« Older Entries

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

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: Should we worry about arsenic in wine?

wineA story about arsenic-laced wine is panicking a lot of people. It’s all about a lawsuit brought against the producers of some wines claiming they contain unsafe amounts of arsenic. As far as I can tell, the lawsuit is an attempt at money grab by a company that performs analyses for substances such as arsenic in beverages. The idea seems to be to cash in on the public fear generated by the lawsuit. People will clamor for the testing of wines, a service the company provides. Any story about arsenic, the fabled “widow maker,” is guaranteed to trigger publicity. Witness Dr. Oz’s shows on arsenic in apple juice and wine.

According to the lawsuit, some cheaper wines contain up to five times as much arsenic as is allowed in tap water, which is 10 ppb. Anything that grows in soil will have some arsenic because arsenic compounds occur naturally. The 10 ppb limit in water has a large safety factor built in, but more importantly, people do not drink as much wine as water. And if they do, they need to worry about the alcohol content far more than about the arsenic content.

 Joe Schwarcz

You Asked: Can the “Smart Drinking Pill” reduce the risk of drinking alcohol?

Screen Shot 2014-12-30 at 6.05.47 PMThe jury is out on whether drinking small amounts of alcohol is beneficial or detrimental. Some studies suggest a drink a day may be good for the heart. On the other hand, alcohol is a known carcinogen linked to cancers of the mouth, esophagus and breast. But when it comes to consuming excessive amounts of alcohol, the verdict is in. Liver damage, hypertension, neuropathies, seizures, gout, pancreatitis and dementia are all possible consequences of too much alcohol. And then of course there is the problem of impaired driving and life destruction due to addiction.
Liver damage is a major concern and one that is addressed by the makers of the “Smart Drinking Pill.” They claim that the mixture of plant extracts, vitamins and minerals in the pill can prevent liver damage and present an “option other than to quit drinking.” Milk thistle, artichoke extract and dandelion root are backed by some evidence in terms of offering liver protection, and the vitamins may be of some help given that people who drink a lot tend to have depleted levels. Liver function is generally determined by measuring blood levels of two enzymes, namely aspartate transaminase (AST) and alanine transaminase (ALT) that are produced by the liver as it detoxifies foreign substances. High levels indicate the liver has to work excessively and is prone to damage.
The single piece of evidence provided by makers of “The Smart Drinking Pill” is a blood test of a single individual whose AST and ALT went from high to normal after two months on the pill with no change in alcohol consumption. And what was this individual’s consumption? Thirty to forty drinks a week! Suggesting that reduction of the liver enzymes means that you can “responsibly enjoy alcohol without having to suffer the negative health consequences” is absolutely foolish. At that level of consumption there are many other risks than liver damage. If someone is drinking that quantity of alcohol the only smart thing to do is to cut back. The Smart Drinking Pill just encourages unhealthy behaviour.
Dr. 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

« 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.