When was the last time you rubbed soy oil on your face? Probably never, right? Unlike olive oil and beef tallow, which have been eaten and used on the skin since antiquity, industrial seed oils like soy and cottonseed have only been in widespread use for the last 100 years or so.
If people didn't historically consume something or use it on their skin, it should give us pause for thought. Yet seed oils are everywhere today—in fast food, restaurant food, supermarket ready meals, and even the majority of ‘natural’, ‘organic’, ‘plant-based’ and ‘vegan’ skin care products.
The problem is that seed oils are high in polyunsaturated fatty acids (or PUFA for short), and PUFAs are far from good for you. Let's take a look at the types of oils used in modern skin care products, and why some of them are healthier and more nourishing than others.
So what are PUFAs, and why are they dangerous?
There are essentially two types of fat: saturated and unsaturated. Saturated fats, like butter, lard, tallow and coconut oil, are solid at low temperatures. Unsaturated fats are liquid at low temperatures, and come in two sub-types: monounsaturated (e.g. olive oil, macadamia oil) and polyunsaturated (e.g. hemp, rapeseed, sunflower and flaxseed). It’s this last sub-type of fats that are highly chemically unstable. Unlike the more stable saturated fats, they have an incomplete hydrogen bond, which means they oxidize—combine with oxygen when exposed to heat and light —very easily.
(Our bodies are warm – and the perfect environment for oxidation to occur and create havoc in our cells!)
The higher an oil is in PUFA, the more prone to oxidation it is. Coconut oil, for example, is made up of over 90% saturated fat, with only a tiny percentage of PUFA. Its chemical composition makes it far less prone to oxidation than something like safflower oil, which is almost 80% PUFA.
To give you an idea of how just how easily high-pufa linseed oil (also known as flaxseed and touted everywhere as a health food) can oxidize, watch this short video:
All this talk about oxidizing is important, because it’s oxidation that makes PUFAs so bad for our health. Oxidation produces free radicals—the nasties that cause our cells to age—meaning that the higher an oil is in PUFAs, the more likely it is to cause free radical damage to your skin.
Endocrine physiologist Dr. Ray Peat explains that eating too many PUFAs can increase many health risks:
“The food-derived polyunsaturated fatty acids play important roles in the development of all of the problems associated with aging—reduced immunity, insomnia, decreased learning ability, substitution of fat for muscle, susceptibility to tissue peroxidation and inflammation, growth of tumors, etc., and are probably involved in most other health problems, even in children.”
To make matters worse, PUFAs are found not only in the foods we eat, but also in the cosmetics we put on our skin. And they’re just as prone to oxidation (and the resulting free-radical damage to our cells) when found in a lotion as they are in a frying pan.
This means that even cosmetics that advertise themselves as natural and free from harmful chemicals can contain damaging PUFAs that cause sagging, wrinkles, and prematurely aged skin. Cosmetic oils like almond, argan, rosehip and grapeseed may be organic and cold-pressed, but they’re still high in PUFAs, and best avoided.
If PUFAs are so dangerous, why are they in everything?
So how did PUFAs come into such widespread modern use? The answer is a whole system of promotion, advertising, and profitability. According to Dr. Peat:
“In the 1940s paints and varnishes were made of soy oil, safflower oil, and linseed oil. Then chemists learned how to make paint from petroleum, which was much cheaper. As a result, the huge seed oil industry found its crop increasingly hard to sell. Around the same time, farmers were experimenting with poisons to make their pigs get fatter with less food, and they discovered that corn and soy beans served the purpose, in a legal way. The crops that had been grown for the paint industry came to be used for animal food. Then these foods that made animals get fat cheaply came to be promoted as foods for humans, but they had to direct attention away from the fact that they are very fattening.”
In other words, the seed oil industry is making a huge profit from selling us these unhealthy, PUFA-filled oils, and they’ve put a lot of time, money and effort into making sure that they’re seen as healthy and nutritious instead. Seed oils actually used to be seen as a waste product: it was not until the invention of the hydraulic press that it even became possible to sell them to the public as food, at an enormous profit to Big Agriculture.
The most ironic thing about this whole situation is that seed oils are so often marketed in beauty products as ‘natural’. In fact, oil can only be extracted from many seeds through a pretty complicated industrial process involving hydraulic presses, high heat, and extreme pressure. You can get oil from olives, in contrast, through simple cold pressing, a far simpler and more traditional technique.
If PUFAs are in everything, how can I avoid them??
Learning to be savvy about reading food and cosmetic labels will help you to avoid PUFAs. Ingredients are usually listed in descending order, so the closer to the top of the list a high-PUFA oil is, the higher the PUFA content of the product.
It's especially important to avoid putting high-PUFA oils on your face, because this is the part of the body that gets the most sun exposure. PUFAs can interact with iron, oestrogen and the sun to produce lipofuscin, the dark brown pigment responsible for liver spots. Many commercial sunscreens do not protect against this particular problem because—guess what?—they’re often high in PUFAs too! Your best bet here is to use a low-PUFA sunscreen such as Miessence Reflect. But more about that another time.
What low-PUFA alternatives should I look out for?
Good oils to keep an eye out for at the top of ingredients lists include:
Given what I have learned about the skin-damaging effects of PUFAs, I use macadamia, jojoba and babassu combined with grass-fed beef tallow in Absolutely Pure Organic Skin Food. Beef tallow is a stable, saturated fat that is chemically similar to sebum, the natural oil produced by our own skin. It’s a more effective moisturiser than high-PUFA seed and nut oils, as well as being kinder to your skin and better for your health.