Tocopherol vs. Tocopheryl Acetate: What's the Difference?

Let's look at the differences between tocopherol vs tocopheryl acetate

There are two forms of vitamin E: tocopherol and tocopheryl acetate. Tocopherol is naturally-occurring, while tocopheryl acetate is synthetic. Both are used in cosmetics as antioxidants, keeping oils from turning rancid, and for their reported benefits on skin (healing, anti-aging).  

The term "vitamin E" actually refers not just to one molecule, but a family of molecules that are chemically similar. That's why sometimes you'll see the words "mixed tocopherols" on a vitamin E label. There are multiple forms of tocopherol, including alpha and gamma, and a sub-family of compounds called tocotrienols.  All of these compounds have the same chemical formula (same amount and ratio of atoms) just in slightly different arrangements (called isoforms.) To simplify, instead of listing out each and every isoform, we refer to these compounds collectively, as "vitamin E."  The most predominant molecule in the vitamin E family is alpha-tocopherol, and most of the time, when one says "tocopherol," they are referring to alpha-tocopherol.  (As I will be doing for the purposes of this discussion.)

Tocopheryl acetate is the ester of tocopherol.  On a molecular level it is an tocopherol molecule with an acetate group added.  It is more stable than tocopherol, typically giving products a longer shelf-life.  In order for the body to absorb and use vitamin E, it must somehow remove the acetate group. Thus, many claim that tocopherol is more bioavailable to skin and for internal use because it can be absorbed without additional metabolism. (Source)

(Alpha) Tocopherol

(Alpha) Tocopheryl Acetate [Note the acetate group on the far left of the molecule]

Interestingly, both tocopherol and tocopheryl acetate can be made synthetically.  So, while tocopherol is usually touted as "natural tocopherol," it may still be synthetic.

Tocopheryl acetate requires more steps and ingredients for production:

Dichloromethane-->Sodium chloride-->Xylene-->Zinc chloride-->Isopropyl ether-->PASSION FLOWER OIL-->SOYBEAN OIL-->SODIUM SULFATE DECAHYDRATE-->Isophytol-->Trimethylhydroquinone-->Vitamin E-->(POLYOL) (Source)

Whereas synthetically-produced tocopherol requires fewer steps:

Acetic anhydride-->Isophytol-->Trimethylhydroquinone (Source)

You'll notice, though, that both of these processes use a chemical called trimethylhydroquinone. Hydroquinone is in a class of chemicals called aromatic organic compounds. (Source) This means not just that it's aromatic in the sense of it being fragrant, but it contains a benzene ring. If you're a longtime reader of this blog, you'll know that I view most compounds with simple benzene rings with caution for their possible xenoestrogenic effects. Animal studies have found hydroquinone to alter immune function and to increase the "incidence of renal tubule cell tumors and leukemia in F344 rats." (Source) While the Cosmetics Industry Review board states that cosmetic use is unlikely to cause these effects, they do recommend its use at less than 1% in a product, and state that it should not be used in leave-on products. So, if one were cautious about what they put on their skin, hydroquinone and hydroquinone-contaminated vitamin E would be an ingredient that I would recommend avoiding. 

What to look for

Now that we know that even "natural tocopherol" can be a synthetic compound and laced with hydroquinone, does this mean that all vitamin E should be avoided? No. There are safe forms of vitamin E. Unfortunately, you're not able to tell the difference just by looking at a label. You have to dig deeper and ask the manufacturer of the product you're using.

The best form of vitamin E when considering contamination concerns, is vacuum-distilled. This means that they'll take an oil with naturally-occurring vitamin E and extract the vitamin E. Vitamin E has a different evaporation point than the fatty acids in the oil. So, under certain pressures the vitamin E separates from the oil, evaporates up through a tube, and is thus completely extracted. 

The oils most frequently used for vitamin E production are corn, soy, and rapeseed/canola. Unfortunately, in the US, 90% or so of these oils are from genetically-modified crops. So, if you want to take it a step further, ask if the vitamin E in the product is certified non-GMO. Certified organic products cannot contain any genetically modified material, so the USDA organic seal on a product would ensure that the vitamin E used is non-GMO. 

Is Vitamin E Safe and Beneficial?

Truly natural vitamin E is not just safe, but highly beneficial and a vital nutrient the body cannot live without. In food and cosmetics, vitamin E prevents oils from turning rancid - a job that the vitamin also performs inside the body. 

Ingestion and topical application of vitamin E has proven to be a powerful force against cancer.  This study found vitamin E to help reduce lung tumors in animals. This study found vitamin E to be anti-inflammatory in the lungs and colon. This study found vitamin E to have a potential role in breast cancer prevention. Applied topically, vitamin E also shows strong anti-oxidant and anti-inflammatory properties. This study found reduced inflammation and incidence of skin cancer in mice treated topically with vitamin E. This study confirmed this potential in humans. Additionally, very recent studies have found that tocotrienols may have the most health-promoting benefits. (Source) Tocotrienols are not found in tocopheryl acetate, and can be found in the highest concentration in solvent-free, vacuum-distilled vitamin E.

What about soy?

Most vacuum-distilled vitamin E is extracted from soybean oil.  There are many people who avoid soy based on hormonal concerns, thyroid issues, and allergies. Only in cases of extreme soy allergy would I suggest avoiding a soy-extracted vitamin E. Vitamin E extracted from soy does not contain any of the isoflavone phytoestrogens, so it is not a concern for the thyroid or hormonal balance.  (Isoflavones are largely insoluble in water and in oil, and are not found in soybean oil [Source].  The vaccuum extraction of the vitamin E from the oil further insures no isoflavone content in the finished vitamin E product, as isoflavones have a largely differing evaporation point than the mixed tocopherols. [Source][Source])  Naturally-extracted vitamin E is highly purified, and also lacks the most of the compounds that trigger allergies associated with soy.