Not the most exciting topic, but many people have mentioned using canola oil. Figured it might be good to post this. Had this in my files & can't find the source(s) now where I copied it from, sorry, but I did research it.
"The Canola Council of Canada has published a report that focuses heavily on the high polyunsaturated fatty acid content of canola oil and the presumed benefits of polyunsaturated oils on various blood parameters (platelet phospholipids, platelet aggregation, eicosanoid production, clotting time). In spite of the many scientific references listed at the end of the report, the author studiously avoids discussion of the toxic effects mentioned by many nutritionists and biochemists, and, instead, attempts to link many of the benefits of Mediterranean-type diets high in olive oil to diets high in canola oil, when in fact, no such evidence is presented, and canola oil has never been part of a traditional Mediterranean diet.
Concerns about the risks of using canola (rapeseed) oil focus on several aspects:
The presence of long-chain fatty acids, including erucic acid, which are thought by some to cause CNS degeneration, heart disease, and cancer;
The high temperatures needed in the refining process to make canola oil palatable, which lead to formation of trans-fatty acids;
Miscellaneous undesirable chemical constituents (thioglycosides and thiocyanates) whose effects are unclear, as their concentration in the refined product is probably very low.
Although Chinese and Indian peoples have long used rapeseed oil in cooking, it was not refined and processed to the extent of modern commercial methods, and it was never considered to be a high quality oil for human consumption. Ayurvedic physicians have for thousands of years classified olive, almond, and sesame as the best oils for human health, and have considered safflower, soybean and rapeseed oils to be undesirable for human consumption except perhaps when no other oil sources were available.
Recent epidemiological studies of high lung cancer rates in Chinese women suggest that wok cooking with rapeseed oil is responsible, rather than tobacco smoking, which was only a weak factor. Chinese rapeseed oil tended to produce the highest emissions of the potentially carcinogenic or mutagenic compounds 1,3-butadiene, benzene, acrolein, and formaldehyde, when compared with soybean oil and peanut oil.
Canola oil contains a long-chain fatty acid called erucic acid, which is especially irritating to mucous membranes; canola oil consumption has been correlated with development of fibrotic lesions of the heart, CNS degenerative disorders, lung cancer, and prostate cancer, anemia, and constipation. [3a, 3b] Canola oil derives from the plants Brassica campestris and B. napus, which have been selectively bred to substantially reduce the erucic acid content. However, some health professionals feel that there is still too much present in current canola oil products for safe use. Some critics of canola oil focus on the fact that rapeseed oil was originally used as an industrial lubricant and known to be unfit for human consumption, although many vegetable oils have been used in industrial applications as well as in foods.
The long-chain fatty acids found in canola have been found to destroy the sphingomyelin surrounding nerve cells in the brain, in some cases leading to a degenerative brain condition remarkably similar to mad-cow disease (bovine spongiform encephalopathy); in advanced cases the brain tissue develops a Swiss-cheese-like appearance, full of holes. Illnesses and conditions that have been associated with canola oil consumption include loss of vision (retinal capillaries are very sensitive and easily damaged), and a wide range of neurological disorders. [3a]
The high temperatures used in canola refining will damage many of the essential fatty acids, which are much more susceptible to damage by heat than saturated fats. (Heat may convert many of the unsaturated double bonds to the "trans" configuration.) While high-quality essential fatty acids are required for human health, in their damaged or rancid forms they become harmful.
Additional problems with canola oil include the presence of minute, but potentially dangerous, amounts of thioglycosides, which have thyrotoxic effects. [3m] To reduce the concentration of these compounds requires processing with alkalinizing agents plus high temperatures; unfortunately, the high temperatures used in processing have other undesirable effects, the most serious of which is the conversion of unsaturated fats to the trans form.
Rapeseed has been selectively bred and genetically engineered [3a] in an attempt to reduce the toxic components and processing methods were developed to further reduce the concentration of undesirable compounds. Prior to its entry into the "health" food market, it was known as rapeseed oil, but savvy marketing professionals knew that the health food market, heavily dominated by young, college-educated women, would not purchase a repulsive-sounding product called rapeseed oil. The name of the selectively bred variety was changed to canola (as in "Canadian oil"; it has been heavily promoted by Canadian government and agricultural organizations) oil; the name rolls off the tongue with a mellifluous sound.
The biochemistry of plants and natural food products is often complex; the total effect of a given food on human health is dependent upon many chemical constituents and their interaction with biochemical pathways of the body. To radically alter our diets based on scientific evidence regarding only a few aspects of this biochemistry is like cooking in the dark.
Common symptom reactions to unhealthy oils and fats, or to an unhealthy balance of the types of fats in one's diet include joint pain and aggravation of arthritic conditions, a general tendency to have increased tissue irritability and inflammation, and, in the case of unhealthy fats such as hydrogenated oils and excessive amounts of fried foods, abdominal fullness and indigestion. While these conditions also may be due to other factors, quality of fats and oils is important. How one feels immediately to within several days after eating specific types of fat is often a useful indicator of whether one's fat consumption is healthy or unhealthy.
Avoid canola oil; there is too much doubt about its safety. Recommended oils and fats, which are essential nutrients, include moderate amounts of meat in the form of clean sources (organically grown, etc.) of beef, lamb, and other red meats, poultry, fish (especially sardines and mackerel), plus olive, almond, or sesame oil; of all the vegetable oils, olive oil is probably the safest and best for health reasons. All of these have been in traditional use in various cultures for thousands of years. Individual differences in metabolism will dictate needs for more or less of these types of oils and fats.
Rapeseed has been around for thousands of years, primarily cultivated in Asia and Europe. But rapeseed oil is loaded with erucic acid, which has been shown to cause lesions of the heart - not a good side effect. So a little genetic manipulation by some plant breeders in Canada created a variety of rapeseed that produced an oil low in erucic acid. They called it LEAR oil, an acronym for Low Erucic Acid Rapeseed.
Meanwhile, the US food industry in the mid-1980s was looking for a new, inexpensive oil to increase production of processed foods. At the time, monosaturated oils, such as olive oil, were being touted as the healthy alternative to saturated and polyunsaturated oils. But olive oil couldnt be produced in the quantities needed for mass production, so LEAR oil was settled on as the practical choice. But it needed a new, more commercial name. They settled on canola - for Canadian oil. And the marketing push was on.
In previous e-alerts I have told you about the importance of omega-3 fatty acids and their benefits to both the immune system and the cardiovascular system. Canola oil contains approximately 10 percent omega-3, giving it an obvious appeal to consumers who, by the mid-80s, were pursuing healthy diets as never before. A marketing strategy was developed to sell the nutritional benefits of canola alongside olive oil and the Mediterranean diet, already branded in the public consciousness as the gold standard of healthy diets.
And the strategy worked. By the mid-90s, canola was considered the healthy choice for cooking and processing. But was it really as healthy as nearly everyone in the food industry establishment claimed?
The zero factor
Canola oil is not a poisonous industrial oil, it doesnt cause mad cow disease, and it doesnt contain chemical warfare mustard gas. These are just three of the most extreme and completely unfounded claims about the horrors of canola.
But canola is not perfect. So far, no studies have been conducted to test the effect of canola oil on humans. But quite a few animal tests have been conducted, and the results are not promising. For instance, there are indications that canola is not healthy for the cardiovascular system, having caused lesions of the heart and vitamin E deficiency in rats. And ironically, one of the primary virtues that makes canola so appealing - the omega-3 fatty acid content - may in fact be the source of a primary problem.
Omega-3 fatty acids become rancid during the heat-intensive processing of canola oil, creating an unpleasant odour (in my mind, the smell is less of a concern than the rancidity, but I digress). The deodorisation process turns a large amount of canolas omega-3 into trans fatty acids.
The Canadian government says the trans content of canola is 0.2 percent, but a University of Florida (US) study in the found trans contents as high as 4.6 percent. This problem is even greater in processed foods where the hydrogenation process sends the trans fat content soaring to as much as 40 percent.
Weve all heard the increasing debate over the dangers of trans fatty acids. A US panel of the National Academy of Sciences submitted a report on their attempt to set a safe intake level for trans fat. The panel reported that trans fat intake creates a serious risk of heart disease, just as saturated fat does. The report concluded with a recommendation that has no grey areas: the only safe intake of trans fatty acids is zero.
Sally Fallon and Mary G. Enig, Ph.D., the authors of the con-ola article, provide an exhaustive and comprehensive look at all the issues surrounding canola oil. But they stop short at making recommendations as to how much canola oil is too much, or if we should be avoiding it at all costs. When I put this question to Dr. Spreen, this was his response:
I dont trust canola at all, for just the reason that there havent been anywhere near enough long-term observations. However, the chemical manipulations involved and the fact that its all being done due to being cheap stuff scares me. Id say intake should be kept to a minimum (you cant avoid it completely...it really is everywhere).
So whats the alternative? What oil should we be cooking with? Olive Oil?
Extra virgin olive oils wonderful, but it does have a unique taste. Im for real butter, palm kernel oil, coconut oil or even lard first, but the negative PR on saturated fat has pretty much killed the use of the last three. Fresh flax oil would be my next choice. (And did you know that the director of the Framingham heart study stated the exact opposite of what weve been told was the result of that study, specifically that the more saturated fat used, the better heart health people seemed to have?)
For now, it would seem that the search will have to go on for a magic oil that we can use for processing and cooking with no adverse side effects. There have been polyunsaturated pretenders, there have been monosaturated contenders, but so far there is no king."