Chances are your kitchen has a bottle of one or more types of vegetable oil waiting to be cooked with. Over the last few decades, vegetable oils have been presented as the healthier choice of oil and have made their way into almost all the food items that we eat. Households extensively include more and more vegetable oil variations in their everyday cooking amidst debates about the actual benefits or harms of this fairly recent invention.
While fats from all plants are vegetable oils, commonly, oil extracted from crops is usually considered vegetable oils. This could be corn, canola, soy, cotton, almond, safflower, sunflower, etc. When compared to animal fats like butter and lard, these vegetable oils have gained a reputation as heart-healthy.
The consumption of vegetable oils has increased significantly in the late 1900s. This could be due to their reputation being heart-healthy compared to animal fats and other oils with saturated fats. The larger consensus is that saturated fats are good and unsaturated fats are bad. This has lead to the adoption of vegetable fats that have monounsaturated and polyunsaturated fats in higher quantities.
But, is vegetable oil good for you? There is an ongoing scientific debate on the health effects of vegetable oil. While the scientific community is still indecisive on the overall health effects, we’ll need to explore and understand a few essential aspects before making the final call for our own kitchens and bodies.
How Are Vegetable Oils Made?
- Most vegetables are not naturally oily and require significant industrial processing to produce edible oil. While products like olives and coconuts have been pressed for centuries, others like corn, soybean, canola are relatively new. The process of extracting oil from these vegetable products requires multiple steps that utilize a host of different petroleum solvents and other chemicals.
- The heavy-duty process usually involves the application of heat, cold solvents like hexane, bleaching agents, degumming agents, high-speed spinning, and deodorizers. Post this, often, they are also purified, refined, or chemically altered as needed.
- A healthier version of making vegetable oils includes crushing or pressing the plants or seeds to extract the oil. A good portion of the population is consciously looking for these options now.
Are Vegetable Oils Healthy?
Vegetable oils are healthy sources of fat generally, with the exception of ones that contain high trans fats. Hydrogenated vegetable oils are always better avoided to prevent health problems.
There is no one-size-fits-all answer to the question – is vegetable oil bad for you, or is it healthy? The matter is one of intense debate that hasn’t been settled. It also varies greatly based on how the oil has been extracted, its smoking pot, the number of fatty acids, including omega-6 and omega-3 fatty acids in the oil, and other factors.
It is safe to say that, in moderate amounts, using vegetable oil for cooking is healthy. The preference is skewed towards naturally pressed oils like olive oil and coconut oil, which are great choices.
Others like soybean oil, peanut oil, sesame oil, cottonseed oil, corn oil, among others, have a high content of omega-6 fatty acids. While these are essential for your body in small ratios, excessive intake may lead to chronic inflammation. This association is still not entirely set in stone as the studies haven’t been very clear on the causal effect of omega-6 and inflammation.
Commercial vegetables that are hydrogenated may also contain trans fats. The hydrogenation process is generally used to harden vegetable oil and make them solid at room temperature. Consuming high amounts of trans fats has been linked to several chronic diseases, some of which are obesity, cancer, diabetes, and heart disease. Check your oil to see if it lists hydrogenated oil. You’re better off avoiding it to ensure better health.
Types of Fatty Acids Available in Vegetable Oils
There are primarily three types of fatty acids present in vegetable oils. No food item contains only one type of fatty acid. All three are present in various proportions in all foods. Here are the main distinctions between the three.
1. Saturated Fatty Acids (SFAs)
Saturated fatty acids have no double bonds giving them better resistance to oxidation and higher tolerance to heat. These are saturated with hydrogen and stay solid at room temperature.
Sources of foods that are rich in saturated fats are butter, clarified butter (ghee), coconut oil, cheese, cream, lard, tallow, and coconut cream.
2. Monounsaturated Fatty Acids (MUFAs)
Monounsaturated fatty acids have a single, double bond. They have a lower resistance to oxidation and lower heat tolerances when compared to SFAs.
Olive oil, avocado, and other nut oils are usually good sources of monounsaturated fatty acids.
3. Polyunsaturated Fatty Acids (PUFAs)
Polyunsaturated fatty acids have two or more double bonds that are more susceptible to oxidation. They can get oxidized by reacting to the oxygen in the atmosphere and also within your body.
When these fats are stored in your cells, they make your cell membranes more sensitive to oxidation and release harmful compounds into your body. Older people who are over 65 years old are more prone to oxidative stress, making PUFAs a poor choice for them.
Vegetable oils like cottonseed, soybean, sunflower, corn, safflower, grapeseed, flaxseed, and walnut have PUFAs that make up for more than 50% of the total fatty acids content.
Cooking With Vegetable Oil
The process of cooking exposes the oil to heat, and all vegetable oils tend to oxidize to some extent when exposed to heat. Different vegetable oils have different heat tolerances. A good rule of thumb is to avoid overheating your oil and stick to the point that is below the oil’s smoking point. This can help minimize the oxidation of the PUFAs in your vegetable oil.
You can also minimize your vegetable oils’ oxidation by storing them in opaque containers and in a dark, cool environment. Always ensure that you don’t keep these oils for too long. It is difficult to detect oxidation in vegetable oil as they don’t emit odor even when they get rancid. This is mainly due to the process of deodorization that they undergo during processing.
What Happens When You Eat Vegetable Oil?
The fats you consume are either spent as energy or stored in your fat cells as a source of energy. Fatty acids are also used to build and repair your tissues and build cell membranes. The kind of fatty acids you consume essentially determine which building blocks are available to your body.
Not all fatty acids are created equal. When you consume vegetable oils that are rich in polyunsaturated fats that are heavily prone to oxidation, they could affect your cell membranes. This is because they are stored in your cells and get inflamed due to oxidation, affecting your membrane’s fluidity. This could potentially lead to several health conditions.
Consuming vegetable oils rich in omega-6 fatty acids has also been linked to increased insulin sensitivity in the body.
Eating repeating heated vegetable oils may lead to higher blood pressure and affect your health adversely due to potentially toxic compounds.
You are what you eat. So it is essential that you’re aware of how each component in the oil you consume alters your body – positively or negatively.
How to Use Vegetable Oils Wisely
Since vegetable oils are the go-to fats in modern times, responsibly choosing the right one is important. For your everyday cooking, understand the type of oil that suits your health better and has fewer negatives.
If you’re cooking at moderate temperatures, try olive oil, which is much less susceptible to oxidation. It has also been around for decades and is pressed rather than processed, making it a better choice.
For higher temperature cooking, you may want to stick to oils that have high saturated fats that don’t oxidize easily. This could be coconut oil or butter. Even with higher saturated fat content, they are better options than PUFAs at higher temperatures.
If you want to cook regularly with vegetable oil, you may want to stick with canola oil that has balanced omega-3 and omega-6 PUFAs as well as MUFAs. It also has a higher smoking point.
Here are some common questions about the benefits of vegetable oils.
1. Do vegetable oils increase inflammation?
There is a growing concern among nutritionists that the high omega-6 fatty acids in most vegetable oils can increase inflammation. While certain studies propose this argument, there is no human evidence to back this claim.
2. Are vegetable oils heart-healthy?
Most vegetable oils are low in saturated fat and have high quantities of polyunsaturated fat. Certain studies have shown that replacing saturated fat with polyunsaturated fat lowers the risk of heart problems by almost 17% by lowering cholesterol. But excess usage of vegetable oil was found to increase the risk of heart disease rather than decrease it, as per another study.
One possible explanation for this is that most vegetable oils are rich in unsaturated fats, both MUFAs and PUFAs. These fats are known to oxidize when heated. When oxidized within the body, they can lead to inflammation of the cells. This could be as severe as causing inflammation in the blood vessels and making them unstable, which could potentially lead to a heart attack.
While nutritionists are also concerned about the high amounts of omega-6 fatty acids in some vegetable oils, there is no evidence as yet that they affect heart health. Omega-3 fatty acids can undercut some of the ill effects that omega-6 may have.
A moderate amount of vegetable oil is safe for your heart health. However, it’s always better to steer clear from heavily processed vegetable oils and opt for naturally pressed oils like olive oil.
3. Do vegetable oils cause depression and ADHD?
The rate of depression, anxiety, and attention disorders in recent years has taken a steep rise. There is no evidence for the cause of the same. While some psychiatry experts have linked omega-6 intake as a contributor to ADHD and depression, there are no studies to support it.
4. Do vegetable oils increase cancer risk?
While some observational data suggest an association between high omega-6 PUFA consumption and cancer, there is no real, conclusive evidence of the same. Cancer risk isn’t very well understood, and it may be premature to look for a causal relationship between cancer and vegetable oil consumption without solid data.
The American Heart Association (AHA) stresses the importance of including PUFAs in your diet and lower the intake of saturated and trans fats. This take is controversial and not agreed upon by many experts. This debate is largely due to the mixed package that most vegetable oils deliver and inconsistent evidence that PUFAs contribute to better heart health overall and reduce mortality due to heart-related diseases.
Vegetable oils with PUFAs can surely help meet your daily requirement of PUFAs. However, experts are also concerned about the overconsumption of certain PUFAs like omega-6 in excess. While the jury is still out, the best we can do is pick the vegetable oils that work the best for us.
Some oils that deliver a good balance of omega-3 and omega-6 are canola oil and flaxseed oil. Pressed oils such as olive oil are rich in MUFAs and have low omega-3 fatty acids. Coconut oil is another option that is rich in saturated fats and works well.
There is no one healthiest vegetable oil available out there. All of these oils are meant to be consumed in moderation. But, if you’re to choose the best of them all, olive oil and coconut oil would be your safest bet.