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You Asked: Is it true that dogs are being poisoned by propylene glycol in some dogfoods?

dog foodNumerous Internet posts attempt to scare dog owners with questions like “Is It a Dog Food Aide or Automotive Antifreeze?” The reference is to propylene glycol, a chemical added to some dog foods to help retain moisture. Of course being an antifreeze component and serving as a food additive are not mutually exclusive. After all nobody worries about eating salt because it is also used in enemas. The potential risk of a substance is determined by studying it, not by making specious associations.

So what do the studies say? Unfortunately when it comes to dogs, not a whole lot. In humans, propylene glycol when ingested is pretty innocuous. Toxicity occurs when blood concentration reach 4 grams per liter, which is unachievable by consuming foods or beverages that contain the chemical. And yes, it is used in human food, mostly to retain moisture, although it also serves as a solvent for flavours. The pharmaceutical industry uses propylene glycol as a solvent in formulations of drugs that are insoluble in water. In beer it can stabilize head foam, in soft drinks and flavoured coffees it carries flavour, it stabilizes whipped cream and prevents the formation of crystals in ice cream.

Canada attaches no numerical value to the maximum amount of propylene glycol that can be used as long as it conforms to “good manufacturing practices.” In the U.S., it can be used up to 50 grams per kilogram of food or beverage. Europe allows maximum of 3 grams per kilogram. The reason for the discrepancy is not clear since there is no evidence that amounts greater than the European limit cause any problem. But this difference between amounts allowed in Europe and the U.S. did cause quite a kerfuffle when Fireball Whisky was recalled in Norway, Sweden and Finland. It seems the American version of the product found its way across the ocean with levels of propylene glycol above those acceptable in Europe.

This precipitated a public outcry in Europe where people recalled with horror the 1985 episode when some Austrian wines were adulterated with diethylene glycol, another chemical that can be used in antifreeze, to make the wines sweeter and more full-bodied in the style of late harvest wines. Nobody was hurt except the Austrian wine industry which suffered an almost complete collapse.

The publicity about the Fireball recall in Europe bounced back to the U.S. where this whisky is a popular choice among the college set due to its low cost and relatively high alcohol content. Rumors that a Fireball recall was underway sent ripples of upset across social sites.There was no recall, but as expected the chemophobes rallied around the “they’re putting antifreeze into our food” battle cry. The fact is that someone would perish from alcohol poisoning long before enough alcohol were consumed to cause a problem with propylene glycol.

Exactly why propylene glycol is found in Fireball whisky isn’t clear. The company goes no further than to say that “the secret to Fireball is buried in the depths of our souls and it’s so damn special that we just can’t share it. Although we’d love to talk Fireball, we have a strict policy that we let our whisky speak for itself.” In all likelihood propylene glycol is used as a solvent for some flavour that is added to the whisky.

While there is no issue with propylene glycol in human food, dogs may be a different case. They often eat the same food for all their meals and the continued ingestion of propylene glycol even in small doses may conceivably be a problem. That is just what a class action lawsuit launched by a California pet owner contends. He claims that two of his dogs got sick and one died after he began to feed his pets with “Beneful” produced by Nestle Purina Dog Care. The lawsuit describes over 3000 complaints on line about dogs developing liver problems, kidney failure, seizures and diarrhea due either to propylene glycol or ochratoxin, a fungal metabolite found in the food.

The manufacturer dismisses the notion that Beneful is the cause of the ailments. Dogs get sick, and owners then look for a cause, with food being a prime suspect, they say. And Beneful is not associated with symptoms any more than any other dog food, whether it contains propylene glycol or not. However, whether that is indeed the case is hard to know. Nobody it seems has actually done a study. Given that propylene glycol is known to be toxic to cats, causing “Heinz body anemia,” and since questions have been raised about its effects on dogs, it may be prudent to choose varieties of dog food that do not contain the chemical.

Joe Schwarcz PhD

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.

 

Dr. Joe Schwarcz

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.

 

Joe Schwarcz PhD

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.

 

Dr. Joe Schwarcz

You Asked: Can the much advertised Lipozene lead to weight loss?

lipozeneThe “active” ingredient in Lipozene is glucomannan, a form of dietary fiber that is extracted from the root of the konjac plant. Fiber, by definition, is any type of food component that cannot be digested and consequently makes its way to the large intestine or colon, where bacteria may break it down into smaller compounds. Most of these, along with intact fiber, are excreted. Glucomannan is made of glucose and mannose molecules joined together in long chains, but unlike digestible carbohydrates like starch, it is resistant to breakdown by our salivary or pancreatic enzymes.

As the indigestible glucomannan sits in the stomach or small bowel before passing on to the colon, it absorbs a great deal of water. This bulky mélange of water and fiber makes for a feeling of fullness and curbs the appetite. There have actually been a few short term studies indicating more efficient weight loss on a low calorie diet when it was combined with about 4 grams of glucomannan per day.

Marketers take such studies and inflate them with hype about easy weight loss. They promise weight loss without the need to diet or exercise. Of course this is a promise that cannot be fulfilled, which is the reason that an American company called Obesity Research Institute was taken to task by the Federal Trade Commission and was made to return 1.5 million dollars to customers who had been victimized by unsubstantiated claims. Two physicians who appeared as “expert endorsers” on infomercials produced by the company were also reprimanded. Seems that money can blur scientific vision.

This is not to say that glucomannan in combination with a low calorie diet and exercise cannot aid in weight loss. It can. But it is not a long term answer to the problem of weight control. This fiber does, however, provide some other possible benefits. It slows the absorption of other carbohydrates into the bloodstream and provides better control of blood glucose. Glucomannan also interferes with cholesterol uptake, so it can lead to lower blood cholesterol. For those in need, it can also be an effective laxative. And if you pop a couple of glucomannan pills before grocery shopping you will feel more full and buy less!

Joe Schwarcz

You Asked: Is it true that some baloney is made with ground-up earthworms?

baloneyAbsolutely not. But here is the question I got: “A friend told me that that ground up earthworms are being used as fillers in many meat products like wieners and bologna. The name on the package is sodium erythorbate. I’ve checked packages at stores here and have found only one brand without this ingredient. My little boy loves hot dogs and I hate to think how many I’ve fed him over the past several years with earthworms in them.”

Hard to know how such silly stories arise. Maybe it is the similar sounds of “erythorbate” and “earthworm bait.” Sodium erythorbate is just a form of Vitamin C and is used as a preservative. It also prevents the formation of potentially carcinogenic nitrosamines is meats processed with nitrite.

Erythorbate is a perfectly safe substance and has absolutely nothing to do with earthworms. It makes a lot more sense to minimize hot dog and baloney consumption because of their high fat and salt content than because they contain sodium erythorbate. There is more baloney in the sodium erythorbate story than there is sodium erythorbate in the baloney.

 

Joe Schwarcz

You Asked: Why is Jerusalem artichoke thought to be healthy?

jerusalem artichoke“But in my judgement, which way soever they be drest and eaten they stir up and cause a filthie loathsome stinking winde with the bodie, thereby causing the belly to be much pained and tormented, and are more fit for swine than for men.” So spoke John Goodyear, a British farmer back in the early 1600s. He was describing the Jerusalem artichoke which had been introduced into Europe by Samuel de Champlain who in turn learned about the vegetable from the Indians. This fascinating tuber is not an artichoke and has nothing to do with Jerusalem. The plant is actually a member of the sunflower family and is sometimes called sunchoke. But it seems that to Champlain it tasted like an artichoke and the term stuck. Why Jerusalem? When the plants were first brought back to Italy from America they were called “girasole” for “turning to the sun.” Somehow this got corrupted to Jerusalem.

Goodyear was right about the fact that Jerusalem artichoke can produce a lot of wind. But he was certainly wrong to suggest that it was more fit for swine than for men. We are actually learning more and more about how healthy this unusual vegetable may be. And its health properties are connected to its wind producing potential. Jerusalem artichokes are very rich in a type of fiber called inulin. By definition, fiber is the indigestible part of a plant food, it cannot be broken down in the small intestine in the way starches, proteins and fat are broken down. So it marches on to the colon where there are plenty of bacteria that can use fiber as food.

Our colon is inhabited by about 500 species of bacteria! Some bacteria are particularly adept at digesting inulin. These are the bifidobacteria, which are generally classified as “good bacteria” because they keep disease causing bacteria in check. They thrive on inulin, which is good. But when they digest this form of fiber, they produce a lot of gas, which may not be so good. But along with the gas they also produce short chain fatty acids which have anti-cancer potential. That’s good. Furthermore a healthy bifido population is conducive to controlling both constipation and diarrhea. These bacteria even increase calcium absorption and there is preliminary evidence that inulin lowers triglycerides in the blood. In Europe and Japan, Jerusalem artichoke flour is commonly added to foods to improve their health potential. So why not give it a try? You can slice the tubers into a salad, stir fry them or shred them and put them in a salad. And you don’t have to go to Jerusalem to get them.

Joe Schwarcz

You Asked: How much salt is too much?

saltReducing sodium intake has been a nutritional mantra for decades. We have repeatedly been told that cutting back on salt lowers blood pressure which in turn lowers the risk of heart attacks and strokes. But these days it seems to be in vogue to question almost every type of dietary advice that has been dispensed by health authorities, including salt intake. Questioning current dogma of course isn’t a bad thing, after all, that is how science progresses. The truth is that often the evidence for recommendations is not as robust as it is made out to be and we have seen views change about the likes of saturated fats, eggs and sugar in our diet as new data emerge. Today, with studies being cranked out at a frantic pace it is possible to find “evidence” for almost any view that one holds, but conclusive evidence, particularly when it comes to diets, is elusive. When it comes to food, the gold standard, the randomized double-blind trial, is extremely difficult to design and carry out.

In the case of sodium, a meaningful trial would mean following groups of subjects for many years and noting the incidence of cardiovascular disease, with the only difference between groups being the amount of sodium in the diet. It is difficult enough to do this over the short term, but that actually has been done. The famous dietary approaches to fight hypertension (DASH) trial managed to test three different levels of sodium intake by providing subjects with all their meals. They consumed either 1500, 2300 or 3500 mg of sodium a day, with results showing a clear link between blood pressure and sodium intake. The 3500 mg level was chosen because it represents the amount of sodium that is consumed on the average by the population. This translates to about 9 grams of salt (sodium chloride), or one and a half teaspoons, most of which comes from processed foods.

The trial lasted only 16 weeks, too short to note a difference in disease patterns. As critics pointed out, demonstrating a decrease in blood pressure with reduced sodium is not the same as showing a decrease in the risk of a heart attack or stroke. But given that there is overwhelming evidence from population studies that high blood pressure is associated with cardiovascular disease, it is reasonable to recommend a cutback on salt. The question is by how much?

That question arises because some recent studies have suggested an increased risk of adverse health outcomes associated with sodium intake in the 1500 to 2300 mg a day range. This, however, may have nothing to do with sodium. It is possible that people with cardiovascular disease, who have been advised to dramatically reduce their salt intake, fall into this range and suffer problems because of the preexisting condition rather than their low sodium intake. In any case, for the general population, the 2300 mg target is reasonable. Debates about low sodium levels presenting a risk may have academic interest but have little practical value. The 1500 mg target is unattainable for most people, and given that our average intake is in the range of 3500 mg a day, emphasis has to be placed on reducing this rather than worrying about too little sodium.

Cutting back isn’t easy. Producers cater to our fondness for salt by adding it liberally to a wide array of foods. A bowl of cereal contains about 300 mg of sodium, a single hot dog can have 800, a slice of bread 230, a cup of cottage cheese 900, a couple of slices of processed cheese 700, and half a cup of commercial tomato sauce 600 mg. A slice of pizza can weigh in anywhere from 600 to 1500 mg of sodium per slice! Obviously it isn’t hard to surpass 2300 mg. So there really is no worry about consuming too little sodium, that isn’t happening in the real world. There is another reason we can dismiss the naysayers who claim that the evidence to support a low sodium diet is too weak. Cutting back on sodium means a decrease in processed food intake and an increase in fruits and vegetables. And there can be no argument against that.

Joe Schwarcz

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