Canthaxanthin: your questions answered

Last updated:
11 April 2010
Your questions answered about Canthaxanthin usage, providing information on a colourant used in some feeds for fish and egg-laying poultry.
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What is canthaxanthin?

Canthaxanthin is substance belonging to a group of naturally-occurring substances called carotenoids. These substances are related to beta-carotene, the red/orange pigment present in carrots; beta-carotene itself is related to vitamin A. The presence of canthaxanthin (and related substances) in feed for poultry and farmed fish can lead to a more intensely-coloured egg yolk and flesh from poultry, salmon and trout.

Are animal feeds permitted to contain canthaxanthin?

Yes, under domestic and European Union legislation canthaxanthin can be added to feeds intended for poultry and for farmed salmon and trout. It can also be used for feed for some ‘companion animals’. The controls in place for farmed animals are based on safety assessments that take into account implications for consumers and the animals themselves.

Is canthaxanthin a natural substance?

Canthaxanthin occurs in nature, for example in aquatic crustacea such as shrimps. However, we understand that much of the material used by the feed industry is made synthetically.

Is it a permitted food colour?

Yes, canthaxanthin is permitted as a food colour (i.e. direct food use), but only for Saucisses de Strasbourg (very little consumption in UK). A similar substance, beta-apo-8’-carotenal, is permitted for use in a larger number of foods.

What levels of canthaxanthin can be used at the moment in feeds intended for livestock? What levels are actually used?

In feeds for laying hens canthaxanthin can be added at up to 8mg per kilogram (mg/kg) of feed. For other poultry the maximum level is 25 mg/kg – the same maximum level applies for feed for farmed salmon and trout. However, in practice (where added) 5mg/kg would be closer to the level typically used in feed for laying hens, with about 20mg/kg being used in broiler and salmonid feed (again, where added). The maximum levels are based on advice from the European Commission’s former Scientific Committee on Animal Nutrition (SCAN). There is no reason why consumers in good health should not continue to consume foods that contain canthaxanthin.

Are any other similar substances added to feed?

Yes, astaxanthin may be used in feed for salmon and trout. Capsanthin, beta–apo-8'-carotenal, ethyl ester of beta–apo-8'-carotenoic, lutein, cryptoxanthin and zeaxanthin are permitted to be added to poultry feed, and citranaxanthin can be added to feed for laying hens.

Do foods that contain canthaxanthin derived originally from animal feed need to be labelled?

At present there is no requirement to label canthaxanthin in food derived from animals that had this substance included in the diet.

Can canthaxanthin used in feed for non-food producing animals?

The acceptable daily intake (ADI) is usually derived from long-term animal feeding studies. First, the so-called No Effect Level (NOEL) is determined. This is the amount of a substance, which can be fed to animals on a daily basis without any toxic effect. This No Effect Level is then reinforced by a large safety factor, usually 100, to arrive at the ADI for man. For example, if the No Effect Level in an animal study is observed to be 100mg/kg bodyweight, this is then converted to an ADI of 1mg/kg bodyweight for humans.

The safety factor accounts for the difference between test species and humans and for the variability between individuals, including differences in state of health and nutrition, age, etc.

The ADI does not represent a level of toxicity; it is in fact a safe intake level. Individuals may exceed the ADI occasionally, so long as their average exposure is below the ADI. Although called an acceptable daily intake, the ADI should always be compared with average intakes over prolonged periods – not with day to day intakes.

Does canthaxanthin have any other effects on animals?

Yes, it is believed that canthaxanthin and some other carotenoids may have positive nutritional effects on the diet – they are believed to act as dietary antioxidants.

When will the in-feed use of canthaxanthin be reassessed?

It is a condition of domestic and European Union legislation that canthaxanthin and most other authorised feed additives must be reassessed. A dossier addressing the safety, efficacy and quality of the additive must be submitted by November 2010 for assessment by the European Food Safety Authority (EFSA). Failure to comply with this requirement will lead to the revocation of the feed additive’s authorisation.

What adverse effects are associated with human exposure to high levels of canthaxanthin?

There is some evidence that very high intakes of the substance leads to some deposition on the retina. This deposition is believed to deplete once exposure to high levels of canthaxanthin has ended. These very high levels of canthaxanthin are well above found in foods derived from animals that consumed feed with canthaxanthin.

Who enforces the current maximum inclusion rates for canthaxanthin in feed?

This responsibility rests with local authority trading standards officers in Great Britain and with the Department of Agriculture and Rural Development in Northern Ireland.

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