Study: Canola Oil Harms Your Brain
Canola oil is the third most widely produced vegetable after palm and soybean oil. For a long time, canola oil has been touted as a healthy fat. But, is it? A study out of Temple University says not only is canola not healthy, but it can impair your brain function. Even though the trials were carried out on mice, results were so compelling that the researchers specifically advised against swapping canola oil for olive oil.
Canola oil is an edible vegetable oil that comes from a cross-breed of the rapeseed plant. The oil of the rapeseed plant naturally contains high levels of erucic acid and glucosinolates, which are toxic to humans. Canadian scientists developed a variant of the plant that is safe for humans to consume.
Around the same time, the sugar industry heavily influenced studies that associated fat intake with heart disease. As these studies demonized saturated fats, which made room for unsaturated fats and oils like canola to be raised on a pedestal as a healthy fat.
But, is it good for you? At a glance, it seems healthy. On further investigation of production practices and how its fatty acids work in your body, it looks like it may not be healthy. Here’s a breakdown of canola oil, how it’s made, and how it can affect your health.
Is canola oil good for you?
Some will say canola oil is one of the healthiest oils you can buy based on its fatty acid profile. Others look beyond the label at growing, processing, and production practices. Here’s what we know.
GMOs and agricultural chemicals in canola oil.
Over 90% of canola oil produced in the U.S. is genetically modified. In 1995, agricultural engineers developed canola plants that could withstand heavy spraying with glyphosate, a widely used agricultural weedkiller. Glyphosate residues are often found in foods long after they’ve left the fields, which is a problem because glyphosate is linked to various conditions like microbiome disruption and certain cancers.
Canola oil processing—it's extensive.
All vegetable oil is processed to some degree. The concern comes in when oils are highly processed. Here is how canola oil is made…
- Separate out the seeds. Cleaning the seeds removes plant material and dirt from the crop.
- Grind the seeds. Seeds are heated to weaken the shells, then rolled with large rollers to crack the shells.
- Heat the seeds. The cracked seeds are heated to temperatures up to 220 degrees Fahrenheit for around 20 minutes, which extracts over half of the oil.
- Mix with solvent. A solvent called hexane is used to extract the remainder of the oil.
- Hexane removal. Heating the oil and seed mixture removes the hexane, but there is concern that some hexane is left behind and ends up in the final product.
- Refine the oil. The oil is further refined by steam distillation, filtration, or treatment with phosphoric acid.
- Deodorize the oil. If a vegetable oil has a neutral taste, it has been deodorized, which involves more heat. This can convert some of the good fats into trans fats.
- Add preservatives. Canola oil oxidizes readily, so manufacturers have to add chemical antioxidants like BHT, BHA, or others so that it remains shelf-stable.
For comparison, to make olive oil, manufacturers press olives. That’s it—something to think about...
The fatty acid profile of canola oil.
Canola oil contains the same ratio of omega-6 to omega-3 fatty acids that research shows can reduce inflammation. There’s a caveat, though. The omega-3 in canola oil is in the form of alpha linoleic acid (ALA) which your body must convert to EPA and DHA in order to be useful.
The problem is, this conversion process is terribly inefficient. Only a small percentage of ALA is converted to EPA, and an even smaller portion of that is converted to DHA. Your body is not able to use the entire amount that is available to convert, which throws off omega-6 to omega-3 ratios considerably.
Diets with a high omega-6 to omega-3 ratio are known to cause health problems including:
- Cardiovascular disease
- Inflammatory and autoimmune diseases
Increased intake of omega-3 polyunsaturated fatty acids (PUFA) (a lower omega-6/omega-3 ratio), may reduce these risks.
Health effects of canola oil.
Canola oil effects memory and cognitive function.
Canola oil may affect your memory and cognitive function. In one study, mice who were fed a diet high in canola oil showed physical signs of degradation. Further, the mice in the canola oil group showed signs of change in amyloids 40 and 42, which in prior studies have been specifically associated with Altzheimer’s disease. The mice fed canola oil also gained a substantial amount of body weight, and nobody wants that.
Canola oil and your lifespan.
Stroke-prone rats fed a diet including canola oil had a shorter lifespan than rats fed diets with other oils.
Canola oil and the cancer connection.
Gastric cancer and breast cancer cells feed on oleic acid (a major component of canola oil) which appears to help cancerous cell lines to grow and spread. In another study, oleic acid was implicated in helping breast cancer cells migrate to other areas in the body.
Better oil choices to replace canola oil.
Olive oil. With its high antioxidant and oleic acid content, olive oil is an excellent choice for most recipes as long as you do not heat it to high temperatures.
Coconut oil. Virgin coconut oil will have a faint coconut flavor unless it’s been deodorized. You may find that the taste works for some dishes, but not others.
MCT oil. MCT oil is typically made from separating out the medium-chain triglycerides from coconut oil or palm oil. Medium-chain triglycerides bypass a lot of your digestive processes and go straight to energy production. MCT oil is too delicate to be heated, though.
Avocado oil. Like olive oil, avocado oil is also high in antioxidants and has a quality fatty acid profile. It has the added benefit that it can be heated to over 500 degrees Fahrenheit, which makes it a good choice for stir-frys and pan-frying.