Although one of the most widely used oils in the food industry, there are still concerns about the safety of canola oil. This fear arises, partly, from the extensive processing that is needed to extract the oil, and partly through the hydrogenation of the oil that increases the amount of trans fat in the final product. So, is canola oil safe?
Though common along the shopping aisles, there is little work done on the effect of canola oil on humans. The canola oil industry primarily sponsors the research that is available on humans, and so caution is needed when interpreting the results. However, there have been plenty of studies on animals, as well as a handful targeting humans, which may indicate a possible negative impact on health.
There have been many studies that link canola oil to oxidative stress and increased inflammation in animals. In rats fed on a diet including canola oil, levels of antioxidants were found to be lower, while levels of ‘bad’ cholesterol increased. However, as with all animal-based research, caution should be applied in interpreting them too far, as effects on humans can differ.
Canola oil was once considered a heart-healthy option, but recent studies have started to suggest this may not be the case. Previously, vegetable-based alternatives to saturated fats were assumed healthier. However, saturated fats are no longer considered a problem, with a 2018 research article in the Nutrition Journal suggesting that making the change from animal-based fats to vegetable-based fats has little, if no, effect on heart health.
A human study that compared the effects of a diet containing refined oils, such as canola oil, with extra virgin olive oil, showed significant benefit in brain function for the olive oil group. While this is more of a benefit of olive oil, rather than a disadvantage of canola oil, it shows that healthier alternatives may exist.
The research currently available suggests there may be harmful effects associated with using canola oil, although nowhere is this conclusive. However, it is interesting to note that in a significant proportion of the studies indicating a negative impact, the comparison is against extra virgin olive oil, one of the most widely researched oils available. With this in mind, it seems sensible that extra virgin olive oil should always be the preferred option if possible.