9 Reasons Canola Oil Is Bad for You (as in, Toss It ASAP)
By: Brent Totty
Is canola oil good for you? It’s a question nutritionists and food industrialists have been debating for decades. The controversy dates back to the 1950s, when the FDA banned rapeseed oil because of its negative effects on the heart, liver and kidney. Before getting into that, you need to first understand what canola oil is, how it’s created and how that impacts your health.
Read up on why this 'healthy' oil doesn't live up to the hype
What is canola oil?
Scientists created the canola plant in the 1970s in response to an FDA ban on rapeseed oil.
In 1956, the FDA ruled that high amounts of erucic acid, linked to heart muscle damage, in rapeseed made it unsuitable for human consumption. Additionally, they determined that high levels of glucosinolates, anti-nutrients found in brassica family plants that prevent iodine absorption, made rapeseed unsafe even for animal consumption.
Rapeseed manufacturers hired Canadian researchers to develop a new variety of rapeseed through plant cross-breeding that minimized glucosinolates and erucic acid. In 1974, their success came in the form of a new product, LEAR (low-erucic-acid rapeseed) oil, or what is now known as canola oil.
How canola oil earned its healthy patina
Meanwhile, the war on saturated fats had just begun, as the sugar industry began paying scientists for studies that linked fat intake with heart disease. As part of that effort, saturated fats became enemy No. 1, giving way to the glorification of low-saturated-fat seed oils like canola that boasted seemingly healthy dietary stats.
All of this led to an increased demand for canola oil.
Related: Report: Sugar Industry Hid Study Linking Sugar to Heart Disease and Cancer
Why canola oil is bad for you
GMOs and pesticides: As production of canola grew exponentially, growers needed a way to protect their crop. In 1995, agricultural giant Monsanto developed Roundup-Ready canola (Brassica napus) plants that were bio-engineered to tolerate to glyphosate, the active ingredient in its weedkiller. This meant farmers could liberally douse their GMO canola crops in glyphosate to kill off weeds without harming their crops.
Studies link high levels of glyphosate exposure to numerous health risks in people, including celiac disease, hormone disruption, and even cancer.
Chemical solvents: Most commercially available canola oil is extracted through a process called hexane solvent extraction.
Hexane solvent extraction is by far the cheapest and most efficient way to extract canola oil. After grinding the seed to a paste, hexane is used to extract the oil, which is then heated to 212 degrees fahrenheit and then bleached to create a lighter-colored final product. These manufacturing processes leave the oils damaged, creating higher levels of oxidation and trans fat content. All refined vegetable oils go through this so-called deodorization, creating trans fat in the process.
Trans fats: A recent test of canola oils on grocery store shelves showed trans contents between 0.56% and 4.2% of total fatty acid content in canola and soybean oils.
In 2003, the FDA ruled that the amount of trans fat in a food item must be stated on the label, but food items could be labeled 0% trans if they contain less than 0.5g/serving. It has been shown that the fatty acids in partially hydrogenated vegetable oil raise bad cholesterol (LDL) and lower good cholesterol (HDL) which causes inflammation and calcification of arterial cells.
More recently, food companies started blending fully hydrogenated oils with liquid vegetable oils in a process called interesterification. This process makes the interesterified oil behave like a partially hydrogenated oil without any of the trans fat. On paper, this sounds great but there haven’t been any studies on the effects of these newly constructed fats on the human body.
Canola oil and its health risks
Most canola oil these days is partially hydrogenated which creates trans fat in the final oil product. The FDA allows for the oil to be claimed as trans fat free at levels below 0.5g/serving, but even the smallest amounts of trans fat raise bad cholesterol (LDL) and lower good cholesterol (HDL).
The trans-fatty acids to blame in partially hydrogenated vegetable oil are 14 cis and trans isomers of both octadecenoic and octadecadienoic acids. It has been shown that the presence of these fatty acids cause inflammation and calcification of arterial cells.
Elevated LDL, lowered HDL, inflammation and calcification of arterial cells are all known to increase the likelihood of coronary heart disease.
On paper, canola oil looks like an optimal vegetable-based oil, with an incredible omega-6 to -3 ratio of 2:1. You want all of the foods you consume to be in the neighborhood of 4:1 and below.
However, the omega-3 fatty acids found in plant-based sources comes in the form of short-chain ALA (alpha linoleic acid). The human body must convert ALA to the long-chain fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) before it can be used. Unfortunately, ALA converts to EPA at a rate of about 5% and an even lower rate of less than 1% to DHA. When taking into account efficiency of conversion in the human body, the 2:1 ratio is really much closer to closer to 8:1.
On a recent Bulletproof Radio podcast episode, (iTunes) board-certified family physician Cate Shanahan, MD, author of “Deep Nutrition,” says that “somewhere between 30% and 50%, maybe 60% even, of the average American’s diet is composed of [soy and canola] vegetable oils. We have far more now in our diet than ever before in history.” Because of this, “the average American now is composed of far more polyunsaturated fat than ever before in history. Now, what does that mean? It means that when you biopsy human fat tissue, it’s composed of a more liquidy kind of fat that is more prone to degradation and inflammation than 50 years ago or than normal,” she explains.
According to Shanahan, consuming too much canola oil and other refined vegetable oils results in cellulite. “We can actually see what happens when our fat is more liquid and more inflammatory [from vegetable oils including canola]. That inflammation is breaking down the supporting collagen structure. That cellulite fat, instead of having three layers of collagen support, has only two layers of collagen support. That’s in one dimension. In another dimension, there’s up-and-down supports as well, and cellulite fat has fewer of those collagen supports as well. It’s much more flimsy, and that’s why it dimples. That flimsiness is a direct reflection of how the inflammation erodes away the collagen,” says Shanahan.
A recent study fed stroke-prone, hypertensive mice canola oil for a period of 25 days to see how it affected their health. Canola oil reduced their antioxidant status, lowered glutathione production (the body’s master antioxidant that flushes toxins from the body), and increased plasma lipid levels, all of which are gateways to cardiovascular disease.
When paired with high salt intake, canola oil causes lipid peroxidation. Lipid peroxidation is the process in which electrons are removed from fats by free radicals, causing cell damage.
Alzheimer’s and memory
Canola oil has a drastic effect on the capacity of your working memory. A recent study tested groups of canola-fed mice and their ability to perform in a memory-based maze test. Mice fed a diet high in canola oil displayed a substantial lowering of post-synaptic density protein-95, which is an indicator of decreased synaptic integrity. Translation: your neurons’ communication hubs start to break down.
Amyloids are complex combinations of proteins that have the potential to become pathogenic, which can lead to a variety of diseases in the human body. Amyloid-beta proteins 40 and 42 have been directly linked to the development of Alzheimer’s disease. Canola oil has a direct effect on the ratio between beta amyloids 40 and 42, which ultimately results in neuron damage, memory degradation and the onset of Alzheimer’s disease.
Asthma and lung inflammation
Vitamin E has two forms: alpha tocopherol (AT) and gamma tocopherol (GT). AT tends to be found in sunflower and olive oil; whereas, GT is found mostly in canola oil. In a recent study to test the effects of oil consumption on lung inflammation, researchers found a direct correlation between high levels of GT and heightened lung inflammation. A 10% reduction in lung function from inflammation for a healthy individual is pretty much like giving them asthma. For those with asthma, reducing lung function has drastic implications on their ability to get proper levels of oxygen in to the body.
Best canola oil substitutes
- Grass-fed ghee (good for cooking)
- Grass-fed butter (use over low heat only)
- Coconut oil (good for cooking)
- Brain Octane Oil and MCT oil (not recommended for cooking)
- Extra virgin olive oil (not recommended for cooking)
- Avocado oil (not recommended for cooking)