Oils, particularly cooking oils, very often fly under the radar when considering the context of what we eat. "Out of sight, out of mind" seems applicable here. We don't really see the oils that our food is cooked in. Sure, we might have a "greasy meal" and notice that our food is taking a swim in some unknown substance, but we still rarely stop to consider what the oil, or the "grease" we are seeing is.
When we cook our own food, we reach into our trusty cupboard, and often pull out a see-through bottle of mysterious yellow liquid, throw it into our pans without a care in the world, and cook away. Voila! The oil is commonly seen as nothing more than a means to cook our food with. Which it often is, by the way. However, the disconnect comes when we don't pay mind to what the oil is doing to our health, our food and our palates.
The most common oils sold, used in cooking and consumed world wide are vegetable oils. Whilst these appear under many different names, vegetable oil is a all-encompassing name, covering a broad variety of oils. Some of the most common examples of vegetable oils are; Palm oil, Soybean oil, canola, rapeseed, corn, sunflower etc. This common household item can be found in almost everyones home. It is cheap, reliable and it's made of vegetables - so it must be healthy, right? Erm, not quite....
See, vegetable oils (and their many derivative forms) are far from healthy. Although commonly touted as "heart healthy" and even endorsed by certain companies (such as our beloved British heart foundation and the American heart association), as a promoter of health due to their supposed "cholesterol lowering effects", there is much more going on, under the surface when consuming these trusty supermarket veterans.
Vegetable oils (sunflower, palm, canola, rapeseed, corn etc) are highly objectionable to our health and actually exacerbate the conditions they claim to help with. That's right, we have been mislead (shock!) by food control agencies and a misrepresentation and demonism of what actually constitutes to good health and good cooking options. Lets take a dive into that statement and see exactly how these seemingly innocent and supposedly healthy oils could be affecting our health and could actually be accelerating aging, disease and declining health.
Oxidation
Refined vegetable oils are made up largely of polyunsaturated fatty acids (PUFAs). These highly refined versions of PUFAs contain high amounts of linoleic acid and are incredibly prone to oxidative damage, and when consumed, cause direct oxidative stress in the body. Whilst that doesn't sound like a good thing to anyone reading this, we have to first understand exactly what oxidative stress is, and how this can wreak havoc on our health.
Think of oxidation like a forrest fire. The forrest fire doesn't start by numerous trees spontaneously combusting at one given moment. It starts with just one event, just one tree or shrub that catches fire. This could be from incredible heats, but for the sake of keeping this aligned with my analogy, it could also be because some careless person made a poor decision, such as throwing a match on the ground in a high risk area. Let us know consider that said matchstick (vegetable oil) is dropped in the dry forest (your body), What happens?
The match lands in a very dry area and starts to smoke, eventually the smoke creates a flame and the fire begins to spread...rapidly. At this point, you may be thinking, "Ste - What the hell are you talking about, I don't eat match sticks and I haven't been into the woods for a decade, I'm good?!" - My point is that the match stick, the seemingly innocent instrument, has the potential to cause complete devastation when it isn't used with caution. The matchstick in our analogy here, is the seemingly innocuous vegetable oil.
It is 'dropped' into our system, where we have a LOT of potential to succumb to oxidative stress (fire), and if we don't call in the cavalry and put this fire out, we are going to quickly have a fully fledged blaze raging internally, showing no signs of slowing down and continuing to spread until the damage is so great, that we have a (health) catastrophe on our hands.
Ok, that doesn't sound good, but I still don't know what oxidative stress is? - Oxidative stress is THE great disease marker. Every chronic disease out there, from alzheimer's to obesity, from diabetes to auto-immune diseases. They all have oxidative stress at their root cause.
Oxidative stress affects the way our cells and mitochondria function. Mitochondria are power plants found in every nucleated cell in the body, and we are made up of literally trillions of cells (around 37.2 trillion to be exact) - it makes sense that if oxidation can alter the delicate functions and balance of these things, that we are playing with fire. The mitochondria, simply put, produce energy (ATP) to make our bodies function and in doing so, create a little by product know as reactive oxygen species (ROS).
These are usually a completely safe and naturally occurring physiological function, balanced and monitored by numerous factors such as internal glutathione production and anti oxidant consumption. However, when we have a state in which reactive oxygen species are rampant, and have an environment to do their dirty work, free radicals form, causing a cascade of inflammation within the body.
The reason vegetable oils cause this oxidation, contribute to increased free radical activity in the body and promote a state of systemic inflammation, is because they are from the family of fats known as Polyunsaturated fatty acids. These fats are extremely sucesptbale to damage from oxygen and can become oxidized very easily. In fact, many of the PUFAs oils are oxidized even during their production. We further oxidize these oils when they are packaged in see through containers, exposed to light (further damage), transported 1000's of miles in hot conditions, to sit on your supermarket shelf for months before being bought by you, the innocent consumer. At his point, you bring them home and throw them in a frying pan at 400 degrees, really putting the final nail in the coffin. If you were luckily enough to have a vegetable oil that wasn't ruined by oxidative stress, at this point, the cooking, you just sealed its fate. Oxygen physically attacks the molecules in these fats and the spread is like that of an explosion - fast and unstoppable. The free radical activity that occurs as a result of this oxidation is a BIG problem.
Now, we eat the food that we cooked in these oils and directly consume pre-oxidized fats and free radicals. These already dangerous and damaged fats now enter the body and wreak havoc on cell balance (homeostasis). To quote Doctor Cate Shanahan "I liken it to eating radiation or eating radioactive food. You're damaging your body from the inside out."
Vegetable Oils and Your Immune System
Considering that fat is an integral part of our cell membranes, it makes sense that all of this isn't good. One huge problem, of which there are many, of this free radical explosion, and the resulting inflammation, is the effect that it has on our immune system.
Put simply, our immune system is in place to protect us from invaders. When we are subject to this free radical damage and our immune cells become damaged, they begin to function and do their job inefficiently.
The immune system is caught in the midst of this 'friendly fire' and when that continues over prolonged periods (eating highly refined PUFAs often) it starts to struggle to identify the good from the bad, the you, from the not you, and as a result, the disregulation of the cells and its system produces antibodies that can be very problematic to the good you.
Antibodies are made to protect you from a future stressor of the same nature - that's what vaccinations do, the antibodies remember that stressor and protect you from that in the future. If these antibodies are being constantly produced because of poor dietary habits, coupled with disregulated function - you have the makings of some very problematic self-attack. This is commonly linked to where allergies come from - your immune system makes a mistake, creates an antibody to a particular trigger and voila - allergy. It takes the removal of these problematic triggers, and the normalization of the immune system, to reverse this condition. The good news is that it can often be done, with dietary interventions and patience.
So, if you've taken anything away from this so far it should be this - absolutely, conclusively, positively do not consume any refined vegetable oils. . .unless you enjoy playing russian roulette with your own health.
"But what about sunflower oil? Fry light? Spreads? Sprays? - They're only 1 calorie per squirt?"
Nope, nope and definitely nope. These are all vegetable oil derivatives and carry the exact same risks, as the simply named vegetable oils, they're merely packaged cleverly and pushed as healthy alternatives due to their low caloric content. These may even contain trans fats, which are so harmful to our body that some progressive cities (NYC 2008) outlawed their use in restaurants and the fight to have them stripped from shelves is stonger than ever. Our Body doesn’t recognize, nor has a system in place to deal with trans fats, therefore they are allowed to circulate until taking up home in our cells and initiate a cascade of problems. In fact, trans fats are so toxic that they have been linked to over 100,000 premature deaths from cardiovascular disease and cancer. Let that sink in for a moment.
"So, if I have been eating these oils all of my life, am i doomed to become a radioactive, self sabotaging freak?"