Which is healthier, olive oil, canola oil, or vegetable oil?
For that matter, what is vegetable oil?
Is it worth paying extra for olive oil?
In this article, I am going to break it down for you.
That way you can make informed decisions about the oils you purchase and cook with.
But first, I want to tell you a bit about what's been going on to make me get so involved with researching this topic.
Why I've Been Researching Cooking Oils
I have spent a lot of time recently investigating oils.
The reason is that the olive oil which I used to purchase at my local grocery store is no longer stocked.
I live in a small rural town which is essentially in the middle of nowhere, so options are pretty limited locally.
The olive oil in question is no longer even stocked at the store which is an hour away.
Why is this so important, and what does it have to do with this topic?
Well, I was researching the other brands of olive oil which were available, and I was somewhat horrified to discover that none of them were actually pure olive oil.
They were actually mixtures containing other vegetable oils - most notably soybean oil.
I have to avoid soybean oil because it acts as an endocrine disruptor.
If I actually want to buy olive oil which is real and pure, I have to order it off the internet now.
So a topic like "Olive Oil vs. Canola Oil vs. Vegetable Oil" is actually a little more complex than you might think.
To examine this question, we need to talk not just about pure olive oil, but also about the stuff which ends up on so many supermarket shelves.
So in essence, I will actually be comparing four different types of cooking oil: canola oil, vegetable oil, pure olive oil, and "olive oil" which contains other oils in it.
Oh, and did I mention that companies do not even necessarily legally need to mention these other oils in their "olive oil" products?
And just to add to the fun, a lot of olive oil is made out of rancid olives.
With that context in place, let's proceed.
What is Canola Oil?
When you are standing in the oils section of your supermarket, you probably see row upon row of canola oil bottles.
Most of these oils are cheaply packaged, and they are low in price to purchase.
This is part of their appeal. The other part is that they have a very light flavor, and do little to disrupt the flavors of the dishes you are cooking.
But lest you be tempted to buy canola oil, let's discuss what you are actually putting in your body.
Canola oil's oddness tends to get overlooked because most of us grew up with it. Familiarity makes us complacent.
But slow down and think for a moment. Ask yourself, "What is a 'canola' anyway?"
Is it some kind of a vegetable?
Actually, canola oil is derived from a form of rapeseed with low erucic acid content.
Specifically it is extracted from the plant's seed.
A number of cultivars may be used in its production, including Brassica napus L., Brassica rapa subsp. oleifera, syn. B. campestris L. andr Brassica juncea ( 1).
Rapeseed is colloquially known as "canola."
This is a contraction which is short for "Canada ola."
"Ola," according to the Canola Council of Canada ( 2) means "oil."
As you might have guessed given the scientific names above, it is a member of the brassica genus.
Brassicas which you may be more familiar with include cabbages, Brussels sprouts, and cauliflower.
Canola oil is a major export of Canada. Indeed, the Canola Council of Canada refers to it as the country's "greatest agricultural success story," and further claims that it is "one of the world's healthiest vegetable oils."
Is it? To try and keep things simple, first we will go over the pros of canola oil.
After that we will go over the cons.
Health Benefits of Canola Oil
1. The fat profile is not too bad.
One good thing about canola oil is that it contains more monounsaturated fat than polyunsaturated fat.
The fat distribution for 1 cup of canola oil is as follows ( 3):
- 138 g monounsaturated fat
- 16.1 g saturated fat
- 61.4 g polyunsaturated fat
Why is this a good thing?
The bonds in polyunsaturated fats are more unstable than those of monounsaturated fats.
That means that when you are cooking on high heat, the polyunsaturated fats are more likely to oxidize than the monounsaturated fatty acids.
You probably are aware that oxidization is bad for your health.
So the fact that canola oil's monounsaturated fats outpace its polyunsaturated fats is a good thing.
That being said, could it be better?
Sure. Take a look at olive oil's fat distribution ( 25):
- 158 g monounsaturated fat
- 22.7 g polyunsaturated fat
- 29.8 g saturated fat
This is of course superior. But it is not as if olive oil is super low in polyunsaturated fat either.
I have seen some people complain that canola oil's percentage of polyunsaturated fat is unacceptable high.
I have seen others claim it is delightfully low.
A more balanced outlook, I think, lies somewhere in between.
2. The omega fatty acid profile is not the worst.
At first glance, the omega fatty acid profile for canola oil doesn't look fantastic:
- 40646 mg omega-6 fatty acids
- 19921 mg omega-3 fatty acids
There are a lot more omega-6 fatty acids here than omega-3s. Nonetheless, this is common among cooking oils.
Nonetheless, the Canola Council of Canada reports that linoleic acid (LA) is one of the prevalent omega-6 fatty acids which canola oil contains.
Conjugated linoleic acids (CLA) have shown benefits for treating diabetes, cardiovascular disease and cancer ( 4).
3. Canola oil contains loads of vitamin E.
According to the same nutritional data we were looking at while analysing the fat profile of canola oil ( 3), this oil is also extremely rich in vitamin E.
1 cup of canola oil provides 38.1 mg of vitamin E, which is 190% of the daily recommended value.
Vitamin E is an important antioxidant. Supplementing with it may have benefits for brain and eye health, and may offer some protection from cardiovascular disease and cancer ( 5).
4. Canola oil is also a rich source of vitamin K.
Along with lots of vitamin E, canola also has a lot of vitamin K.
The same nutritional resource referenced above states that 1 cup of canola oil contains 155 mcg of vitamin K, which is 194% of the daily recommended amount.
While vitamin K is not as well known as some of the other vitamins like C, D, A and E, it is essential for blood coagulation and calcium binding.
Supplementing with vitamin K2 can reduce fractures by up to 80% ( 6).
It can also reduce your risk of heart disease ( 7) and reduce your risk of certain forms of cancer ( 8).
To read about vitamin K's advantages in-depth, please see my article "14 Health Benefits of Vitamin K."
5. Canola oil can reduce cholesterol and triglycerides-but the data is weak, and may be overshadowed by heart disease risks.
If you are looking for cardiovascular benefits, you may have heard that canola oil is a heart-healthy choice because it reduces cholesterol.
It is true that there is research backing this up.
Studies ( 9, 10, 11, 12, 13, 14) indicate that both LDL cholesterol and triglycerides may decrease by as much as 25% when consuming canola oil.
HDL levels appear to be largely unaffected.
So why are these results not necessarily a big deal?
Well, these studies only looked at a short duration of time - just a few weeks in most cases.
Other research has indicated that vegetable oils might actually raise your risk of cardiovascular disease over a longer timeframe, even with the short-term improvements in markers such as cholesterol ( 15, 16).
So I hesitate to really call the improved markers a "benefit" of canola oil, being as it is possible that overall, canola oil is still bad for cardiovascular health.
Nonetheless, it seemed like this was the most logical section to put this information in.
More research is definitely a must in this area.
Health Drawbacks and Concerns Involving Canola Oil
Now, at this point you might be thinking, "Canola oil doesn't sound that bad after all."
There are a number of health concerns with canola oil however, largely involving how it is processed. Let's go over those now.
1. Erucic acid
Interestingly enough, there was a time when canola oil was banned by the FDA.
This was right after it originally came out in 1956.
The reason for the FDA's concern was the presence of what is known as "erucic acid" ( 17).
Studies show that erucic acid can wreak havoc on heart health ( 18).
Another issue was the bitter taste of the oil, which was a result of compounds called glucosinolates ( 19).
Agricultural researchers didn't give up though.
It took until the 1970s, but eventually they manage to grow rapeseed plants which had a low erucic acid content as well as fewer glucosinolates.
Originally, this form of rapeseed was known as "low-erucic acid rapeseed," or "LEAR."
Naturally that wasn't the easiest name to brand and sell, so they came up with "canola" instead.
Now, this might make you think that canola oil is "safe," since it contains only low levels of erucic acid.
While this does make it less concerning than it would be if it contained high levels, it does not necessarily make it harmless - especially since we tend to consume a lot of oil in our everyday meals.
Take a look at this study ( 20), where researchers had rats consuming 0.5% or 5% concentrations of erucic acid.
The erucic acid was profoundly damaging, even lethal.
Rats in both experimental groups (5% and 0.5%) were subject to its toxic effects.
Wondering how much erucic acid is permitted in your canola oil?
The United States caps the concentration at 2%, while the EU caps it at 5%.
Obviously, both are bad.
There are standards which need to be met for a product to legally be marketed as "canola" oil.
According to the Canola Council of Canada, they are ( 2) as follows:
"Seeds of the genus Brassica (Brassica napus, Brassica rapa or Brassica juncea) from which the oil shall contain less than 2% erucic acid in its fatty acid profile and the solid component shall contain less than 30 micromoles of any one or any mixture of 3-butenyl glucosinolate, 4-pentenyl glucosinolate, 2-hydroxy-3 butenyl glucosinolate, and 2-hydroxy- 4-pentenyl glucosinolate per gram of air-dry, oil-free solid."
"Less than 2% erucic" acid may still be more than you want to be consuming, as you now are aware.
Further studies on erucic acid show that it may be linked to heart disease ( 21), reduced platelet counts ( 22), systolic pressure decreases ( 23), and kidney problems ( 24).
2. Canola oil is almost always genetically modified.
Want to avoid eating genetically modified foods? Then you will want to stay away from canola oil.
One paper ( 26) reports,
"GM canola comprised nearly 90% of he 6.6 million ha grown in 2009."
That would be bad enough - but it gets worse.
The reason why so many canola plants are genetically modified is because pest control is a problem.
This led Monsanto to develop a genetically modified form of canola in 1995 which can withstand harsh pesticides like glyphosate.
So that means that chances are 9 out of 10 that the canola oil you are purchasing is genetically modified.
It also has been exposed to large amounts of toxic pesticides.
3. Canola oil is heavily processed.
The process used to extract canola oil so economically from the seeds of the rapeseed plant is called "hexane solvent extraction."
Here are the steps which are involved in this process:
- First the seeds are filtered.
- After the filtering is complete, the seeds are placed inside a screw press machine. Inside, they are subjected to high heat. Around three-quarters of the oil content of the seeds is extracted via this process.
- As if this harsh process were not enough, it continues. Producers are unwilling to say goodbye to the profits from the remaining quarter of the oil still locked in the seeds. So they dump the seeds into a chemical bath for a little more than an hour. Exposed to the hexane in the bath, the seeds release the remaining oil.
- Once this wash process is finished, the oil is exposed to sodium hydrochloride. This is done to remove more contaminants.
- The oil emerges from this process with an unappetizing dark color. Naturally, this could eat into profits, so producers bleach the oil.
- At this point, the oil is still not satisfactory, because it smells dreadful. So it undergoes a further process called "steam injection." This gets rid of the stench.
Lovely, right? The description above is downright unappetizing.
What is more unappetizing is realizing that trace amounts of chemicals may remain in the canola oil which reaches the grocery store shelves.
How concerning is this?A Harvard resource states ( 27),
"It has been estimated that refined vegetable oils extracted with hexane contain approximately 0.8 milligrams of residual hexane per kilogram of oil (0.8 ppm) (2). It is also estimated that the level of ingestion of hexane from all food sources is less than 2% of the daily intake from all other sources, primarily gasoline fumes. There appears to be very little reason for concern about the trace levels of hexane in canola oil."
Does this mean that there really is very little reason for concern?
It all depends on how trusting you are of this statement.
Personally, I find it more disturbing that we are consuming that much hexane just walking around and breathing!
If we can consume less hexane, we should.
You probably do not have the luxury of moving to a location with cleaner air, but you can opt to avoid hexane-processed oils such as canola oil.
4. Canola oil may be high in trans fats.
Earlier I talked about how the high presence of monounsaturated fats and the lower percentage of polyunsaturated fats in canola oil is a good thing.
There is a caveat though, because this is not the full picture.
Your canola oil may also contain unhealthy amounts of trans fats.
According to this research ( 28), anywhere from 0.56%-4.2% of all fatty acids contained in various canola and soybean oils may consist of trans fats.
This trans fat isn't present naturally in the rapeseed. It is a direct result of the manufacturing process, specifically the use of hydrogenation.
Indeed, trans fats may not be mentioned on the labels for canola oil products - or a product may be labelled "0 trans fat."
But that does not mean that it really has no trans fats.
They could be present in those small amounts.
How do you know? One thing to look for is the phrase "partially hydrogenated oil."
This indicates that the oil has gone through the aforementioned process.
This in turn generally means some trans fats are present in the finished product.
A company can get away with this legally so long as the amount does not exceed 0.5 grams.
Trans fats raise LDL cholesterol levels and lower levels of HDL.
Studies have found that consuming more trans fats can raise your chances of getting heart disease ( 30).
Astonishingly, according to the source above, "Based on the available metabolic studies, we estimated in a 1994 report that approximately 30,000 premature coronary heart disease deaths annually could be attributable to consumption of trans fatty acids."
If you want to take chances with your health, go for it. Personally, I want to avoid trans fats as best I can.
5. Eating genetically modified foods like canola oil may harm your liver and kidneys.
I have already talked a bit about the fact that most canola oil is genetically modified.
But what can that actually do to your body?
Two critical organs which can be adversely affected are your liver and kidneys.
This research ( 31) found that in 43.5% of all male subjects, consuming genetically modified foods led to kidney disruptions.
In 30.8% of female subjects, GMO foods caused adverse effects for the liver.
6. High Blood Pressure and Shorter Lifespan
This animal study looked at how long rats lived after consuming a variety of oils ( 32).
The rats which were fed the canola oil lived "relatively shorter" lives than those which were fed on other oils.
Blood pressure also increased for the rats.
Key Points About Canola Oil:
What is Vegetable Oil?
Next up is "vegetable oil." It is hard to come up with a vaguer name than that.
Actually, "vegetable oil" refers to a whole category of oils, not a single oil.
A vegetable oil is simply any cooking oil which is then extracted from one or more vegetables.
Canola oil is one example of vegetable oil, but so is olive oil.
Actually, to be precise, olives are fruits, not vegetables. Technically, this makes olive oil a fruit oil.
Nonetheless, this does not stop anyone from calling it a "vegetable oil."
Other examples include soybean oil, corn oil, sunflower oil, peanut oil, sesame oil, and more.
For this reason, we cannot really make any blanket statements about whether or not "vegetable oil" is good or bad for you.
The assessment depends entirely upon which oil we are talking about.
You already know that canola oil is not a great option, and you understand the reasons why.
With the exception of the olive oil, be vegetable oils which I've mentioned above should generally be avoided for cooking, just like canola oil.
The reasons on the whole tend to be similar. These oils:
- Contain high amounts of omega-6 fatty acids.
- May be high in polyunsaturated fats, trans fats, or both.
- Are almost always GMO.
- May contain contaminants from processing, including chemical toxins.
- May cause problems for heart health.
- Can increase inflammation and promote disease.
None of this is to say that these oils are entirely devoid of nutritional value. Like canola oil, many of them do contain useful nutrients.
But that does not mean that they are necessarily a good source of those nutrients.
As the drawbacks tend to outweigh the benefits, it makes more sense to get those nutrients from other healthier sources.
Key Points About Vegetable Oil
What is Olive Oil?
Olive oil is a cooking oil which is made using an extract from olives.
At least, that is true when you find a quality product - others may contain more than just oil from olives-more on that in the "drawbacks" section further down.
Assuming you can find high-quality olive oil, it is a significantly healthier choice for cooking than canola oil or most other vegetable oils.
Below, I will share some reasons why this is true. Then I will go over some potential drawbacks you should be aware of.
Health Benefits of Olive Oil
1. A better fat profile.
Here again is olive oil's fat distribution ( 25):
- 158 g monounsaturated fat
- 22.7 g polyunsaturated fat
- 29.8 g saturated fat
While there are still polyunsaturated fats present, they make up a smaller percentage than canola oil's.
That makes olive oil safer to cook with at higher temperatures than canola oil since it is less likely to form dangerous oxidation.
Meanwhile, the omega-3/omega-6 ratio is still quite bad.
According to the link above, there are 1,644 mg of omega-3 fatty acids in one cup of olive oil.
In the same cup, there are 21,088 mg of omega-6 fatty acids.
2. Olive oil is a great source of antioxidants.
Not only does olive oil heat well without oxidizing too badly, but it can actively fight oxidation in your body.
It is able to do this thanks to the presence of abundant antioxidants ( 33, 34).
3. Olive oil has an anti-inflammatory effect.
While the high omega-6 fatty acids in olive oil are not good news, they are counterbalanced to some degree by some of olive oil's other properties.
Olive oil contains a compound called oleocanthal.
This compound behaves in the body much like ibuprofen does.
Indeed, 3.4 tablespoons of extra virgin olive oil may have the equivalent effect of 10% of an ibuprofen dosage ( 35).
Olive oil also is a source of oleic acid, which may be able to decrease inflammatory markers ( 36, 37).
4. Reduce your risk of stroke.
Olive oil is a wonderful heart-healthy choice for cooking.
A meta-study which encompassed 841,000 participants confirmed this. The researchers discovered that it decreased stroke and heart disease risk.
Moreover, it was the only monounsaturated fat source which did ( 38).
Still looking for more evidence?
This study looked at 140,000 subjects in total, and confirmed similar findings ( 39).
5. Improve cardiovascular markers, preventing heart disease.
You now know that your chances of stroke may be lower if you consume olive oil, but that is not the only way that this oil may enhance cardiovascular health.
Researchers have found that the consumption of olive oil can help to keep blood clotting under control while also reducing the oxidation of LDL cholesterol ( 40, 41, 42, 43, 44, 45).
Olive oil may also reduce blood pressure ( 46, 47, 48).
6. You may lose weight while using olive oil.
Studies ( 49) have shown that consuming olive oil does not necessarily cause you to put on weight.
Further, there is even research ( 50) which suggests that eating more olive oil could help you to lose weight.
7. Olive oil may have benefits for brain health.
You probably are aware that more and more people are getting dementia, and there is no known cure.
Alzheimer's appears to be associated with beta-amyloid plaques in the brain.
Animal research ( 51) indicates that consuming olive oil may help to get rid of these plaques.
There is also research in humans ( 52) demonstrating improved brain function in those who consume a lot of olive oil as part of their diets.
More research is warranted in this area, but for now, the initial results seem promising.
8. Your risk for type 2 diabetes might decline with the help of olive oil.
When your diet is rich with olive oil, it may help to regulate your insulin sensitivity ( 53, 54).
Studies ( 55) show that eating Mediterranean diets which include olive oil can help to reduce instances of diabetes.
9. Possibly prevent cancer.
Cancer, like dementia, is an epidemic for which there is no reliable preventative or cure.
Nonetheless, the risk of cancer seems to be lower in the Mediterranean region, and it has been suggested that olive oil might play a role in that ( 56).
It is believed that this possible effect could be attributed to the antioxidants in the oil ( 57, 58).
There have been some exciting studies conducted in test tubes which seem to confirm the anti-cancer effects of olive oil compounds ( 59, 60).
10. Combat arthritis.
Because olive oil is a powerful anti-inflammatory oil, it may help to reduce the symptoms of rheumatoid arthritis ( 61, 62).
For extra effectiveness, one can try combining this treatment with fish oil ( 63).
11. Fight bacterial infections.
Olive oil has antibacterial properties ( 64).
It may be particularly effective against Helicobacter pylori ( 65), including strains which are antibiotic-resistant.
One particularly impressive study ( 66) indicates that taking 30 grams of extra virgin olive oil once a day for a two week period may be sufficient to kill Helicobacter pylori altogether in up to 40% of infected persons.
Want to learn more about olive oil? Be sure to see our article on Health Benefits of Olive Oil (coming soon).
Potential Drawbacks and Concerns of Olive Oil
You can see that olive oil has a lot of excellent health benefits. Nonetheless, it is not without its potential issues.
1. Not all olive oil provides the full range of benefits.
A lot of the olive oils you see for sale have been refined.
This is especially true in the lower price range.
The type of olive oil you should shop for is the "extra virgin" variety.
Extra virgin olive oil (EVOO) contains all the nutritious compounds which are so good for your health.
More refined types of olive oil do not have all of these compounds, and therefore may provide fewer health benefits.
2. Some olive oil is made of rancid olives.
Surprisingly, a lot of olive oil which winds up in stores (especially in the United States) is made from old, moldy olives ( 67).
This low-grade olive oil is common for a couple of reasons.
First of all, selling it obviously helps producers to waste fewer fruits and make more money.
Secondly, a lot of consumers do not know the difference between low and high grade olive oils.
Indeed, some US consumers actually have a completely inverted understanding of olive oil flavors.
They believe that a lighter, cleaner flavor means higher-quality olive oil.
You actually want your olive oil to be bitter. This usually is an indication that is a higher grade, and contains more of the nutrition you are looking for.
It also takes practice to the point where you can refine your palate to the point where you can tell appropriate bitterness apart from mustiness.
One thing you can do is look on the back of the olive oil to see if there is any information on where the olives came from.
Note that this is not the same thing as finding out where the olive oil was manufactured.
A label might for example state that the olive oil was "made in Italy" on the front.
But if you turn it over, you might see that the back label adds something like, "Made from olives imported from Argentina, Spain, and Tunisia."
That means that those olives had to be shipped to Italy first, which can take a long time, and may involve exposing the fruits to sub-par conditions.
It also suggests that it is possible that these olives may have been rancid to begin with.
The oil may have essentially been cobbled together out of leftovers from various olive producers.
The olives were no longer of an adequate freshness or quality to be used in high grade products, so they were instead combined to create low grade products.
If you want to use oil made out of rancid fruit, that is up to you, but personally it is something I would like to avoid.
3. Not all products labeled "olive oil" really are olive oil.
An even bigger problem with "olive oil" is that a lot of it actually is not really "olive oil" to begin with.
Even olive oil which is labeled "extra virgin" may be mixed with other types of oil such as soybean oil, sunflower oil, or corn oil ( 68).
Sometimes these cheaper vegetable oils are not mentioned at all on the label, so the olive oil is effectively fraudulent.
That means that you may think you have just purchased a bottle of healthy, wholesome olive oil, but may actually be polluting your body with inferior vegetable oils.
Worse, you may have good reasons to be proactively trying to avoid some of these oils.
I, for example, try to avoid soy-based products.
There are also indications that the hormonal imbalances caused and perpetuated by phytoestrogens and xenoestrogens may lead to long-term health problems.
Naturally, I was pretty horrified when I found out that I have probably been consuming soybean oil day in and day out for years without even knowing it.
So you need to be very careful when you are shopping for olive oil.
Do your research into different brands, and make sure that the product you are buying is actually real, uncontaminated olive oil, not comprised partly of another vegetable oil posing as such.
Key Points About Olive Oil
Conclusion
Selecting a healthy cooking oil can be a real challenge.
Not only do you need to know what types of oils to avoid, but you need to actually locate high-quality products to purchase.
Olive oil is a worthy choice since it is good for your heart, brain, and general health.
Its antioxidant and anti-inflammatory properties can help improve function and prevent disease body-wide.
Just make sure the olive oil you are getting actually is olive oil, and that it is extra virgin and not rancid.
