Well, lookie here … turns out canola oil may help people with type 2 diabetes control their glucose levels. At least that’s the conclusion from a study reported in Science Daily with the rah-rah headline Canola oil may be an oil of choice for people with type 2 diabetes:

Canola is Canada’s oil and new research from St. Michael’s Hospital suggests it should also be one of the oils of choice for people with Type 2 diabetes. Dr. David Jenkins, head of the hospital’s Clinical Nutrition and Risk Factor Modification Centre, compared people with Type 2 diabetes who ate either a low glycemic index diet that included bread made with canola oil, or a whole wheat diet known to reduce the risk of cardiovascular disease.

His study, published today in the journal Diabetes Care, found that those on the canola bread diet experienced both a reduction in blood glucose levels and a significant reduction in LDL, or “bad,” cholesterol.

Even more exciting, he said, was the finding that the canola bread diet seemed to have the most significant impact on people who needed help the most — those whose HbA1c test measuring blood glucose over the previous two or three months was highest.

Well, that’s it, then. Time to call all your friends and relatives with type 2 diabetes and tell them to stock up on canola oil so they can go on that canola bread diet. Clearly some specific property in an oil chemically extracted from rapeseeds helps control diabetes.

On the other hand, maybe we should take a peek at the study first. Here’s part of the abstract:

The study was a parallel design, randomized trial wherein each 3-month treatment was conducted in a Canadian academic center between March 2011 and September 2012 and involved 141 participants with type 2 diabetes (HbA1c 6.5%-8.5% [48-69 mmol/mol]) treated with oral antihyperglycemic agents. Participants were provided with dietary advice on either a low-GL diet with ALA and MUFA given as a canola oil-enriched bread supplement (31 g canola oil per 2,000 kcal) (test) or a whole-grain diet with a whole-wheat bread supplement (control). The primary outcome was HbA1c change.

Hmmm … economics professor Thomas Sowell (author of The Vision of the Anointed) once wrote that when students in his classes declared this-or-that to be good or bad, he always replied with “Compared to what?” Seems to me this study didn’t compare canola oil to any other fats or oils; it compared two rather different diets, one of which happened to include canola oil. So I found the full study. Here are some quotes from that:

The study was a parallel design, randomized trial wherein each 3-month treatment was conducted in a Canadian academic center between March 2011 and September 2012 and involved 141 participants with type 2 diabetes (HbA1c 6.5%-8.5% [48-69 mmol/mol]) treated with oral antihyperglycemic agents. Participants were provided with dietary advice on either a low-GL diet with ALA and MUFA given as a canola oil-enriched bread supplement (31 g canola oil per 2,000 kcal) (test) or a whole-grain diet with a whole-wheat bread supplement (control). The primary outcome was HbA1c change.

The study followed a randomized, parallel design with two treatment arms of 3 months duration as follows: 1) a low-GL diet with a canola oil–enriched bread provided as a supplement (test) or 2) a high wheat-fiber diet emphasizing whole-wheat foods (control).

The dietitians and participants could not be blinded …

I understanding blinding a group of dieticians wouldn’t get past the ethics committee, but couldn’t we at least poke them in the eye?

… but equal emphasis was placed on the potential importance of both diets for health.

Okay, so no placebo effect. Both groups were told they were going on a good diet.

The test diet included 4.5 slices of canola oil–enriched whole-wheat bread (500 kcal/day) provided as a supplement. The supplement delivered 31 g canola oil or 14% of total dietary calories of a 2,000-kcal diet. The control diet included 7.5 slices of whole-wheat bread without canola oil per day (500 kcal).

A little math tells us the canola oil provided 280 of the 500 calories in the bread. In other words, the canola bread was 56% fat by calories, or 62 fat calories per slice. We can also determine that the canola bread contained 111 total calories per slice. The wheat breads I looked up online also contain 3-4 grams of protein per slice, so let’s figure 3.5 * 4 cals/gram = 14 protein calories … now subtract here, divide there, roll a set of dice, count on our fingers … I’m getting a figure of 8.78 carbs per slice on the canola bread. Multiplied by 4.5 slices per day, that’s 39.5 carbs from the canola bread.

The commercial whole-wheat breads I looked up contain around 12 carbs per slice. Multiplied by 7.5 slices per day, that’s 90 carbohydrates. So that’s a good guess as to what the control group was consuming as carbohydrates from bread. Now if only we had an idea about the non-bread portions of the two diets …

Dietary advice on the test diet emphasized low-GI foods, including legumes, barley, pasta, parboiled rice, and temperate-climate fruit, as outlined in previous studies. For the control diet, participants were instructed to avoid white-flour products and replace them with whole-wheat breakfast cereals, study breads, brown rice, and so forth.

Boy, if I didn’t know better, I’d say the canola-bread diet was designed to result in both a higher fat intake and a lower carbohydrate intake, and hence a lower glycemic index than the control diet.

By design, the test diet resulted in significantly greater increases in MUFA and ALA intake and corresponding lower carbohydrate intake, and hence GL, relative to the control diet.

I see. So what this study actually demonstrated is that replacing calories from refined carbohydrates with calories from fat results in better glucose control. And yet the headline in Science Daily was about the wonders of canola oil, and the study’s conclusion was:

A canola oil–enriched low-GL diet improved glycemic control in type 2 diabetes, particularly in participants with raised SBP …

I’m thinking the canola oil itself had nothing to do with it. The answer to Sowell’s question (“Compared to what?”) is that compared to a diet that includes bread and cereal, a fattier diet with a lower glycemic index is better for diabetics.  Perhaps canola oil got such a special mention because of this fact, which appeared at the bottom of the Science Daily article:

This research was funded by the Canola Council of Canada, Agriculture and Agri-Food Canada, Loblaw Companies, and the Canada Research Chairs Program.

For the record, I don’t know if canola oil has any harmful effects on humans. There are internet articles claiming canola oil will cause a slew of health horrors, but I don’t find those articles convincing. Perhaps canola oil has a neutral effect on health. But I don’t consume the stuff for two reasons:

One, the whole pitch for canola oil is that it’s mostly monounsaturated, like olive oil – i.e., it’s very low in artercloggingsaturatedfat! Well, heck, even TIME magazine has come around to admitting that there’s no need to avoid saturated fat. (Check out this TIME video on that subject.) So at best, canola oil is an answer in search of a problem.

Two, this is how it’s made:

I’d rather not consume a fat that has to be bleached and de-odorized before it reaches a state we could charitably call “not disgusting.” Coconut oil, butter, bacon grease, beef tallow, chicken fat – they all taste great without any industrial processing. And if you replace the refined carbohydrates in your diet with any one of them, you’ll probably end up with better glucose control.

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41 Responses to “How To Sell Canola Oil With Almost-Science”
  1. Boundless says:

    > … I don’t know if canola oil has any harmful effects on humans.

    Having an unfavorable n6/n3 ratio, and probably nil DHA or EPA in the Omega3, it probably is not beneficial on that basis alone. Then we have the issue processing residues and other processing side effects. Then we have a pretty high likelihood that the crop was GMO, with unknown genetic issues, plus glyphosate or glufosinate ammonium uptake (as that is the whole point of the RR- and GA-resistant strains).

    And of course, there is no heirloom strain (other than actual rapeseed), as “canola” is a relatively recent forced hybrid. Supposedly (prior to the GMO variants) only “traditional” breeding techniques were used, but in industry parlance that could include radio-mutagenesis, chemo-mutangenesis, embryo rescue and other extreme techniques excluding explicit gene insertion.

    Canola is mutant rapeseed.
    Rapeseed itself is questionable as a human food.

    Thanks for tearing into the report. It is 100% typical of what passes for science in contemporary nutrition research. Expect it to be distorted and amplified by mass media, perhaps a Time “drink more canola oil” cover to cancel out the recent butter recant.

  2. fredt says:

    The video has missed a bit. Human food canola, in the plant that I am familiar with, only uses cold pressed for food grade. Freeze it to remove wax, steam and filter to reduce the foam and odor a bit, shipped by truckload to a bottling plant. The remainder goes to industrial canola. Normal industrial canola is equal price, and when treated to low foam standards brings a higher price.

    Now the anti canola group will likely tell you otherwise, and I do not know what happens in other plants, but the oil from here is the best of the seed oils. I, personally, use very little oil anyway, maybe 4 liters a year.

    Not my circus, not my monkeys, I just visit with the monkeys.

  3. Mark says:

    Your clip (when originally posted) made me stop eating canola oil. Plus, canola’s a GMO so no thanks.

  4. Compare the results in that study with this similar, but better controlled, and longer lasting study http://www.ncbi.nlm.nih.gov/pubmed/24625239
    The control was soy/safflower oil – canola and olive groups both had improvements in NAFLD.
    Canola oil group also had lower BG, insulin, etc.
    But – only the olive oil group had NORMAL glycemic measures by the end of the study.
    I suggest the Canadians run their study again using olive oil as control.
    And that both groups redo their studies with a ghee group.
    I think it likely that just restricting PUFA and linoleic acid produced benefits in olive oil group – and the extra omega-3 in the canola oil group was not a complete substitute for cutting omega-6.

    • Tom Naughton says:

      Good suggestion, but of course they’ll never do that.

      • Jill says:

        Seriously Tom, with crowdfunding sites available now, no reason devoted Fatheaders and Wheat Belly aficionados couldn’t fund just such a clinical trial if you or someone else wanted to organise it….

        And think of the publicity potential!

  5. Bret says:

    “An answer in search of a problem.” Love it!

  6. gallier2 says:

    Avoid industrially deodorized oils anyway.

    Minor component Refining target (concentration in fully refined oil)
    Trans Fatty acids < 1.5% for oils rich in linolenic acid (soybean oil, rapeseed oil, canola, etc)
    < 1.0% for other vegetable oils (corn oil, sunflower oil, etc)

    http://lipidlibrary.aocs.org/processing/deodorization/index.htm

  7. NM says:

    So what this study’s headline accurately should have been is:

    “Digesting Less Glucose is Reflected by a Blood Marker That’s Used to Indicate One Has Digested Less Glucose”.

    Somehow, that’s less interesting to the Canola paymasters.

  8. TMA says:

    Great post Tom. It is amazing how these oils are just declared to be healthy because they are “vegetable oils.” Yes, because when we hear the word “vegetable” we all think of rapeseed, safflower and cottonseed. The burden of evidence should be on these chemically-extracted oils to prove they are not harmful, since, as you point out, we have much more natural and time-tested oils at our disposal.

    • Tom Naughton says:

      Unfortunately, the powers that be did the opposite: they assumed that saturated fats are bad, and therefore oils low in saturated fats must be good.

  9. Zenmooncow says:

    7% of canola is saturated to if your eating high amounts of it, fast and highly processed foods.
    A pizza here, a donut there , french fries , hamburger bun , A bag of potato chips

    If you eat 1000g of this stuff a day guess what:

    You’re still eating a lot of saturated fat, except it’s less stable and less satisfying than animal fat.

  10. Lawrence M says:

    “This research was funded by the Canola Council of Canada, Agriculture and Agri-Food Canada, Loblaw Companies, and the Canada Research Chairs Program.”

    There’s no way this study could have come out with any other outcome with sponsors like those! It’s really criminal that studies like this can actually get published and are allowed to influence people who have no clue that it’s basically a paid product advertisement being passed off as science.

    Same thing happened with a study a couple months ago by some researcher who had previously published a study about gluten sensitivity. Now he published a new study saying he was wrong and that there’s no such thing as gluten sensitivity. Turns out the study was funded by the largest maker of bread in Australia. Hmmm.

  11. Curtis Miller says:

    Hmm I once thought that science was supposed to start with no bias and go from there, I guess I was wrong.

    Nice post Tom. In Sally Fallon’s book “Nourishing Traditions” she mentioned how they make margarine, which for the most part is pretty disgusting. After my mom found out she went back to eating butter.

    Another thing that amazes me is the wasted money trying to prove the new “man made” products are healthier for you than what people have ate for thousands of years. The saying “The definition of insanity is doing the same thing over and over and expecting a different result” seems to apply here.

    Also have you ever seen the documentary called Farmageddon? Just watched it last night and would love to hear your comments on it.

  12. Elle says:

    “For the record, I don’t know if canola oil has any harmful effects on humans.”

    There is definitely a harmful effect on my tummy. Soybean oil gives me an upset stomach. But my body wants to get rid of canola oil as fast as possible. To the extent I have a hard time believing our bodies were designed to consume it.

    • Tom Naughton says:

      I don’t think we were designed to consume any chemically extracted seed oils. I probably should have said I don’t know if canola oil is any worse than any other vegetable oil. I think they’re pretty much all at least a little harmful because they displace beneficial fats in the diet.

  13. Nowhereman says:

    The sad thing about this is if you completely ignore the horrible conclusions and view the study objectively, the study itself is actually decent science, with some very interesting possibilities. But the conclusion (the one paid for by the canola companies) is so different, that it comes to anyone actually looking at the study as someone filed off the original conclusion (carbs and sugar are bad and going low carb and low sugar while substituting a fat in their place helps diabetics) to an insert of canola oil helps diabetic.

    In short, if the study had been conducted without undue influence by the canola mafia, with proper controls put in place, it might well have been a very good study that came out in favor of low-carb, low-sugar.

  14. A Canadian says:

    This is completely unrelated but:
    https://www.youtube.com/watch?v=Y5QUDFZ10Z8
    Imagine if say the Daily Show people made a spoof like this about the U.S. debt.
    #canadian #humblebrag

    Hey, where does canola oil come from anyways? And are the people there wasting their tax dollars subsidizing this industry? (The same industry that then pays for these lobbyists)
    Boy, I sure wouldn’t want to be them!

    If I were a Hindu or Buddhist I’d swear this is karma for U.S. environmentalists spreading anti- harp seal hunt & anti- Oil Sands propaganda. (Not that Canadians aren’t doing that too – thanks a lot, David Suzuki)

    I wish Canadian environmentalists would go after Big Canola.

    I was just reading Ezra Levant’s book Ethical Oil & looking around Youtube. Seems Saudi Arabia is giving money to Canadian protesters to go after the oil sands now that we’re starting to be able to export it. There’s an American environmentalist group that wants to block development of the Northern Gate which would pipe oil from Alberta to the Canadian West Coast…..bypassing the U.S. altogether. I’m sure that’s just a coincidence & they have no ulterior motives… no need to “follow the money”

    Saudi light crude oil that used to come in to some of our pipelines will now be replaced by Canadian heavy crude that’ll be exported.
    Our oil sands suffer from such bad propaganda there are protesters who’d literally prefer to keep the Saudi oil flowing…. Saudi Arabia a country that has the Koran as the constitution, treats women as slaves & funds international Islamic terrorism has a better public image than us. Same thing with Venezuela, the communist anti-America dictatorship that also has oil sands but looser environmental standards.

    fun fact: Canada has an estimated reserve of 1.7 trillion barrels of heavy crude (and that’s a conservative estimate). This is more than all the world’s current known reserves of light crude.
    It also costs more to extract the oil, so we could in effect work as a worldwide safety valve if prices soar, feeding North America for 100 years while scientists get to work on matter-antimatter warp drive technology

    • Tom Naughton says:

      The YouTube video apparently doesn’t play in the U.S.

      • A Canadian says:

        It was a comedy skit about the Canadian Mint making a coin celebrating the large 57 billion $ gov’t deficit budget they were having that year. It showed money being flushed in a toilet.
        Cost of the coin: 1,650$ (each Canadian’s share of the deficit)

  15. B35 says:

    I am finished with my first day of Health Class, most of the day was about self-esteem and being who you are and kindness to others and stuff like that. We got our outdated health books today and they recommended a low-fat low-cholesterol diet, which made a small part of me want to go to the authors and blast a bunch of holes in the so called “perfect” diet endorsed by the USDA and other paid off nutritional “experts”. Luckily I found that we will not be using those books because they are outdated.

    I myself had only gotten 3 hours of sleep, so I honestly was really in no mood to debate anyone about what constitutes a diet. But I borrowed a few lines from Fat Head when a few of us were talking about the “Health” books and how we heard we would watch Supersize Me later.

    Hopefully a few kids won’t buy into the low-fat high-carb and sugar diet that everyone is pushing. Things may be looking up for real nutritional science after all

    • Tom Naughton says:

      We can hope.

      • B35 says:

        Semi-good news though, I looked at the posters in the room, and it seems they are saying that eating too many carbohydrates is not good for you. Bad news is that the overall aspects of the room seem to still promote a low-fat diet. I am happy that at least they are saying to many carbs is bad for you.

        Also, does anyone know a study on what effects different diets have on you if you happen to not get much sleep?

        • Tom Naughton says:

          The anti-fat message has been pounded in for so long, it will be difficult (if not impossible) for some “experts” to let go of it.

        • Walter Bushell says:

          But, but and butt. If you don’t eat carbs or fats you’re going to die one way or another unless you get the bulk of your calories from alcohol.

          Which I think is a bad idea.

  16. I consider any scientific study that feeds bread to diabetics to be unethical. Here, have some cyanide with that: we want to see what it does to you.

    • Tom Naughton says:

      Agreed, but of course the irony is that for years it was considered unethical to put diabetics on a high-fat diet in a study — that’ll give them heart disease, you see.

  17. Thanks Tom. We were discussing this Canola study on a diabetes forum. I’ve now shared your article there too.

  18. B35 says:

    I just found out from my father that the new breakfast meals provided to preschoolers consist of mostly a smuckers waffle or pb and j sandwich, fruit juice, a piece of fruit, and cereal. In all it is more than 40g of sugar, not counting the piece of fruit, I don’t even know how many carbs are in there besides. Needless to say, only a few grams of protein and a tiny bit of saturated fat, if any, is present in that so called “balanced breakfast”. They essentially are feeding these kids sugar, sugar, and more sugar. I don’t even know what the lunch is like.

  19. Glen says:

    The canola oil extraction process is very similar to coconut oil extraction. It’s also (as fredt said) not the only way of getting the oil. Canola is a nice, natural seed oil that has been used for thousands of years.

    • Tom Naughton says:

      Thousands of years? By whom?

      • Joe says:

        Maybe Glen was confusing rapeseed oil for linseed oil (also know as flaxseed oil) which has been used for hundreds of years for furniture polish and is the oil in the oil paint used by artist for hundreds of years.

        Just a thought.

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