Dr. Oz is a powerful guy, blessed with a name that conjures up wizardry. He just unveils his latest “miracle,” which seems to happen on an almost daily basis, and people scamper off to the nearest the health food. Recently the great Oz anointed the oil extracted from the fruit of the palm tree that grows in Indonesia and Malaysia as a wonder product that can aid weight loss and reduce the risk of Alzheimer’s and heart disease. Introduced to this marvel by his a guest, a homeopath, Dr. Oz excitedly gushed about the beta carotene and “special form of vitamin E” found in “red palm oil.” A curious business. Tell me, does a Professor of Surgery at Columbia University with over 400 research publications under his belt really need advice on nutrition from a homeopath?
As is usually the case with Oz’s miracles, there is a seed of truth that then gets fertilized with lots of verbal manure until it grows into a tree that bears fruit dripping with unsubstantiated hype. For example, one study did show a reduction in the severity of cholesterol-induced atherosclerosis in rabbits fed high doses of red palm oil. This has little relevance for humans but magicians who pull rabbits out of hats may consider adding red palm oil to the diet of their little assistant. The red colour of the oil comes from beta-carotene, the same substance that contributes to the hue of carrots and many other fruits and vegetables. It is the body’s precursor for vitamin A, which makes it an important nutrient.
Unfortunately, in many areas of the developing world there is a shortage of both beta carotene and vitamin A in the diet leading to a high incidence of blindness, skin problems and even death. In such cases red palm oil would be useful, but of course there are numerous other ways to introduce beta-carotene into the diet including “golden rice” that has been genetically modified to provide the nutrient. Aside from remedying a vitamin A deficiency, there is not much evidence for increased intake of beta carotene outside of that contained in a balanced diet. There are suggestions that higher blood levels of beta carotene reduce the risk of breast cancer in high-risk women, but the beta-carotene levels may just be a marker for a better diet.
As far as the Alzheimer’s connection goes, Oz may have been referring to a study in which 74 seniors with mild dementia were compared with 158 healthy seniors. People with dementia had lower levels of beta-carotene and vitamin C in their blood. Again, this does not prove that the lower levels are responsible for the condition, they may just signal a diet that is poorer in fruits and vegetables. Tocotrienols, the “special form of vitamin E” Oz talked about, have shown some borderline effects in Alzheimer’s patients at doses way higher than found in red palm oil. There is no evidence for preventing the disease.
What about the claim that red palm oil causes loss of belly fat? That seems to come from a rat study in which a tocotrienol-rich fraction extracted from palm oil caused a reduction in fat deposits in the omentum, the tissue that surrounds organs. There was no evidence of abdominal fat reduction, and furthermore, the study involved putting the animals on an unnatural and unhealthy diet. But these are not the facts that the audience was treated to on the Dr. Oz Show.
What the eager viewers witnessed were three visually captivating but totally irrelevant demonstrations of the purported health benefits of red palm oil. First in line was a piece of apple that had turned brown because of “oxidation.” This could be prevented with a squirt of lemon juice, Oz explained. Then came the claim that red palm oil protects our brain the same way that lemon juice protects the apple. This is absurd. Vitamin C inactivates polyphenol oxidase, the enzyme that allows oxygen to react with polyphenols in the apple resulting in the browning. The human brain, however, bears no resemblance to an apple, except perhaps for the brains of those who think it does. Yes, oxidation is a process that goes on in the human body all the time and has been linked with aging but suggesting that beta-carotene because of its antioxidant effects protects the brain like lemon juice protects the apple is inane.
Just as zany was the next demo in which two pieces of plastic half-pipe representing arteries were shown with clumps of some white guck, supposedly deposits that lead to heart disease. Oz poured a gooey liquid, representing “bad fats” down one of the tubes, highlighting that it stuck to the goo. Then he proceeded to pour red palm oil down the other pipe and lo and behold, the deposits washed away. Totally meaningless and physiological nonsense. The homeopath then explained that saturated fats behave like thick molasses cruising through the cardiovascular system, but palm oil does not, despite being high in saturated fats. While saturated fats may lead to deposits, they do not do this by “thickening” the blood. Arterial deposits are the result of some very complex biochemistry and are not caused by “sludge” in the blood. Oz even exclaimed that this demo was indicative of how red palm oil reduces cholesterol in a month by 40%, better than drugs. A search of Pubmed reveals no such study.
The final demonstration involved Dr. Oz lighting a candle and a flare, without wearing safety glasses mind you. The message seemed to be that the body burns most fats slowly, but it burns red palm oil with great efficiency, preventing weight gain. Where does this come from? Possibly some confusion about medium chain triglycerides which are somewhat faster metabolized than other fats. But these are not found in palm oil. They are found in coconut oil and palm kernel oil. Oz and his homeopath expert were as confused about this as about the rest of red palm oil info they belched out.
Aside from scientists who took issue with the misleading information, animal rights groups also attacked Oz’ exhortations about the benefits of the oil claiming that it will lead to destroying larger stretches of the jungle, home to many wild creatures including the orangutan. They maintain that when the jungle is cleared every living creature is either captured or killed and adult orangutans are often shot on sight. A tragedy. Another tragedy is that Dr. Oz could be doing so much good if he just focused on real science, as he sometimes does, instead of drooling over the latest “miracle” as presented by some pseudo expert.
Joe Schwarcz, Ph.D., is the Director of McGill University’s Office for Science and Society and teaches a variety of courses in McGill’s Chemistry Department and in the Faculty of Medicine with emphasis on health issues, including aspects of “Alternative Medicine”. He is well known for his informative and entertaining public lectures on topics ranging from the chemistry of love to the science of aging. Using stage magic to make scientific points is one of his specialties.
Miracles are pretty rare events. Except on television’s “Dr. Oz Show,” where they appear with astonishing frequency. Oz of course doesn’t claim to raise the dead or part the Red Sea, but he does raise people’s hopes of parting with their flab. And he’s certainly not shy about flinging the word “miracle” about. But it seems miracles fade as quickly as they appear. Raspberry ketones, acai berries and African mango, once hyped as amazing “fat busters,” have already given way to newer wonders.
Granted, Dr. Oz, or more likely his producers, do not pull miracles out of an empty hat. They generally manage to toss in a smattering of stunted facts that they then nurture into some pretty tall tales. Like the ones about chlorogenic acid or Garcinia cambogia causing effortless weight loss. The former piqued the public’s interest when the great Oz introduced green coffee bean extract as the next diet sensation. Actually “chlorogenic acid” is not a single compound, but rather a family of closely related compounds found in green plants, which perhaps surprisingly, contain no chlorine atoms. The name derives from the Greek “chloro” for pale green and “genic” means “give rise to.” (The element chlorine is a pale green gas, hence its name.)
An “unprecedented” breakthrough, Dr, Oz curiously announced, apparently having forgotten all about his previous weight-control miracles. This time the “staggering” results originate from a study of green coffee bean extract by Dr. Joe Vinson, a respected chemist at the University of Scranton who has a long-standing interest in antioxidants, such as chlorogenic acid. Aware of the fact that chlorogenic acid had been shown to influence glucose and fat metabolism in mice, Vinson speculated that it might have some effect on humans as well. Since chlorogenic acid content is reduced by roasting, a green bean extracts was chosen for the study.
In cooperation with colleagues in India who had access to volunteers, Dr. Vinson designed a trial whereby overweight subjects were given, in random order, for periods of six weeks each, either a daily dose of 1,050 mg of green coffee bean extract, a lower dosage of 700 mg, or a placebo. Between each six-week phase there was a two-week “washout” period during which the participants took no supplements. There was no dietary intervention; the average daily calorie intake was about 2,400. Participants burned roughly 400 calories a day with exercise. On average there was a loss of about a third of a kilogram per week. Interesting, but hardly “staggering.” And there are caveats galore.
The study involved only eight men and eight women, which amounts to a statistically weak sample. Diet was self-reported, a notoriously unreliable method. The subjects were not really blinded since the high dose regimen involved three pills, the lower dose only two. A perusal of the results also shows some curious features. For example, in the group that took placebo for the first six weeks, there was an 8 kilogram weight loss during the placebo and washout phase, but almost no further loss during the high dose and low dose phases. By the time, though, that critics reacted to Oz’s glowing account, overweight people were already panting their way to the health food store to pick up some green coffee bean extract that might or might not contain the amount of chlorogenic acid declared on the label. As for Dr. Oz, he had already moved on to his next “revolutionary” product, Garcinia cambogia, unabashedly describing it as the “Holy Grail” of weight loss.
We were actually treated to the Grail in action. Sort of. Dr. Oz, with guest Dr. Julie Chen, performed a demonstration using a plastic contraption with a balloon inside that was supposed to represent the liver. A white liquid, supposedly a sugar solution, was poured in, causing the balloon, representing a fat cell, to swell. Then a valve was closed, and as more liquid was introduced, it went into a different chamber, marked “energy.” The message was that the valve represents Garcinia extract, which prevents the buildup of fat in fat cells. While playing with balloons and a plastic liver may make for entertaining television, it makes for pretty skimpy science.
Contrary to Dr. Oz’s introduction that “you are hearing it here first,” there is nothing new about Garcinia. There’s no breakthrough, no fresh research, no “revolutionary” discovery. In the weight control field, Garcinia cambogia is old hat. Extracts of the rind of this small pumpkin-shaped Asian fruit have long been used in “natural weight loss supplements” Why? Because in theory, they could have an effect.
The rind of the fruit, sometimes called a tamarind, is rich in hydroxycitric acid (HCA), a substance with biological activity that can be related to weight loss. Laboratory experiments indicate that HCA can interfere with an enzyme that plays a role in converting excess sugar into fat, as well as with enzymes that break down complex carbohydrates to simple sugars that are readily absorbed. Furthermore, there are suggestions that Garcinia extract stimulates serotonin release which can lead to appetite suppression.
Laboratory results that point toward possible weight loss don’t mean much until they are confirmed by proper human trials. And there have been some. Fifteen years ago a randomized trial involving 135 subjects who took either a placebo or a Garcinia extract equivalent to 1500 mg of HCA a day for three months, showed no difference in weight loss between the groups. A more recent trial involving 86 overweight people taking either two grams of extract or placebo for ten weeks echoed those results. In-between these two major studies there were several others, some of which did show a weight loss of about one kilogram over a couple of months, but these either had few subjects or lacked a control group. Basically, it is clear that if there is any weight loss attributed to Garcinia cambogia, it is virtually insignificant. But there may be something else attributed to the supplement, namely kidney problems. Although incidence is rare, even one is an excess when the chance of a benefit is so small. So Garcinia cambogia, like green coffee bean extract, can hardly be called a miracle. But it seems Dr. Oz puts his facts on a diet when it comes to fattening up his television ratings.
Joe Schwarcz is director of McGill University’s Office for Science & Society (mcgill.ca/oss). He hosts The Dr. Joe Show on CJAD Radio 800 AM every Sunday from 3 to 4 p.m.
I must say I was a bit shocked two weeks ago when I was contacted by a producer for The Dr. Oz Show inviting me on to discuss alternative medicine. We have been quite critical of Dr. Mehmet Oz over his promotion of dubious medical treatments and practitioners, and I wondered if they were aware of the extent of our criticism (they were, it turns out).
Despite the many cautions I received from friends and colleagues (along with support as well) – I am always willing to engage those with whom I disagree. I knew it was a risk going into a forum completely controlled by someone who does not appear to look kindly upon my point of view, but a risk worth taking. I could only hope I was given the opportunity to make my case (and that it would survive the editing process).
Of course, everyone was extremely friendly throughout the entire process, including Dr. Oz himself (of that I never had any doubt). The taping itself went reasonably well. I was given what seemed a good opportunity to make my points. However, Dr. Oz did reserve for himself the privilege of getting in the last word—including a rather long finale, to which I had no opportunity to respond. Fine—it’s his show, and I knew what I was getting into. It would have been classy for him to give an adversarial guest the last word, or at least an opportunity to respond, but I can’t say I expected it. Read more »
*This blog post was originally published at Science-Based Medicine*
When I was in medical school at Columbia University College of Physicians and Surgeons, Dr. Mehmet Oz had the reputation of being a competent and caring cardiothoracic surgeon whose research interest was reducing preoperative stress. I remember hearing about a music study of his in which soothing melodies reduced blood pressure and heart rates in patients preparing for heart surgery. I felt pleased that a surgeon was leading the charge in improving patients’ O.R. experiences, and had no inkling that 15 years later Dr. Oz would be America’s chief snake oil salesman.
I have been slow to criticize Dr. Oz on my blog because of a sense of loyalty to my medical school, however yesterday he crossed the line when things got personal – a friend of mine was negatively impacted by his misinformation to the point where her life was endangered. From watching his TV show, she was led to believe that she would put herself at risk for thyroid cancer if she got a mammogram. Several of her relatives have had breast cancer, and she should be particularly vigilant in her screening efforts. However, because Dr. Oz said that mammograms may themselves cause cancer, she opted out of appropriate screening.
My colleague Dr. David Gorski at Science Based Medicine has done an excellent job of documenting Dr. Oz’s almost Charlie Sheen-like career descent. Although he began his work as (presumably) a science-respecting surgeon, he now spends a lot of his time hosting a TV show that features faith healers, anti-vaccinationists, and psychics.
But how does the average lay person know how to evaluate Dr. Oz’s health claims? When Oprah’s network promotes him as “America’s physician” the platform itself offers him credibility, and a reach that can damage and misinform millions like my friend. I have a feeling that many of my peers at Columbia are concerned about Dr. Oz’s promotion of quackery, but once they’ve invested in his brand for so long, it’s easier to turn a blind eye to his nuttiness than to oust him from his academic positions. At what point is a celebrity doctor doing more harm than good to an institution’s reputation? Is he now “too big to fail?”
But back to my main point – dear readers if you watch Dr. Oz and think that he’s a credible source of health information, please be aware that much of what he says is inaccurate, exaggerated, and based on mystical belief systems. Please don’t act on his advice without checking with your own physician first.
Sadly, good science doesn’t always make good television. But the truth can make you well. Be warned that you are unlikely to find the truth consistently on the Dr. Oz show.
Dear Oprah and Dr. Oz,
Diabetes is very expensive to manage and to treat the complications of, but what comes at an even higher cost is the damage of statements from a doctor, claiming that diabetes is reversible. I was diagnosed as a child, and my type 1 diabetes is not the result of any controllable factors. However, I have many friends who have type 2 diabetes who can make the same claim.
I can’t lie – I had a lot of hope about your episode regarding diabetes. Even though it was billed as “the silent killer” and even though I knew you’d show the darkest side of diabetes-related complications possible to “sensationalize” this disease, I was holding out because I wanted this episode to be accurate. Read more »
*This blog post was originally published at Six Until Me.*