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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

You Asked: Nutritional yeast and adverse reactions?

nutritional yeastHad a question from a gentleman with a history of bloating after meals. He had a particularly bad episode after a dinner that included chicken Florentine soup and he wondered whether the “nutritional yeast” added to the soup could be the cause.  Nutritional yeast is just an inactivated form of the yeast that has been used for brewing beer and making wine for millennia. Because it has been inactivated with heat or salt, it does not cause fermentation, that is it does not convert sugar into alcohol. It is basically composed of protein with a good load of vitamins and minerals and has commonly been used as a dietary supplement. Indeed, Marmite and Vegemite are two formulations of the yeast that are popular in the UK and Australia, although having tasted these, I can’t understand why.

Nutritional yeast is basically used to add flavour to foods. Part of the effect is due to its natural content of glutamic acid which brings out flavour. Indeed, glutamate is the active component of the classic flavor additive monosodium glutamate (MSG). Some people do have an adverse reaction to glutamate but it is rare. It is, however, possible that some other component in nutritional yeast can cause a problem in susceptible individuals. Idiosyncratic reactions to food are not uncommon. The only way to determine if the yeast causes a problem is to carry out a challenge. Has anyone experienced an adverse reaction with nutritional yeast?

Dr. Joe Schwarcz

You Asked: What are Bach flower remedies?

Bach remediesBach flower remedies have been around for close to a hundred years and were the brainchild of Edward Bach a British physician. Actually, there doesn’t seem to have been much “brain” involved in the development of this curious alternative healing method. Bach was a traditionally trained physician who became disenchanted with the way medicine was being practiced and began a search for novel healing methods. Then in 1930, at the age of thirty, as he was walking through a field of flowers glistening with dew, he had an epiphany. He somehow surmised that the spiritual essence of a flower was transferred to the dew when the flower was exposed to the sun, and that this dew had healing properties.

This remarkable insight came to Bach, as he maintained, through “inspiration.” He found that to sense a flower’s specific therapeutic potential, all he needed to do was hold a petal in his hand. Bach then went on to develop his healing essences by exposing flower petals floating in a glass bowl filled with spring water to sunshine. He claimed that in this fashion the flower’s spiritual energy was transferred to the water, a few drops of which could then be used for healing purposes. Bach’s bizarre notion was that the spirit of the plant communed with the human spirit and alleviated negative moods and the “lack of harmony” between the soul and the body which causes disease. Illness, Bach maintained, “will never be cured by present materialistic methods, for the simple reason that disease in its origin is not material, but is the result of conflict between the Soul and the Mind and will never be eradicated except by spiritual and mental effort.”

Different flower essences are used for different purposes. For example, wild oat essence directs the confused or lost individual toward his or her life path. This, it is said, is the perfect remedy for the “seeker” type personality to ease his soulful yearnings and tiresome wanderings. Wild Oat is also recommended for youth seeking a vocation or anyone experiencing a mid-life crisis. So where is the proof for such claims? The marketers of Bach remedies say that they have no interest in proving the remedies work, they just let the customers make up their own mind. But actually others have carried out placebo-controlled trials. What did they show? That all subjects, whether in the Bach flower essence group or the placebo group, experienced a decrease in anxiety, but there was no difference between the groups.

The conclusion is that Bach-flower remedies are an effective placebo for anxiety but do not have a specific effect. So if you are using “Five Flower Rescue Remedy” to ease fear and restore state of calm and confidence, as is claimed, you are actually getting an inconsequential dose of flower extract with a heaping dose of placebo. Of course I may only have this opinion because I’m not taking any beech flower essence which “helps lessen one’s tendency to be judgmental toward others or hypersensitive to their environments. Critical and blaming natures are often an indication of inner feelings of vulnerability and insecurity. This essence neutralizes intolerant and critical attitudes with feelings of tolerance and acceptance.” I wonder which essence is a cure for nonsensical thinking?

 Dr. Joe Schwarz

You Asked: What is Rooibos tea?

Screen Shot 2014-12-19 at 1.45.44 PMI had a feeling that doing a PubMed search for Dr. Annique Theron would not yield much.  In fact it yielded zero results.  I can’t even find a biography of Dr. Theron, so I have no idea what sort of doctor she is.  But she does exist.  Pictures of the lady are not hard to find.  After all, she founded a company, modestly named Annique, that sells a line of teas and cosmetics based on her “amazing” discovery.  That discovery occurred back in 1968 when, according to the company’s promotional material, Theron stumbled on the natural healing powers of South African Rooibos tea.  She was struggling to calm down her allergenic baby, and for some reason decided to dope her with a concoction made by steeping the leaves of the Asphalatus linearis plant in hot water.  It worked!  So she claims anyway.  In fact it worked so well that Theron decided to investigate its potential in other conditions and found it to have anti-allergenic properties.

She began to spread the word in a book entitled “Allergies: An Amazing Discovery.”  The book appears to be out of print and there is nothing published in the scientific literature by any Annique Theron, so it is hard to know what evidence she had for her amazing discovery.  But it wasn’t long before people were attributing all sorts of miraculous effects to Rooibos tea.  Not only was it anti-allergenic, it was was anti-bacterial, anti-viral and anti-aging.  Dr. Theron sure saw its potential, and not being anti-profit she founded the “Annique” company that quickly developed an inventory of all sorts of products based on Rooibos tea.  There were digestive aids, detox teas, happy teas along with a whole line of cosmetic products.

Truth be told, Rooibos tea was around long before Theron’s supposed discovery.  Dutch settlers in South Africa brewed the needle-like leaves as an alternative to expensive tea which had to be imported.  It was enjoyed mostly for its sweet taste until Theron put it on the world map with her undocumented discovery.  Researchers, wondering if the plant contained any compounds that could substantiate the folkloric stories, began to study its chemistry.  And they isolated a number of compounds with biological effects, including some antioxidants such as aspalathin and nothofagin. One substance they did not find was caffeine.  Advertisers tout the antioxidant capacity of Rooibos, pointing out that it surpasses that of green tea.  This is a laboratory finding that doesn’t have much meaning for consumers.  What about all the other research that Rooibos tea boosters tout?  Well, if you are interested in whether Rooibos tea prevents the breakdown of red blood cells in Japanese quail, the answer is yes, to a moderate extent.  Or if you want to know if it can suppress the age-related accumulation of lipid peroxides in rat brain, you’ll find a slight effect there too.  Interested in whether the leaves of the plant contain estrogenic compounds? They do.

The fact is that while academically interesting, such research is marginal in terms of any meaning for humans.  And there are no controlled trials showing any benefit for people.  The taste, though, may be interesting.  The newest incarnation of Rooibos is as so-called “red espresso.”  It’s made in an espresso machine using the powdered leaves instead of coffee.  This is what the ad for the world’s first tea espresso sounds like: “With its unique combination of health properties, plus delicious taste and style, red espresso revolutionizes the café space by making it something never thought possible: healthy.  Loaded with antioxidants and 100% natural.  Of course you can say the same for coffee.


Dr. Joe Schwarcz

You Asked: Blueberries and Milk

blueberries and milk“I put blueberries and milk on my cereal in the morning. Which one should I give up?” That was the question I received via email. A reference was included to a study about the antioxidant activity of blueberries being impaired when consumed with milk, as well as one about milk consumption being linked to greater risk of bone fractures and to earlier mortality. While both these studies appeared in the peer-reviewed literature and are interesting, their practical significance is questionable.
The milk study focused on people drinking more than three glasses of milk a day and could not rule out “reverse causation,” namely that some subjects were drinking more milk because they already had risk factors for osteoporosis. As far as earlier mortality goes, the authors suggest it may be linked to an inflammatory effect attributed the galactose, a breakdown product of lactose, the sugar found in milk. But this is pure conjecture. It is also possible that people who drink a lot of milk have a higher calorie intake or a lower vegetable intake, or exercise less, all of which can be confounding factors. Milk may not be as important a dietary component as Canada’s Food Guide suggests, but there is no need to avoid it. Moderation is the key.

Blueberries are widely perceived as “healthy” based upon their content of antioxidants. These naturally occurring substances are found in numerous fruits and vegetables and are thought to be responsible for the benefits attributed to a diet that contains lots of plant products. Laboratory investigation can determine the antioxidants present in food but to what extent they are absorbed into the bloodstream is a more difficult question. We don’t eat single food components, we eat food. Studies have shown, for example, that polyphenols, a family of antioxidants found in tea, are more poorly absorbed when milk is added to tea because proteins in milk bind to the polyphenols. The blueberry study aimed to investigate the fate of two particular antioxidants, namely caffeic and ferulic acid when consumed with or without milk. Eleven subjects, a very small number in terms of scientific studies, consumed 200 grams of blueberries either with 200 mL of whole milk or 200 mL of water. For two days prior, the subjects were asked to abstain from foods containing antioxidants including all fresh fruits and vegetables as well as tea, coffee, juices, wine and chocolate. This unrealistic eating pattern already adds confusion to the study.

In any case, analysis of the subjects’ plasma indicated a somewhat reduced antioxidant content when the blueberries were consumed with milk. This has little relevance to health. Blueberries are not commonly consumed with milk, except perhaps when they are eaten together with cereal. And there is no compelling evidence that the antioxidant content of plasma is a determinant of health. Furthermore, the plasma’s antioxidant potential is determined by the overall content of the diet and is not going to be affected to any significant extent by the handful of blueberries added to cereal whether consumed with or without milk.


Joe Schwarcz


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