100-200 calories a day and only has a “modest effect” on weight loss. Without diet or exercise, 100-200 calories is not enough to significantly boost metabolism.
7. Red palm oil
Dr. Oz: "Miracle oil for longevity. ... There’s a secret inside the flesh of this fruit, extending the warranty of nearly every organ in your body. This mega-oil may very well be the most the most miraculous find of 2013."
He touted it as a "miracle solution of 2013" and said that it could even prevent dementia and Alzheimer’s.
However, there is no research on the direct relationship between red palm oil and dementia/Alzheimer’s. In fact, studies have shown that taking Vitamin E supplements, like red palm oil, have no effect on the onset of these conditions. There is also no direct study between consuming red palm oil and gaining medical benefits. A 2005 study concluded that "Vitamin E had no benefit in patients with mild cognitive impairment." What's worse, a 2004 study found that increased intake of saturated fats, like those in red palm oil, can actually lead to "cognitive decline among older persons."
Experts at the University of California Berkley said that there are far better and more natural ways to get your daily doses of carotenoids and vitamin E, such as fruits, vegetables, whole grains and nuts.
The Huffington Post reached out to Oz for comment but has not received a reply.
Clarification: Language has been updated to clarify Henry Miller's position is with the Hoover Institution, located at Stanford University. This post has also been updated to reflect that Williams is no longer a Safslim spokesperson.