Popular “detox” cleanses, including one promoted by Dr. Mehmet Oz on his popular TV show, are unproven and ineffective, a CBC Marketplace investigation reveals.
Marketplaceteamed up with some sorority sisters at Western University to test Dr. Oz’s 48-hour cleanse, which he promotes on his website and his much-watched television show. The show also investigated two other trendy treatments that claim to “detoxify” the body.
Despite bold promises that the treatments would purify, detoxify and boost energy and optimize organ function, the cleanses lacked any scientific evidence of efficacy, or clear idea of what toxins they would actually diminish.
Consumers are inundated by headlines that say our bodies absorb a wide variety of environmental toxins on a daily basis, from mercury in fish to carpet off-gases to chemicals in our drinking water. Detox programs are often advertised as a remedy for this.
Detox cleanses are the darlings of celebrities including Gwyneth Paltrow, who publishes cleanse diet recipes on her website Goop, as well as Demi Moore, who actively promotes the use of leeches as a detoxifying treatment.
SEE: 10 truths about juice cleanses. Story continues below:
People undergoing chemotherapy, diabetics, people with nutritional deficiencies and people with kidney disease should not try a juice fast. The high sugar consumption involved in juice fasts can skyrocket blood-sugar levels in diabetics, which can result in fatigue, unexplained weight loss, blurry vision, excessive hunger and thirst, and wounds or infections that heal more slowly than usual. According to USA Today, the high levels of potassium and minerals from excessive juice consumption can build up in the blood to hazardous levels in those with kidney disease. And the high levels of antioxidants and low levels of protein can be dangerous for those undergoing chemo.
While the juice form does hydrate and supply nutrients, registered dietitian Jennifer Nelson says there's no reliable scientific research to support claims that juicing your produce is healthier than eating it whole. Actually, the fiber and some of the antioxidants found in the skins and seeds of fruits and vegetables are often eliminated in the juicing process. For example, the white pulp in an orange provides flavonoids, but that's usually left behind. Because juice doesn't offer the fiber contained in fruits and veggies, the body absorbs fructose sugar more easily, which can affect blood-sugar levels, according to Food Republic. If you do decide to try a juice cleanse, drink more veggie juices (carrots and beets not included) and limit fruit juice to one glass a day in order to avoid this potential side effect. None of this means you shouldn't drink juice. It simply means, instead of drinking only juice for weeks, a healthier route might just be including juices in a balanced diet of fruits, vegetables, lean protein and whole grains. (Photo courtesy of Flickr/plindberg)
You're not going to feel as satisfied and full if you drink your meals instead of chewing them, Livestrong.com explains. Additionally, the fiber that's been left out of the juice would have helped slow consumption and make you feel more sated.
You should always be skeptical when a diet requires extreme restrictions and cuts out entire food groups. There's a reason dietary guidelines include various categories of food: You can't get all of your essential vitamins and minerals out of just one. Livestrong.com explains that juice fasts frequently lack substantial amounts of protein and fat. "Few fruits contain significant amounts of fat and protein, and vegetables that contain these macronutrients -- such as avocados, beans and lentils -- do not lend themselves to juicing," Livestrong says. "Without sufficient protein, your body has no raw materials with which to build new tissue. A lack of fat leaves your skin and hair in poor shape and contributes to malabsorption of fat-soluble vitamins." Extend your juice fast, and you might just cause serious damage. Dr. Glenn D. Braunstein, chairman of the Department of Medicine at Cedars-Sinai, says that longer fasts could result in electrolyte imbalances. Additionally, if you're not getting enough calories, your body could start using muscle tissue instead of fat for energy. (Photo courtesy of Flickr/Arenamontanus)
Will you lose weight? Probably -- you're cutting out all of the fat from your diet and drastically lowering your caloric intake. But you'll most likely put it right back on after the fast. "There's nothing wrong with going on a juice fast for a few days," said Dr. James Dillard, assistant clinical professor at Columbia University College of Physicians and Surgeons in New York City, on WebMD. "But it's not a great way to lose weight, because you'll gain it all back -- you yo-yo. It's just like the Atkins diet. The weight you lose is water weight." And Dr. Braunstein (of Cedars-Sinai) says this type of deprivation can also result in dizziness, nausea, constipation, fatigue and irritability. Additionally, if you do this to your body enough, you could permanently lower your metabolism -- as if it's not tough enough to lose weight as it is. New York Times writer Judith Newman tried a juice cleanse and wrote about her experience: "This kind of cleansing puts a lot of stress on your body," she wrote. "Your body wants and expects food. And as with most crash diets, which is really what this is, your body thinks it's starving. It doesn't know it's going to get more food. So it lowers your metabolism, and if you do this enough, it can lower your metabolism permanently."
Don't get me wrong: A "detox diet" to rid my body of all the crap I've recently put in it sounds convincing, even to me. Who wouldn't want to "cleanse" their body of all the chemicals, fat and alcohol they've consumed? The fact is, though, our body does an excellent job of this already; our liver, kidneys and intestines filter the unwanted things we ingest and expel them through urine, bowel movements, breath and sweat. We don't need to punish ourselves with strict juice-only diets to eliminate the bad stuff. People were talking about detoxification back in the early 1900s, according to QuackWatch. Supporters of the process claimed that "intestinal sluggishness causes intestinal contents to putrefy, toxins are absorbed and chronic poisoning of the body results." Scientists abandoned this theory, though, in the 1930s, and these mysterious "toxins" that everyone keeps trying to get rid of have never been discovered. "Our bodies are very good at eliminating all the nasties that we might ingest over the festive season," said Dr. John Emsley, a chemical scientist quoted in the Washington Times in a story about the potential of detox diets to get rid of all the junk we put in our bodies over the holidays. The idea of detoxing our bodies by "drinking fancy bottled water or sipping herbal teas is just nonsense." (Photo courtesy of Flickr/lululemon athletica)
The weight loss industry is a business -- a booming one at that. As of February 2011, the weight loss market was valued at almost $60 billion, including bariatric surgery, diet soft drinks, health club revenues and more by Marketdata Enterprises. BluePrintCleanse, a popular New York-based manufacturer, will charge you $65 a day for its cleansing package of juices. Los Angeles-based Pressed Juicery offers three different cleanse packages, each providing five juices and one almond milk for a total cost of $70 a day. Want to juice at home? Get ready to put down some money. Juicers range from $30 to $300. And since you shouldn't be saving unpasteurized juice for later, you might want to buy one for the office while you're at it. (Photo courtesy of Flickr/Andrew Stawarz)
Proponents of the juice fast claim it will cure your case of the sniffles and even treat cancer. There has been no scientific evidence suggesting it will do anything but help increase your vitamin intake -- which, yes, could benefit your health, but the calorie restriction and lack of protein might actually slow healing. Your body needs all the vitamins, minerals and nutrients it can get to heal. The best thing you can do with your diet is to make sure you're not depriving it of an essential nutrient and eat balanced, well-portioned meals. As for cancer, the American Cancer Society states that current scientific research does not support fasting (including juice fasting) to treat it. Additionally, as previously stated, those undergoing chemotherapy should not attempt a juice fast because of the risk posed by the high levels of antioxidants and low levels of protein.
It's true. Many people who try these detox diets report having more energy and feeling more focused. However, as Mayo Clinic explains, this could be due to the belief that they're doing something good for their bodies. That said, you could also argue that there's nothing wrong with a placebo effect if it does the job. As the NYT writer who tried one of these cleanses wrote, "What's so bad about feeling a little better, even if there's no demonstrable proof that you actually are better?"
“In looking at the medical literature on these things, there has never been a properly conducted scientific investigation of any of these treatments that I’ve been able to find,” Dr. George Dresser, a toxicologist, pharmacologist and an internal medicine specialist at London Health Sciences Centre, told Marketplace co-host Tom Harrington. “It’s an intensely popular topic. And it’s popular because people are interested in a quick fix to health ”
In addition to Dr. Oz’s cleanse diet, the show also looked at two other detox programs and examined the science behind the treatments. The full investigation, Detox Challenge, airs tonight at 8pm (8:30pm NT) on CBC Television.
Dr. Oz advice controversy
Dr. Oz -- who is the vice-chair and professor of surgery at Columbia University, as well as the host of the popular Dr. Oz Show -- markets his 48-hour cleanse as “the ultimate detox solution,” which promises to “revitalize you from the inside out“ and boost liver and kidney function. Dr. Oz does not charge money for the cleanse recipes; they are based on ingredients you can buy at the grocery store.
A group of sorority sisters from Western University volunteered to help Marketplace test the cleanse. Half of the group participated in the Dr. Oz cleanse, which required that the students observe a strict diet and refrain from alcohol and caffeine, and not eat any food after 7 p.m. They also drank detoxifying teas and took soothing baths as prescribed by the diet, while the other students ate and drank normally.
To test the efficacy of the cleanse, all students had their liver and kidney functions tested both before and after the 48-hour period. At the end of the 48-hour period, however, Dr. Dresser was unable to detect any physiological benefit at all, or even tell which students had participated in the cleanse.
Dr. Dresser told Marketplace that he doubted that any detox cleanse would have a real benefit, regardless of the duration.
Despite a CV that boasts degrees from Harvard and the University of Pennsylvania medical school, Dr. Oz has been the target of growing criticism from fellow medical and science professionals for his promotion of products and methods that lack evidence. “Given his education and influence,” wrote Erin May on the Harvard University science research blog Policylab, “there’s no excuse for the unsubstantiated claims and sensational language that is so pervasive on his show.”
In response to some of these criticisms, a spokesperson for Dr. Oz told one newspaper: “Our audience are not scientists, and the show needs to be more lively than a dry scientific discussion.” Dr. Oz declined to be interviewed for the Marketplace story.
Cleanses lack evidence
Detox cleanses, programs, supplements and scrubs line the shelves of health food and drug stores and fuel a multi-billion dollar industry.
Dr. Dresser, who is also a professor of toxicology and pharmacology at Western University, worked with Marketplace to test Dr. Oz’s cleanse and says that many detox treatments on the market are vague about what they do or how they work.
“It’s sometimes difficult to know exactly what toxins they’re talking about,” he says.
He says that hype about detoxifying “superfoods” is not supported by science. “There is no evidence that I can see that there are specific foods that are better at detoxifying than others. I think that the value of food is its nutrient value. And I think that we should all be consuming good-quality food. But in terms of one food being able to detoxify or enhance elimination of noxious substances in your body, I don’t think there’s any evidence for that.”
While the Dr. Oz cleanse had no medical benefit, Dr. Dresser says that it is not dangerous. “The good news, I suppose, is that the detox treatment didn’t result in a negative change in health status. But there was also no improvement.”
Dr. Dresser says that the detox trend is fuelled by our desire for a quick-fix solution to health.
“From a health-behavior standpoint,” he says, “I think that if you read any claim that says, in two days or seven days, or thirty days, ‘I can substantially change your health status,’ I think you should be skeptical.”
“I think that there’s a lot of these things, like the detox treatments, where there isn’t substantial evidence for benefits,” he says. “And yet people are using them. And, in a way, that’s an indictment of us in the medical system for not communicating better what we know.”
In 2009, the UK group Voice of Young Scientists published The Detox Dossier, a report on popular detox treatments.
The group found companies that market detox products were unable to point to evidence that supported their claims, or even come up with a coherent definition of what “detox” means. In addition: “many of the claims about how the body works were wrong and some were even dangerous.”
As one of the report’s authors, biologist Harriet Ball, wrote: “Detox is marketed as the idea that modern living fills us with invisible nasties that our bodies can’t cope with unless we buy the latest jargon-filled remedy.”
Dr. Dresser says that our bodies already cleanse and detoxify our bodies quite effectively.
“The liver is incredibly efficient at getting rid of those noxious substances. The kidneys do a great job at eliminating many toxins that are soluble in water,” he says.
“We have everything we need inside of us right now.”