If You Think Canola Oil Is Good For You. Think Again
Canola oil is regularly promoted as a healthful cooking fat. A new study, however, suggests that it could be more harmful than helpful — particularly for the brain.
Even though canola oil is a vegetable oil, we need to be careful before we say that it is healthy.
With high polyunsaturated fats and low saturated fats, canola earned its reputation as a healthy oil alternative when we were learning how devastating trans fats are to heart health. It has the lowest percentage of saturated fats of any vegetable-based oil and a decent amount of phytosterols, compounds linked to lower cholesterol. It’s also inexpensive, especially compared to olive oil—the king among healthier oils—making it one of the most popular cooking oils in the world.
While its heart-healthy reputation is respectable, little research has investigated canola’s effect on brain health. Recent studies have found positive correlations between olive oil and brain function, including a potential decrease in risk of developing Alzheimer’s disease. The latest study on canola oil found much the opposite.
Researchers used a mouse model to examine the effects of a diet rich in canola oil versus a normal diet on brain tissue. One group of mice was given the human equivalent of two teaspoons of canola daily, the other group was fed a normal diet; both groups were observed for six months.
At the end of the study, the research team found that the mice fed canola oil had a significantly worse working memory than the control group. And their brains showed a reduction in a particular peptide, amyloid-beta 1-40, which the researchers said leads to an increase in the toxic amyloid proteins associated with Alzheimer’s disease.
“Amyloid-beta 1-40 neutralizes the actions of amyloid 1-42, which means that a decrease in 1-40, like the one observed in our study, leaves 1-42 unchecked,” explained senior study investigator Dr. Domenico Praticò, of the Lewis Katz School of Medicine at Temple University. “In our model, this change in ratio resulted in considerable neuronal damage, decreased neural contacts, and memory impairment.”
The researchers noted that the mice fed canola oil also gained more weight than the group fed a normal diet.
Since this was a mouse study, it’s difficult to say exactly how these outcomes translate in humans, or if they do. As a preliminary look into canola’s effects on brain tissue, the results are concerning while not conclusive.
“Even though canola oil is a vegetable oil, we need to be careful before we say that it is healthy. Based on the evidence from this study, canola oil should not be thought of as being equivalent to oils with proven health benefits,” said Dr. Praticò in a recent press statement.
The study was published in the journal Scientific Reports.
Healthy Cooking Oils. Replacing bad fats (saturated and trans) with healthier fats (monounsaturated and polyunsaturated) is better for your heart. One way you can do this is by choosing healthier nontropical vegetable oils for cooking and preparing food.
Remember: There’s no cutting calories.
Every oil out there has about 120 calories and 13 g of fat per tablespoon—there’s no variety that’s magically lower in calories than all the rest. What really makes cooking oils different is their composition: Each one has a unique ratio of saturated fat to monounsaturated fat (MUFA) to polyunsaturated fat (PUFA). This ratio determines whether the oil is a solid or a liquid, how well it can withstand high temperatures, and what effects it’ll have on the human body.
Choose “cold-pressed” and/or “expeller-pressed” when possible.
These terms refer to the way the oil was processed. Cold-pressed oils are pressed at low temperatures, which means they retain all the flavors, aromas, and nutrients that would otherwise be destroyed by heat. Expeller-pressing is another clean way of producing oil: It means that oil was extracted mechanically (i.e., good old-fashioned squeezing) instead of chemically. Olive, sesame, sunflower, canola and coconut oil can all be extracted using cold-pressed methods and used for flavor in marinades, salad dressings, and baked goods.
Pay attention to smoke. point
Smoke point is the temperature at which oils start to break down, lose nutrients, and develop off flavors. (You’ll know it’s happening if the oil is letting off wisps of smoke.) Some oils have higher smoke points, so they’re better for high-heat cooking like deep frying and searing. Other oils have low smoke points, and should probably be reserved for applications like dressing. Here is a link to each oil’s smoke point so you can choose accordingly. A simple rule of thumb is that the lighter the color of the oil, the higher its smoke point.
Saturated fats – Bottom line is, the fewer the better. Less than 7 percent of your daily fat calories should come from saturated fats. Cut back on saturated fats by avoiding dairy items (milk, cheese, yogurt, etc) that are labeled “whole” and “2 percent.” Limit the amounts of red meat and other animal proteins you eat. You can do this by cutting back how often you eat them, how much of them you eat at a meal or both.
Trans fats – Eliminate all trans fats from your diet by staying away from foods that contain hydrogenated or partially hydrogenated oils. (Read the ingredient list!) Shortening and stick margarine contains trans fat.
Monounsaturated fats –Eat plenty of olives, avocados, and nuts. Use olive oil for cooking and vegetable oil for baking.
Polyunsaturated fats – You probably get enough omega-6 in your diet, so focus on having more foods packed with omega-3 (salmon, walnuts, etc).