Let me start this discussion of with some common sense. Humans have not consumes seed oils in large quantities for most of our existence. Seed oils is a modern addition to the human diet. It is astounding that ancient fats and oils such as butter, ghee, lard and tallow are blamed for heart disease, which did not exist till the modern industrial era, and modern oils that are mass produced in factories, putting the natural ingredients through chemical processes and then say this is super healthy for us!
It is time to stop blaming modern diseases on ancient foods and maybe wake up a bit and realize that it is the modern foods that are causing the modern diseases.
Why are seed oils so bad?
1 How its made
The process of manufacturing contributes to teh negative health impact of common seed oils.
The processes involved in creating seed oils is definitely no natural. All seed oils needs to be refined, bleached, and deodorized before they are considered good enough for us to use as food. The more you process food, the worse its health benefits become.
So in order to get to the oils you use to cook with, seeds from soy, corn, cotton, safflower, and rapeseed (canola oil) or sunflower plants mus be heated to extremely high temperatures which of course causes the unsaturated fatty acids to oxidize, which is not good as far as health is concerned. Next step lets use a solvent (like hexane) to get as much oil from the seeds as we can.
If you thought this was the end, no, these extracted oils do not smell very palatable. So manufacturers have to deodorize the oils otherwise you would not touch it with a ten foot pole. Lastly chemicals are added to get the oil to look pretty and colourful in a bottle. All in all the natural part of the product has been beaten to death before it ever reaches your mouth.
2. It was never part of our lifestyle
Humans did not eat seed oils until the 1900. When proctor and gamble took toxic oils and refined it to make edible oils and margarine’s. Together with Ancel Key’s now debunked lipid heart hypothesis, they pushed the narrative that natural oils from animal are bad for your heart and vegetable oils are now good for you. Since the introduction of seed oils in the human diet, together with sugar and refined foods, we have seen a dramatic increase from 0 to the worlds foremost killer – heart disease. Yet the idea that animal fats cause heart disease persists – strange?
3. Seed oils are unstable, especially when cooking with it.
The fatty acids in seed oils are very unstable when exposed to heat, light, and chemical inputs. This instability cause the oils to easily oxidise under these conditions and this causes the formation of trans fats and lipid peroxides. We should all know by now that trans fats are really bad for our health and they play a contributing role in the development of cardiovascular disease and type 2 diabetes.
Lipid peroxides, are toxic byproducts which form in when the oils are exposed to light and heat and these will damage your DNA, proteins, and membrane lipids throughout your body. When these lipid peroxides accumulate in the body it causes faster aging and is a big driver in chronic diseases.
Causes higher inflammation in the body
It is well know that omega 6 fatty acids are a pro-inflammatory fatty acid. It has to be said that inflammation is not all bad, it is the way the body protects and heals itself. However, when the inflammation is chronic because of our diet, it leads to a variety of inflammatory chronic diseases.
Omega 3 fatty acids on the other hand is an anti-inflammatory fatty acid, and it promotes health. I a healthy diet, the ratio of omega 3 to omega 6 fatty acids should be 1:1. This creates a balanced environment where the body can use inflammatory marker to heal and anti-inflammatory markers to keep inflammation at bay.
In our modern lifestyles the omega 6 to omega 3 ratio is 10:1, and this causes a highly inflamed environment in the body. Seed oils contribute to this inflammatory state s their omega 6 to omega 3 profile is also not balanced. Canola oil is 2:1 and it does not seem problematic until you realize how much of the oils we consume. When you add up the amount of seed oils we consume in premanufactured foods, and processed foods, it becomes clear that our seed oil consumption has gone of the charts, and with that, so has our inflammatory diseases.
Free radical formation due to reheating oils
Most households will reuse oil especially if they have deep fired some chips or so. Restaurants definitely reuse their seed oils to prepare our food. This continued reuse of heated seed oils causes the formation of free radicals that cause oxidative stress in the body. It damages DNA, proteins, and lipids throughout the body as well. The damages caused by the free radicals leads to high blood pressure, heart disease, and intestinal and liver damage.
This is sadly a slow process so most people snide at you when you tell them this. The answer usually is, I have been using these oils for years and I am still fine. You might be, you might not be. You might feel fine while the systems in your body is busy breaking down. Your body is fantastic like that, It will make you feel great so you can carry on finding food and keeping it alive while it will fight an internal fight to fix everything.
When all the inflammation and damages come to head, they come with a bang. One day you are feeling great, the next day you have all the symptoms of type 2 diabetes, or heart disease, or metabolic syndrome. One day you are healthy and the next you are diagnosed with a chronic disease. You can choose to live healthy and bypass that. Get rid of the man made oils, and use what nature has provided.
I urge everyone that reads this article, make three changes in your life right now, and you will immediately improve your current and future health.
- Replace seed oils and margarines with butter, ghee, lard or tallow.
- Remove sugar from your diet. When you feel like something sweet, eat some honey.
- Remove processed food from your diet and replace with single ingredient foods.
Videos that explain why you should not use seed oils:
- Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis: https://openheart.bmj.com/content/2/1/e000196
- The effect of short-term canola oil ingestion on oxidative stress in the vasculature of stroke-prone spontaneously hypertensive rats: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3215974/
- Effects of Cyclic Fatty Acid Monomers from Heated Vegetable Oil on Markers of Inflammation and Oxidative Stress in Male Wistar Rats: https://pubmed.ncbi.nlm.nih.gov/29920087/
- The effect of pan frying on thermooxidative stability of refined rapeseed oil and professional blend: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4711448/