Delta-tocopherol
A natural form of vitamin E extracted from plant oils, added to slow down oxidation and stop fats going rancid.
What is it?
Delta-tocopherol is one of four naturally occurring forms of vitamin E (alongside alpha-, beta-, and gamma-tocopherol). In food additive use it is isolated or concentrated from plant oils, most commonly soybean oil. It is the least abundant tocopherol form in the human diet but has the strongest antioxidant activity in fat-based systems among the tocopherols.
What does it do?
It breaks the chain reaction of lipid peroxidation by donating a hydrogen atom to free radicals formed when fats react with oxygen. This stops the cascade that causes rancidity, off-flavours, and the breakdown of fat-soluble nutrients such as vitamins A and D. It works particularly well in high-fat and oil-rich products where oxidation would otherwise happen quickly.
Where you will see it
Found in vegetable oils, margarines, spreads, fat-based dressings, fried snack products, and some fat-containing baked goods. It may also appear in some infant formula and follow-on formula products where fat stability is critical. On a UK ingredient label it appears as 'delta-tocopherol' or 'antioxidant (E309)'.
What the science says
Antioxidant activity and tocopherol comparisons
Among the four tocopherol forms approved as food additives (E306 to E309), delta-tocopherol has lower biological vitamin E activity than alpha-tocopherol but considerably stronger antioxidant capacity in food matrices. This makes it particularly valued in food manufacturing even though it contributes less to the body's vitamin E status per gram than E307.
Delta-tocopherol shows greater peroxyl radical-scavenging capacity in lipid systems than alpha-tocopherol, making it more effective as a food preservative antioxidant, though it has lower biological vitamin E potency.
EFSA 2015 re-evaluation
EFSA's Panel on Food Additives and Nutrient Sources (ANS) re-evaluated all tocopherol food additives (E306 to E309) in 2015. The panel concluded that the tocopherols were not of safety concern at the levels used in food. No numerical ADI was established, in line with the approach for substances that are normal dietary constituents. The panel noted that dietary exposure from additive use was well within the range of background dietary intake from food naturally containing tocopherols.
EFSA ANS Panel concluded that tocopherols (E306 to E309) as food additives are not of safety concern at the reported use levels, and no numerical ADI was considered necessary given their status as normal dietary components.
High-dose tocopherol supplementation signals
The science around tocopherols at very high supplemental doses (grams per day, far above additive exposure) is more nuanced. A large clinical trial found that high-dose alpha-tocopherol supplements were linked to a modestly increased risk of prostate cancer in men. This finding applies to concentrated supplements, not to tocopherols used as food additives, where the doses are a small fraction of supplemental levels. Delta-tocopherol specifically has not been the subject of this concern, and some laboratory research suggests it may have different or even protective properties at higher doses, though human evidence is limited.
The SELECT trial found that men taking 400 IU/day of alpha-tocopherol (vitamin E) supplements had a statistically significant 17% increased risk of prostate cancer versus placebo. The effect was not observed for delta-tocopherol specifically.
Laboratory and animal studies suggest delta-tocopherol may inhibit certain cancer cell lines, but human evidence is absent and these findings cannot be extrapolated to food additive use.
Where it stands with the regulators
Who should be careful
People with a soy allergy should be aware that delta-tocopherol used as a food additive is often derived from soybean oil, though the protein residues responsible for soy allergy reactions are not typically present in highly refined tocopherol extracts. Those concerned should check with a clinician. Look for 'E309' or 'delta-tocopherol' on the ingredient list.
The honest read
Delta-tocopherol is a compound the body already encounters through ordinary foods such as wheat germ, nuts, and vegetable oils. The questions that exist in the science are around concentrated tocopherol supplements at doses many times higher than any food additive use, and specifically around alpha-tocopherol (E307), not delta-tocopherol. The additive form is used at levels that add a small increment on top of normal dietary intake. The 2015 EFSA review did not flag outstanding data gaps or call for further restrictions.
Related additives
Common questions
Is E309 banned in the UK?
No. Delta-tocopherol (E309) is an approved food additive in the UK and EU, listed on the FSA's approved-additives register and permitted under assimilated EU Regulation 1333/2008.
Is E309 the same as vitamin E?
Delta-tocopherol is one of eight naturally occurring compounds that together make up what we call vitamin E. It is a minor dietary form of vitamin E, with lower biological vitamin E activity than alpha-tocopherol (E307) but stronger antioxidant action in food fats. In food additive use it functions as a preservative rather than a vitamin supplement, though it does contribute a small amount of vitamin E to the diet.
What foods contain E309?
Vegetable oils, margarines, fat-based spreads, salad dressings, some fried snack products, and certain baked goods are the most common sources. It may also appear in infant formula. Look for 'E309' or 'delta-tocopherol' in the ingredients list.
Is E309 vegan?
Yes. Delta-tocopherol used as a food additive is derived from plant oils, most commonly soybean oil, making it suitable for vegans and vegetarians.
Sources
- UK FSA Approved Additives and E Numbers
- EFSA ANS Panel: Re-evaluation of tocopherol-rich extract (E306), alpha-tocopherol (E307), gamma-tocopherol (E308) and delta-tocopherol (E309) as food additives, EFSA Journal 2015;13(6):4247
- Klein EA et al., Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT), JAMA 2011;306(14):1549-1556
- Kamal-Eldin A & Appelqvist LA, The chemistry and antioxidant properties of tocopherols and tocotrienols, Lipids 1996;31(7):671-701
- Jiang Q et al., Gamma-tocopherol and its major metabolite, in contrast to alpha-tocopherol, inhibit cyclooxygenase activity in macrophages and epithelial cells, PNAS 2000 (related tocopherol research)
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