Hidden Nightshades:
Potato Starch

What is potato starch?

It's a food additive: an ingredient you wouldn't find in your home kitchen that's used in commercial food products. Food additives are used to change the shelf life, thickeness, flavour, colour, mouth feel or other qualities of food, and starches are very common.

Potato starch is mostly used as a thickener. It isn't something you can see or taste - it's a highly processed product that has little to do with actual potatos. It's made by crushing potatoes, extracting the starch and washing it. The resulting slurry is dried, typically through a process of settling, hydrocycloning, or centrifugation, and then dried to a powder. Voila: a white powder with no flavour of its own that works well to thicken and stablise food.

What does this mean for avoiding nightshades?

As it's made with potato - which is a nightshade - potato starch can be a problem if you have an allergy or sensitivity. As always, it's best to complete an elimination diet that includes potato starch to check whether it's a problem for you - everyone is different and it may not cause problems for you.

This is especially important if you eat a lot of pre-made foods (ie anything that comes in plastic, a can, a jar or from the freezer). Potato starch is used in everything: soups, sauces, frozen meals, pasta dishes, chilled products, snacks, desserts - EVERTHING! It's one of the most common food additives and if you want to avoid it, you will need to read the labels on everything you buy.

This can be very helpful in identifying why you're still experiencing symptoms if you've cut the obvious nightshades from your diet. If you are not eating foods cooked completely from scratch and you are not reading ingredient labels, you are probably eating potato starch. Working out where it's coming from will help you avoid the symptoms that are still causing you problems.

Spotting the starch

Potato starch will be included on ingredient labels, but it won't always appear clearly. Items like 'starch', 'vegetable starch' or 'modified starch' may be potato starch, or could be nightshade-free ingredients like corn starch or wheat starch. There is no way to tell - this is totally acceptable practice under the law in every country I'm aware of, and it's up to you to decide whether it's worth taking a risk.

Bottom line?

This is a common hidden nightshade that you may need to avoid. It can mean a bit of adjustment if you usually eat meals made from processed ingredients, given they're likely to contain potato starch. Knowing your level of tolerence, reading ingredient labels and making your own meals from scratch will help you manage this ingredient.