Canola oil - The dangers

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A friend who used Canola oil suddenly found his pots and pans all sticky, gluey and hard to clean.

He was puzzled. He had been told - by his health conscious wife, his sister and the lady at the supermarket - that Canola is the "best" and the healthiest cooking oil. But the way the oil stuck to his pots and pans told him something wasn't right.

When he switched back to using peanut oil. The pots and pans became easier to clean again...

My friend's experience with Canola may not be scientific. But it does raise questions about the goodness of this highly touted oil.

Geneically modified food

Part I of this article had touched on the history and origin of Canola Oil. And we saw that it is an artificial food created through genetic manipulation of rapeseed, whose oil is toxic.

That, in itself, should raise alarm bells. But no. Firstly, the average consumer would not know the history and would assume that Canola is just another plant, like corn or soybean or olive. Secondly, within the scientific community, genetically modified foods or GM foods are not necessarily viewed with suspicion. I once met a nutritionist who declared that "Canola oil is healthy because it is genetically modified."

Erucic acid and Lorenzo's oil The reason for genetically modifying rapeseed - which led to the creation of Canola - is to reduce is content Erucic acid. Erucic aid bitter tasting and it has been associated with Keshan's disease, a condition afflicting women and children, which causes the heart to function abnormally. However, Keshan's disease is caused primarily by a lack of selenium in the diet. Also, traditional societies in China and India that used rapeseed oil for cooking did not have problems with it until they stopped using saturated fats along with rapeseed oil. A 4:1 mixture of Erucic and Oleic acid makes up "Lorenzo's Oil". Lorenzo's oil is a movie based on the true story about a couple's search for a remedy to cure their son, Lorenzo, who suffered from adrenoleukodystrophy (ALD) - a rare disorder that leads to progressive brain damage. Erucic acid may not be as harmful as it is believed to be, but could well have medicinal value.

Such a viewpoint is not surprising. Scientific fiddling with nature is often viewed as a triumph. Another nutritionist I met boasted that a particular "health product" that she was marketing was made by "taking out the bad things from milk and putting in the good things."

While the original Canola was created through genetic modification, further genetic modifications were introduced along the way. Once involved tweaking the composition of Canola to increase its content of Oleic acid, the monounsaturated fatty acid that is abundant in olive oil. This produced High Oleic Canola oil.

Another modification, in 1995, introduced Canola that is resistant to the pesticide, Roundup. Today, about 82 percent of the world's Canola crop is genetically modified. The dangers associated with Canola oil only go to show that GM Foods inevitably come with problems.

Canola - no human studies

Possibly the greatest danger of Canola oil is that no long term studies have been done on humans.

The oil is simply assumed to be "the healthiest" based on its composition of saturated, monounsaturated and polyunsaturated fats. And also based on scientific understanding - as well as misunderstanding - about the value of these different types of fatty acids.

It's like the case with margarine. For decades, scientists declared it to be healthy. It is only now that scientists are starting to realise that the trans fats present in margarine causes heart disease, cancer, obesity and other health problems.

But it is already too late. Over the decades, billions (yes, billions, not just millions) of people have suffered from taking margarine regularly. Yet the idea that "margarine is healthy" remains deeply entrenched.

Will Canola be the next "margarine". Only time will tell. By then, it may again be too late.

The first published studies LEAR oil, performed in 1978, had mixed results. Rats that were genetically selected to be prone to heart lesions developed more lesions on LEAR oil and flaxseed oil, than those on olive oil or sunflower oil. But rats genetically selected to be resistant to heart lesions showed no significant difference between the four oils.

These studies all point in the same direction - that canola oil is definitely not healthy for the cardiovascular system. Like rapeseed oil, its predecessor, canola oil is associated with fibrotic lesions of the heart. It also causes vitamin E deficiency, undesirable changes in the blood platelets and shortened life-span in stroke-prone rats when it was the only oil in the animals' diet. Furthermore, it seems to retard growth, which is why the FDA does not allow the use of canola oil in infant formula. When saturated fats are added to the diet, the undesirable effects of canola oil are mitigated. Most interesting of all is the fact that many studies show that the problems with canola oil are not related to the content of erucic acid, but more with the high levels of omega-3 fatty acids and low levels of saturated fats. - Dr Mary Enig The Great Con-ola

In 1979, the Canadian Institute for Food Science and Technology examined 23 studies that looked at the effects of LEAR and other oils on heart lesions in rats. They found that saturated fats protected against heart lesions while high levels of omega-3 fatty acids correlated with high levels of lesions. Erucic acid showed a lesser correlation with heart lesions.

Another study by the Canadian Institute in 1982, found that when saturated fats in the form of cocoa butter were added to the diets, the rats had better growth and a significant lowering of heart lesions.

In 2000, two Canadian studies found that rats bred to have high blood pressure as well as to be prone to stroke had shortened life-spans when they were fed exclusively Canola oil.

In 1997, Canadian researchers reported in Nutrition Research that piglets developed signs of Vitamin E deficiency when they were fed a milk replacement containing Canola oil – and this was despite the fact that the milk replacement had adequate amounts of vitamin E. Piglets that were fed soybean oil-based milk replacement did not show such symptoms.

In 1998, the same group of researchers reported in the journal, Lipids, that piglets fed Canola oil suffered from a decrease in platelet count and an increase in platelet size. They also bled longer when cut or injured. Again, these effects were reduced when the piglets were given saturated fats.

Another study, reported in The Journal of Nutrition in 1999, confirmed these results.

Trans fats

In her article, The Great Con-ola, leading fats and oils researcher Dr Mary Enig highlights yet another problem with Canola - most of the omega-3s in canola oil are transformed into trans fats during the deodorization process. And if you research about trans fats, you will know that they are very, very harmful.

Dr Mary Enig further draws attention to the fact that adding saturated fats to the diet removes or at least reduces the problems associate with Canola. This leads Dr Mary Enig to question the idea that monounsaturated fats are good for health. She concludes:

Obviously monounsaturated fatty acids are not harmful in moderate amounts in the context of a traditional diet, but what about in the context of the modern diet, where the health-conscious community is relying on monounsaturated fats almost exclusively? There are indications that monounsaturated fats in excess and as the major type of fat can be a problem. Overabundance of oleic acid (the type of monounsaturated fatty acid in olive and canola oil) creates imbalances on the cellular level that can inhibit prostaglandin production. In one study, higher monounsaturated fat consumption was associated with an increased risk of breast cancer. Even the dogma that monounsaturated fatty acids are good for the heart is at risk. According to a 1998 report, mice fed a diet containing monounsaturated fats were more likely to develop atherosclerosis than mice fed a diet containing saturated fat. In fact, the mice fed monounsaturated fats were even more prone to heart disease than those fed polyunsaturated fatty acids.