Colouring additives in most of the eggs you buy

All major egg producers and most small ones - even those which claim to be free range - use colouring additives in the feed they give their hens.

It is completely unnecessary in a free range flock, as hens running on good pasture and at low stocking densities will obtain enough carotenoids from the green feed in the paddock to maintain good yolk colour. The colour will vary – depending on what each hen has been eating – but many egg producers want to use additives to provide consistent, bright yolk colour.

Many of those additives are synthetic - adding to the chemical cocktail mix in food. But even those which are claimed to be 'natural'  can present health problems. They may be derived from natural products but they are manufactured in factories – often in China.

Three of the most widely used egg yolk pigmenters are:

Canthaxanin or Canthaxanthin which appears to be an unsafe additive. It can cause violent diarrhea, nausea, stomach cramps, dry and itchy skin, hives, and other side effects such as breathing problems; tightness in the chest; swelling of the mouth, tongue or throat; a skin rash or hives and is particularly dangerous for pregnant or breast-feeding women or people allergic to vitamin A or carotenoids.

Capsicum

Allergic reactions to capsicum may occur. People should stop eating eggs with capsicum-based colouring and seek emergency medical attention if they experience symptoms of a serious allergic reaction including difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives.

Other less serious side effects have also been reported such as upset stomach; migraine; heartburn; diarrhea; or burning sensation in the mouth or throat.

Use of Capsicum is not recommended for pregnant women.

Marigold

Some people experience breathing problems, tightness in the chest, swelling of the mouth, tongue or throat. A skin rash or hives may occur.