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You Asked: Is there any benefit to drinking Yerba mate tea?

yerba mateYerba Mate, the ad says, has powerful rejuvenating effects. Well, who wouldn’t go for a little rejuvenation? So what is this wonder product? Yerba is a tea brewed from the dried leaves of the Ilex paraguariensis plant, a small shrub that grows in Paraguay, Brazil and other South American countries. The tea is also sometimes known as Paraguay tea. The Guarani Indians of Paraguay and Argentina have been brewing this beverage for centuries and claim it can do everything from boosting energy levels and intelligence to providing all the nutrients needed for life. In Europe mate is often used for weight loss, though there is no scientific evidence to show that the plant boosts metabolism or acts as an appetite suppressant. But what about the other claims?

An analysis of extracts taken from the mate plant reveals the presence of a couple of hundred compounds, as one would expect for any plant material. There are vitamins and minerals and the usual array of antioxidants but there are no magical ingredients. Any stimulation from the beverage can probably be ascribed to caffeine, although yerba contains less than coffee or other teas. Claims about yerba mate being “nature’s most perfect beverage” or “the beverage of the Gods” are just hot air. And speaking of hot, that’s how yerba mate is traditionally consumed. That can be a problem. Drinking mate tea has been linked to esophageal cancer in South America where the beverage is consumed at extremely high temperatures.

A rarely discussed problem with consuming plant extracts is misidentification, mislabeling or adulteration. Here’s an interesting, but hopefully rare, case in point. A family of four in New York City shared a pot of mate tea. An hour later the 10 year old son became restless and agitated and had to be taken to hospital. His pulse was rapid, his pupils dilated and nonreactive, his skin was flushed and his mucous membranes were dry. These are typical signs of anticholinergic poisoning, meaning that the activity of acetylcholine, an important chemical for conveying messages between nerve cells was being impaired. Doctors quickly injected him with physostigmine, a drug that boosts acetylcholine activity. Recovery was swift. But by then his eighteen year old brother reported feeling confused and loss of memory.
Since there are no compounds in yerba mate tea that could explain these effects, adulteration of the beverage was suspected.

A chemical analysis revealed the presence of atropine, scopolamine and hyoscyamine. Tell-tale components of the belladonna plant, a classic anticholinergic poison! Nobody knows how belladonna leaves got into the tea but eventually seven other cases of poisoning turned up. Still these are isolated incidents, and the chance of anyone having a reaction to yerba mate is remote. But so is the chance of any rejuvenating effect. Incidentally, the Guarani Indians traditionally drink yerba mate out of a bull’s horn, which seems appropriate given some of the outlandish claims that are made on behalf of the beverage.


Joe Schwarcz

You Asked: Should we worry about plastic pollution?

plastic pollution in oceanPlastics are the fabric of modern life. They’re in our cars, our planes, our kitchens, our electronics, our furniture, our bottles, our packaging, our floors and our medical equipment. We are using more and more plastics and unfortunately also discarding more and more. And that’s a problem. Plastic debris is commonly sighted on the landscape and is accumulating in marine habitats. A recent study revealed that plastics make up 50-80% of shoreline debris and accumulate in certain areas of the oceans. There is already a huge plastic wastedump in the middle of the Pacific Ocean! Besides being an eyesore, plastic debris poses a danger for wildlife. Marine mammals can become entangled in plastic bags or six-pack holders, and even worse, ingestion can cause death by blocking the digestive tract or by causing the animal to starve due to false satiation. Then there is the problem of potentially toxic compounds such as phthalates or bisphenol A leaching out of plastics. Because some of these chemicals are fat-soluble, they accumulate in adipose tissue of fish. Since humans are at the top of the food chain, we may possibly be exposed to physiologically meaningful amounts, although so far there is no evidence of any harm to people.

Some people believe that switching to bioplastics may be the key to reducing plastic pollutants in the environment. The term ‘bioplastic’ refers to materials made from natural sources such as corn. The common assumption is that these are biodegradable, but that isn’t necessarily the case. It is true that under suitable conditions bioplastics can be degraded by microbes, but this doesn’t happen in landfills where many plastics end up, and even elsewhere the biodegradation is very slow. Then there is the issue of “microplastics,” tiny particles found in many consumer products. They are usually used as abrasives and exfoliants in facial scrubs, shampoos, toothpaste, eyeliner, lipgloss, deodorants and soaps. Due to their miniscule size, these particles typically escape removal at sewage treatment facilities after being washed down the drain and can end up being consumed by animals. As a result, companies are being pressured to end the use of microplastics and switch to other natural alternatives like apricot shells and cocoa beans. Plastics are an integral and irreplaceable part of our lives but we need to take better care with how they are used. One way is to place more emphasis on recycling. So, don’t neglect your blue box. Feed it regularly.


Dr. Joe Schwarcz & Alexandra Pires-Ménard

You Asked: What is Gerson therapy?

gersonWhat sort of treatment do you think cancer patients would receive at the Gerson Institute in San Diego? Actually, they would receive no treatment at all, because the “Gerson Therapy” is not sanctioned in the United States. But they would receive plenty of information about traveling to Gerson clinics in Mexico or Hungary, as well as about providing basic “Gerson care” for themselves at home. The Institute does not limit itself to providing information about cancer. It seems the Gerson therapy is effective against virtually every disease. How can this be? Because “it restores the body’s incredible ability to heal itself with no damaging effects, and rather than treating only the symptoms of a particular disease, it treats the underlying cause of the disease.” Right. And the tooth fairy leaves coins under the pillow.

Cancer is a terrible disease that often defies conventional treatment. But the failure of science-based medicine can mean success for the marketers of “alternative” therapies who are unencumbered by the need to furnish evidence. They just have to clamor about how conventional doctors slash (surgery), burn (radiation) and poison (chemotherapy) their patients, hastening their demise, while they offer kinder, gentler, life-saving “natural” treatments. Desperate patients, they well know, will do desperate things. At any cost.

The “Gerson Institute and Cancer Curing Society,” as it officially call itself, adorns its seductive brochure with the credo, “healing with nature.” Aside from the absurd, but appealing notion that “nature” is more adept at healing disease (which it incidentally causes with reckless abandon through natural bacteria, viruses, fungi and moulds) than research-based medicine, one has to question the “natural” aspect of the Gerson regimen.

Is the squirting of coffee up one’s rear end “natural?” What about gulping desiccated liver capsules? Or administering ozone rectally? All these have been part of the program. To say nothing of drinking several glasses of raw calf liver extract a day! That lunacy was given up after several patients’ deaths were linked to a bacterial infection associated with the extracts. The foul liver juice was replaced by a more taste-bud friendly green leaf-apple juice blend, a dozen glasses of which have to be downed to “flush the toxins” responsible for cancer out of the system. Just what these toxins are is never addressed. But to make sure they are eliminated, patients are also dosed with pancreatic enzymes, iodine, vitamin B12, niacin, thyroid hormone, potassium, coenzyme Q10 and organic flax seed oil. Of course all of these bizarre interventions would be acceptable if the treatment worked. Let’s face it, conventional chemotherapy is no picnic. But there is a difference. Chemotherapy at least, has a chance of working.

As the name suggests, there actually is a person behind the Gerson therapy. An established physician, Dr. Gerson fled his native Germany when the Nazis came to power and eventually settled in New York in 1936. As a young doctor he had been tormented by migraines and had sought relief by experimenting with different diets. He traded in his wursts, schnitzels and sauerbraten for a plant based diet that apparently resolved his migraines. Gerson theorized that contamination with artificial fertilizers and pesticides was responsible for his misery. He began to prescribe his “natural” plant-based diet to other migraine sufferers who soon claimed to experience all sorts of additional benefits, including resolution of tuberculosis. Needless to say, there was no objective evidence that any patients had actually been cured in this fashion. How could there be? TB, a bacterial infection, cannot be cured by diet.

And then Gerson had an epiphany. If TB responded to his regimen, why not cancer? By 1958 he had published his book, “A Cancer Therapy,” in which he described curing fifty patients of terminal cancer. That astounding claim prompted the U.S. National Cancer Institute to undertake a review of Gerson’s cases with the conclusion that the validity of the cancer diagnoses and the supposed cures could not be substantiated. Gerson retorted that the review had been unfairly influenced by the “cancer establishment,” for the simple reason that his natural cure was a threat to the grotesque profits realized by the pharmaceutical industry from its expensive but useless chemotherapeutic drugs. That tired old refrain has practically become the anthem of the “alternative” medicine community.

The problem with the Gerson therapy, as now promoted by his daughter Charlotte, and practiced in the Mexican and Hungarian clinics, is not that it is scientifically implausible, nor that it is tortuous to follow, nor that it is repugnantly expensive. The problem is that there is no evidence that it works! The Gerson clinics make all sorts of claims about euphoric patients returning home, cured of their disease. But no follow-up is ever carried out. And whenever independent researchers have tracked Gerson patients, they have found that most had succumbed to cancer within five years of having been “cured” of the disease.

Of course there is even less information available about the success or failure of the “home” version of the Gerson therapy. Administering coffee enemas at home may be a bit of a challenge, but the juicing can be done. Not with any old juicer, though! No siree. We are told that “Dr. Gerson’s research indicates that it is imperative for cancer patients to have a two-step juicer with a separate grinder and hydraulic press. One step juicers generally do not produce the same quality of enzyme, mineral or micronutrient content.” Really? I don’t seem to be able to find that bit of research in the peer-reviewed literature.

The Gerson website actually recommends a specific juicer that will run you in the neighbourhood of $2000. Surely, though, that’s a bargain if it will help you beat cancer. Don’t even think about buying a cheaper juicer, though, because as the Gerson Institute’s captivating brochure tells us, “in fact some patients have failed to experience results simply by using the wrong juicer.” Yup-that must be why they failed to cure their cancer. Wrong juicer! Those cutting-edge researchers at the Gerson Institute surely would not lie to us, would they?

Joe Schwarcz

You Asked: Are chia seeds really that healthy or is it just nonsensical hype?

chiaIt isn’t nonsensical hype but neither are chia seeds some sort of wonder product. A plant growing from a seed is pretty amazing.  So is the hype that grows from a seed of truth in the area of nutritional supplements.  Salba is a case in point.  What is it?  A grain that originated in South America and is reputed to have been revered by the Aztecs because it served as a source of energy for their runners.  I don’t know that, but I do know that the seeds served as the source of the “hair” that sprouted from those little ceramic novelty animals known as “Chia Pets.”  Indeed, it was the speed with which those salba sprouts grew that intrigued University of Toronto researcher Vlad Vuksan.  Did these seeds have some special property, he wondered?  Chemical analysis showed that they were an excellent source of alpha linolenic acid, an omega three fat, as well as of fiber.  Vuksan, whose research focuses on the nutritional aspects of type 2 diabetes became interested because of accumulating evidence that whole grains can play a role in reducing the risk of diabetes and heart disease.  And then the next thing we know is that Salba is being touted by a commercial enterprise as “Nature’s Most Powerful Whole Food,” and people are shelling out money for the seeds that according to the marketers “have been extensively researched at the University of Toronto.”  Now, Vuksan is a respected researcher, but the evidence in this case constitutes one published paper that describes a trial with just twenty subjects.  And the results are not what one would call dramatic.

The subjects were all type 2 diabetics, so the results cannot be automatically extended to the general public.  Everyday they consumed either an average of 37 grams of salba seeds or an equivalent amount of wheat bran.  That’s a lot of seed, about six tablespoons.  The hope was that salba would help with blood glucose control, but it did no better than the bran.  On the other hand it did reduce the systolic blood pressure by some 6 mm of Hg, which is significant.  Salba also reduced C-reactive protein which is a measure of inflammation and had a small effect on reducing the blood’s clotting ability.  These are welcome changes since diabetics are at increased risk for heart disease.  But they hardly justify the hype that has been created by advertisers on behalf of salba.  We hear comments that just 3.5 ounces of salba has as much omega-3 fats as 28 ounces of salmon and as much calcium as 3 cups of milk and as much iron as five cups of raw spinach.  Well, 3.5 ounces is 97 grams, almost three times as much as was used in the study, which already was a large amount.  People who take the “recommended” dose on the package would take 12 grams a day, which yields a trivial amount of calcium and iron.  Furthermore, the type of omega-3 in salba is not the type we find in fish.  And if it comes to that, flax is a much cheaper source of vegetable based omega-3 fats.  Yes, eating whole grains is a good idea, but before we attribute any magical properties to salba we need more than one small study on diabetics that shows a modest decline in some cardiovascular risk factors but shows nothing about disease outcome.  For now, I’m not slaughtering and eating my Chia pet.


Joe Schwarcz

You Asked: What is histaminosis?

scromboid poisoningMention “histamine” and the word “allergy” pops to mind. Rightly so, because during an allergic reaction certain white blood cells known as mast cells and basophils release an inordinate amount of histamine, a chemical that then travels through the bloodstream and fits into “receptors” in cells that make up our tissues much like a key fits into a lock. And when the “key” fits, it unlocks the typical symptoms such as the watery eyes, runny nose, hives, itching and breathing problems we associate with allergies. Simply put, an allergy is a hypersensitivity disorder of the immune system, essentially a response to substances that most people’s bodies perceive as harmless. “Antihistamines” control allergy symptoms by blocking histamine activity. But our body can also produce enzymes such as histamine-N-methyltransferase and diamine oxidase (DAO) capable of inactivating histamine. A deficiency in these enzymes leads to a disease known as histaminosis or histamine intolerance (HI). This can be a real nuisance for the 2% of the population that suffers from this condition. The problem is that histamine is not only produced by cells in our immune system, it can also occur naturally in some foods such as champagne, wine, beer, sauerkraut, vinegar, pickles, mayonnaise, tofu cheese, sausages, processed meats, mushrooms, prepared salads, tinned vegetables, dried fruits, seeds, nuts, yeast, chocolate, cocoa cola and crustaceans. Fish present a particular problem because naturally occurring bacteria in fish produce an enzyme called histidine decarboxylase that forms histamine from histidine, an amino acid that is released when fish proteins decompose.

Even people who do not suffer from the enzyme deficiencies that cause histaminosis can react to large amounts of ingested histamine with vomiting, diarrhea, skin rash, headaches, dizziness, itchiness of the skin, tingling of the mouth and lips and a peppery taste sensation. The term used in this case is “scromboid poisoning” after the family of fish such tuna, sardines, mahi-mahi, swordfish and marlin. Thes are the most likely to be tainted with histamine. Contrary to popular belief, histamine cannot be destroyed by cooking or freezing. If you are preparing the fish, then you must ensure proper temperature control. In addition, fish should be purchased from reputable suppliers who store fish on ice or under refrigeration. In case you should ever find yourself a victim of scromboid poisoning, remember to take oral antihistamines that can quickly resolve the symptoms. But for those with histamine intolerance, antihistamines may be ineffective. That’s because there are different types of histamine receptors and antihistamines block only some. Since there is no cure for histamine intolerance, patients must adjust to a low-histamine diet. A major problem is that people may suffer for a long time from an array of symptoms that can include digestive problems, migraines, “brain fog” and respiratory issues before they are ever diagnosed with histaminosis. It takes a vigilant physician to think of doing a test for the specific enzyme deficiencies involved. But when a diagnosis is made, adherence to a low histamine diet can change what seems like an endless misery to a life worth living.

Alexandra Pires-Ménard

You Asked: Time Conundrum

radiationI was fascinated by yesterdays announcement that “old light”
 revealed trace evidence in the background radiation of the earliest
  trillionth of a trillionth (and then some) of a second of the “big bang”.
 What I don’t grasp is the measurement of the timescale, if we are talking
 about the creation of the most elemental forces, aren’t we talking about the
 creation of time itself too? If so how do we establish a time-scale to
  measure what involves-among other things- the creation of the time that we
 are measuring by?  A big bang of thanks to who-ever can answer in layman’s

All we can really say is that if you run the clock backwards, this event would have happened 10^(-34) or so seconds before all our equations blow up (going backwards from today).  This is a short time, granted, but the equations are still valid for another factor of a billion or so smaller intervals, so this doesn’t cause any existential crises for space and time.

With no relevant data probing earlier times, though, all sorts of things could have happened in those earlier times: the universe could have quite comfortably been going on forever before this event, then suddenly entered this new phase. Or, space and time somehow popped into existence and triggered this evolving universe, but the physics that we have carefully built up over the centuries doesn’t give a lot of guidance for how this would happen or what it would mean. It is possible that there is information from this earlier time encoded in our universe, but that is a pretty fuzzy frontier of current research.


Dr. Gil Holden

McGill Physics Professor

You Asked: Where do antivenin’s for snake bite come from?

antiveninTo make an antivenin, small doses of poison are injected into horses or goats.  The amount of toxin is not enough to kill the animal but is enough to trigger the production of antibodies.  These are specialized proteins which recognize the toxin and neutralize it.  As the dosage given to the animal is increased, more and more antibodies are generated.  Blood is then removed and the antibodies are isolated from the serum.  Recent research in India has shown that chickens can also be used.  Again, small doses of the venom are injected, but this time the antibodies are isolated not from the chicken’s blood, but from the eggs it lays.  The process is more economical than using horses or goats and seems to be associated with fewer side effects.  The main worry about using antivenin is the possibility of an allergic reaction.  The extraction of antivenin from plasma is not a perfect process and various cellular components are extracted along with the desired antibodies.  These are foreign to humans and can cause severe allergic reactions, including anaphylaxis.  That’s why, time permitting, allergy tests are performed before the antivenin is injected.  Antivenins are not available for all snake poisons and they do not always work.

Joe Schwarcz

You Asked: Are foam puzzle mats toxic for children?

matsThere was a question about the possible toxicity of the popular foam puzzle mats that children play with and on. The concern is about exposure to formamide being released. This chemical is used in the manufacture of ethylene vinyl acetate (EVA) foamed plastics to make them more pliable. It’s a liquid, but like any liquid formamide does evaporate. There is no question that exposure to the liquid should be avoided; it is corrosive and has been linked to problems in a developing embryo. But the small amounts that outgas from foam present a totally different situation. The vapour dissipates quite quickly but nevertheless French and Belgian authorities deemed some levels unacceptable and established limits of formamide release from foams used in childrens’ play mats and toys. Studies, however, show that outgasing drops off very quickly and the amounts that could conceivably be inhaled by children playing on EVA foam mats are way below levels that could cause health issues. I certainly wouldn’t let my grandson play on an EVA mat, which he does quite often, if I thought there was any risk.


Joe Schwarcz

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