Olive Oil vs. Canola - Healthy, Healthiest, or Not?

Olive oil or canola? There is some disagreement as to which is the best cooking oil to use.  Some sources say olive oil is the healthiest oil for cooking, others recommend canola.  Setting aside other possible contenders like the resurgent coconut oil, between olive oil and canola which is better?

What is Canola? (Canadian Oil Low Acid) - Canola Facts

Canola is a vegetable oil derived from rapeseed that has been been bred using traditional breeding techniques. Canadian researchers pioneered this process to reduce the higher erucic acid levels and its associated toxicity found in natural rapeseed. It explains canola's name which is a contraction of Canadian oil low acid. Canola advocates say that its greater polyunsaturated fat content and lower saturated fat content than olive oil's argue for its superiority. They point to observational studies that show reductions in cardiovascular disease from substituting polyunsaturated fats for saturated fats, a finding that cannot be said of carbohydrates and is unclear for monounsaturated fats.

Possible Canola Dangers

Canola's detractors think the evidence for the benefits of polyunsaturates and the evils of saturates weak with the reality possibly being the reverse.  They argue that the studies showing benefits from polyunsaturated fats didn't segregate the effects of polyunsaturated omega 3 fatty acids from those of omega 6s. Therefore the perceived benefits may be due solely to omega 3s while omega 6s may have negative effects.  This is part of the thinking behind the theory that suggests that people should balance the ratio of omega 3 to omega 6 oils consumed in their diets. Saturated fats on the other hand are not as bad as they were once thought; especially as the negative effects of sugar and refined carbohydrates are increasingly recognized and their role as possible confounders in earlier studies on saturated fats sinks in.  Saturated fats are more stable at temperatures below their smoke point.  Polyunsaturated fats are less chemically stable and theoretically more prone to oxidation.  While canola is usually described as having a neutral taste, critics report instances of canola developing a rancid taste and smell.

Others skeptical of canola meanwhile note that canola can be described as man-made and unnatural. Even if accepting of traditional breeding techniques, the majority of seeds used in canola production today are not just the result of traditional breeding but have also been genetically modified. Consequently some see its safety as suspect whether for not enough time having passed for potential problems to come out or a general distrust and aversion of GMO foods. Canola also requires significant processing to extract the oil which exposes it to high heat and chemical treatment during the refining and deodorizing process. The refining does have the benefit of making canola more suitable for higher heat cooking.  

Olive Oil

Proponents of olive oil say that it is the time-tested traditional oil that forms the basis of the healthy patterns of eating described as Mediterranean-style diets.

Extra virgin olive oil is minimally processed and has much higher levels of antioxidant tocopherols and polyphenols. It also imparts a taste which depending on the situation can be a plus or minus.  On the other hand it has a relatively low smoke point. Refined olive oil though lower in polyphenols is better suited to higher heat cooking.

A new study also shows another possible advantage for olive oil.  It turns out that the different kinds of vitamin E in the two oils, alpha tocopherol in olive oil and gamma tocopherol in canola, may have different effects.  In the study the alpha tocopherol in olive oil was shown to improve lung health while the gamma tocopherol in canola worsened lung health.

Articles

O'Connor, Anahad. (May 29, 2014). Vitamin E May Harm, or Help, Your Lungs. The New York Times.