Is Vitamin E A Preservative and Can Too Much Cause Pro-Oxidation?

There seems to be much confusion and mis-information (or half understood repeated stuff) going around about Vitamin E and while I’m not the world’s greatest (or even top 100th) authority on all things ‘E’ I have been pondering, experimenting and researching this long enough to throw warrant me throwing my own hat in the ring.

So here are some myths that I’ve seen

• Vitamin E as a preservative.

Vitamin E is NOT a preservative. Well, by that I mean that it has no anti-microbial powers.   Vitamin E is often added (in the form of tocopherol) to a personal care product to help slow down oxidation.  Oxidation is a process where chemicals start to fall apart because the energy or conditions brought about due to light, heat or moisture exposure.  Oxidation is a big problem for vegetable oils, especially the nice ones with lots of Omega fatty acids in their make-up and so it is important that we try to hold it back.  Oxidative breakdown leaves the oil smelling rancid and with a deeper colour. The oil may become more irritating and less cosmetically appealing.

• We shouldn’t add more than 0.1% or so Vitamin E to our products as adding too much turns it into a pro-oxidant.

I have no idea where this notion came from and it has been puzzling me for some time.  I wonder if it was something that someone said on google one time, then someone else saw it and without thinking it through shared it until it went viral.  Or maybe not. Anyway, it made no sense to me although I’m always happy to be corrected by good science.

So – antioxidants prevent or hold back oxidation (rancidity etc).

Pro-oxidants bring it on.

Only they don’t usually bring on oxidation per se.  Pro-oxidant reactions are there to help the antioxidant molecule self-destruct when the environment for performing their original function ceases to be relevant.  Think of it like this, there is a time and a place for everything.  Antioxidant activity is very energy intensive and it is best if when not needed any more these molecules dis-arm or change to more peace keeping roles.  That prevents them messing up other reactions or taking energy away from other reactions.

I don’t know why I’ve got so many war analogies but I like this vision too:

The antioxidant is like a highly trained soldier with the ability to diffuse or lessen the impact of bombs. To do this the antioxidant has to be very powerful but power can be used for good or evil, it can also be used by mistake.  When the antioxidant reaches an environment where there are no risks it is a good idea for it to disarm and chill out.

Pro-oxidant reactions have been documented for vitamin E (tocopherol).  What I’ve found from my reading is that these pro-oxidant reactions are involved in LDL (low density lipoprotein) reactions that are carried out within the body (Anaerobic conditions – without oxygen).  There is some debate as to how important these reactions are but rest assured these conditions are NEVER replicated in a cosmetic making this fact interesting but largely irrelevant.

In terms of 0.1% being the limit for Vitamin E that also seems rather weird.  Wheat Germ oil is an oil renown for its high vitamin E content and that has around 0.119%.  But we must remember that it has a small amount because wheat germ oil is usually bound up safe and sound within the wheat and not squeezed out with much force and determination into a glass bottle and popped onto a damp bathroom shelf.   Nature doesn’t need any more vitamin E to protect wheat germ but what we are doing with the oil when we make cosmetics is UN-NATURAL.

The cosmetic industry, both the natural bods and the regular joe’s have been using Vitamin E (tocopherol) at concentrations from below 0.1-2% for many years and I haven’t found a shred of evidence to date that the higher amounts cause more trouble than they are worth in terms of oxidation.

Vitamin E at high concentrations (2% and above) CAN be irritating to the skin and there have been studies into that.  That is why I’d not recommend going to the higher levels unless you want to market a vitamin E cream for therapeutic use.  In that case I’d also get the formula dermatologically assessed.

• Vitamin E Acetate and Vitamin E Natural (Tocopherol) are both antioxidants and can be used to prolong oil shelf-life*

This one can be blown straight out of the water easy as pie!

It is all to do with the molecules chemical structure and that’s as much chemistry speak as I’ll do.

To be an antioxidant you need to have at least one hand with which to grab and diffuse your prey.  Tocopherol has that,  Vitamin E Acetate does not because the acetate part has its hands full with no capacity for more.

IF you want to add vitamin E for skin benefits you can add either.

IF you want to add vitamin E for its antioxidant benefits you can add Tocopherol.

• Natural Vitamin E is just natural vitamin E.  Any type will do.

This is also wrong.  Vitamin E is actually a mixture of isomers (isomers are different shapes of the same molecule). Only one shape of vitamin E – alpha – has the skin repairing capacity.  However, ALL shapes of Vitamin E have antioxidant capacity.

You will pay more money for vitamin E that is all Alpha tocopherol as naturally it comes in a bunch of shapes and sorting out just the alpha takes time and money.

I usually tell clients to save the alpha tocopherol for the skin repair creams and use the mixed tocopherol for its anti-oxidant powers and some general skin conditioning.

Vitamin E acetate can be metabolised by the skin albeit less effectively than tocopherol and so can be used for skin conditioning. *

I am not always right and I would encourage you to think about EVERYTHING you are told and do your own research.  Even though you are reading this on a blog I’d encourage you NOT to believe everything you read in forums or from other brand owners.  I often have clients tell me they have spent years researching and when they talk to me it is clear to me that what they have spent years doing is reading re-hashed opinions and half-truths. That is quite sad.

Google Scholar and Deep Dyvve are your friends. That is where ‘research’ is done.

Have fun and enjoy your Vitamin E.

Amanda x

* I had to amend the heading of my vitamin E vs Vitamin E acetate bit and add a sentence as I didn’t make the features and benefits of vitamin E acetate clear enough before. 

 

UPDATE 3rd May 2019

OK so I found out where the 0.1% Vitamin E pro-oxidant drama came from and now I can’t work out why I didn’t spot this way back when…

Here is a reference to a good paper on this subject:

Prooxidant Activity of Oxidised a-Tocopherol in Vegetable Oils.

Chapman, Timothy M.; Kim, Hyun Jung; Min, David B.

Journal of Food Science, Volume 74 (7) – Jan 1, 2009.

This paper looks at vegetable oils and their ability to withstand oxidation.  The paper does indeed show that vitamin E can act as a pro-oxidant in some cases and that 0.1% is a very rough approximation of how much vitamin E nature often (but not always) pops into her oils.  However, this is an over-simplification of what’s going on and so it still isn’t necessarily true to conclude that too much vitamin E WILL give you problematic pro-oxidisation.

Here is a brief summary:

• Vitamin E exists in many isomers and oils that have an excess of alpha tocopherol are at higher risk of pro-oxidation than those that don’t but again, it is slightly more complex than that.
• Other isomers of Vitamin E don’t seem to promote pro-oxidation even when they are present in relatively high levels.
• Vitamin E isn’t the only antioxidant in vegetable oils.

 

So, the bottom line is that using mixed tocopherols is the best idea, keeping below 2% is a given for all applications but for antioxidant I typically tell people 0.1-0.5%. This may be too much in some cases but stability testing can help you work that out.