Annatto (E160b): The Natural Colour That Can Still Trigger Skin
Annatto (E160b) is a plant-derived yellow-orange food colour in cheese, butter and snacks, and a recognised, if uncommon, trigger of hives in sensitive people. What it is, where it hides on UK labels, and calm steps if you suspect it affects your skin.
What annatto (E160b) is
Annatto is a natural yellow-orange food colour extracted from the seeds of the achiote tree (Bixa orellana), which grows in tropical parts of the Americas. It has been used to colour food for centuries and is one of the oldest natural colours still on shelves today. Its two active pigments are bixin, which is oil-soluble, and norbixin, which is water-soluble. Manufacturers pick whichever suits the product, which is why annatto works in both fatty foods like butter and watery ones like drinks.
On a label it appears as Annatto, Annatto extract, Bixin, Norbixin, or its European number E160b. Its job is purely cosmetic. It gives food a warm golden or orange tone without changing the flavour, which is the classic reason a naturally pale cheese ends up looking rich and orange.
Which foods it is in
Annatto turns up most often in dairy and snack foods. Common places to find it include:
- Coloured hard cheeses such as Red Leicester, some Cheddar, and double Gloucester
- Butter, margarine and spreads
- Custards, dairy desserts and some ice creams
- Smoked fish and smoked cheese, where it deepens the colour
- Crisps, snack foods and cheese-flavoured products
- Breakfast cereals
- Breaded or battered products, where it warms the coating colour
Because it is a natural colour, annatto also appears in products marketed as free from artificial colours. That is worth knowing, because a shopper avoiding synthetic dyes may still meet annatto in a clean-label product.
The UK rules
Under UK food labelling law, additives used as colours must be declared in the ingredients list, either by name or by their E-number, alongside the word telling you what they do, so you will see something like “colour: annatto” or “colour (E160b)”. This applies to pre-packed food sold in the UK.
Annatto is a permitted colour in the UK and is assessed as safe for the general population at the levels allowed. Unlike the six synthetic “Southampton” colours (the azo and related dyes linked to activity and attention in children), annatto does not carry the Food Standards Agency warning that a food “may have an adverse effect on activity and attention in children”. That warning applies specifically to certain synthetic colours, not to annatto.
The skin connection
Annatto is a good example of a natural additive that is not automatically gentle. It is a recognised, if uncommon, cause of hives (urticaria) and angioedema (deeper swelling, often around the lips or eyes), and it can aggravate existing chronic hives in people who already have them.
Most reactions appear to be what doctors call pseudo-allergic, meaning the skin responds without the classic antibody-driven allergy mechanism. A smaller number of genuine antibody-mediated cases have been reported, but these are unusual. In practice this means standard allergy tests often look normal even when someone clearly reacts, which can be confusing and is one reason a careful symptom diary is so useful. True food-colour allergy of any kind is uncommon. Intolerance or sensitivity, where the skin reacts without a formal allergy, is the more usual picture.
How to spot it on a label
Scan the ingredients list for any of these:
- E160b
- Annatto or Annatto extract
- Bixin
- Norbixin
Because it is often described simply as “colour”, check the bracket or the word that follows. A useful habit is to read the whole colour section of a label rather than stopping at the first name you recognise, since a product can carry more than one colour at once.
A balanced take on the evidence
It is worth keeping annatto in proportion. The great majority of people eat annatto-coloured cheese and butter with no trouble at all, and health authorities regard it as safe at permitted levels. The reports of hives are real but relatively rare, and tend to concentrate in people who already have chronic urticaria or who react to a range of additives.
So annatto is neither a hidden menace nor something to dismiss. If you have no history of additive-related skin trouble, there is little reason to avoid it. If you do have unexplained hives, it is one of several natural and synthetic colours worth having on your radar, rather than the single likely cause.
What to do if you suspect it triggers your skin
If you think annatto might be affecting your skin, a calm, structured approach beats cutting foods out at random:
- Keep a symptom diary. Note what you ate, when, and when any skin reaction appeared. Cheese and dairy are the usual hiding places, so start there. Patterns over a couple of weeks are far more telling than any single day.
- Try a like-for-like swap. An uncoloured Cheddar or butter lets you compare the same food with and without the colour, which is a gentler test than removing whole food groups.
- Talk to a professional. If reactions are frequent, persistent, or worrying, see your GP, who may refer you to an allergist or a registered dietitian. Any elimination diet, particularly for a child, should be done under guidance so nothing important is lost from the diet.
- Treat serious reactions as emergencies. Rapid swelling of the lips, tongue or throat, or any difficulty breathing, needs urgent medical help. Call 999.
This article is educational and is not medical advice. It is here to help you ask better questions, not to replace a proper assessment.
Check products against your list
A free scanner like Yuka gives a packaged product a general health score, a useful broad read, though that verdict is the same for everyone rather than tuned to your skin. Fig is genuinely good if you are managing a defined eating pattern. To check a product against the specific things that make your skin react, a personal-list app like ClearaScan lets you save your triggers once and scan any product, food, medication or cosmetic, against your ingredient guard list, flagging only yours. So if annatto (E160b) is on your list, it flags a coloured cheese or spread that contains it while ignoring everything that does not concern you. Its Reaction Journal lets you tie a flare back to the product that caused it, a shared Care Circle lets family scan for you, and a Trusted Products list keeps what you have cleared. It is currently in early access. (Disclosure: our editor co-founded ClearaScan, and we are not paid to mention the others.)
The Sensitive Skin Ingredient Decoder
A free one-page guide to reading a skincare label fast: the irritants to watch, the fragrance loopholes, and what "fragrance-free" and "hypoallergenic" really mean.
Common questions
It is natural, so surely it is safe?
Natural does not mean non-reactive. Annatto is plant-derived, but it is still a documented, if uncommon, trigger of hives in some people. For most of us it causes no problem at all, but a small minority react to it just as they might to a synthetic colour.
Is annatto vegan and vegetarian?
Annatto itself is plant-based, extracted from the seeds of the achiote tree. The products it colours, such as cheese, may or may not be suitable, so always check the rest of the ingredients list.
Why is my cheese orange when the milk is white?
Almost always annatto, added purely for colour. It does not change the taste or texture. Red Leicester, some Cheddar and double Gloucester are traditionally coloured this way.
How would I know if annatto was affecting my skin?
Reactions such as hives or itching usually appear within a few hours of eating a coloured food. A written symptom diary is the most reliable way to spot a pattern, since reactions can be delayed. This is not a diagnosis, so share any pattern with your GP.
Is there a simple way to test whether annatto is the trigger?
Uncoloured versions of the same foods, such as a pale undyed Cheddar or an uncoloured butter, make an easy comparison. Only make bigger dietary changes with guidance from a GP or registered dietitian, especially for children.