Chicken tikka masala: the silent, delicious, colorful killer

Britain's beloved chicken tikka masala contains dyes linked to "hyperactivity, asthma, and even cancer."

Tartrazine, a dye made from coal tar, is banned in Norway, Finland and Austria.

As well as being used in a variety of cakes, soft drinks and sauces, some egg manufacturers feed it to their chickens to make their yolks extra yellow. But scientists believe it can cause blurred vision and purple skin patches and is particularly hazardous for asthmatics and anyone allergic to aspirin.

Sunset Yellow is also banned in Norway and Finland but elsewhere is used in juices, sweets and sauces. Scientists have linked it with chromosome damage and kidney tumours as well as abdominal pain, hives, nausea and vomiting.

Ponceau 4R, which is illegal in the USA and Norway, is believed to cause cancer in animals.