Soy allergy: the two questions worth separating

Soy is one of the declared allergens, so the obvious sources are labelled. The two questions that actually come up are whether the highly refined derivatives matter, and where soy protein arrives without the word soy.

Lecithin and refined oil are the common questions

Soy lecithin, E322, is an emulsifier extracted from soybean oil and used in chocolate, baked goods and spreads. The refining leaves only trace quantities of soy protein, and most people with soy allergy tolerate it without difficulty. European and British labelling still requires it to be declared, which means a label reading soy lecithin is not necessarily telling you about a meaningful protein exposure.

Highly refined soybean oil is in the same position for the same reason. Cold-pressed or unrefined soybean oil is not, since the protein has not been stripped out. As with peanut oil, this is a judgement to make with an allergist against the individual history rather than from a general rule, and severe reactions change the calculation.

Where soy protein arrives unannounced

Hydrolysed vegetable protein is the most common. It is a savoury flavouring used in stocks, gravies, crisps, instant noodles and processed meats, and it is frequently made from soy. Textured vegetable protein is soy protein by another name and is the basis of a great many meat substitutes and cheap processed meat products.

Soy sauce underpins most East and Southeast Asian cooking and appears in marinades, dressings and sauces that give no other indication. Miso, tempeh, natto, tofu, yuba and edamame are all soy under names that do not say so, and the vegetarian and vegan products that have replaced meat and dairy in recent years are very often soy-based.

Vitamin E and the small print

Tocopherols, listed as E306 to E309 and often described as vitamin E, are widely used as antioxidants and are commonly derived from soybean oil. Like lecithin, they are highly refined and carry very little protein. They are worth knowing about mainly so that their appearance on a label is not mistaken for a significant soy exposure.

Names worth knowing

Ingredients worth recognising on sight, with the other names each one appears under. Several of these are soy under a name that does not say so.

Soybean

SoyaSoySoy FlourEdamame

Soy Lecithin

Soybean LecithinSoya Lecithin

Soy Sauce

Soya SauceShoyu

Hydrolysed Vegetable Protein

HVPHydrolyzed Vegetable ProteinHydrolysed Soy ProteinTextured Vegetable Protein

Tofu

Bean CurdSoybean CurdDried Bean Curd

Tempeh

Tempe

Natto

Miso

Miso PasteShiro MisoAka Miso

A selection, not the full list.

Check a whole label at once

Recognising these by eye is the hard way to do it. Photograph the ingredients panel and NoshWise reads every line against this profile, names what to avoid, and says why.

Scan a label

Common questions

Is soy lecithin safe with a soy allergy?

Usually. Soy lecithin is highly refined and retains only trace soy protein, and most people with soy allergy tolerate it. It must still be declared on European labels. Confirm with your allergist, particularly if reactions have been severe.

Is soybean oil safe with a soy allergy?

Highly refined soybean oil has had the protein removed and is generally tolerated. Cold-pressed and unrefined soybean oil has not, and is not considered safe on the same basis.

What is hydrolysed vegetable protein made from?

Often soy, though it can be made from maize or wheat instead, and the label does not always say which. It is a savoury flavouring found in stocks, gravies, crisps, instant noodles and processed meats.

Is textured vegetable protein soy?

Usually yes. Textured vegetable protein is generally soy protein, and it is the basis of many meat substitutes and inexpensive processed meat products.

Does vitamin E on a label mean soy?

Tocopherols, E306 to E309, are often derived from soybean oil. They are highly refined and carry very little protein, so they are rarely a meaningful exposure, but the soy origin is real.