Vegetable Oils a Fat Lot of Good!

That is about the size of it, well according to a couple of hours of internet surfing (do we still surf the internet or is that a very uncool thing to say?) it is. So it is lucky then that we have alternatives:

"Vegetable oils won't clog your pores, are light weight and blend well with your skin, clear pimples, prevent cancer and generally make life better".

My whole entire 17 years of working as a Cosmetic Chemist has seen me operate in this space where veggies rule and can cure everything. In fact, there is so much 'information' online nowadays that it is tempting to just go with the unquestioning flow and accept that the future is vegetable. After all veggies are great.

Only I don't want to do that.

My not wanting to do that has nothing to do with me wanting to promote petroleum - I don't because as far as resources go, petroleum is unsustainable. No, what I would like is to take a closer look at vegetable oils and find out if they really can do all of those wondrous things and if so, how...

Before we delve into the wild world of vegetable oils we should define the alternatives - petroleum and silicone oils a little better:

Petroleum Oils

Petrolatum, petroleum jelly, liquid paraffin, mineral oil and the like come from oil that is dug out of the ground or sea-bed and refined. They are all types of hydrocarbons with different melting points, spread characteristics, skin feels and solubilizing power.As far as chemical reactivity goes hydrocarbons are pretty far down the track of 'active' ingredients and instead concentrate what they are good at - providing barrier protection and a base for other things to disperse into.

If used directly on the skin these cosmetic grade materials tend to sit somewhere around the top layers of the skin where they form an occlusive barrier akin to putting on a waterproof jacket unless they are blended into a cream. When in a cream their ability to form a heavy, waterproof layer diminishes and instead they form a more 'breathable' film like any other type of oil.

Because of their un-reactivity and lack of active components petroleum oils tend to have very long shelf life when compared to other ingredients, are usually clear to white and are usually the same from batch to batch no matter where they are made. Petroleum oils do have a smell characteristic of these hydrocarbons - some people think of that smell as 'chemical', which it might be but it usually isn't over-baring and doesn't tend to linger in the final product.

In terms of allergens petroleum derivatives of cosmetic or pharmaceutical grade are generally allergen free and as such remain the mainstay of the pharmaceutical industry. There simply isn't anything in them to be allergic to.

Silicone Fluids

While petroleum oils and vegetable oils are all built on the carbon molecule silicone fluids are built around silicone. Carbon comes from plants and animals so your petroleum was once a plant or an animal it just died hundreds if not thousands of years ago. Silicone comes from sand.

Silicone fluids such as the Dimethicones are simple un-reactive base oils that are generally used to improve shine, slip, to disperse actives or to form a barrier on the skin just like their petroleum brothers and sisters. Silicone fluids come in all shapes and size some being ultra-light and quick to absorb or evaporate (ideal for deodorants or hair products) while others are very heavy, thick and substantive.

Silicone fluids are made by combining silica (sand) with petroleum-derived carbons to make clear, stable liquids. Again their shelf life is usually very good and their batch-to-batch reliability is high. You get the same product time after time.

Just like petroleum derivatives the silicone fluids are a low-allergy option for the same reasons - namely their chemical inertness.That said both petroleum and silicone derivatives can feel itchy if applied directly as it tends to form a barrier that over-heats the skin.

So how do vegetable oils compare?

Vegetable Oils are altogether different. If you could look into a vegetable oil and see the different chemicals swirling around you would see that there is a party going on! Give each different chemical a colour and your vegetable oil would be all the colours of the rainbow. This is what makes the study of vegetable oils both fascinating and confusing. There are just so many things to consider, so many parts that can do something, including irritate!

Globally Soybean oil is right up there in terms of volumes manufactured and sold each year. Looking inside the soybean oil we would find what in my eyes can only be described of as a chemical factory:

Soybean Oil Typical Chemistry:

Just looking at that table gives you a good idea of how different vegetable oils are from either silicone fluids or petroleum oils. A table for the latter would look like this in comparison:

Before we all jump for joy and sing 'all hail the vegetable oil' it is worth taking a step back and asking ourselves some questions:

1) What do we need our oil for?

Having had more than my fair share of itchy skin days I know the value of a good moisturizer and by good I mean emollient and soothing, not anti-ageing, anti-wrinkle, plumping, antioxidant and so on and so forth. When your skin is so sore that even water irritates you just need emoliency - some fat to replace the skin barrier so that it can set about repairing its self.

In that situation I have always found reverting to my tried and tested no-frills petroleum cream the best solution once I can get over my moral outrage at using a non-sustainable feedstock on my tired skin.

That said, if you are looking for oil that doubles up as a skin active then going veggie may well be the right choice.

From a formulators perspective vegetable oils should NEVER be treated with a 'one-size-fits-all' mentality. Each oil has different polarity, activity, stability, and solubility and needs to be dealt with as a discrete chemical and not just another oil.Our vegetable and carrier oil master data table does show that the majority of vegetable oils share the same or similar HLB values their chemistry can be quite different. Handle them appropriately!

Now with my accounting hat on I'd advise choosing your oil carefully to ensure you are working these assets to their full potential!

2) What are we putting with our oils?

Are you making an oil-only serum or an emulsion? Is it a face wash or a facemask? Is it for a baby or toddler or the 55-70 demographic? People often ask us if you can use things like Rosehip or carrot seed oil straight onto the skin. The answer is that theoretically you can but it is unadvisable as they are highly active and could irritate.

Plus there is only so fast your skin can mop up the goodness so your efforts to speed up skin recovery may well end up down the drain. Again if all you need is a little emollient skin feels then check out the simple base oils, petroleum's or silicones first - especially if your target market has sensitive skin.

3) What do you want to claim?

I've saved the biggest call until last. As I mentioned at the beginning of the article vegetable oils are touted as being able to do everything from make you look younger to cure your cancer. Both are huge calls and finding tangible evidence to support these types of claims for a skin care product has been tricky.

Vegetable oils have been widely studied in skin care, usually vs. petroleum oil and have been found to have some efficacy in the following areas:

• Moisturisation
• Improving the appearance of blemishes/ acne
• Wrinkle Reduction.
• Barrier Repair
• Psoriasis Management
• Alleviating the symptoms of Eczema.

Three key benefits of vegetable oils that have been established through peer reviewed scientific research are as follows:

A ) The simple fact that the applied oil (any oil) helps to moisturize the skin (lock in moisture, prevent it drying out) improving its feel, look and health.

B ) The action of Essential Fatty Acids on the skin.These essential fatty acids – fats that the skin and body need but don't make (we usually eat them) are important to the optimal functioning of our skin.

C ) The anti-inflammatory role of antioxidants on the skin and the fact that vegetable oils naturally contain these (Vitamin E, Carotenoids (Vitamin A precursors), Gamma-oyzanol (from Rice Bran), sesaminol (Sesame) and more.

So what about the other things that vegetable oil is claimed to be?

In terms of comedogenicity that is a tricky one. Much of the work done on what is or isn't comedogenic was carried out in the 1950's - 1970's and involved animal models and neat materials. The research findings have taken on the position as urban truth rather than robust science and as such I'm inclined to be skeptical of both the term and this now outdated science.

Some murmurs have been made from time to time about particular oils being able to boost the skins natural UV protection. This has been studied (Sea buckthorn oil is a good example of this) but the little result achieved was attributed to diet rather than skin care. In terms of natural skin care and vegetable oils the antioxidant path is the one most promising but we are a fair way off using plant grown SPF filters...

Claims about the weight (or weightlessness) of one vegetable oil vs. another can be a little far fetched at times but do have their basis chemistry.A look the chemical breakdown of the oil will quickly show you how heavy or light the oil might feel – does it contain lots of very long chain wax esters or is it mainly short chain fats? But for true weightlessness you would probably have to go for a silicone or specially manufactured petroleum derivative.

So are vegetable oils a fat lot of good?

Yes, yes they are. In terms of what they can do for your skin and/or hair the possibilities are endless and with more oils being discovered, processed and made available each year the opportunity to play and get creative is enough to keep us chemists off the streets until retirement. So, while it would be foolish to think that all of life's problems can be solved with vegetable oil you wouldn't be going too far wrong.

Come and play.

Amanda Foxon-Hill

26 March 2014