« Older Entries

You Asked: Does taking a supplement of maca root have any merit?

pillsA good story can sell a product especially when it comes to dietary supplements. Talk about some legendary use by natives, throw in terms like increased stamina, improved mood, natural and aphrodisiac, and you are off and running to the marketplace. Maca root powder, here we come! Maca is grown mostly in Peru and its cooked root, with a composition much like wheat or rice, has a long history as a dietary staple. But it is stories about the enhanced virility of Inca warriors who supposedly downed maca root before going into battle that captured the imaginnation of supplement manufacturers. Although there is no evidence that the Inca fighters actually did this, legends are often based on kernels of truth.

Couple this with anecdotes of Peruvians eating maca root for energy and improved sexual function, and you have a basis for carrying out studies that may potentially lay the groundwork for marketing. After all, plants are fascinating chemical factories and it is conceivable that maca may have some biologically active compounds. None have been detected so far, but that is not surprising. It takes a monumental effort to isolate, separate and identify the hundreds of compounds found in plants, and that is only the beginning. Then comes the even greater challenge of testing candidate compounds for biological activity. That’s why when it comes to herbal products, the simplest process is to test crude mixtures.

There have been studies of various maca root preparations, and although not compelling, they are suggestive of some potential benefit. In one small study, men taking 1500 or 3000 mg per day of powdered root claimed increased sexual desire compared with a placebo. There was no measurable change in sex hormones and curiously the effect was not dose dependent. Another study in young men showed a slight but significant improvement in erectile dysfunction, and one in postmenopausal women resulted in decreased anxiety and depression and some improvement in sexual function compared with placebo. Again, there were no changes noted in any hormone levels.

As usual with such dietary supplements, the consumer is at the mercy of the manufacturer in terms of product quality. There is no systematic checking by regulators that the product actually contains what it is supposed to contain or whether it harbours lead, cadmium or arsenic, all of which are possible soil contaminants and capable of ending up in the marketed product. Given that maca is widely consumed as a food, it is unlikely that any of the root powders pose a significant health risk, although headaches, stomach problems, sweating and sleep disruption have been reported in rare cases. It seems that for people looking for a little boost in stamina and sexual function, a daily dose in the range of 1500-3000 mgs of “Peruvian ginseng,” as maca is sometimes called, is an option. It may actually do something, especially if you think it will.


Read more

Unexpected consequences are part and parcel of science

 Screen Shot 2014-11-07 at 10.31.47 PMScience is as a quest for knowledge. Sometimes it ends with a clear-cut result, often not. The Earth goes around the sun. Water is composed of hydrogen and oxygen. The speed of light is 299,792,458 meters per second. These are facts and will never change. But knowledge is often fluid, conforming to new information as it comes to light. We no longer think maggots spontaneously arise from decaying flesh or that heart attack patients have to be kept on six weeks bed rest. These beliefs, though, were reasonable based on the knowledge available at the time.

Scientists are sometimes accused of being slipshod, too profit-motivated, or even incompetent for having made a decision that eventually turned sour. The prescribing of thalidomide, the introduction of DDT and the routine use of hormone replacement therapy at menopause are commonly cited as scientific errors, yet these were all backed by appropriate peer-reviewed studies. It often takes years for problems to emerge, and not having foreseen them does not mean that researchers erred or were motivated by interests other than the honest pursuit of science. Of course, when unexpected consequences do occur, it is important to recognize them. Making a change is not an admission of failure, indeed it is one of the hallmarks of science.

When back in the middle of the last century research revealed that cholesterol levels in the blood were associated with a risk for heart disease, it made sense to suggest that eggs, because of their significant cholesterol content, should be consumed in a limited fashion. That, though, was just an educated guess. Science dictates that such a guess be followed up and be properly evaluated. But it can take years of studies to determine if a hypothesis is correct, and such studies, particularly in the are of nutrition, are not easy to carry out. Food frequency questionnaires are notoriously unreliable, and there are all sorts of confounding factors such as genetics, age, weight and other dietary components that have to be taken into account.

Furthermore, no decision can be made based on any single study; a preponderance of evidence is required to arrive at a conclusion. With eggs, sufficient data has now been collected to indicate that their consumption does not have a significant effect on blood cholesterol levels. Indeed, the expert panel in the US that every five years makes dietary guideline recommendations has concluded that “cholesterol is not a nutrient of concern because cholesterol from foods doesn’t cause higher blood cholesterol levels.”

As far as scientific questions go, the effect of eggs on blood cholesterol was a relatively easy one to answer. But this is not always the case. Consider the question of chemicals that are suspected of causing cancer. Obviously people cannot be given suspected carcinogens and in any case, such trials would take decades to reveal an effect. Therefore, “knowledge” emerges from human epidemiological evidence along with studies in animals and cell cultures.

Various organizations classify carcinogens into different categories, with the most widely referenced one being the International Agency for Research on Cancer (IARC). Its Group 1 substances are definitely known to cause cancer based on human evidence and include tobacco, the combustion product benzopyrene, asbestos, benzene, formaldehyde, dioxin and ultraviolet light. Aflatoxins from molds, infection by helicobacter pylori bacteria, herbal remedies containing Aristolochia species, x-rays, occupation as a painter and alcoholic beverages are also on this list.

Group 2A is a compilation of “probable” carcinogens as determined by strong evidence from animal studies but limited human evidence. Lead compounds, acrylamide in baked goods, emissions from frying foods, hairdressing as an occupation, shift work, the herbicide glyphosate and insecticides such as diazinon and malathion are in this category. “Possible” carcinogens for which there is insufficient animal evidence and limited evidence in humans fall into Group 2B and include coffee, pickled vegetables, radiofrequency fields, titanium dioxide and DDT.

Combining all three groups, there are more than 450 substances or processes that are classified as known, probable or possible carcinogens. What do we do with this information? We can limit alcohol consumption, take care with sun exposure, treat helicobacter infection, avoid charred foods and of course shun smoking. As far as the other agents are concerned, sometimes we have to be satisfied with knowing that not everything can be known. Outside of occupational exposure, there just isn’t enough known to make sweeping recommendations. But if you are offered a job as a chimney sweep, don’t take it.

Read more

Bee Buzz

beesBees are critical to agriculture, there is no doubt about that. They fertilize various crops by spreading the pollen that they collect to meet their protein and fat needs. Recently there has been much concern about declining bee populations in some areas and speculation has focused on insecticides known as “neonicotinoids.” Many media reports have tried and convicted the “neonics” and urged that they be banned. But as is so often the case, media reports only scratch the scientific surface and deeper digging produces a different buzz. Neonics at a certain level of exposure can disorient or even kill bees, which comes as no surprise since they are insecticides, and bees are insects. The question is whether these chemicals can be used in a way that protects plants without harming bees.

Neonicotinoids, first introduced in 2004, are modeled on nicotine, the natural insecticide produced by the tobacco plant. One advantage is that instead of spraying, these chemicals can be applied to the seeds of crops such as corn, soybeans and canola. They then end up distributed throughout the plant as it grows and are ready to dispatch any insect that dares to dine on the foliage. Bees don’t do that, they go for the nectar in the flowers which has only traces of neonics. Yet bee deaths have been linked with neonic-coated corn and soy seeds, mostly in Ontario. But curiously, not with canola seeds in western Canada which are also treated with the same pesticides. So what is going on?

Mechanical planters use a jet of air to blow seeds into the soil. Commonly talc or graphite are added as lubricants to reduce friction between the seeds but these can rub off and can carry insecticide contaminated dust into the air, exposing flying insects such as bees to the neonics. The concern is that the tainted bees return to the hive where they can expose fellow bees to the neonics and wreak havoc. A novel polyethylene wax lubricant that can replace talc and graphite has shown a significant reduction in airborne insecticide during planting. There are also polymers being developed to help the insecticide stick to the seeds.

The planting of canola uses different technology and doesn’t produce comparable amounts of dust. Some 20 million acres of canola are planted in Canada with neonicotinoid treated seed and there has been no impact on bee health at all. So it seems the problem may not be the neonics as much as the seeding methodology. Neonics are also commonly used on cut flowers and on plants purchased from nurseries but whether these affect pollinators is an open question.

In any case, the neonics are only part of the picture when it comes to bee health. There are mites, parasites and viruses that can infect bees, and transporting hives, which is commonly done, also stresses them, as do harsh winters and long springs. Specifically, the Varroa mite can affect bee health significantly, and it is interesting to note that in Australia, which is free of these mites, no problems have been seen with bee populations in spite of extensive use of neonicotinoid coated seeds.

So while the neonicotinoids may be a factor in the decline of bee populations in some areas, they are not the only factor. Furthermore, loss of bee colonies has been observed in places where neonicotinoids are not used at all, and history records many cases of unusual deaths of honey bee colonies long before neonics were introduced.

Still, there are some troubling developments. A recent British study showed that bees are more attracted to a sugar solution laced with neonics than to one without, implying the bees may be getting some sort of a buzz from the chemicals and may be more likely to visit plants containing them and end up contaminating hives. And a study in Sweden showed a reduced density of wild bees, but not honey bees, in a field planted with neonic-coated seeds.

Because of the cloud hanging over neonics, Europe and Ontario have decided to greatly restrict their use. It will take a while to see the effect, not only on the bees, but also on crop yields which have steadily increased since the introduction of the neonicotinoids. If yields are to be maintained, it may be back to the insecticidal sprays which come with problems of their own, not only for pollinators, but for people as well. Of course in the western world we can forego insecticides and just pay more for our locally-grown food.

Read more

Murky Mercola

mercolaIf you haven’t heard of Joe Mercola, you have not been surfing the waves of health advice on the web. He is an osteopathic physician whose practice now is limited to offering mostly iffy medical advice on his website and selling a variety of questionable products. He claims his website “is not a tool to get me a bigger house and car, or to run for senate.”. He says he funds his site and therefore, is not handcuffed to any advertisers, silent partners or corporate parents and profit generated from the sale of the products he recommend goes right back into maintaining and building a better site, “ a site that, startling as it may be with all the greed-motivated hype out there in health care land, is truly for you.” Gee, that sounds like motherhood and apple pie. It seems though that not every penny earned goes back into the managing the website. Mercola lives high on the hog in a multi-million dollar estate in Chicago. That wouldn’t be objectionable if the edifice were built on gains from promoting sound science. But that is not the case.

Besides being critical of vaccination, calling microwave ovens dangerous, questioning whether the HIV virus is the cause of AIDS, opposing homogenized milk, claiming that sunscreens increase the risk of skin cancer, Mercola hypes and sells a variety of pseudoscience-laced products. Let’s start with “Dr. Mercola’s Earthing Universal Mat,” which is described thus: “When you walk barefoot on the Earth, there’s a transfer of free electrons from the Earth into your body that spread throughout your tissues. The effect is sufficient to maintain your body at the same negatively-charged electrical potential as the Earth. This simple process is called ‘grounding.’ If you constantly wear materials like rubber or ‘plastic’ shoes, which are both very effective insulators, you’ll be disconnected from the natural energy that flows from the Earth.” Well, in my view, the only thing you will be disconnected from is science. This business of improving health by walking barefoot or by using Mercola’s Earthing Mat is nonsense. But Mercola tells us that his mat “is a great way to complement any outside ‘barefooting’ you might be able to fit into your busy schedule. It’s a quick and easy way for you to get started grounding whether at home, at the office, or almost anywhere you go.” I prefer to get my grounding from science not fairy tales.

Dr. Mercola also sells books such as “Dark Deception” in which he describes how we need sun exposure for health. But he would prefer to expose you to the tanning beds he sells, the same ones health experts agree are dangerous and increase the risk of skin cancer. There is also Dr. Mercola’s “organic deodorant” with “baking soda as the “active ingredient.” Except that it isn’t very active. There are also supplements galore. Like “breast health formula,” “mushroom complex” and “silver solution,” none of is a solution to anything. His bamboo toilet paper I’m sure does as good a job as any other, but the claim that it is better because it is free of toxic BPA can be safely flushed away.

Read more

Should one worry about reboiling water for coffee or tea?

coffeeAn article is circulating on the internet about the dangers of reboiling water and concentrating dissolved chemicals. It amounts to baseless fear-mongering. Lets consider fluoride as an example. Suppose you put a liter of water containing 1 ppm fluoride in a kettle and boil it. You then take 200 mL to make a cup of coffee or tea. That means you will ingest 0.2 mg of fluoride. If you now let the water keep boiling until 100 mL evaporates…which would take a long time…and you take 200 mL from the remaining water to make your next cup of coffee, you will be ingesting 0.22 mg of fluoride. This is an insignificant difference, even if there were an issue with that amount of fluoride, which there isn’t. The same argument applies to any other solutes in water. To imply that making your next cup of coffee from boiled water is going to have any sort of impact on health is absolute nonsense. With tea there may actually be a slight difference but that has nothing to do with taste not toxicity. Boiling drives oxygen out of the water and deoxygenated water tends to taste more flat.


Read more

Is it true that ice cream that doesn’t melt easily should be avoided?

icecreamJoe Mercola, the font of much Internet poppycock, thinks that the safety of ice cream is somehow related to the ease with which it melts. He and other bloggers not well versed in science suggest that ice cream that does not melt easily should be avoided. There are ice creams that don’t melt as readily as others but that doesn’t mean that eating them poses a risk. There are a number of factors that determine how readily an ice cream melts. Basically, the melting rate is determined by the additives used. Ice cream is a mixture of fat globules, water, sugar and air. For a smooth texture the separation of fat and water must be avoided as well as the formation of large ice crystals. Emulsifiers such as mono and diglycerides prevent the fat from separating and guar gum and calcium sulphate add thickness. The thick texture also results in an ice cream that is more difficult to melt.There is no problem with these additives. The glycerides are basically a type of fat that occur naturally in many foods, guar gum is extracted from a bean and calcium sulphate is used in much higher doses in calcium supplements. People who suggest that ice cream is somehow toxic because it stays solid longer need to solidify their knowledge of chemistry.

Read more

You Asked: What is “meat glue?’

meat glueThe idea of eating a steak made from pieces of meat scrap glued together is likely to stick in the craw for most people.  But there are also those who are ready to shell out a small fortune at New York’s uppity WD-50 restaurant for a chance to sink their teeth into “shrimp noodles” concocted with the same “meat glue.”

So, what is this “meat glue?”  Rest assured that no horses were condemned to the glue factory to produce it.  What we’re talking about is an enzyme called transglutaminase that allows a mouthful of shrimp to be served in the form of noodles that look, but certainly do not taste, like regular pasta.  How does it do this?  By facilitating a chemical reaction that forges links between structural protein molecules. Proteins of course are composed of chains of amino acids, and transglutaminase links the amino acid lysine in one chain to glutamine in an adjacent chain.  If these chains are located on the surface of adjacent pieces of meat, the pieces get stuck together almost like magic.  The joint then looks just like one of the white streaks of gristle or fat commonly seen in meat.  It’s so strong that the meat doesn’t even tear along the “fault line.”

Transglutaminase is not foreign to the human body.  We produce it to aid in blood clotting, a process that requires protein molecules to form interlinked complex structures.  Skin and hair are also composed of proteins that have been bound together, and transglutaminase plays a role here as well.

In the 1990s, the food industry discovered that this enzyme can be isolated in good yield from the bacterium Streptoverticillium mobaraense and that it can be used to “restructure” meat, fish and poultry.  For example, with the help of transglutaminase, bits of chicken left over after the carcass has been processed, instead of being discarded as waste, can be glued together to produce chicken patties.  Similarly, artificial crab legs and shrimp can be made by sticking together ground pieces of cheaper seafoods such as Pollock. While the taste of such artificial foods can be criticized, there is no health issue associated with consuming transglutaminase.  As any other protein, it is readily broken down into its component amino acids in the digestive tract.

“Meat glue” is produced for the food industry under the name Activa by the giant Japanese company Ajinomoto which also markets monosodium glutamate (MSG).  It did its work quietly behind the scenes until celebrity chef Heston Blumenthal brought it out of the shadows at the Fat Duck, the restaurant on the outskirts of London that has been labeled by many as the best eating place in the world. Blumenthal’s enthusiasm for creating novel dishes with transglutaminase rubbed off on Wylie Dufresne at New York’s famed WD-50 restaurant who managed to grind shrimp into noodles with the help of transglutaminase and served it on a bed of smoked yogurt.

Other chefs who pursue what has been called “molecular gastronomy,” defined as the application of scientific principles to the creation of new dishes, are pushing the transglutaminase envelope.  Around the corner are filet mignon with strips of bacon glued to its surface, fish coated with chicken skin to enhance flavour and shrimp burgers held together by cross-linked proteins.  How about chicken fat stuck to steak to add a new dimension to chicken fried steak?  Just in case your cholesterol isn’t high enough.

Unfortunately transglutaminase also lends itself to some less savory applications.  Such as producers or butchers using it to bind meat scraps too small to be sold into slices that look every bit as delectable as prime cuts.  The seamless joints are virtually undetectable. Ditto for any difference in taste.  Just take the bits of meat, sprinkle them with transglutaminase, place them on a sheet of plastic wrap and roll tightly into the shape of a tube.  Refrigerate for a few hours and then unwrap.  You’ll be looking at meat that for all the world looks like a single piece of filet.  And it can be priced accordingly.

Clearly there is deception involved here.  The customer is not getting what he or she is paying for.  There are some other issues as well.  Transglutaminase can be isolated from blood, with bovine and pig blood being used commercially.  This can be a problem for people adhering to religious dietary laws.  Not only can transglutaminase be used to make “restructured meat,” it can also be used to improve the texture of hot dogs and sausages.  Meat glue is not allowed in Europe, but can be used in Canada as long as it is declared on the label like any other additive.  For example, if Chicken McNuggets were glued together with this enzyme, it would have to be listed on the ingredients list, which is available from McDonald’s.  It’s not.  So no “meat glue” there.  Whether or not some unscrupulous butchers use it to make fake steaks, is another matter.

Any butcher engaging in such clandestine operations may pay a price.  While ingesting transglutaminase is no problem, inhaling the powder can damage the lungs.  Consumers don’t have to worry about this, but there is an issue with cooking glued meat.  The surface of meat is always covered with bacteria but the microbes are readily killed by cooking.  However, with structured meat, some of the outside becomes the inside, and if the meat is not thoroughly cooked, as is of course possible for people who like their steak rare, bacteria on the inside may survive.  This is the reason why hamburger meat, a classic “outside becomes inside” situation, has to be cooked through and through.

Read more

You Asked: What is cream of tartar good for?

cream of tartarIt is a cheap, safe, readily available mild acid.  It is ideal for the generation of carbon dioxide from baking soda.  In fact, one version of baking powder is a mixture of sodium bicarbonate and cream of tartar.  When the mixture dissolves, bubbles of carbon dioxide are released.  The same chemistry can be used to keep drains clear.  Just make up a mix of one cup bicarbonate, one quarter cup cream of tartar and one cup of salt (for increased density) and periodically pour a few spoonfuls down the drain.  The bubbling action can dislodge small blockages.

Candy makers also know all about cream of tartar.  Candies are basically made by cooling down solutions in which a lot of sugar has been dissolved.  But this has to be done in a fashion that ensures small crystal formation otherwise the candy becomes too brittle and crunchy. If a small amount of cream of tartar is added, some of the sucrose is hydrolyzed to glucose and fructose which are less likely to form large crystals.

There is something else that cream of tartar can interfere with.  Protein molecules joining to each other.  That’s just what happens when we whip egg whites to make meringue.  Coiled proteins unwind and link up in a rigid three-dimensional network.  Sometimes, however, the proteins form too many links to each other and overcoagulation results.  This causes the meringue to be lumpy.  The addition of cream of tartar limits the extent to which proteins can bond to each other.  So it is a pastry chef’s beloved friend.

If that still isn’t enough to make you appreciate cream of tartar, how about its cleaning abilities?  A blackened aluminum pot will shine like new if you boil water with two spoonfuls of cream of tartar per liter in it.  Finally, cream of tartar complexes iron so it will even take rust stains out of fabrics and the bathtub.  Obviously no household should be without it.

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.