Are Seed Oils & Vegetable Oils Making Us Sick?

One of the biggest pieces of advice I can offer to someone who is looking to improve their overall health is to eliminate seed oils. But this is easier said than done. Seed oils are everywhere in the modern American diet. As consumers we have to educate ourselves on the ingredients in the food we eat. If seed oils are in everything, we should probably know they are!  So let’s start there… What exactly are seed oils, and why are they bad for you? In this post I’ll tell you everything you need to know, including potential risks and how to avoid seed oils.

What Are Seed Oils?

Seed oils, sometimes known as vegetable oils, are oils that are extracted from the seeds of various plants. Common seed oils are soybean oil, sunflower oil, canola oil, corn oil and vegetable oil. Vegetables oils are often combinations of several different types of oil. While these oils can be marketed as “healthier alternatives” to saturated fats like butter or animal fats, it is important to examine the nutritional composition of seed oils and processing methods to truly understand their impact on our health. 

Seed oils, while they are a fairly recent addition to the human diet, are now in nearly EVERYTHING you purchase that is considered “shelf stable”. Start looking at labels the next time you are at the grocery store. If it’s packaged, chances are very high that it contains a high processed seed oil. 

The History of Seed Oils

Seed oils are a fairly recent addition to the human diet, and the history of how they came to be used in American food is really interesting. In the 1870s, cottonseed oil had been used as a primary fuel source and for lighting fuel. After oil was discovered in Pennsylvania, cottonseed oil was quickly replaced and became known as “toxic waste”. However two soap makers named Proctor and Gamble discovered that they could use cottonseed oil to make soap rather than the traditional way with rendered pork fat. It was a much cheaper ingredient, and they also discovered that they could chemically alter the cottonseed oil through a process called “hydrogenation” to make it into a more solid cooking fat that resembled lard. Fast forward and Crisco was introduced in the early 1900s as a “healthier” alternative to traditional fats like butter and lard. 

In fact, in the 1940s even the American Heart Association (known as a physicians organization dedicated to heart health) endorsed industrial seed oils as a healthier alternative to saturated animal fats. I also find it incredibly fascinating that this endorsement came shortly after a 15 million dollar donation from Proctor and Gamble, the creators of Crisco (source). *Insert Kermit the frog drinking a cup of tea

Soon many other seed oils followed and with the help of strategic marketing they became wildly popular.

How Are Seed Oils Made?

After Proctor and Gamble discovered the process of hydrogenation, more seed oils came about with the invention of the stainless steel roller press in the late 1800s. This steel roller press was a new and improved way to squeeze oil out of hard seeds. Prior to this invention, the only plant-based oils came from fruits like the olive, coconut and palm, or seeds like flax seed and sesame seeds, which could be extracted using a slow-moving stone press.

With their new steel roller press, manufacturers started with the cheapest seeds possible (like soy, or canola seeds). The oil is extracted at incredibly high temperatures, then they are refined and chemically altered to improve taste and shelf life. Many commercially available seed oils undergo refining processes that involve the use of steam, chemicals, and mechanical extraction. In fact, the last fraction of oil is removed with hexane, a toxic solvent (source). These processes can result in the removal of beneficial compounds, such as antioxidants and vitamins, while introducing harmful substances like pesticides and chemicals.

Some seed oils are next hydrogenated, a chemical process that is used to turn liquid oils to a solid when they are at room temperature. During the hydrogenation process, trans fats or trans fatty acids are created. Trans fats can have really terrible effects on health, including increase risk of heart disease, diabetes, obesity, and even cancer (source). If a food label reads “Partially hydrogenated” oil, then this indicates presence of trans fats. Companies must list trans fats on food labels only if there is more than half a gram per “serving,” (source), which is concerning that there may be trans fats in some foods without it being listed on the label. Another reason to avoid processed and packaged food whenever possible.

Today, 80% of all vegetable oil comes from soybeans. 

What Are Seed Oils Used For?

Because vegetable oils are so versatile and cheap to make, they are used in all sorts of ways across the United States and the world. In the US, nearly any packaged food item, fast food, even fancy restaurants and popular baby formula brands contain seed oils. No wonder consumption of seed oils has sky rocketed over the last 100 years! 

Seed oils are often hiding in foods that you might think are safe. Be sure to always check labels! Some items with seed oils that might surprise you:

• Bread
• Coffee creamer
• Candy
• Salad dressings
• Crackers
• Mayonnaise (even some avocado-oil mayo)
• Ice Cream
• Dairy free cheese
• Oat Milk
• Baby formula
• Popcorn

What Makes Seed Oils Bad For Your Health?

There are a few problems with consuming seed oils, such as:

1. Industrial seed oils are unstable, and they oxidize easily
2. Seed oils contain harmful chemicals and additives
3. Seed oils typically come from genetically modified crops
4. When seed oils are heated to high temperatures, toxic byproducts are created 
5. Seed oils negatively impact our bodies ratio of omega 6 to omega 3 fatty acids

Keep reading to learn some of the potential health risks with consuming seed oils. 

Risks of Consuming Seed Oils

Is consumption of seed oils contributing to the rise in chronic disease over the past century? I think there might just be a correlation. High intake of vegetables oils has been linked to all kinds of health problems. Here are a few to consider: 

1. Asthma:

Consuming seed oils can increase your risk of asthma. A high intake of omega-6 fatty acids relative to omega-3 fatty acids increases pro-inflammatory mediators associated with asthma (source).

2. Impact on Brain / Mental Health

High intake ratio of omega-6 to omega-3 fatty acids may increase risk for depression, anxiety, dementia and cognitive decline (source). Fat intake greatly influences our cell health, as well as our tissue and organs. Our brain is 60% fat, so our cognitive health can be directly influenced by our dietary fat choices. An animal study even showed the connection between high omega 6 consumption and alzheimer’s disease. 

3. Autoimmune disease

Autoimmune disease is when your immune system attacks healthy cells in the body. Research suggests that seed oils may be contributing to the rise in autoimmune diseases by increasing chronic inflammation and increased oxidative stress in the body (source). This is again caused by increasing the ratio of omega-6 to omega-3 fatty acids in the body. 

4. Diabetes & Obesity

Seed oils are high in linoleic acid. Research suggests that overconsumption of this fatty acid can alter our neurotransmitter signaling, which can cause over eating and weight gain (source). In a study of mice, the results showed that when the mice were given a diet high in soybean oil the results were fatty liver disease, diabetes, obesity and insulin resistance (source).

5. Heart Disease

Research shows that consuming high levels of linoleic acid can contribute to heart disease. Seed oils high in linoleic acid increases oxidative stress, higher levels of oxidized LDL, and chronic inflammation (source). 

6. IBS / IBD

Research suggests that high intake of seed oils may alter your gut microbiota and promote gastrointestinal inflammation. 

7. Macular degeneration

Age related macular degeneration (AMD) is the leading cause of blindness globally. This is actually a condition where it is widely recognized that an imbalance of omega 6 to omega 3 fatty acids is the culprit (source). 

I think that the consumption of seed oils has really sky rocketed in the last 50 years. With these oils being a somewhat new introduction into the human diet we probably don’t even know all of the long term effects! 

How To Avoid Seed Oils

The best way to avoid seed oils in your diet is to cut out all ultra-processed foods. Nearly all packaged foods that are considered shelf stable have industrial seed oils. Limiting eating out will also help, because most restaurants liberally use vegetable oils, and not just the fast foods. Learn to primarily cook your own food at home from scratch using whole food, and organic ingredients when possible.

Learn how to read labels. Not sure what to look for? Seed oils and vegetable oils come from many different plants / seeds and have different names. Watch out for any of these ingredients:

• Hydrogenated Vegetable Oils
• Hydrogenated Oils
• Partially Hydrogenated Oils
• Trans Fats
• Soybean Oil
• Palm Oil
• Lindseed Oil
• Corn Oil
• Cottonseed Oil
• Poppyseed OIl
• Sunflower Oil
• Safflower Oil
• Grapeseed Oil
• Canola Oil
• Rapeseed Oil
• Peanut Oil
• Rice Bran Oil

Another way to avoid the side effects of seed oils is to avoid eating grain-fed meat. Evidence suggests that animals that are fed grains can transfer toxic buildup from industrial seed oils through their meat to us. 

What Are Healthy Alternatives to Seed Oils?

The solution is not just to cut out all fats; in fact our bodies need fat to function properly! There are plenty of healthy fats and oils that are great to cook with and consume. One of the best ways to choose is to think about the ones that have been around for centuries. What did our ancestors use to cook with? These have truly stood the test of time. 

Some healthier oils and fats that are great to cook with:

• Coconut Oil
• Butter & Ghee
• Lard
• Extra-virgin olive oil **
• Tallow

**Beware of counterfeits when you buy olive oil. It has been discovered that up to 80% of imported olive oil contains counterfeit oils like vegetable oils (source). This fact blew my mind! Dr. Berg has a post and video helping you to determine if olive oil is real or not.

My personal favorites are probably grass-fed butter, coconut oil and avocado oil. 

Unsaturated vs. Saturated fats

Structurally, unsaturated fats are different than saturated fats. Saturated fats are considered “stable”. because they are saturated with hydrogen atoms, which makes them solid at room temperature. They are able to withstand higher heat. On the other hand unsaturated fats have one or more double bonds, which means they are missing hydrogen atoms on the fatty acid chain. The result is that they are more flexible and susceptible to oxidation or becoming rancid. 

Where the double bond is on the chain determines whether it is an omega-6 fats or an omega-3 fat. Our bodies need both types to function, however seed oils can skew this natural balance of fats in our body and result in health issues. 

Smoke Point of Cooking Oils

Another factor to consider when choosing an oil to cook with is smoke point. Every oil, no matter what type has a smoke point that refers to the oil’s resistance to heat. In most cases an oil’s smoke point is the highest temperature limit that it should be heated to prevent poor tasting food and releasing harmful compounds into food and the air. At certain heat all oils will begin to break down, potentially releasing these harmful compounds.  

If your cooking oil starts smoking, that is a good sign that you are using too much heat. However you can’t just use this smoke test, especially if you are using a polyunsaturated fat. These types of fats are unstable and will start breaking down long before they start smoking. 

Conclusion – Try Your Best, Don’t Stress

If you are anything like me, information like this can be overwhelming. Seed oils can be hard to avoid, and it can feel frustrating at times to find healthy food (in your budget). My advice is do your best to educate yourself and make good choices, but don’t let seed oils stress you out. I think that the human body was designed to be incredibly resilient, and consuming seed oils occasionally won’t kill you. Do your best and don’t let fear or overwhelm consume you when it comes to seed oils, or anything else in the health and wellness sphere!