Canola, a vegetable oil that has long been touted as a healthier alternative for cooking and salad dressings, may not be as healthy as people think. A new study published in the current issue of Nature has found a link between consumption of canola oil and dementia.
Canola is made from the seeds of a plant from the brassica family, which also includes cabbage, mustard, brussels sprouts and broccoli. The canola plant itself is the product of selective breeding by Canadian scientists during the late 1970s. The purpose was to remove the eruric acid, a substance long thought to be toxic in high doses (this conjecture has been supported by recent studies in the European Union).
Today, canola oil is among the most popular oils among consumers and is widely used in the restaurant industry. There are several reasons for canola’s popularity: it is inexpensive, has a high smoke point and can be used at temperatures of up to 460º Fahrenheit, has little in the way of a distinctive taste, and is low in unsaturated fats. Because of that last point, it is considered “heart healthy.”
While canola may reduce the risk of heart disease, science is now raising serious concerns about its effects on the brain. Specifically, long-term use of canola oil may cause a build-up of amyloid plaques in the brain – a condition strongly linked to Alzheimer’s disease and other neurodegenerative disorders. On top of that, it has also been implicated in weight gain.
Professor Domenico Praticò, a professor at Temple University’s Lewis Katz School of Medicine, was one of the authors of the study. He says, “Canola oil is appealing because it is less expensive than other vegetable oils, and it is advertised as being healthy. Very few studies, however, have examined that claim, especially in terms of the brain.”
Praticò and study co-author Elizabetta Lauretti had previously studied the effects of extra-virgin olive oil on the brain. In that study, laboratory mice genetically engineered to have Alzheimer’s disease were fed a diet rich in olive oil. Those mice experienced an improvement in memory function as the plaques in their brains were reduced. In the current study, extra-virgin olive oil was replaced with canola for a year. The mice who were fed canola oil demonstrated significant memory impairment when subjected to a maze test. Furthermore, there was an increase in the formation of plaques in their brains as well as a loss of synapses (connections between neurons).
In addition, the canola group of mice experienced substantial weight gain.
Praticò says, “Based on the evidence from this study, canola oil should not be thought of as being equivalent to oils with proven health benefits.” He notes that there is more work to be done. Follow-up studies are being planned to determine if short-term consumption of canola oil can be harmful to the brain, as well to learn more about the extent of the brain damage – and whether or not the effects are specific to Alzheimers. “There is a chance that the consumption of canola oil could also affect the onset and course of other neurodegenerative diseases or other forms of dementia,” Praticò notes.
Aside from its dubious health benefits, it should be pointed out that nearly all canola oil is genetically modified – and it all likelihood, those plants were sprayed with glyphosate – the active ingredient in the controversial herbicide, Roundup. Even “organic” canola is likely to be contaminated. Further study is called for, but what is presently known about canola oil strongly suggests that its purported health benefits are overstated and people would do well to avoid having it in their diets.