In my last post, I looked at the debunking of the war on saturated fat which showed that the fat was getting some undeserved bad rap. One brilliant reader suggested that I do some research on canola oil as a follow-up to that article, and so here we are today looking at the controversy surrounding canola oil. Initially, I was confused because as far as I knew, canola oil is beneficial to health. Turns out there is a lot going on with this oil, and there is some debate on whether it is good or bad.
A brief history
Canola oil is the product of rapeseed oil modification that was undertaken by Canadian scientists back in the day to make the oil safe for human consumption. In its original state, the rapeseed oil contained erucic acid and glucosinolates. Erucic acid has links to heart muscle damage, and the glucosinolates prevent the body from absorbing iodine and also give the oil a bad taste. The genetically modified oil we now have is low in both glucosinolates and erucic acid.
Canola oil became popular after it was shown to have a positive effect on heart health, insulin sensitivity, and overall well-being. Canola oil is high in monounsaturated fat (about 63%, and nearly as high as olive oil) and it has phytosterols that absorb cholesterol. The oil is known to lower both LDL cholesterol and triglycerides while maintaining the levels of HDL cholesterol. Cholesterol remains one of the common risk factors when it comes to three of the world’s deadliest diseases – heart disease, stroke, and type 2 diabetes.
In the past, canola oil also boasted of low levels of saturated fat, but this fat is quite irrelevant now. Besides these health benefits, the oil has a low smoke point which makes it ideal for frying and many people view it as one of the affordable healthy oil options. Currently, canola oil is the third most produced oil in the world and it is very popular in China and India, where it is considered part of a healthy lifestyle.
Canola oil comes with a bit of baggage. One of the supposed benefits of the oil is its 28% polyunsaturated fat which includes both omega-3 and omega-6 fatty acids. Polyunsaturated fat is one of the healthy fats, but if the balance between omega-3 and omega-6 is not maintained at around 2:1 it becomes problematic. Research has shown that most diets do not deliver the right balance of the fatty acids and most people are in the 15:1 range. This means that instead of canola oil consumption being healthy, it may actually contribute further to this imbalance.
Fatty acids fight inflammation, but when an imbalance occurs, it actually increases the chances of inflammation, which in turn increases the risk of health problems such as heart disease, cancer, and diabetes. To top it all, the omega-3 from plant-based sources, of which canola is one, exists in a short-chain form which requires conversion into long-chain fatty acids before it is appropriate for use in the human body. Unfortunately, our bodies are not very efficient at this conversion, and this raises the proportion of omega-6 further.
The processing that canola oil undergoes raises some concern. The oil extraction involves the use of hexane, a solvent that is also a widely known neurotoxin. Canola oil manufacturers claim that all the hexane is removed during processing. Although there is no evidence showing any health risk due to ingesting traces of hexane, this is still worrying. The oil also goes through a deodorization process which is known to create trans-fat, and we know that this fat is bad news. Again, manufacturers claim that they keep on modifying processes to limit the number of trans-isomers.
Most of the oil we buy comes with the ‘no trans-fat’ label, however, an independent study revealed that most of the commercial canola oil contains 0.56-4.2% trans-fat. The labels are there because the amount of trans-fat in the oil is considered safe according to food safety standards. This misrepresentation of the truth is unsettling and it raises the question of what else is kept under wraps about the production process.
Other not-so-great things I found out about canola oil include the synthetic antioxidants it has and the genetic modification. Canola oil manufacturers add synthetic antioxidants to make the oil last longer, however, these antioxidants are potentially carcinogenic and toxic if consumed over a prolonged period. Additionally, the canola plant was made resistant to glyphosate (the main ingredient in the herbicide, Roundup) when it was genetically modified. This is good for business but not for health. The plant is continually exposed to the glyphosate which has links to fertility problems, hormone disruption, cancer, heart disease, and neurological problems.
Canola oil received a lot of attention when it was the subject of a study which showed a possible link to an increased risk of Alzheimer’s. I was not shocked by the study itself, but I was taken aback by the people who went on to conclude how terrible canola oil is, based on an incomplete study. The 2017 study conducted by Elisabetta Lauretti and Domenico Praticò claimed that mice which were on a canola oil diet displayed inhibited learning ability and signs of working memory suppression.
Just by going over the study, I could see that there were a lot of gaps in the methodology. For starters, no group of mice was subjected to another oil diet, e.g. olive oil, for comparison. Additionally, the results were inconclusive as the mice only showed a slight difference in one out of three behavioral tests, and one protein analysis. I wonder how these results led to the ‘significant deficits of working memory’ conclusion.
Furthermore, I would obviously expect the mice feeding on fat to show signs of obesity compared to those on a normal diet, without even being told. I also think the obesity distorted the results to a large degree before we even consider how inconclusive they were. I was happy that the researchers themselves did say the results require more study. It is safe to say that those people who went on to conclude that canola oil causes or increases the risk of Alzheimer’s made the wrong conclusion. There is no direct link between the oil and the disease at the moment, especially considering that it has not even been established among mice
And the conclusion
I am no medical expert, but I do like to use relevant and verifiable facts to draw conclusions. From the research that has been conducted, it is widely accepted that canola oil lowers cholesterol, however, there are concerns over its production and overall health. Canola oil has its benefits and shortfalls, but so do other oils. For example, sunflower oil receives commendation for its health benefits, but it is very high in omega-6 and it is probably not a great cooking oil choice.
The question is whether canola oil benefits outweigh the bad. Are we not just better off vying for other cholesterol-lowering foods, and should we stop using canola oil altogether?
I think it is all about taking everything with a dollop of caution. The best idea is to work toward keeping everything healthy and consuming moderate amounts of oil. I do believe that canola oil is not as bad as other vegetable oils (no study has established any direct link to any disease), but I think that its health benefits are overrated. Those levels of omega-6 are quite high, and remember, most of the canola oil we consume is highly processed, and we know not to trust these processed foods.
The good thing is that there are other options. Olive oil, especially extra virgin, is almost always the best, and perhaps the healthiest choice. The problem is that olive oil is quite expensive and it has a low smoke point which makes it ideal for drizzling, sautéing, and baking, but not for deep-frying. Some cheaper, healthy alternatives that have higher smoke points include coconut, grapeseed, and avocado oil.
Why not keep some olive and other healthy oils at hand, and avoid cooking with canola oil unnecessarily. If you really have to use canola oil make sure to do it sparingly, and if you have a bit more to spend, go for cold-pressed canola oil, which is better because it skips the heavy processing bit. Incorporate natural sources of healthy fats into your diet including fatty fish, seeds, and nuts, and use healthier forms of cooking like steaming, boiling, and grilling. Whatever you do, keep it healthy, and stay informed – who knows what we will be told next?