Health

Blame the Bagel

Chemical Institute of Canada — Tue, 07 Feb 2012 03:34:03 GMT

I’m grumpy now. Maybe it’s because I had a bagel for breakfast. Or maybe it’s because I just read an excerpt from a book that claims that eating a bagel can make one grumpy. The book is called “The Happiness Diet: A Nutritional Prescription for a Sharp Brain, Balanced Mood, and Lean, Energized Body.” What is that wondrous prescription? It seems simple enough. If you want to be happy, stay away from bagels, egg whites, sugary soft drinks, margarine, soy yogurt, fruit smoothies, canned soup, agave nectar and deli meats. Who says this? Dr. Drew Ramsey, a clinical professor of psychiatry at Columbia University in New York.

The idea that happiness is to be found in eating the right foods is a pretty appealing one. I’m game to try a happiness diet, but first, I say, show me the science. The evidence against bagels, according to Dr. Ramsey, is as follows: “At first bagels boost a person’s energy, but after a few hours you come crashing down looking for another fix in the modern American diet. That crash can cause people to feel irritable, lightheaded or sad.” Really? Has anyone ever studied such a bagel effect? Nope. But there are studies that show a low carbohydrate diet is associated with irritability, tension and depression. MIT researchers have found that carbohydrate intake is one of the factors that controls the brain’s production of serotonin, a chemical that plays an important role in the control of our mood. Starchy foods increase serotonin production, so one could argue that bagels can actually elevate mood. So where then does the idea that bagels wreak havoc with mood come from? Confusion about complex carbs such as found in bagels and simple sugars as in let’s say, doughnuts. A high intake of simple sugars can cause a quick release of insulin that prompts cells to absorb the sugar leaving low levels in the bloodstream. A drop in blood sugar can cause irritability in some people, although this is certainly not universal.

What about those egg whites? Well here, the problem isn’t what is in them but what is not. The yolk! The claim is that people who don’t eat the yolk because of a fear that the cholesterol it contains is poison for the heart are missing out on omega-3 fats, vitamin D, vitamin B12 and folate which “regulate mood by improving the health of brain cells and contribute to feeling more stable, energetic, and less blue.” Yes, it is true that these nutrients play a role in brain function. But you certainly do not have to rely on eggs to supply them. The omega-3 content of eggs is negligible, and as far as folate goes, an egg yolk has about 25 micrograms whereas a serving of broccoli has 300. But that is hardly the point.

The point is that diet is a very complicated business and foods are composed of a complex array of chemicals and a suggestion that ten specific foods can interfere with our happiness is enough to make one grumpy. Or maybe it’s just that I’ve been eating too much non-organic celery. Dr. Ramsey claims that 57 different pesticides have been found on celery and at “least 12 are neurotoxins, and anything that is toxic for the brain is toxic for a stable well-balanced mood.” Well 57 pesticides may be permissible but that doesn’t mean that they are present on every celery stick we eat. Very few actually are, and they are found in trace amounts. Maybe I should suggest to Dr. Ramsey that he investigate what Snow White fed to the seven dwarfs. Did she sneak some non-organic celery into Grumpy’s supper and keep Happy from eating bagels? Dr. Ramsey seems to enjoy dealing with fables.

Chaga-The Not-So-Magical Mushroom

Chemical Institute of Canada — Mon, 30 Jan 2012 03:32:30 GMT

If you wanted to find some “Chaga” mushroom you would tromp through a forest looking for a birch tree with an unusual growth on its trunk. Although it is classified as a mushroom, Chaga doesn’t look like one. Instead of having gills, this mushroom is permeated with numerous pores. Under pressure it crumbles readily, revealing a brownish inside with cream coloured veins.

Why would anyone seek out this ugly parasite that grows from a wound on the bark of a birch tree? Probably because of stories that circulate about the mushroom being prized for ages by natives in northern Asia, Europe and America for its medicinal powers. Folklore speaks of the Chaga mushroom treating virtually every known ailment ranging from intestinal worms and heart disease to diabetes and cancer. It has been around for 4000 years, the story goes, and has been alluringly referred to as “Nature’s Silver Bullet” and “Gift from God.” Largely ignored by the western world for hundreds of years, the tale continues, Chaga is now being recognized for its energy boosting, immune system improving, stress reducing, detoxifying and anti-cancer properties. And where are these revelations about the wonders of Chaga to be found? Mostly on web sites that sell an array of Chaga pills and extracts.

The marketing of Chaga follows a popular and effective formula. An obscure natural substance that virtually nobody has heard about is touted as a non-toxic answer to our health problems. On what basis? There are the usual personal testimonials, there’s reference to historical use and to studies that have shown some sort of biological activity in some sort of laboratory study. Of course, many mushrooms contain compounds that have biological activity. That doesn’t necessarily imply desirable activity. Amanita muscaria, for example, is highly toxic and psilocybe mushrooms can cause hallucinations. But certainly some fungi have been found to contain pharmacologically useful compounds. It may even be that Chaga has such. But before swallowing the idea that swallowing Chaga pills or extracts or teas is a good thing to do, we had better look at the evidence.

Anecdotes about arthritis symptoms improving after drinking Chaga tea, or eczema resolving, or sleep improving, or blood pressure dropping do not amount to scientific evidence. So what kind of scientific evidence exists? One study that is commonly quoted reports the effect of a Chaga mushroom extract on human white blood cells exposed to the oxidizing agent hydrogen peroxide in the laboratory. The cells treated with the extract showed a 40% reduction in DNA damage. This is often described as “promising anti-cancer activity.” That’s a big stretch. The reduction in DNA damage is an interesting observation, but is essentially meaningless. Such effects can be seen with virtually any fruit or vegetable extract that contains antioxidants. It doesn’t translate to anything meaningful in terms of ingestion of any Chagas preparation.

Laboratory studies have also shown that Chaga, like any other plant material, contains an array of triterpenes, sterols, beta-glucans, flavonoids, melanins, polyphenols, saponins, amino acids, vitamins, minerals and fiber. In some context all of these have biological activity, and with clever writing and selective reporting they can be made to look like miraculous ingredients. For example, one bit of supporting evidence offered for the use of Chaga extracts is that during the 1917 influenza epidemic, while the white population was dropping like flies, physicians noted that the Native American population was virtually unaffected. “After close inspection, these physicians attributed the herbs that the Indians were ingesting to their heightened immunity.” First, there is no evidence that natives were specially protected, and even if they were, it cannot be concluded that it was because of any natural products they were taking, and there is certainly no evidence that they were indulging in any Chaga preparations.

The bottom line is that there is no evidence that ingesting any form of Chaga is beneficial. There are no placebo-controlled randomized trials of Chaga pills or extracts. Pills are available, but as with any such product there is no standardization, there is no way to tell what the pills really contain. As far as Chaga teas go, there are numerous recipes that undoubtedly result in different compositions of the final product. It is certainly possible that future research will show that some standardized preparation of Chaga, or a specific dose of a compound found in Chaga, has a therapeutic effect. But so far nothing like that has been shown.

I know that anytime I make such comments I am barraged with emails claiming that evidence for Chaga benefits is being suppressed by Big Pharma in order to protect its interests. I am also treated to a plethora of anecdotal accounts of pain disappearing, stomach problems resolving, waning energy being restored and skin taking on a youthful appearance.

The only truly documented evidence I’ve been able to come up with refers to the combustibility of the fungus. Chaga is sometimes justifiably referred to as a “tinder fungus.” That’s because its porous nature gives it a very large surface are and makes it very easy to light. It seems to be just the right substance with which to start a fire. A useful thing to know for people interested in wilderness survival. Unfortunately its use in disease survival is a different matter.

Parabens and Breast Cancer

Chemical Institute of Canada — Fri, 20 Jan 2012 03:04:57 GMT

Sometimes researchers remain stubbornly wedded to their ideas even when their own work begins to unravel the fabric they have woven. I believe such is the case with Dr. Phillipa Darbre of the University of Reading in England. Back in 2004 Darbre achieved tabloid fame with her allegation that antiperspirants were implicated in breast cancer because they accosted breast tissue with preservatives known as parabens. These compounds have estrogenic properties and estrogens have indeed been implicated as significant players in breast cancer.

Darbre showed the presence of parabens in cancerous tissue taken from breast cancer patients and suggested a cause and effect relationship, buttressing her argument by pointing out that most breast cancers occur in the quadrant of the breast closest the armpit where shaving nicks would allow entry of antiperspirants most readily. The study was small, only some twenty patients, and she had no controls. She had no idea whether parabens were also present in the breast of healthy women. Furthermore, she never determined if her subjects had actually used antiperspirants. The study was castigated by many breast cancer researchers with suggestions that even a high school science fair participant would recognize the need for controls. They pointed out that breast tumours have long been known to occur more frequently in the top quadrant of the breast closest the armpit simply because that area has the highest concentration of tissue.

Stung by the accusations, Darbre has cranked out a series of papers demonstrating the estrogenic effects of parabens and measuring their concentration in various tissues. Her latest paper, published in the Journal of Applied Toxicology, not one of the world’s most impactive journals, furthers her attempts to forge a link between these chemicals and breast cancer. This time she has investigated more patients, 40 of them, and took 160 samples, analyzing them for different parabens. She did not study any samples from healthy women, in other words, still no controls. She did, however, compare parabens concentrations in tumour areas and elsewhere.

There was no relationship between amount of parabens detected and tumour location, an observation that runs contrary to parabens playing a decisive role. This time she did determine whether the patients had used antiperspirants and as it turns out seven out of the forty had not. So the parabens were coming from elsewhere; no great surprise here because these chemicals are widely used in a variety of cosmetics and foods. Darbre clearly states that the presence of a chemical in breast cannot be taken to imply causality, which of course is true. But she then goes on to discuss all sorts of reasons why her negative results do not rule out this possibility. For example, she says, absolute levels of parabens may not be the main determinant of risk because of variations in individual susceptibility. Small amounts may trigger it in some people, not in others, so there may be no correlation. An attempt to rationalize her preconceived notions. And what about the possibility that parabens play no role at all? Has she considered that? But a seductive hypothesis with which one has become identified is rarely given up even when confronted by cruel facts.

Oscillococcinum and Carey Price

Chemical Institute of Canada — Tue, 27 Dec 2011 21:02:40 GMT

I like Carey Price. He’s become the heart of the Montreal Canadiens. Carey is an excellent goaltender with a lot of gumption. But something he doesn’t have is a scientific background. That of course is par for the course for most athletes. But Carey is now set to become the spokesperson for Oscillococcinum, a homeopathic product that claims to treat the common cold as well as the flu. Don’t do it Carey! This is not a valid claim and homeopathy, simply put, is bunk. Let me provide something to back up my claim. Something that homeopaths are not familiar with. It’s called “evidence.”

Let’s start by making some Oscillococcinum. Take the carcass of a duck and place 35 grams of its liver and 15 grams of its heart in a one liter bottle filled with a solution of pancreatic juice and glucose. Wait forty days until the liver and heart have disintegrated and then dilute the solution to 100 liters. Then take one liter of this solution and dilute it again to 100 liters. Repeat this dilution process another 199 times, shaking the solution in a specific fashion each time. Then take a small pellet of milk sugar and moisten it with the resulting solution. Package the pellets in a box labeled as “Oscillococcinum” and market it to consumers who wish to prevent or treat the flu homeopathically.

First of all, let’s understand what homeopathy is. Unlike what many believe, it is not the generalized treatment of disease with natural substances. Homeopathy was the brain child of Samuel Hahnemann (1775-1843), a German physician who introduced the idea that “like cures like.” A substance that causes symptoms of illness in a healthy person, he maintained, will cure a sick person who suffers from the same symptoms. But to affect the cure, Hahnemann argued, the substance has to be repeatedly diluted and thumped against a leather pillow after each dilution. The greater the dilution, the more powerful the remedy! (Hmmm…can you die from an overdose if you forget to take the remedy? Just a thought).

An extreme dilution of an extract of cantharide beetles, for example, was to be an effective treatment for urinary tract infections because a concentrated extract caused a burning sensation in the urethra. Hahnemann carried out numerous such “provings” on his family and friends and came up with a “Materia Medica,” or compendium of homeopathic substances to use in the treatment of disease. But he did not come up with Oscillococcinum. That invention came from Dr. Joseph Roy, a French physician who served in the French army during World War I.

It was during that war that the Spanish flu took the world by storm, eventually killing about thirty million people, 50,000 or so in Canada. Roy naturally took a great interest in the flu and sought to solve its mysterious cause by examining the blood of victims under the microscope. He described seeing tiny microbes that darted or “oscillated” quickly back and forth. He named these “oscillococci” and claimed that they were also to be found in the blood of patients suffering from diseases as diverse as cancer, tuberculosis and gonorrhea. This “universal germ” as he called it, was responsible for many illnesses! If these oscillococci were causing the symptoms of disease, Roy concluded, then a homeopathic solution of the same should be curative.

Actually, this doesn’t even make sense within the tenets of homeopathy which would require a demonstration that oscillococci can cause symptoms in a healthy person. No such effect has ever been shown, which comes as no surprise given that nobody else has ever seen Roy’s oscillococci. To this day we do not know what Roy actually saw through his primitive microscope, but whatever it was, he also observed it in the liver of the muscovy duck. Appropriately diluted, Roy therefore claimed, this duck liver would work against cancer, syphilis, scabies and of course the flu. The other claims have fallen by the wayside, but homeopaths still believe that Oscillococcinum can treat the flu. They have been energized by the finding of viruses in birds, including ducks, which they suggest buttresses the “like cures like” argument, an argument that most scientists find is totally baseless.

Hahnemann was not bothered by the fact that after about 12 of his specified dilutions there was not a single molecule of the original substance remaining, because he knew nothing about molecules. Today, homeopaths have to recognize this fact and explain that the dilutions and shaking leave some sort of imprint on the structure of the water used to carry out the dilutions, and that this altered water somehow drives the disease out of the patient. But in any case, why should a molecular imprint have any curative properties? And exactly what is being imprinted? The duck heart and liver contain thousands of different molecules. The imprint of which one cures the flu? And why don’t all the other molecules that the water has come into contact with leave an imprint? After all the water used to make the remedy has been through sewers and other peoples’ bodies at one time or another. Why do these not leave an imprint?

Mainstream scientists of course find the notions of increased potency with dilution and associated changes in the structure of water all but impossible to accept and take a very skeptical view of homeopathy. But an implausible mechanism for homeopathy does not mean the practice can be dismissed as ineffective. Perhaps homeopathy operates through some modality that science has not yet discovered. Most unlikely to be sure, but not impossible. The true measure of any medical intervention is whether it can be shown to be effective through controlled trials.

Homeopathy has been with us for over two hundred years and has indeed been subjected to a large number of controlled trials. Researchers at the University of Bristol, led by Dr. Peter Juni, decided once and for all to assemble the results of these trials and determine the efficacy of homeopathy. They searched through the scientific literature and found 110 proper placebo-controlled studies. Their overall conclusion? “We found an effect for homeopathic therapy which is compatible with a placebo effect.”

What about the effect of Oscillococcinum specifically? That too has been examined. Dr. A. J. Vickers of the Memorial Sloan-Kettering Cancer Center in New York looked at the seven studies of Oscillococcinum listed on PubMed, the website which compiles peer-reviewed scientific publications. His conclusion? “Current evidence does not support a preventative effect of Oscillococcinum-like homeopathic medicines in influenza and influenza-like syndromes.” He did, however, find that Oscillococcinum increased the chance of a patient considering the treatment to be effective. We are talking about the good old placebo effect. I hope Carey Price gets to read this. And perhaps it will convince him to stop spreading unscientific myths and get back to something he does really well, stopping pucks.

The Crooked House

Chemical Institute of Canada — Sun, 27 Nov 2011 02:02:56 GMT

Agatha Christie's "The Crooked House" is a great story. The plot revolves around an elderly tycoon who requires daily insulin shots. He also suffers from glaucoma for which he has been prescribed eyedrops. Everything is fine until someone in the "Crooked House" switches the eyedrops with the insulin. Murder most foul!

Does the chemistry make sense? Let's do a little detective work of our own. As clearly stated in the novel, the eyedrops contain physostigmine, a substance introduced in the late 1800's for the treatment of excess pressure in the eyeball, a symptom characteristic of glaucoma. Physostigmine, or "eserine" as it is also known, opens up the tiny ducts through which excess fluid is normally expelled from the eye. Could this drug really be lethal if injected into the bloodstream?

Physostigmine has a long and interesting history. It is the active ingredient in the "ordeal" bean, found in the Calabar region of Nigeria. Why the term "ordeal" bean? Because it was traditionally used by certain tribes as a test of guilt. Someone suspected of having committed a crime was forced to swallow a handful of beans. If he died, he was guilty. Unfortunately, he probably died even if he wasn't guilty. Physostigmine is known to enhance the activity of acetylcholine, a chemical essential for the proper functioning of our nervous system. It does this by inactivating an enzyme called cholinesterase which normally degrades acetylcholine after it has done its job. The result is a buildup of acetylcholine which can lead to paralysis of the respiratory muscles and death. Maybe if the accused were really confident of his innocence, he would eat the beans quickly, vomit and survive!

By the late 1800's, physostigmine had been isolated from the Calabar bean and was widely used in the form of eyedrops for the treatment of glaucoma. The amount needed on a daily basis was very little, but there certainly would have been enough active ingredient in a bottle to kill if directly injected with a syringe. Had a physician arrived soon enough, the effects probably could have been reversed. Atropine, found in the belladonna plant, can block the receptor sites on nerve cells which are normally activated by acetylcholine. This antidote was routinely carried by the doctors of the day, not necessarily to deal with phytostigmine poisoning, but because atropine is a potent heart stimulant. But if the victim had lived, there would have been no murder, and no story. Who needs a story though, when real life poisonings may be stranger than fiction!

Formaldehyde in Baby Shampoo-Crunch the Numbers, Crunch the Scare

Chemical Institute of Canada — Mon, 14 Nov 2011 02:12:54 GMT

It is a very small molehill. But to the folks at the Campaign for Safe Cosmetics (CSC) it seems more like Mount Everest. This organization’s recently released report features a cute baby smothered in lather, sitting in a bathtub under the headline “Baby’s Tub Is Still Toxic.” What is this all about? Acrylic monomers leaching out of the tub? Lead in the water? Chemicals out gassing from the shower curtain? Reactions to mould on the grout? Nope. The warning is about the trace amounts of formaldehyde or formaldehyde-releasing compounds added to some baby shampoos to prevent bacterial contamination.

Reading this report may send any mother who has used a baby shampoo preserved with formaldehyde into a state of panic, fearing they may have doomed their offspring by exposing them to a “known carcinogen.” Well, let’s throw in a little science before we throw out the baby shampoo. Yes, formaldehyde is a likely carcinogen. But that categorization was made on the basis of inhaling the chemical in significant amounts under occupational exposure. Embalmers and pathologists have indeed experienced a slight increase in cancer rates attributed to formaldehyde, mostly of the nasal cavity. However, data indicate that no tumours have been found when occupational exposure was below 2.4 mg of formaldehyde per cubic meter of air.

Now let’s crunch a few numbers. A shampoo preserved with a formaldehyde-releasing agent such as “quaternium-15” has a formaldehyde yielding potential of 0.4 mg per gram. And let’s say that about 10 grams of shampoo, a rather generous amount, are used to wash baby’s hair. So we have the possibility of releasing 4 mg of formaldehyde into the air. But wait! Formaldehyde is very soluble in water, so very little will evaporate. But let’s really play it safe and assume that half, or 2 mg, will evaporate. Now, assuming that the volume of air in a bathroom is about 10 cubic meters, and that there is zero ventilation, the concentration of formaldehyde will be 0.2 mg per cubic meter, or one tenth the amount that has never caused a tumour even with continuous exposure! Of course, here we are not talking about continuous exposure. Nobody bathes a baby for eight hours a day. Therefore any suggestion that formaldehyde in shampoo presents a cancer risk is unfounded. Actually, mommy’s breath may be a greater risk. Formaldehyde is a product of human metabolism and breath can contain concentrations of formaldehyde at 0.4 mg per cubic meter. Maybe the greatest benefit of fear mongering about formaldehyde in shampoo is to make mommy breathless.

While inhalation of formaldehyde from shampoo is a non-issue, problems due to skin exposure cannot be so readily dismissed. Formaldehyde is a known allergen and can trigger rashes and inflammation, but these effects are also dose dependent. Skin sensitization can occur when the concentration in a solution is above 0.2%. And how much is present in baby shampoo? If all the formaldehyde were instantly released from quaternium 15, the concentration in baby shampoo would be 0.04%. But quaternium-15 is a slow releaser, so the effective concentration is far less than that. There may be some babies that react to these remarkably small amounts, but far fewer than would react to the bacterial contaminants in a poorly preserved product.

As can be seen, once appropriate calculations are made, the clamor to remove formaldehyde as a preservative from baby shampoos amounts to no more than unscientific noise. But as far as marketing goes, the public is right even when it is wrong, and manufacturers are working towards using alternate preservatives such as benzyl alcohol, potassium sorbate, sodium benzoate or methylisothiazolinone. Of course one can dredge the scientific literature and come up with risks for these as well. Dig deep enough and at some dose you can find some sort of risk with any chemical.

Furthermore, if we want to eliminate all risks from formaldehyde, we’ll have to get rid of particleboard, permanent-press fabrics, varnishes, paints, carpeting, curtains, nail polish as well as many types of insulation and paper products, all of which are manufactured with formaldehyde and can out gas the compound. In some cases, as with the notorious trailers that were supplied to victims of the Katarina disaster, out gassing can be enough to cause severe eye irritation and respiratory symptoms. To curb formaldehyde exposure we would also have to forget about fireplaces, gas cookers, driving cars and of course, smoking. Even then we would be ingesting some formaldehyde because it occurs naturally in virtually all foods.

When it comes to the use of products for the hair, there is one area where formaldehyde poses a real concern. Some of the “Brazilian” hair smoothing products contain sufficient formaldehyde to pose an occupational hazard to hair dressers. Here the chemical is not used as a preservative, it is one of the active ingredients needed to form links between protein molecules in hair. And unfortunately the presence of formaldehyde in these products can be hidden by using alternate names for the chemical on the label. Methylene glycol, methanal, oxomethane and formalin are some of these. Often these products declare themselves to be “formaldehyde-free.” You certainly wouldn’t want a baby lying all day in a hair dressing salon where such products are used to “smoothen” hair. But washing baby’s hair with baby shampoo, any kind of baby shampoo, is a completely different story. So let’s get formaldehyde out of Brazilian hair products but let’s not throw out the baby with the bath water. Trace amounts of formaldehyde in shampoos prevent bacterial contamination, a significant problem, at minimal risk.

If you want to worry about a real risk in the tub, consider that about 150 children in North America, the majority under four years old, end up in emergency rooms mostly because of tub falls, many of which could be prevented with the use of a vinyl mat. Now that really matters! But I suspect that the folks behind the Campaign for Safe Cosmetics might then make an issue of the phthalate plasticizers that leach out of the mat.

Rat Scan

Chemical Institute of Canada — Wed, 02 Nov 2011 03:21:00 GMT

The dog has been called man’s best friend. But rats certainly have never been referred to in that endearing fashion. Yet, they can save lives as well as dogs; maybe even better. How? By using their remarkable sense of smell. Dogs of course have a great sense of smell. A lady’s dog saved her life a couple of years ago by constantly sniffing at a mole on her leg which turned out to be a malignant melanoma. It seems that unusual protein synthesis as happens in such tumors is accompanied by unique odors. Indeed, the fact that diseases have certain smells has long been known. The ancient Chinese supposedly diagnosed some diseases by sniffing a patient’s saliva as it was dropped into a flame. But the human nose isn’t nearly as reliable as that of a rat.

Bart Weetjens, a Belgian researcher working in Tanzania came up with an interesting idea triggered by the Dutch word for tuberculosis, “tering.” It translates as “the smell of tar,” apparently because tuberculosis patients exude a tar-like scent. Weetjens wondered whether it might be possible to diagnose the disease in its incipient stage, when the human nose would pick up nothing, but a more sensitive one might. This would be of tremendous potential benefit because some two and a half million people a year die from TB, mostly in the developing countries. With early detection the disease is curable. But early detection is very difficult, in fact it takes experts looking through a microscope at sputum smears taken over several days to confirm the presence of disease. Weetjens was familiar with some work using rats to sniff out landmines. The rodents were trained by rewarding them with food at the appropriate time to sniff out explosives. In Mozambique a dozen rats successfully sniffed out twenty land mines. And no, the rats didn’t blow up.

So if they could sniff out explosives, why not TB? Saliva from tuberculosis patients was put in little dishes and when the rats approached the samples they were reward with peanuts and bananas which are rat delicacies. They learned well. When tested with 10,000 saliva samples, the trained rodents sniffed out the ones infected with the tuberculosis bacterium 77% of the time. They did even better when confronted by bacteria grown in culture dishes. They got these right over 90% of the time.

I don’t think your doctor is going to reach into his drawer to take out a couple of rats on your next office visit. Tuberculosis is not a widespread problem here. But in sub-Saharan Africa or in Southeast Asia, rats just may be the way to go. And who knows? Eventually they may even be trained to sniff out other diseases. Cat scans have proven themselves, so why should we be surprised by a rat scan?

Taking a Look At Randomized Controlled Trials and Observational Studies

Chemical Institute of Canada — Wed, 19 Oct 2011 02:45:49 GMT

Your grandmother, if you were lucky enough to have one, probably told you to eat your fruits and veggies. And now it seems that those grandmothers who meddled with our dietary habits and urged kids to eat their peas and carrots were bang on. Grandmas have been joined by a plethora of scientists who tell us that we should be eating anywhere between five and ten servings of fruits and vegetables a day. Grandmothers went by instinct, but science progresses through studies. So what evidence do the scientists have for providing their advice?

The strongest evidence would come from randomized, controlled trials in which two groups of people are followed for years with one group being subjected to some sort of intervention. In this case, one group would eat a limited amount of fruits and vegetables, the other would consume the recommended amount. All other lifestyle factors such as exercise, smoking, total calorie intake, exposure to pollutants and medications would have to be the same. Ideally the average age of the two groups would be the same and they would be drawn from the same socio-economic background. Such studies are expensive and very difficult to organize and none for fruit and vegetable intake have been carried out.

The closest is the study that compared the DASH diet (Dietary Approaches to Stop Hypertension) to a typical North American diet. The DASH diet featured more fruits and vegetables but it was also lower in refined carbohydrates, higher in fiber, higher in low fat dairy products, nuts and poultry at the expense of red meat. Blood pressure decreased with the DASH diet but fruits and vegetables were not the only distinguishing difference. So for the overall benefits of fruits and vegetables we are left with “observational studies.” These fall into two categories: case-control or cohort studies. In either case there is no intervention by the researchers, they just observe a group of subjects and note their exposure to some factor of interest and record disease outcomes.

In a case-control study subjects with a certain disease are compared to a group that is matched in every way except for the presence of the disease in question. A classic example is smoking. When groups of lung cancer patients were compared to healthy people, it became clear that the cancer patients were much more likely to be smokers. Cohort studies furthered this link. In these studies, groups of smokers and groups of non-smokers were recruited and were followed for years. The smokers were more likely to develop lung cancer.

Another type of cohort study involves following a large group of subjects for many years, evaluating their lifestyles usually through elaborate questionnaires, and recording cases of disease. A classic example is the Nurses Health Study that began in 1976 by recruiting over 120,000 registered nurses. Some interesting findings have emerged in terms of diet. For example, higher intake of red meat was associated with an increased the risk of premenopausal breast cancer. A Mediterranean type of diet with vegetables, nuts and fish reduced the risk of heart disease and stroke, a high intake of green leafy vegetables reduced the risk of cognitive impairment, and high intakes of folate, vitamin B6, calcium and vitamin D reduced the risk of colon cancer. Numerous other case-control and cohort studies have shown an association between increased fruit and vegetable intake and reduced risk of various diseases.

One can always argue that an observational association can never prove cause and effect, that only a randomized controlled trial can do that. But in this case we have such an overwhelming number of observational studies that show the benefits of fruit and vegetable intake that it would be a waste of energy and money to organize randomized trials. Grandmas were right. Eat those fruits and veggies.

A Tiff with the Physicians Committee for Responsible Medicine

Chemical Institute of Canada — Thu, 22 Sep 2011 02:39:00 GMT

Recently I wrote a column on hot dogs that are advertised as having no synthetic preservatives. The reference is to nitrites that are used to prevent botulism. I pointed out that these “natural” hot dogs actually use celery juice as a preservative because of its high nitrite content. The fact is that whether nitrite comes from a lab or a plant is irrelevant. In the column I also objected to a billboard funded by the Physicians Committee for Responsible Medicine that equated eating hot dogs to smoking cigarettes. My comments elicited a letter to the editor from Susan Levin, M.S., R.D., director of nutrition education at the Physicians Committee for Responsible Medicine. This organization identifies itself as a “Washington, D.C.-based nonprofit organization dedicated to promoting preventive medicine, especially better nutrition, and higher standards in research.” I disagree with that description. I consider PCRM to be a fanatical animal rights group with a clear cut agenda of promoting a vegan lifestyle and eliminating all animal experimentation. Her letter is reproduced below, followed by my response to Ms. Levin.

Susan Levin’s letter to the editor:

“As a dietitian with the non-profit organization that put up the Indianapolis billboard that writer Joe Schwarcz refers to, highlighting the link between hot dogs and colorectal cancer, I want to set the record straight about our public education efforts.

Contrary to Schwarcz's insinuations, our billboard is based on a recent landmark report from the American Institute for Cancer Research and the World Cancer Research Fund.

After reviewing all existing data on nutrition and cancer risk, including more than 58 published studies, nine teams of scientists from around the world concluded in 2007 that processed meats increase one's risk of colorectal cancer, on average, by 21 per cent for every 50 grams of processed meat consumed daily. That's about the size of a typical hot dog. Just this year, the same prestigious organizations updated that report - the most comprehensive ever conducted on colorectalcancer risk. Scientists concluded that 45 per cent of all colorectal-cancer cases could be prevented if we ate more plant foods and less meat and made other lifestyle changes. Based on these findings, the report suggests that people completely cut processed meats out of their diets.

More than 400 Canadians a week are diagnosed with colorectal cancer, according to the Colorectal Cancer Association of Canada. Avoiding hot dogs, bacon, pepperoni and other processed meats could help reduce that tragic toll.”

My response to Ms. Levin follows. (You’ll note that I make reference to Bastyr University, her alma mater. This is not exactly Harvard. Bastyr is a school of naturopathy that teaches homeopathy, reiki, and various other “alternative” modalities.)

“I would like to offer a few comments pertaining to your letter. First, let me mention that I have been following PCRM since its inception and am very familiar with its agenda and antics. I probably know more about the organization than you do, so please spare me arguments about it being science-based and a champion for public health. We both know what the actual agenda is.

Second, if you read any of my books, especially my “An Apple A Day,” or “Foods That Harm, Foods That Heal,” although I suspect they are not on the reading list at Bastyr University, you’ll know that I am very much an advocate of a plant based diet, but I see no problem with moderate meat consumption. I have no argument against a vegan diet, but I do not think it is necessary, and neither does the evidence suggest that it is. I have an issue with any kind of extremism, and PCRM is certainly an extremist organization. And I consider the billboard I referred to, the one that equates hot dogs to cigarettes not only to be extreme, but scientifically unsupportable.

I agree that there is sufficient evidence to suggest a link between cured meat consumption and colorectal cancer, although the association is weak, with an RR (relative risk) consistently less than 2. Indeed the most recent analysis, a review in the European Journal of Cancer Prevention, concludes that "currently available epidemiological evidence is not sufficient to support a clear and unequivocal independent positive association between processed meat consumption and colorectal cancer."

But let’s take the WCRF (World Cancer Research Fund) data, in spite of the weakness inherent in any such observational studies, and accept the 20% increase in risk with a hot dog a day. Since the colorectal cancer risk is about 7%, a 20% increase would mean roughly one extra case per one hundred people who eat a hot dog or its equivalent every day. And not many eat a hot dog every day. Anyway, I certainly do not push hot dogs, and as I clearly stated in my column, cured meats should be limited, but comparison to cigarettes is totally unjustified. The increase in cancer risk by smoking is 2000%! Alcohol is a greater risk in colorectal cancer than cured meats.

My main complaint against PCRM is that it masquerades as a just scientific body. Cherry-picking data, a common PCRM practice, does not mesh with the scientific method. Should a study come out demonstrating some benefit from consuming dairy products, or absolving meat of some accusation, would PCRM publish that on its website? We both know the answer to that question. That’s the difference between an operation like yours and my Office. We go where the data lead, we don’t lead the data. Having a preconceived agenda leads down a treacherous road. You might want to take a look in the closet of the organization that you are working for. You’ll find more than the occasional skeleton. Extremism in the pursuit of an agenda is almost always a vice, while moderation is a virtue. That is true even when the agenda has some valid points.”

Cranberries and Urinary Tract Infections

Chemical Institute of Canada — Mon, 12 Sep 2011 15:48:32 GMT

Mention cranberry juice and “urinary tract infection” springs to mind. Most women and many men are familiar with the frequent urination and accompanying burning sensation that signals a bacterial invasion of the urinary tract. Today antibiotics solve the problem, but what did people do before? “Flushing the system” seemed a logical approach. All sorts of beverages were tried, but by the mid-1800s books on folkloric medicine were suggesting the use of cranberry juice. Based on anecdotal evidence, the juice developed a solid reputation for treating and preventing urinary tract infections.

Once bacteria had been identified as the cause of UTIs, scientists began to explore possible mechanisms by which cranberry juice could offer relief. Acidifying the urine to make it more inhospitable to bacteria was a possibility, as was the antibacterial action of hippuric acid, a component of cranberries. But trying to explain how cranberry juice worked before clearly demonstrating that it did was putting the cart before the horse. Finally, in 1994, Harvard researchers decided to mount a proper clinical study of the claims. They enrolled 153 older women, half of whom were given 10 ounces (285 millilitres) of cranberry juice every day, while the other half were given a look-alike drink containing no cranberry. The women who drank cranberry juice were 58 percent less likely to have levels of bacteria in their urine that would be expected to cause infections. As we would eventually learn, the effect was not due to acidity of the urine, nor to the antibacterial effect of hippuric acid. It had to do with compounds that prevented bacteria from adhering to the lining of the urinary tract.

Bacteria produce adhesives that enable them to stick to tissues so they can pick up nutrients more readily. These molecules fit into specific receptor sites on the epithelial cells that line the urinary tract. As was cleverly shown by Yale University researchers in 1994, compounds in cranberries block these receptors. Urine samples were collected from volunteers who were then given four ounces (115 millilitres) of cranberry juice to drink. Four to six hours later urine was again collected and incubated with E. coli bacteria, the kind that normally are responsible for urinary tract infections. The experiment was then repeated with eight ounces (230 millilitres) of juice. Separately, the scientists cultured cells taken from the lining of the human bladder and then mixed them with the urine samples. Lo and behold, the bacteria did not stick as effectively to the cells when the urine samples came from women who had consumed cranberry juice! Furthermore, the more juice consumed, the less the bacteria adhered to the cells.

Although the specific ingredients in the juice responsible for this effect have not been conclusively identified, speculation is that substances known as trimeric procyanidins may be responsible. Unfortunately, however, not every study has shown that cranberry juice acts favourably on UTIs. In some it worked no better than placebo. And there’s no question that in women with a history of UTIs, antibiotics (trimethoprim-sulfamethoxazole) prevent recurrence far better than cranberry juice. But of course with antibiotics there is the problem of resistance.

These procyanidins may do more than prevent urinary tract problems. Most ulcers are caused by infection with the Helicobacter pylori bacterium. Well, it seems that the procyanidins may also prevent these bacteria from infecting the stomach. Researchers in China chose a population with a high rate of Helicobacter infection, and in a placebo-controlled double-blind study, gave 97 people 500 millilitres (just over two cups) of cranberry juice for 90 days, while 92 others got a placebo. They found that H. pylori was eradicated in 14 people in the cranberry group but in only five in the placebo group. Not an earth-shaking difference, but significant nevertheless, especially given the resistance issues we are now encountering with antibiotics.