Is Rapeseed Oil Bad for You? Here’s What You Need to Know About Its Risks and Benefits
Key takeaways:
Food-grade rapeseed oil is more commonly known as canola oil. It was developed in Canada in the 1970s. And compared to the industrial-grade version, it contains less erucic acid — a toxic compound found in the rapeseed plant.
Rapeseed oil contains unsaturated fats, omega-3 fats, and vitamins. It has also been linked to lower LDL (bad) cholesterol. But it is heavily refined and may come with potential risks when used as a frying oil.
Limiting your intake of ultra-processed foods can help offset the potential risks of eating too much rapeseed oil and improve your overall health. To avoid health risks, you can also look for a cold-pressed variety of canola oil or opt for unrefined types of oil, like olive or avocado oil.
Rapeseed oil — commonly known as canola oil — is an ingredient found in many packaged foods. Although it’s generally considered safe and even heart-healthy, some people argue that you should avoid it.
So is rapeseed actually healthy? Let’s take a closer look.
What exactly is rapeseed oil?
Rapeseed oil is made from the seeds that develop from the yellow flowers of the rapeseed plant. There are two types of rapeseed oil:
Industrial rapeseed oil: This type is high in erucic acid — a natural toxin — and is not edible. It’s used as a lubricant and is often found in cosmetics and detergents.
Culinary or food-grade rapeseed oil: In the 1970s, Canadian scientists found a way to lower the amount of erucic acid content in industrial rapeseed oil to create low erucic acid rapeseed (LEAR) oil, also known as canola oil. The name “canola” is an abbreviation of “Canadian oil low acid. ”It is often used in cooking, baking, and food manufacturing.
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Rapeseed oil vs. canola oil
The specific differences between industrial-grade rapeseed oil and canola oil come down to how much erucic acid is found in each. Industrial rapeseed oil has more than 40% erucic acid. By definition, canola oil must have less than 2% erucic acid.
In the U.S., if you see a bottle of rapeseed oil in the grocery store, it’s actually canola or LEAR oil — not industrial rapeseed oil. In this article, when we refer to rapeseed oil, we’re talking about canola or LEAR oil.
Is rapeseed oil bad for your health?
According to the FDA, rapeseed (canola) oil is safe to consume in moderation. It may possibly even help manage or reduce levels of LDL cholesterol levels, which is sometimes called “bad” cholesterol.
But as with any food, the health benefits of rapeseed oil depend on how much and how often you eat it, along with the quality of the oil you’re consuming (more on this later).
Consider this: Enjoying a tablespoon of cold-pressed rapeseed oil on a salad will have different health effects than eating french fries that have been deep fried in rapeseed oil. Plus, it’s important to take a person’s whole diet into account — not just one food.
Why rapeseed oil is thought to be bad for you
Despite containing safe levels of erucic acid, edible rapeseed oil varieties get a bad rap. Common concerns include:
Trans fat content: The FDA allows products to be labeled as trans-fat-free as long as they contain less than 0.5 g of trans fat per serving. One tablespoon of canola oil has around 0.2 g of trans fat. While this is a small amount, it can add up if you eat a lot of the oil. And a diet high in trans fat can pose serious health risks, including heart disease, stroke, and Type 2 diabetes.
Sourcing from genetically modified (GMO) crops: Some people have raised concerns that GMO foods are low in nutrients and potentially even have toxic effects on the body. There isn’t conclusive evidence behind these claims. But since 95% of rapeseed plants in the U.S. are genetically modified, some people say you should avoid the oil for this reason.
Potential toxins from processing: Oils are extracted from seeds and vegetables using a chemical called hexane. Although animal studies have found hexane to be toxic, it’s currently not considered cancer-causing in humans.
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When does rapeseed oil become harmful?
Eating too much erucic acid has been linked to heart disease. European experts recommend that people limit their erucic acid intake to 7 mg per kilogram of body weight. For a person who weighs 80 kg (about 175 lbs), the upper limit would be 560 mg.
For reference, 1 tablespoon of canola oil can contain a maximum of 280 mg of erucic acid. This means a person who weighs 80 kg can have around 2 tbsp of canola oil per day.
According to a recent report from the Canadian Grain Commission, however, the erucic acid content in canola oil is barely detectable (around .01%). But it’s unclear what the precise percentage of erucic acid is in canola oil brands used in the U.S.
Keep in mind, many ultra-processed foods contain canola oil or LEAR — this includes foods and drinks that are considered healthy. So it can be easy to exceed the recommended limit, which can be concerning. Foods that commonly contain rapeseed oil include:
Margarine
Shortening
Salad dressings
Baked goods
Mayonnaise
Another health risk linked to rapeseed oil is its use in fried foods. Reheating these types of oils can release fumes that are toxic to the body when inhaled or eaten. Regular consumption of fried foods has been linked to many types of cancer.
Are there any health benefits of rapeseed oil?
Rapeseed oil is considered to be heart healthy because it is high in unsaturated fat and low in saturated fat. There are 14 gr of fat in 1 tablespoon of rapeseed oil, which includes:
1 g saturated fat
9 g monounsaturated fat
4 g polyunsaturated fat (both omega-3 and omega-6 fatty acids)
Here’s a closer look.
Rapeseed oil and omega fats
Many Americans eat too many omega-6 fatty acids. A high intake of omega-6 fat has been linked to obesity. On the other hand, omega-3 fat is linked to lower levels of inflammation and better heart health.
The recommended ratio of omega-6 fats to omega-3 fats is 1:1 or 2:1 — and rapeseed oil has a ratio of about 2:1. The lower the ratio, the higher the percentage of beneficial fatty acids (omega-3s) you’re getting. In this way, rapeseed oil is relatively healthy compared to some other oils. For example, corn oil has a 46:1 ratio.
Other nutrients in rapeseed oil and their potential benefits
Rapeseed oil naturally contains phytosterols, plant compounds that are linked to lower cholesterol levels. It also contains some vitamin E and beta-carotene, which are considered antioxidants.
However rapeseed oil is highly processed, which reduces the presence of these nutrients. Some examples of methods used in the refining process include:
Heat
Hexane solvents
Filtering
Deodorizing
Bleaching
One potential way to ensure that you’re getting the maximum benefit out of canola oil is to look for a cold-pressed option. Because cold-pressed oils aren’t produced with heat, they are more likely to retain vitamins and antioxidants.
One small study has suggested that cold-pressed rapeseed oil may be effective at lowering cholesterol, including LDL cholesterol. But this study compared the cold-pressed variety to butter. There aren’t any studies comparing cold-pressed rapeseed oil to the standard type. Cold-pressed rapeseed oil is also not as easily available and may be more expensive.
How much rapeseed oil is safe to use?
In general, federal dietary guidelines recommend no more than about 27 g of oil per day for someone eating a 2000-calorie daily diet. That’s about 2 tablespoons of oil in total.
What are some healthier alternatives to rapeseed oil?
If you are concerned about rapeseed oil, you might consider using olive oil or avocado oil, which are high in monounsaturated fats. These unsaturated fats are linked to better heart health as well as improved blood sugar and blood pressure.
To increase your omega-3 intake, you can also try flaxseed oil or hemp seed oil. But cooking with these oils is not recommended, because they break down at high temperatures. Instead, use them as a salad dressing or to drizzle on vegetables.
The bottom line
While rapeseed oil has some heart-protective benefits, it’s highly refined to remove erucic acid, a naturally occurring toxin. Rapeseed oil, also known as canola oil, is found in many ultra-processed foods, so it’s easy to eat more than recommended. Limiting your intake can help lower any risks associated with consuming too much canola oil. And for less processed and similarly beneficial healthy fats, you can try olive, avocado, or hemp oil.
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References
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