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GMO Paranoia And The Hollow Health Claims Of Cheerios

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Make no mistake about it. General Mills’ introduction of Cheerios sporting the label “Not Made With Genetically Modified Ingredients” is a mere marketing ploy and has nothing to do with health or nutrition. Let’s start the dissection of this blatant attempt to capitalize on the anti-GMO paranoia by looking at the main ingredient in Cheerios, namely oats. Samuel Johnson, the 18th century writer who compiled the first authoritative dictionary of the English language whimsically defined oats as the grain “eaten by people in Scotland, but fit only for horses in England.” A clever Scot supposedly retorted “that’s why England has such good horses, and Scotland has such fine men!”

Modern science, as it turns out, supports the ancient Scotch penchant for oats. A form of soluble fiber in the grain known as beta glucan has been shown to reduce levels of cholesterol in the blood which in turn is expected to reduce the risk of heart disease. You couldn’t tell this by the Scottish experience, though. Scotland has one of the highest rates of heart disease in the world. It seems all that haggis, refined carbs and a lack of veggies is too great a challenge for Scotch oats to cope with. Actually you need at least 3 grams of beta glucan daily to have any effect on blood cholesterol and that translates to roughly a cup of cooked oat bran or a cup and a half of oatmeal. Or about three servings of Cheerios. And that makes the cholesterol lowering claims prominently featured on the Cheerios box ring pretty hollow. There are far better ways to reduce cholesterol than gorging on Cheerios.

At least, though, the cholesterol lowering claim has some scientific merit. The “no GMO” claim has none. To start with, there are no genetically modified oats grown anywhere, at least not in the current sense of the term which refers to the splicing of specific foreign genes into the DNA of a seed. Such “recombinant DNA technology: is generally used to confer resistance to herbicides or protection from insects, but resistance to drought and enhancement with nutrients hold great potential. Although it is this new-fangled technology that garners attention these days, the fact is that virtually everything we eat has been genetically modified in some fashion over the years, either by traditional crossbreeding or through the use of chemicals or radiation both of which can scramble the genetic material in crops. The latter processes are based on the hope that a useful mutation will occur by chance, but basically it comes down to a roll of the dice. Just do enough experiments and a valuable mutant may surface. Radiation breeding has produced many varieties of rice, wheat, peanuts and bananas that are now widely grown. If you are eating red grapefruit, or sipping premium Scotch whisky made from barley, you are enjoying the products of this technology.

So if “genetically modified” oats do not exist, what sort of monsters is General Mills protecting us from? As is the case with any commercial cereal, Cheerios contains a number of ingredients with nutritious whole grain oats at the top of the list. Next come modified corn starch and sugar. It is to these two ingredients that General Mills refers when it talks about “GMO-free.” Much of the corn and some of the sugar beets grown in North America are genetically modified to resist herbicides and ward off insects. But by the time the highly processed starch and sugar extracted from these plants reach the food supply, they retain no vestige of any genetic modification. There is no way to distinguish the starch or sugar derived from genetically modified plants from the conventional varieties. The GMO-free Cheerios will not differ in any way from the currently marketed version except that the price may eventually reflect the greater cost of sourcing ingredients from plants that do not benefit from recombinant DNA technology.

The reason for the addition of sugar to Cheerios, actually in small doses compared with other cereals, is obvious. But why is corn starch added, and why is it modified? Nobody likes soggy cereal, and a thin layer of modified starch sprayed onto the little “O”s helps keep the interior dry. The modification in this case has nothing to do with genetic modification. Starch is a mixture of essentially two “polymers,” or giant molecules, both composed of units of glucose joined together. In amylose, the glucose units form a straight chain, while in amylopectin, the main glucose strand features many branches of shorter glucose chains. The properties of any starch depend on the relative proportion of amylose and amylopectin as well as on the degree of branching.

Starch has many uses in the food industry. It can thicken sauces, prevent French dressing from separating, substitute for fat or keep cereals dry. But these uses require starches of specific composition, either in terms of the length of the glucose chains or the degree of branching. In other words, the native starch has to be “modified” by treatment with acids, enzymes or oxidizing agents. There is no safety issue here, modified starches are approved food additives. Of course that doesn’t prevent scientifically illiterate alarmists from scaring the public by blathering on about modified starch being used as wallpaper glue and insinuating that any food made with it will literally stick to our ribs. The modified starch used in glue, namely a “carboxymethylated” version, is not the same as used in food, but even if it were, so what? Just because water can be used to clean garage floors and is found in tumours doesn’t mean we can’t drink it. Talking about washing garage floors, Cheerios also contains tripotassium phosphate, a powerful cleaning agent. It is added in small amounts to adjust the acidity of the mix used to formulate the cereal. This too has raised the ire of some ill-informed activists who do not realize that we consume all sorts of naturally occurring phosphates regularly in our diet. Quacking about the dangers of tripotassium phosphate in Cheerios makes about as much sense as hyping Cheerios that are “Not Made With Genetically Modified Ingredients.”

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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.

Yet Another Reason Why Dr. Oz Cannot Be Trusted: False Claims About Red Palm Oil

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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.

The Science Of Radiofrequency: Why Cell Phones, Microwaves, Wi-Fi, And Smart Meters Are Unlikely To Pose Health Risks

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Cell phones, microwave ovens, wi-fi, smart meters. What do they have in common? They all emit radiation in the radiofrequency range. And they all radiate controversy. Given that these devices are set to become as commonplace as light bulbs, it is understandable that questions arise about their possible health effects. There are all sorts of allegations that exposure can trigger ailments ranging from headaches to cancer. Allegations, however, do not amount to science. And there is a lot of science to be considered.

Let’s start with the fact that an alternating current flowing through a wire generates an electromagnetic field around it. This field can be thought of as being made up of discrete bundles of energy called “photons” that are created as the electrons in the wire flow first in one direction then in the other. Photons spread out from the wire, their energy depending on the frequency with which the current changes direction. The number of photons emitted, referred to as the ‘intensity’ or ‘power” of the radiation, depends on the voltage, the current and the efficiency of the circuit to act as an antenna.

In ordinary household circuits, the direction of the current changes sixty times a second, that is, it has a frequency of 60 Hz, the unit being named after Heinrich Rudolf Hertz, the first scientist to conclusively prove the existence of electromagnetic waves. The photons emitted by such a circuit travel through space and have the capacity to induce a 60Hz current in any conducting material they encounter. Essentially, we have a “transmitter” and a “receiver.” If special circuitry is used to produce current in the range of 10 million (10MHz) to 300 billion Hz (300 GHz), the photons emitted are said to be in the radiofrequency region of the electromagnetic spectrum. That’s because with appropriate modulation at the transmitter (amplitude modulation (AM), or frequency modulation (FM)) these photons can induce a current in an antenna that can be converted into sounds or images.

But what happens when photons in this energy range interact with living tissue, such as our bodies? The greatest concern would be the breaking of bonds between atoms in molecules. Disrupting the molecular framework of proteins, fats and particularly nucleic acids can lead to all sorts of problems, including cancer. However, photons associated with radiofrequencies do not have enough energy to do this, no matter what their intensity. An analogy may be in order.

Consider a weather vane sitting on a roof. It is mounted on a sturdy metal rod, but of course can spin. You decide you want to knock it off the roof, but all you have are tennis balls. You start throwing the balls, but even if you hit the support, nothing happens. You just can’t impart enough energy to the ball to have it break a metal rod. And it doesn’t matter if you gather all your friends, and they all throw balls at the same time. You may have increased the “intensity” of your efforts, but it doesn’t matter, because no ball has enough energy. Of course if you had a cannon, you could knock down the target with one shot. That’s why high energy photons such as generated by very high frequency currents, as in x-rays, are dangerous. They can break chemical bonds! While you are not going to damage the weather vane with the tennis balls, you can surely make it spin, and the friction generated will heat up the base, the extent depending on how many balls are thrown.

Now, back to our photons. In the radiofrequency region, no photon has enough energy to break chemical bonds, but they can make molecules move around, generating heat. The more photons released, the greater the heating effect. This is exactly how microwave ovens work. They operate at radiofrequencies, but at a very high intensity or “power” level, meaning they bombard the food with lots of photons causing the food to heat up. You certainly wouldn’t want to crawl into a working microwave oven and close the door behind you. Similarly, you wouldn’t want to stand right next to a high power radio transmitting antenna, such as used by radio or TV stations, because you could get burned very badly. But the number of photons encountered drops very quickly with distance as they spread out in all directions, so that even standing a few meters from the base of such an antenna would not cause any sensation of heat. Just think of how quickly the heat released by a light bulb drops off with distance.

The “smart meters” that are being installed by electrical utilities monitor the use of electricity and relay the information via a built-in radio transmitter. But the radiation to which people are exposed from these meters quickly drops off with distance, as with the light bulb, and is way below established safety limits. Furthermore, the smart meters only transmit for a few milliseconds at a time for a grand total of a few minutes a day! Cordless phones, cell phones, routers, baby monitors, video game controls and especially operating microwave ovens expose us to similar radiation, usually at far higher levels. Smart meters are responsible for a very small drop in the radiofrequency photon bucket.

It must be pointed out, though, that safety standards are essentially based on the heating of tissues. But what about the possibility of “non-thermal” effects? What if radiofrequency photons cause damage by some other mysterious mechanism? Over the last 30 years more than 25,000 peer-reviewed papers have been published on electromagnetic fields and health, many devoted to non-thermal effects. Health agencies do not find present evidence persuasive of a hazard at ordinary exposure levels, and given the extent of research that has been carried out, it is unlikely that one will be identified in the future.

Although an overwhelming number of studies on cell phones and brain cancer have shown no effect, admittedly some have suggested a barely detectable link. Despite the weak evidence, the International Agency for Research on Cancer has classified electromagnetic fields associated with radiofrequencies as “possibly carcinogenic,” indicating a level of suspicion without any implication that the fields actually cause cancer. This notion pertains to cell phone use and has nothing to do with the far weaker fields associated with wi-fi and smart meters. I would have no issue with a smart meter in my house.

What then about those consumers who claim they have developed symptoms after smart meters were installed? I think it is appropriate to consider John Milton’s poetic view of the power of imagination: “The mind is its own place, and in itself can make a heaven of hell and a hell of heaven.”

***

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.

Eat To Save Your Life: Another Half-True Diet Book

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I am hesitant to review diet books because they are so often a tangled mess of fact and fiction. Teasing out their truth from falsehood is about as exhausting as delousing a long-haired elementary school student. However, after being approached by the authors’ PR agency with the promise of a book that contains science-based nutrition information I decided to agree to the review. This is how the book was described to me in an email:

In their provocative new book, Eat to Save Your Life, best-selling authors Dr. Jerre Paquette and Gloria Askew, RRN, sort through the piles of information and misinformation about nutrition to reveal the true connection between food and health. Fed up with the advertising hype and conflicting nutritional advice, the duo provides common sense explanations for consumers everywhere who are looking to make smart nutritional choices.

Unfortunately, I was sold (quite predictably) a bill of goods. And rather than ignore the book and simply not do a review, I figured that maybe a negative review would reduce the number of incoming PR requests for future tomes of pseudoscience. In the end, I’ll probably just become the focus of personal attacks by dedicated proponents of various snake oils.

That being said, I thought it might be somewhat instructive to remind Better Health readers of certain basic “warning signs of pseudoscience” that I accidentally overlooked in agreeing to review the book. For a more complete review of similar “signs” I highly recommend Dr. David Gorski’s 2007 classic, humorous take on predictable arguments and behaviors of alternative medicine proponents (written in the style of comedian Jeff Foxworthy).  As for me, I tend to think of much of the world of integrative medicine as a militant group of bakers eager to add odd, inert and occasionally toxic substances to cake recipes.

And so, without further ado, here is a small sample of what authors Askew and Paquette have added to their half-true diet book recipe:

  • The “one true cause” fallacy: The book opens with an interesting review of vitamin C deficiency, noting that it (apparently) took the British Royal Navy 40 years before they accepted that the treatment for scurvy was citrus extract (rather than flogging). Citing this incident as an example of nutritional deficiency leading to life-threatening illness,  it’s a short ride to the “one true cause” fallacy whereby the authors postulate that there are untold numbers of modern diseases caused by unrecognized nutritional deficiency syndromes. Nutritional deficiency may be the one true cause of most diseases, you see.
  • The appeal to research without references. Countless appeals are made to “mounting evidence” of this and that (arthritis being caused primarily by food-related inflammation for example), either without reference footnotes, or with mentions of sources of dubious credibility (such as the Canadian Association of Naturopathic Doctors).
  • The appeal to supplements in lieu of vaccines. No diet advice would be complete without a gratuitous attack on vaccines, right? The authors suggest that flu vaccines (for example) only provide immunity for 2 months “and only for certain individuals.” Meanwhile, they assert that a combination of Echinaceagarlic, and vitamin C support the immune system to successfully fight of viruses. These claims are simply unproven and multiple studies have already found no benefit (over placebo) of these supplements at preventing and treating the common cold.
  • Over-diagnosis. If you think that the world of medicine is predisposed to seeing disease where there is none, try the alternative medicine world. The authors assert that everything from zits, to rashes, to “brain fog” are potential signs of grave underlying immune compromise – caused by, you guessed it, dietary deficiencies.
  • Over-supplementation. The authors argue that “supplementation is a necessity in our nutrient-robbed world.” However, new evidence doesn’t support supplementation for the general population, though it had beentraditionally felt that multi-vitamins might be valuable. In addition, new studies are finding that food sources are preferable to supplements for daily nutritional requirements (such as calcium) and that anti-oxidants such as vitamin E may do more harm than good.
  • The “organic is more nutritious” argument. Although a recent systematic review of the scientific literature found no support for the notion that organic foods contain more nutrients than those grown with traditional methods, the authors attribute Americans’ supposed vitamin deficiencies to poor soil quality caused by non-organic farming methods.
  • Nutrigenomics and DNA hype. The authors do not take a sufficiently skeptical view of the emerging field of nutrigenomics (whereby certain foods and supplements are recommended to individuals based on their genetic profiles). They even suggest that nutrigenomic testing is so much fun, it’s “almost like being part of a CSI television show.” Who cares if it’s no more accurate than fortune telling?

So what’s the half true part? Well, obesity is certainly a driver of many modern illnesses, and obesity is caused by (in no small part) nutritional choices. The authors cite statistics on the ravages of heart disease, high blood pressure, and diabetes on the U.S. population which are all quite true. (How this supports the “deficiency” argument is somewhat lost on me – because it would seem more logical that a possible excess of nutrients could be the “one true cause” of a lot of these diseases, but I digress).

There are real nutritional deficiencies that cause medical problems, such as iron-deficiency anemia, neural tube defects related to folic acid deficiency, vitamin D deficiency and rickets, and osteoporosis contributed to by low calcium levels. These conditions underscore the importance of healthy eating habits, but do not support the idea that the entire population is deficient in these nutrients. In fact, a large population study analyzed by the CDC, suggests that most Americans are not deficient in any major nutrient even with their current sub-optimal and obesogenic eating habits.

In general, fair-minded individuals will find Eat To Save Your Life to be yet another example of a half-true, hysteria-peddling, micro-nutrient-obsessed diet advice book. Ironically, the book’s title itself states the opposite of what we really need to be doing to reduce obesity-related diseases: stop eating (so much) to save our lives.

This book may be purchased (against my medical advice) at Amazon.com.

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This post originally appeared at the Science Based Medicine blog.

Dr. Oz’s Silly Weight Loss Recommendations Lead To Fat TV Ratings

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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@mcgill.ca

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.

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