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YOU ASKED: Why do we refrigerate our eggs?

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The Secret World Inside Us

gut microbiomeRecently, there’s been an influx of media attention on guts. More specifically, the microbes that live in your gut. Extensive research is being done on these little guys as they seem to be having a real impact on our health. These gut microbes may be miniscule but their function is major. And I learnt all about them at “The Secret World Inside You” exhibit now on display at the American Museum of Natural History in New York.

Before I begin walking you through the exhibit, first a brief explanation as to what microbes even are. Microbes are microscopic living organisms that can only be seen with the help of a microscope. And they are everywhere – in every fold and lining of our bodies, including our inside. They literally govern the world inside us and are responsible for much of how we function.

Our skin is the first point of contact for microbes, which is most probably why it’s the first section you get to in this exhibit. There is not one individual whose microbiome is like that of another. However, what came as a real shocker was the fact that people living together – families, roommates, and yup, pets too –share certain microbe make-up. So much so, that when one person leaves the nest for a few days, the microbiome of the house shifts until they return home again. Pretty sweet, no? Everyone sharing the same types of microbes…(It could also be slightly gross if you think about it too much, so just don’t). It was also pointed out how certain microbes, as distant as they may seem, are actually closely linked. Let’s take cheese, for example. The holes in Swiss cheese are made from a bacterium that is similar to one located on the skin, which is why (some) feet take on a cheesy-like smell. On feet, the Brevibacterium linens bacteria converts amino acids into smelly sweat, but in the world of dairy, it serves to ripen Limburger cheese. Delicious? Depends.

Now perhaps it’s my age and the fact that my ovaries now twitch on a regular basis thanks to all the babies on my FB feed, but the next section of the exhibit was hands down my favourite. “Before Birth”, the world of the baby and the microbiome of the mama. Now one would think that the two are inextricably linked since the fetus is totally reliant upon the mother; however, to my surprise, the mother’s microbiome does not mix with the fetus at all. In fact, if the microbiome of the mother interacts at all with the fetus, it could be very risky. And it’s thanks to the placenta, the gatekeeper in this whole process, why the two don’t mix. After visiting this exhibit, I really developed a whole newfound respect for the placenta since it serves a pivotal function, allowing nutrients and oxygen to enter the amniotic sac and preventing any other materials from doing so.

Now once a woman’s water breaks all rules are off. The baby is now cooked enough to not only mingle with the microbes of its’ mother but to start developing a microbiome of their own. And the birth canal is where this all happens. When the baby travels through the canal, the mother’s microbes get pressed into the skin, nose and eyes, and even swallowed by the little one before being delivered to the baby’s gut where they can then start their own gut microbiome. This process is crucial in the development of a baby’s healthy immune and digestive system. (How awesome!) But you may be wondering (as was I), about those C-section deliveries since these babies do not go through the birth canal picking up the mother’s microbes along the way. Instead, these babies pick up microbes from the doctor’s hands and the environment. They end up lining the baby’s digestive tract and in turn have an impact on their immune system, causing C-section babies to be at a higher risk of a variety of conditions, such as asthma and allergies. To test this, studies are now being done where the baby, immediately post-C-section delivery is slathered with a gauze pad that soaked up the microbes in their mother’s birth canal right before birth. Time will tell whether this can benefit the baby but most signs point to yes, which is good news since about one mother in three now gives birth by C-section in the United States.

As life goes on, microbes live, grow and multiply based on what we feed them. Meaning, the food we eat and the choices we make influence our gut bacteria. This has spawned a huge new area of research looking at individual variation when it comes to weight gain and loss, which was another section of the exhibit that I found fascinating, since like the majority of people on the planet I have a few pounds that just won’t relent.

Different people react to different foods in different ways. This is not a novel idea. I mean, just look at allergies and adverse food reactions. Some people have them, some people don’t. But what if this can be attributed to the type of microbes living in your gut? Let’s take a “healthy” food like a tomato, for example. Could you imagine if someone’s blood sugar spiked after eating tomatoes the same way it would after eating a donut? And research has shown, that this is the case! And yet in another individual, tomatoes can have zero spike effect. This whole new line of research could be a breakthrough in terms of weight control. Costly, but important. I know I’d be among the first to sign up to find out just what type of bacteria I have going on in my gut. Of course, as the exhibit suggests, one cannot know whether obese people are obese due to their microbiome or if there are external factors that caused their microbiome to be as such in the first place. It’s the chicken or the egg debate and we shall leave it to science to continue the research.

After leaving the exhibit, I realized that the microbiome is truly a hotbed of scientific research. We know so much but at the same time there are so many question marks about how we can use, manipulate, and alter our microbiome to enhance our health. And I am confident that science will, at one point or another, provide us with these answers; but until then, I’m just going to hope that my gut bacteria interact favourably with tomatoes.

You can visit “The Secret World Inside You” exhibit at the American Natural History Museum in New York where it will be on display until August 2016.

Emily Shore

You Asked: Is there really a “dirty secret” about almonds?

Screen Shot 2015-03-30 at 11.35.07 AMAnytime you see an article that starts off with the heading “The Truth About….,” it’s a pretty safe bet that you will not get the truth. And so it is with an article circulating about almonds. “The Truth About Almonds: Almost No One Knows This Dirty Secret.” What is the “dirty secret?” That the almonds are treated with the fumigant propylene oxide to prevent contamination by salmonella bacteria. Salmonella infection is not pleasant to say the least. But people mostly associate it with contaminated eggs, not almonds. Where do the bacteria come from? Mostly fecal matter. Easy to see how eggs can be contaminated as they are laid. But almonds? Birds and insects can spread the bacterium after contacting fecal matter, but exposure may also be indirect through contaminated irrigation water. Salmonella bacteria can survive a long time even in dry conditions and dry heat treatment is not very effective at killing them. But fumigation with propylene oxide is. The nuts are placed in a chamber with liquid propylene oxide and the pressure is then reduced to allow quick evaporation of the liquid. The vapour destroys bacteria very effectively, preventing the possibility of food poisoning. There is no secret here. And nothing dirty is going on.

So what is the alarm all about? That propylene oxide is an animal carcinogen. That does not mean it is known to cause cancer in humans. And even if a substance is a human carcinogen, dosage still matters. While “carcinogen” is a frightening term, all it means is that the substance is capable of causing cancer in some animal at some dose. But there is a threshold effect. In rats no cancer can be found at any dose less than nine milligrams per kilogram of body weight, which has been established as the No Observed Adverse Effect Level (NOAEL). In other words at that dosage there is absolutely no problem detected.

Canada does not grow almonds so there has not been an application to allow the use of propylene oxide. This is not the same as it having been banned, as some alarmists claim. However, since Canada does import almonds that may have been treated with the chemical, the Pest Management Regulatory Agency has looked at the animal data and concluded that the maximum permissible residue is 300 parts per million. That is way below the NOAEL. And how much are almond eaters actually exposed to? The only way to know is to test for residues. That’s why the Canadian Food Inspection Agency tested over a thousand samples of spices, herbs, cocoa powder and nuts, including almonds. Guess what they found? No residue at all! So there is no reason to be concerned about propylene oxide in almonds because it isn’t there. And that is the truth.

Joe Schwarcz

You Asked: Are pasteurized cheeses safe to consume?

Screen Shot 2014-12-26 at 2.45.34 PMWhile selling raw milk in Canada is illegal, the sale of cheese made from unpasteurized milk is allowed as long as the cheese has been aged at 2 degrees C or above for at least 60 days. Studies have shown that if this procedure is followed, the added salt and acids produced by the added bacterial cultures prevent harmful listeria, salmonella and E. coli bacteria from growing. The risk that remains is very small but not zero. It is the soft and semi-soft cheeses that have a better chance of retaining problematic bacteria and this is where the issue gets more complicated because these cheeses reach their peak ripening point at 20-30 days. Quebec, contrary to the rest of Canada and most U.S. states, now allows soft cheeses like Brie and Camembert made from unpasteurized milk to be sold without the 60 day requirement, citing the European example where these cheeses have always been made from raw milk with no problem.

Still, to be on the safe side, it would be prudent to avoid raw milk cheeses during pregnancy, infancy or by people with compromised immune systems. But identification of cheeses made from unpasteurized milk is difficult since labeling is not required. Many artisan cheeses will voluntarily reveal that they are made from raw milk, hoping to capture the attention of foodies who believe that the taste is superior. Whether that is true is arguable. It is interesting that people who clamor for the labeling of any food that may somehow be linked to genetic modification are silent about asking for the labeling of raw milk cheeses.


Dr. Joe Schwarcz

Seeds of Hope

seeds of hopeWhy would anyone oppose a technology that dramatically increases crop yields and protects farmers from excessive exposure to pesticides? Because of irrational fears about the technology involved, which is of course genetic modification. A battle is now brewing in India and Bangladesh over the planting of eggplant that has been genetically modified to resist attack by insects. Eggplant is a staple in many dishes in India and Bangladesh but unfortunately the plant is susceptible to attack by the fruit and shoot borer and farmers have to spray to prevent infestation on a regular basis.

Most farmers are poor and are not well trained in pesticide use and put themselves at risk. But a gene from the soil bacterium Bacillus thuringiensis can be incorporated into the eggplant’s genome and the plant will then secrete a protein that kills insects but is harmless to humans. Activists have organized protests with people dressed up like giant eggplants carrying placards about Indians being lab rats and companies putting poison into the food supply. Their cause is championed by environmentalist Vandana Shiva who suggests that GMO means God Move Over. She also claims that with genetically modified seeds giant corporations are trying to control all of agriculture. In fact the genetically modified eggplant seed is being donated for free by Monsanto and farmers will be allowed to propagate Bt eggplant using seeds from plants they have grown without having to pay any royalties. It is estimated that the technology could raise yields by about a third through controlling pests and go a long way towards solving the malnutriton and hunger problems that plague India and Bangladesh.

Of course hunger isn’t limited to these countries. In Africa cassava is a staple crop for some 250 million people. But two viruses can ravage the crop. One destroys leaves, the other, called brown streak virus, destroys the roots, something that isn’t evident until harvest time. These viruses are transmitted by the whitefly whose range is expanding due to climate change. Researchers are working on developing genetically modified strains of cassava that are immune to the brown streak virus. Of course, nobody is suggesting that genetic modification is the only answer to the whitefly problem. Planting rows of Tithonia diversifolia, a wild sunflower that whiteflies prefer, can also draw these pests away from cassava. Modern farming technology should be based on using the best combination of practices and in many cases that means the appropriate use of genetically modified seeds. Why deter farmers from using methods based on sound facts by promoting mythical fears?


Joe Schwarcz

Dr Oz and phthalates

phthalateThe title of the segment on the Dr. Oz Show was “The Secret Ingredient Companies are Hiding in Your Food.” What could that be? Some opiate to keep you coming back for more? Tetrahydrocannabinol to increase appetite? No. The segment was all about chemicals called phthalates. And companies are not hiding their presence any more than they are “hiding” the presence of numerous substances that are not added to our food supply on purpose but can be detected through sophisticated analytical methods. These include pesticide residues, corrosion inhibitors, PCBs, detergents, chloroform, cadmium, radium, mercury, aflatoxins, bacteria and a host of others. Some of these are man-made, some occur naturally, but all are potentially toxic if present in a high enough dose. They end up in our food supply for the simple reason that if substances come into contact with each other, there will be a transfer of material from one to the other. If chloroform forms in water as a result of chlorination, which it does, some will be transferred to food that comes into contact with the water. Flourinated compounds used to produce grease-proof packaging can leave residues in food, aspergillus fungi can contaminate apple juice with their toxic metabolite patulin, wine may harbour residues of isinglass, a fish protein used to remove fine particles, and the potential carcinogen acrylamide forms when bread is baked.

None of these substances appears on food labels, not because there is some conspiracy to hide them, but because they are unavoidable. So it is with the phthalates. They do end up in our food supply because these chemicals have widespread applications. They lend flexibility conveyor belts, tubes used in milking machines and to plastic water pipes. They help the dispersal of pesticides, they’re found in caulking and in printing inks used on food packaging.

It’s no surprise to anyone familiar with chemical analysis that phthalates can be detected in our urine. Their presence, though, did come as a big surprise to the ten women Dr. Oz selected to have their urine analyzed for phthalates. None of the women had ever heard of phthalates before, which is quite surprising given the amount of publicity they have received. Their faces filled with panic when Oz revealed that they all tested positive for phthalates, chemicals that had been associated with endometriosis, weight gain, respiratory problems as well as brain and behaviour changes in children.

But here is the crux of the problem. Associations do not prove cause and effect. Just because women are more likely to suffer from endometriosis if they have higher levels of phthalates in their urine doesn’t mean that phthalates are the cause. Perhaps they have greater phthalate exposure because they eat more fatty foods like dairy and meat which are known to have higher amounts of phthalates. Perhaps they used more scented products most of which contain phthalates to inhibit the evaporation of the scent and they were somehow reacting to some of the numerous chemicals that make up scented products.

None of this is meant absolve phthalates from all blame because there are sufficient laboratory studies, animal experiments and human epidemiological data that suggest the need for further investigation. But there is no need for panic. There are numerous other substances that could be detected in our urine that could also be vilified in the same fashion as the phthalates. How many? At least 3,079 compounds can be detected, of which 2,282 come from diet, drugs, cosmetics or environmental exposure. Enough chemicals there for Dr. Oz to discuss and panic audiences for many years.


Joe Schwarcz

Antibiotics linked to childhood obesity

obesity & antibioticsA newly published study in JAMA Pediatrics indicates that children who had had four or more courses of antibiotics by age two were at a 10% higher risk of being obese by age five.  Researchers from the University of Pennsylvania and the Bloomberg School of Public Health examined the records of more than 64,500 children between 2011 and 2013. The children were followed until the age of five. In addition to show a link between antibiotic use and childhood obesity the study also indicated that the type of antibiotic also appeared to make a difference.  Children who were given repeated doses of broad spectrum antibiotics, that target a variety of microbes, were nearly twice as likely to become obese when compared to those who received the narrow spectrum varieties aimed at specific species. The researchers corrected their data to take into account variations in obesity risks associated with ethnic and socioeconomic factors. They also discounted the possibility that other medications given alongside antibiotics might be responsible for the weight gain.

The study confirms that the microbial gut population plays a role in obesity and that antibiotics can alter its composition to foster weight gains. A notion supported by animal studies carried out by Dr Blaser of New York University in New York  and published last August in the prestigious journal Cell. In one study three groups of mice were followed. One group was treated with low doses of penicillin in the womb. A second group received the same dose after weaning. The third did not receive any penicillin. Both groups that received penicillin showed an increase in fat mass when compared to mice not treated with antibiotic. The interesting feature though, was that the increase was higher in the group receiving penicillin stating in the womb. This suggests that mice are more prone to weight gain when receiving antibiotics early in life.

Another experiment was the carried out by determine if the weight gain was caused by the antibiotic or by altered bacterial population in the gut. Bacteria were transferred from penicillin treated mice to specially bred germ-free mice and antibiotic free mice. The researchers discovered that mice receiving bacteria from the antibiotic-treated donors became fatter than the germ-free mice inoculated with bacteria from untreated donors. This showed, according to the researchers, that the altered microbes are driving the obesity effects not the antibiotics.  It also contradicted the theory that antibiotics in farming causes weight gain in animals by reducing total microbial population and therefore the competition for nutrients.

It has been known for decades that over prescription of antibiotics could lead to the growth of resistant bacteria. Now here is another potential health effect to consider. It suggests that doctors should, as much as possible, reduce restrict their prescriptions of antibiotics in children and more specifically of the broad spectrum type.


Ariel Fenster

Flowers, bells, birds didn’t lift the plague from all their houses

quarantineBecause of the Ebola crisis, the word “quarantine” is appearing with increased frequency in news reports and daily conversations.

The term derives from “quaranta giorni,” meaning 40 days, and traces back to the 14th century when the city of Dubrovnik, now in Croatia, was under Venetian rule. The Great Pestilence, or the Great Plague, as it was known at the time, was devastating Europe. As a form of protection, Dubrovnik declared that all ships and people had to be isolated for 40 days before entering the city. Later, the disease would be referred to as the Black Death — probably because of the gloom it brought, although some theorize that the “black” referred to the terrible dark bruising of the skin due to internal bleeding, a hallmark of the disease.

Between 1345 and 1360, the plague wiped out roughly half of Europe’s population. The cause was unknown, but it was clear that the disease was contagious. Once it took hold, it spread like wildfire. In Milan, doctors advised that victims should be walled up in their homes along with healthy family members — a measure that apparently worked, since Milan had the lowest death rate from the plague in all of Italy.

It would not be until 1894 that Alexandre Yersin of France’s Pasteur Institute would identify a bacterium as the causative agent while investigating an outbreak of the plague in Hong Kong. The bacterium, eventually named Yersinia pestis in his honour, is thought to have originated in Asia, where it found a hospitable environment in fleas, which would readily transmit it through their bites. Since fleas infested rats and mice, rodents that were regular passengers on ships, the disease spread throughout the Mediterranean and Europe.

Infection with the bacterium can take several forms, with “bubonic plague” being the most notorious. This term originates from the Greek for “groin,” due to the characteristic swellings of the lymph glands particularly in the groin, an area close to the legs, where flea bites are most likely to occur. In “septicemic” and “pneumonic plague,” bacteria enter the bloodstream and can be transmitted from person to person, especially though the coughing associated with pneumonic plague.

When science fails to find an explanation for a phenomenon, superstition and quackery rush in to fill the void. And there certainly was no scientific explanation for the plague in the 14th century. The Church decreed that the Black Death was punishment for human sin. Lepers, because of their outward signs that resembled the plague, were blamed, as were astrological alignments and volcanic eruptions.

“Flagellants” believed God’s punishment could be avoided by stripping to the waist and whipping themselves as they marched from town to town. Jews were also targeted, accused of poisoning wells. Many Jewish communities in Europe were exterminated in hopes of bringing an end to the plague. In Cologne, thousands of Jews were burned alive after being accused of starting the plague. Black cats also became victims. They were thought to be witches in an animal form, casting their spell on the population. Since cats were a natural enemy of the disease-carrying rats, hunting them actually increased the spread of the plague.

As far as treatments went, there were none. Since the plague was often accompanied by a terrible smell, people walked around with flowers under their noses hoping to ward off the stench and the disease. This, of course, did nothing. Neither did the burning of aromatic woods to purify the atmosphere. Other attempts to remedy the “bad air” included the ringing of bells and the firing of guns. Birds were released indoors so that the flapping of their wings would break up the pestilence. Bathing was thought to be dangerous, as was the consumption of olive oil. And one of the most bizarre pieces of advice given to men was that if they valued their lives, they must preserve their chastity. Apparently no such advice was given to women.

The belief that pleasant smells were of some help persisted through the 17th century, when the Great Plague once again terrified Londoners. The classic children’s rhyme about a “pocketful of posies” dates back to that time. Posies were flowers, but as the lyrics indicate, they did not do much good against the “ring of rosies,” the rose-coloured rash in the form of a ring around flea bites. The outcome of the disease was clear: “Atishoo, atishoo, we all fall down.” And some 100,000 citizens of London did.

Holding garlic in the mouth, swishing vinegar or burning sulphur to get rid of the “bad air” did no good. Smoking was also thought to be protective, and even children were forced to smoke tobacco, with threats of being whipped if they didn’t.

Cases of the plague still occur today, but they are rare. The first effective treatment appeared in 1932 with the advent of the sulphonamide drugs, but today the standard treatment is in the form of such antibiotics as streptomycin, chloramphenicol, tetracycline and the fluoroquinolones.

Unfortunately, the possibility of using the bacterium as a form of biological warfare exists. Indeed, recognition of the contagious nature of the plague resulted in the first example of biological warfare in 1347, when in an attack on the Crimean city of Caffa, the Mongols catapulted the bodies of plague victims over the city walls. More recently, in 1940, a Japanese plane dropped a load of infected rat fleas over a Chinese town, causing a local plague. Today, stories circulate about various countries having developed strains of the bacterium that are resistant to all drugs as bacterial warfare agents.

But for now, our major worry is the Ebola virus, and quarantine is the most effective way to halt its spread. In this case, about 21 days after exposure to an infected person is sufficient, that being the incubation period for the disease. If no symptoms appear after this period, there is no worry about the infection being passed on. It appears that contagion occurs only when symptoms are present. But if quarantine isn’t instituted when appropriate, we may have to confront a scourge that will outdo the Black Death.

Joe Schwarcz

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