« Older Entries

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.

Read more

Fish and Brain Health

brain foodIs fish really brain food? P.G. Wodehouse certainly thought so. In his wonderful “Jeeves” stories, Bertie Wooster encourages his brainy butler to eat more fish whenever a particularly challenging problem arises. But to what extent does fiction mirror real life? One can make a theoretical case for fish consumption based on the fact that docosahexaenoic acid, or DHA, the famous omega-3 fat in fish, is the main component of brain cell membranes, and that communication between brain cells is a function of the integrity of these membranes.

There is actually some experimental evidence to support a link between fish consumption and brain health. Infants born to mothers who consumed more fish during pregnancy have been shown to have improved verbal intelligence, better fine motor skills and pro-social behavior. A study has also correlated fish intake during pregnancy with IQ in 8-year old children. It is likely that these effects are due to increased blood levels of DHA in the offspring, but as is generally the case, the scenario is complicated. When blood is drawn from umbilical cords, it turns out that the concentration of the various fatty acids depends on the genetics both of the mother and the baby. In other words, depending on genotypes, an infant may benefit more or less from fish in the mom’s diet.

What about brain function at the other extreme of life, senior citizens? To get some insight here, researchers examined MRI brain scans of 260 individuals over the age of 65 who had normal cognitive function looking for differences associated with fish consumption as determined by dietary surveys. Subjects who ate baked or broiled but not fried fish every week had larger grey matter volumes in the areas of the brain responsible for memory and cognition. Interesting, but there was no determination as to whether these increased volumes translated to any change in brain power.

Curiously, no relationship was found with omega-3 fat intake as calculated from the diet surveys, suggesting that eating fish weekly may prevent brain ageing regardless of omega-3 content. But it may also be that eating fish is a marker for some other effect. People who ate fish were more likely to have a university education than those who didn’t. So perhaps it is mental exercise that was responsible for the changes in brain volume. There is also evidence that eating fish reduces the risk of heart disease. Maybe eating fish makes people smarter and more capable of understanding why they should be following the guidelines designed to reduce the risk of heart disease.

Read more

Tempest in a K cup

K cupsA question came up about the risks of chemicals leaching out of those convenient coffee K cups. Yes, chemicals do leach out. That of course is the idea, you want to leach out the hundreds of compounds that contribute to coffee flavour and aroma and you also want a good shot of the stimulant caffeine. However, the likely reason for the question was concern about chemicals leaching out from the plastic. Yes, that happens too.

Anytime two surfaces come into contact, especially if one is a liquid, there will be transfer of chemicals. I don’t know exactly what plastic is used in these cups since the company maintains that this is proprietary information. By its texture, it seems the plastic is either polystyrene or polypropylene. It certainly is not polycarbonate which would be a source of bisphenol A (BPA). Traces of styrene, the compound from which polystyrene is made, may leach out. But styrene also occurs naturally in coffee beans, so all coffee will have some styrene. This is really not much of an issue because styrene is quickly metabolized and excreted.

If anyone has concerns about styrene, they had better stay away from cinnamon which can have as much as 39,000 ppb of styrene as opposed to the 5 ppb that may be leached out from polystyrene. They will also have to stay away from beer which has up to 25 ppb of naturally occurring styrene. If the K cup is made of polypropylene, there is no issue whatsoever. No compound of any consequence leaches out of this plastic. Basically what we have here is a tempest in a Kcup. If there is to be a concern, it centers in the environmental unfriendliness of these little cups which may pose a big problem in terms of where they end up.

Read more

But it comes from the Earth!

freezeYou may have heard of propylene glycol in several contexts. It is used as a safer alternative to ethylene glycol in antifreeze, as a preservative in foods and cosmetics, as a solvent in some pharmaceuticals and as a carrier of nicotine and flavours in electronic cigarettes. Propylene glycol also appears in the list of substances used by Tom’s of Maine, a company that prides itself on using natural ingredients in the consumer products they sell. According to Tom’s: “We’re always thinking about natural ingredients, where they come from and what they can do for a healthy world. That’s because ingredients derived from nature and handled responsibly tell you something important about a product. Something that feels good. And feeling good is what our ingredients list is all about.”

In that ingredients list the source of propylene glycol is described as “natural gas from the earth.” This is ridiculous on many levels. Propylene glycol is made via standard synthetic methods from propene oxide which in turn is made from propene. It is true that propene does occur in small amounts in natural gas, but that is not from where it is sourced. Propene is made by the catalytic cracking of larger molecules in petroleum. Of course, whether the starting material for the synthesis of propylene glycol comes from natural gas or not is totally irrelevant. Petroleum is no less natural than natural gas.

This is not meant to impugn propylene glycol in any way. It is a safe enough chemical. But trying to build up its image by claiming that it comes from “natural gas in the earth” is pure nonsense. And I won’t even mention that there are all sorts of gases “in the earth,” hydrogen sulphide for example, which will do away with people quite nicely. Basically, the term “natural” which has become so common in marketing has also become meaningless. If one ignores processing, every substance in the world can be described as natural because all raw materials come from nature. Where else would they come from? A car could be described as natural since the metals, leather and plastics used all can somehow be traced back to substances that can be found in nature. We either need some proper definition of the term natural that can be applied to marketing or eliminate its use completely.

Read more

Joe Schwarcz’s The Right Chemistry: Paraben phobia is unjustified

ParabenThe public mistrust of preservatives can be traced back to a 2004 paper by Dr. Philippa Darbre of the University of Reading

Stories about recalls of various consumer products are all too common these days, but one about contaminated children’s sunscreen lotion caught my attention. Not because it posed a significant risk, which it didn’t, but because the report mentioned “glucono delta lactone.” This is a compound I worked with extensively back in my graduate school days, using it as a starting material for the synthesis of various carbohydrates. What was it doing now, in a story about a sunscreen recall?

Cosmetic products, particularly those that are water-based, are prone to contamination by bacteria, moulds and fungi. This is not only a “cosmetic” problem, as it were, it is also a health issue. One would therefore presume that the inclusion of preservatives to ensure a safe product would be seen by consumers as a positive feature, but such is not the case. Preservatives are regarded by many as nasty chemicals that are to be avoided.

This mistrust can be traced back to a 2004 paper by Dr. Philippa Darbre of the University of Reading that described finding traces of parabens, a commonly used class of preservatives, in breast tumours. The study received extensive press coverage, with few accounts pointing out that there had been no control group. Since parabens are widely used in foods and cosmetics, they can conceivably be detected in most everyone.

Although Darbre admitted that the presence of parabens did not prove they caused the tumours, she did alarm women by pointing out that these preservatives have estrogen-like activity and that such activity has been linked to breast cancer. What she failed to mention was that the estrogenic activity of the various parabens is thousands of times less than that of estrogenic substances found in foods such as soybeans, flax, alfalfa and chickpeas, or indeed of the estrogen produced naturally in the body.

Regulatory agencies around the world have essentially dismissed Darbre’s study and maintain that there is no evidence linking parabens to cancer. Dr. Darbre, undoubtedly disturbed by being rebuffed, has continued to publish research about parabens, attempting to justify her original insinuation of risk. Her latest paper describes the enhanced migration of human breast-cancer cells through a laboratory gel after 20 weeks of exposure to parabens. One is hard pressed to see the relevance of this “in vitro” experiment to the use of 0.8% parabens in a topically applied cosmetic.

Nevertheless, because of the concerns that have been raised about parabens and other synthetic preservatives, the cosmetics industry is turning toward the use of “natural” substances that have an unjustified public image of being safer.

As I have said many times before, the safety and efficacy of a chemical does not depend on whether it was made by a chemist in a lab, or by Mother Nature in a bush.

Its chemical and biological properties depend on its molecular structure and the only way to evaluate these is through appropriate experiments.

It is through such experiments that glucono delta lactone’s ability to impair the multiplication of microbes was determined. In solution, the compound slowly converts to gluconic acid, creating an inhospitable acidic environment for bacteria and fungi. Marketing-wise, glucono delta lactone can be labelled as “natural” because it can be found in honey and various fruits where it is formed from glucose by the action of enzymes released from the Aspergillus niger, a ubiquitous soil fungus that commonly taints plants.

Industrially, glucono delta lactone is produced by fermenting glucose derived from corn or rice with the same fungus. But acidification alone is not enough to eliminate the risk of microbial contamination, so the producers of the children’s sunscreen turned for help to that spicy mix of vegetables known as kimchee.

Korea’s national dish is traditionally made by fermenting cabbage, cucumber and radishes with the bacterium, Leuconostoc kimchii. One of the products secreted by the bacteria during the fermentation process is a peptide (a short chain of amino acids) that has antimicrobial properties.

“Leucidal Liquid” is a commercial extract of the antimicrobial peptide produced by the action of Leuconostoc kimchii on radishes. In combination with glucono delta lactone, it forms an effective preservative system; but as evidenced by the sunscreen recall, not in all cases. The lotions were free of contaminants before being shipped to retailers but some samples on the shelf were later found to contain bacteria and fungi that could have caused a problem if absorbed through cuts or lesions.

Contamination would most likely not have occurred if parabens, a far more effective preservative, had been used. But the label could then not have declared the product to be “natural.”

And here we have a curiosity.

Compounds in the parabens family actually do occur in nature. Methylparaben can be found in blueberries and interestingly, in the secretions of the female dog where it acts as a pheromone notifying the male that its advances are welcome. But since extracting parabens from berries or canine secretions is not commercially viable, the compounds are produced synthetically. This means that even though the final product is identical to that found in nature, it cannot legally be called “natural.”

A further issue, at least in the eyes of the chemically unsophisticated, is that benzene, the starting material for the synthesis, is derived from petroleum. Thanks to activist dogma, labelling any chemical these days as “petroleum-based” is tantamount to calling it toxic.

So far, no manufacturer has tried to counter this assault by describing petroleum as an organic substance formed through the natural decomposition of biological matter by soil-dwelling microbes, but similar seductive innuendo about “natural” ingredients is not uncommon in the cosmetics industry.

Phenoxyethanol is sometimes advertised as a natural alternative to parabens because it occurs in green tea, but in fact is commercially made from petroleum-derived phenol.

Some companies tout sodium hydroxymethylglycinate as a natural preservative, basing on the fact that it is made from glycine, an amino acid abundant in the human body. But glycine has to be put through a series of synthetic modifications to produce the preservative.

The demonization of synthetic preservatives has led not only to the glorification of less-effective natural products but to a host of “preservative-free” ones as well. These should only be trusted if they come in either single-use vials, or if the sterilized contents are sealed in a container with a pump that prevents entry of microbes when it is used.

Otherwise “preservative-free” can quickly become “bacteria-filled.”

Read more

Green tea extracts and liver disease

green tea extractI think we are safe in saying that green tea doesn’t make taste buds frolic. So why do people drink it? The same reason for which the Chinese have been consuming it for millennia. Its supposed health benefits. Green tea doesn’t contain the flavourful compounds that form when tea leaves are allowed to ferment. During fermentation enzymes are released that convert the naturally occurring polyphenols in the leaves to a host of tasty compounds. Instead of being fermented, green tea is made by steaming or drying fresh tea leaves in order to prevent oxidation of the polyphenols. It is these polyphenols that in laboratory and animal studies show anti-cancer effects as well as increased rates of metabolism.

But how can on benefit from tea’s polyphenols without having to put up with green tea’s unappealing flavor? Supplement manufacturers have found a way. Just extract the catechins, the main class of polyphenols in tea, and plunk them in a pill. Then promote the pill as a cancer-fighting or fat burning supplement. But here we run into a problem. Such dietary supplements are poorly regulated and the amount of catechins they contain can be far greater than that available from drinking tea. The high doses may indeed help to increase metabolism and result in weight loss but possibly at a high cost. Just ask the teenager who walked into the emergency room at Texas Children’s Hospital with his chest, face and eyes bright yellow due to severe liver damage after using a concentrated green tea extract he bought at a nutrition store as a “fat burning” supplement. Doctors feared he may need a liver transplant but luckily his liver, an organ that has regenerative properties, managed to recover. He did, however, have to give up sporting activities and will require regular checkups of his liver function.

Unfortunately this is not an isolated case and such cases are not limited to green tea extracts. Various herbal supplements have been linked with liver damage, some because of undeclared ingredients, such as steroids. These are promoted as bodybuilding supplements and may actually have an effect because of the hidden steroids. People generally assume that herbal products that are sold are tested for safety and efficacy but this is not the case. Until regulations are tightened the incidence of liver damage from dietary supplements is going to continue to increase.

Read more

The Problem of Herbicide Resistance

herbicide
Farmers who are growing herbicide resistant crops such as corn or soy may start to identify with Audrey Jr. in Little Shop of Horrors. In that film, later made into a Broadway musical, a dorky florist’s assistant cultivates a plant he names Audrey Jr. after the co-worker he pines for. This is no ordinary plant, this one craves blood to grow and its constant cry to “feed me” wreaks havoc with human lives. While there are no plants that suck blood, although ones like the Venus fly trap do dine on insects, there are ones which at least figuratively suck farmers’ blood. We are talking about weeds that can no longer be killed by herbicides. Weeds along with insects are farmers’ great enemies. They compete with crops for nutrients in the soil, reducing crop yields. Various herbicides are available to kill weeds but the problem is that they damage crops as well. That’s why farmers welcomed the introduction in the 1990s of soybeans and corn that were genetically engineered to resist the herbicide glyphosate. Fields could be sprayed to wipe out weeds without harming crops. Yields and profits increased. But in the long run, you can’t beat biology. It was no secret from the beginning that eventually weeds would develop resistance to glyphosate.

This is what farmers are now seeing. The lifeblood sucking weed that corn, cotton and soy growers are worried about is called palmer amaranth. It has already devastated cotton fields in the south and is moving into corn and soy fields in the Midwest, probably introduced by manure from cows fed cottonseed contaminated with palmer seeds. Short of pulling out weeds by hand, which is possible but very labour intensive, farmers will have to look for new technologies. On the horizon are crops that have been genetically engineered to resist 2,4-D and glufosinate, two very effective herbicides that traditionally cannot be sprayed on growing crops because they will kill them just like they kill weeds. But 2,4-D will kill weeds that are resistant to glyphosate and will not harm the crops that have been engineered to resist the chemical. Of course this isn’t a long term solution because the weeds will eventually develop a resistance to 2,4-D as well. And 2,4-D doesn’t have quite as good a safety profile as glyphosate. Weeds that cannot be destroyed by herbicides are a farmer’s bane, and eventually, like Audrey Jr. they come out on top.

 

Read more

Fenugreek and Sotalone

fenugreek and sotaloneIf you have eaten curry, you have probably tasted fenugreek. The seeds of this plant as well as its fresh leaves are commonly used as ingredients in curries. They are added for taste but they also impart a smell that is due to sotalone, a compound that at low concentrations has a distinct maple syrup-like odour. Since sotalone passes through the body unchanged, it can impart a scent both to the urine and sweat. The compound is actually used as one of the flavor components in artificial maple syrup and can be isolated from fenugreek seeds. Facilities that process the seeds often smell strongly of maple syrup and the scent can be carried quite some ways by the wind. Back in 2005 Manhattanites began to complain of a strong maple syrup odour and rumours circulated about it being some sort of chemical warfare. It took a while but eventually the smell was traced to a company in New Jersey that was processing fenugreek seeds. That rumor even made it on to an episode of 30 Rock, the popular sit com.

It is not only curry eaters who can smell of maple syrup. It can be an issue for lactating mothers who take fenugreek supplements to increase milk production. While there is much anecdotal evidence that this works, the few studies that have been carried out have shown mixed results. There is always a question of just how much to take, which is tough to answer because herbal supplements are difficult to standardize and often there is a mismatch between what is indicated on the label and what is actually in the product.

Herbal remedies are drugs and like any drug can have side effects. As a food fenugreek rarely causes problems but as a supplement it can result in loose stools and intestinal discomfort. Allergy to fenugreek is possible especially in people who have allergies to peanuts and chickpeas which are in the same botanical family. Since fenugreek can lower blood glucose, it can in some cases cause hypoglycemia. This is of special concern in diabetics because fenugreek may enhance the effect of antidiabetic drugs. On the other hand, because it can lower blood glucose, fenugreek may be of some benefit to diabetics, but again there is the problem of knowing how much to take because of lack of standardization.

Since fenugreek can cause uterine contractions, it should not be taken during pregnancy.When taken for lactation, the advice that is often offered is to slowly increase the dosage until the sweat or urine begins to smell like maple syrup. Breast fed babies may also smell of maple syrup if the mom has been ingesting fenugreek and that can lead to false diagnosis of “maple syrup urine disease.” This is a serious genetic disorder characterized by a deficiency in enzymes that metabolize the common amino acids valine, leucine and isoleucine. A buildup of these amino acids and their breakdown products can lead to severe neurological damage and eventually death. One of these breakdown products is sotalone, the odour of which was usually a clue to the diagnosis of maple syrup odour disease. Today, should the condition be suspected based on a baby’s failure to thrive, testing of the blood amino acids can detect the condition even before any scent appears. Serious consequences can then be avoided by adhering to a diet that is based on a special formula free of the problematic amino acids.

Some women take “Blessed Thistle” along with fenugreek because this herb also has a reputation as a lactating agent. In this case there is insufficient evidence for efficacy or about the safety of taking this herb during pregnancy or while breast feeding. Blessed thistle is not the same as “milk thistle” which in spite of its name has nothing to do with encouraging milk production. The plant derives its name from the characteristic white streaks on its leaves. An extract of milk thistle, often called “silymarin” is composed of several compounds that have a protective effect on the liver. Some strudies have shown a benefit in cirrhosis as well as fatty liver disease. One study even claimed effective treatment of poisoning caused by Amanita phalloides, one of the most deadly mushrooms known. It contains compounds that attack the liver.

Read more

« Older Entries
Blog authors are solely responsible for the content of the blogs listed in the directory. Neither the content of these blogs, nor the links to other web sites, are screened, approved, reviewed or endorsed by McGill University. The text and other material on these blogs are the opinion of the specific author and are not statements of advice, opinion, or information of McGill.