Scientists in Pennsylvania say the untested claims of canola oil's healthfulness aren't based on facts and that it's better to stick with olive oil.
Canola oil has long been pitched as a healthy cooking oil, but according to a new study that might not be entirely true.
Researchers found that what its manufacturers call “the world’s healthiest oil” is actually linked to obesity, memory impairments and other harmful effects on the brain.
Our data would not justify the increasing tendency of replacing olive oil with canola oil as part of a good and healthy dietary alternative in non-Mediterranean countries.
In recent years, the use of canola oil has become popular due to its low cost and the perception that it shares some of the health benefits of olive oil. However, the chronic consumption of canola oil hadn’t been studied to see how it might affect the development of neurological diseases.
In a recent study, senior author Domenico Praticò of the Lewis Katz School of Medicine at Temple University in Philadelphia and colleagues undertook an investigation to see if it canola measured up to its healthy billing.
The scientists divided mice models with Alzheimer’s into two groups. One group was fed a diet that was augmented daily with the human equivalent of two tablespoons of canola oil, while the other was fed a normal diet.
All the mice were observed for six months. When the mice on the canola-rich diet reached one year in age, they had gained weight and were suffering from a significantly impaired memory, compared to the mice in the control group.
In addition, neuro biochemical analyses showed they had a reduction in synaptic integrity (a synapse refers to the junction between nerve cells where impulses pass). The decrease in synaptic integrity means the transmission of impulses from one nerve cell to another doesn’t function as well. Earlier studies have shown this loss is strongly correlated to the cognitive decline in AD.
The mice that were fed canola oil didn’t show an increase in the amyloid plaque or tau neurofibrillary tangles characteristic of AD. Nonetheless, they had a statistically significant elevation in a parameter called Aβ 42/40, which suggests they had a higher likelihood of accumulating plaque in the brain.
“Overall our findings do not provide support to some of the current ideas suggesting healthy benefits deriving from the regular consumption of canola oil,” the authors wrote. “Although we recognize that more studies are needed to investigate the biological effects of this oil, our data would not justify the increasing tendency of replacing olive oil with canola oil as part of a good and healthy dietary alternative in non-Mediterranean countries.”
In an interview with Olive Oil Times, Simon Poole, physician and author of The Olive Oil Diet contrasted the health benefits of the MedDiet with the apparent health risks of canola oil.
— Dr Simon Poole (@tasteofthemed) December 7, 2017
“While we need to be cautious about extrapolating from animal studies, this study confirms that we can’t replace olive oil with other oils and expect to see the same health benefits. Previous work by the same research team demonstrated advantages in cognitive function with olive oil. These are consistent with other studies that have shown a marked reduction in neurodegeneration in mice with the use of olive oil polyphenols such as oleuropein.
“There is now ample evidence to associate the MedDiet, which involves the regular use of olive oil, with improved cognitive function and lower incidence of AD. The authors of this study are correct in citing the paucity of data on the health properties of other oils which are so often promoted as possible alternatives to olive oil.”
While canola oil boasts a cheaper price than olive oil, it could be costly in terms of harmful effects on the mind and body. The study, which was published in the journal Scientific Reports, shows that health claims attributed to canola oil don’t have merit.