Canola oil, found in countless foods, is a vegetable-based oil. Canadian scientists developed a version of the rapeseed plant that's edible, which by itself, harbors toxic compounds known as glucosinolates and erucic acid. The term "canola" comes from "Canada" and "ola" indicating oil. Many individuals have taken canola oil out of their diets because they're worried about its production methods and health effects. If you're wondering whether you should use canola oil, you might want to read the below studies that have examined its effects.
Canola oil is high in omega-6 fat content, which is one drawback. When you increase your omega-6 to omega-3 fatty acid ratio, it increases your obesity risk, according to a study published in the National Institutes of Health. In the past several decades, saturated fat and total fat intake as a part of total calories has been continually decreasing in Western diets, whereas the intake of omega-3 fatty acid decreased and the intake of omega-6 fatty acid increased.
This results in an increase in the ratio of omega-6 to omega-3 from 1:1 to 20:1 or higher today. This fatty acid composition change parallels a substantial increase in the prevalence of obesity and overweight.
2. Cognitive Decline and Incidence of Dementia
The journal Scientific Reports published a study where researchers studied mouse models of Alzheimer's disease. The researchers found a canola oil-rich diet worsened memory issues over six months as well led to weight gain.
When the mice that were fed a canola oil-rich diet were compared to mice fed a regular diet, the researchers found the mice fed the canola oil-rich diet experienced weight gain and substantially worse working memory. Also, the mice fed the oil showed a decrease in a form of amyloid-beta known as 1-40, which was linked with an amyloid-beta plaque formation increase and damage to synapses — structures that are responsible for brain cell communication.
Translational Psychiatry published a 7-year longitudinal study of the omega-6 to omega-3 polyunsaturated fatty acid ratio (PUFA) and mood disorders that followed in young individuals with an at-risk mental state. While some studies suggest that individuals with a mood disorder have a greater PUFA ratio and lower omega-3 PUFAs, it's not known if a high n-6/3 ratio means depression vulnerability. Researchers tested this theory in a follow-up study lasting seven years of young people with an ultra-high risk (UHR) phenotype. This greater n-6/3 PUFA ratio predicted mood disorders in UHR people over a seven year follow-up.
4. Heart Disease / Cardiovascular Disease
Research published in journal Biomedical & Life Sciences shows high levels of omega-6 to omega-3 ratio are linked with increased total cholesterol, cholesterol/HDL-c ratio, LDL-cholesterol, triglycerides and apo B levels.
According to the journal Atherosclerosis, 14 cis and trans isomers of both octadecadienoic and octadecenoic acids are the trans-fatty acids in partially hydrogenated vegetable oil that are to blame. It's been shown these fatty acids cause calcification and inflammation of arterial cells. Your risk of coronary heart disease increases with:
Calcification and inflammation of arterial cells
These days, most canola oil is partially hydrogenated, creating trans fat in the oil. If food has below 0.5 grams of trans fat within one serving, the FDA permits the food label to read 0 grams of trans fat. However, this "hidden" trans fat can still lower good cholesterol (HDL) and raise bad cholesterol (LDL).
The National Institutes of Health published a study that examined hypertensive, stroke-prone mice fed canola oil for a 25-day period to see how it affects their health. The study found canola oil had these gateways to cardiovascular disease.
Lowered glutathione production (your body's ultimate antioxidant that flushes your body of toxins)
Reduced their antioxidant status
Increased plasma lipid levels
6. Lung Inflammation/Asthma
EurekAlert published a study that shifts our understanding of vitamin E, tying the increased consumption of seemingly healthy vitamin E-rich oils (soybean, canola, corn) to the increasing incidence of asthma and lung inflammation.
In a study testing the effects of consuming oil on lung inflammation, the scientists found a direct link between high GT levels (a form of vitamin E found in Canola oil) and heightened lung inflammation. A 10 percent lung function reduction from inflammation for a healthy person is similar to giving them asthma.
While Canola oil has been a popular fat source for cooking in individual’s homes and commercial kitchens for baking, frying and sautéeing for years, research and studies have now revealed that what was previously thought as a healthy oil, may now be harmful to health.