EFSA publishes general guidance on 90-day feeding studies on whole food and feed

The European Food Safety Authority (EFSA) has published its first general guidance for carrying out 90-day feeding studies on whole food and feed in rodents. It will support applicants in carrying out feeding trials related to applications for novel foods and food and feed derived from genetically modified organisms. The guidance, developed by the EFSA’s Scientific Committee, outlines a randomised block test design to maximise the power of the experiment while avoiding unnecessary use of test animals. With respect to animal welfare, the guidance recommends housing rodents as pairs in order to reduce stress in the animals.

90-day animal feeding studies are used to provide information for the risk assessment of food and feed and/or of individual substances contained therein. The objective of a 90-day feeding trial is to detect any possible toxicological effects of the test diet compared to the control diet. EFSA’s guidance document – which complements the general procedure set out in the OECD guideline for the testing of chemicals[1] – provides specific advice to applicants on how to design, conduct, analyse, report and interpret 90-day oral toxicity studies carried out in rodents with whole food or feed, such as for novel foods or food and feed derived from genetically modified organisms. It also includes directions for the preparation of appropriate test diets, statistical analysis and for further harmonised reporting of the results.

Should 90-day feeding studies be carried out with whole food/feed, the Scientific Committee recommends the use of a so-called randomised block design. This design involves dividing the experiment into blocks (“mini-experiments”) of two animals per cage, which are matched for age and weight. Such a design takes into account animal welfare by recommending, in accordance with EU legislation[2], that rodents should be socially housed to avoid stress caused by solitary housing. It also increases the power of the experiment by reducing possible sources of variation between the tested animals which are unrelated to the experiment itself (eg body weight of animals, location of the cages etc.). The Scientific Committee recognises that other test designs may be used for 90-day oral toxicity studies of whole food and feed in rodents if warranted. Applicants should always investigate and scientifically justify their testing strategy.

The guidance, prepared at the request of the European Commission, is part of the Scientific Committee’s ongoing efforts to contribute to the advancement of risk assessment methodologies. It was subject to a public consultation from 7 July to 15 September 2011. The views of Member States, industry, non-governmental organisations and academia received during the consultation were carefully considered by the Scientific Committee in finalising the guidance.

Notes to editors

Whole food or feed refers to a product to be consumed respectively by humans or animals, which is composed of a multitude (up to thousands) of individual substances. For example, whole foods from plant-based products range from maize or potatoes to more refined products such as fruit juices or flour. Individual ingredients used in the products are outside of the scope of this guidance document.

The power of the experiment refers to the probability that a defined pattern in data will be detected and that the extent of the pattern will show a statistical significance.

EFSA’s Scientific Committee supports the work of EFSA’s Scientific Panels on scientific matters of a horizontal nature and is responsible for general co-ordination to ensure consistency in the scientific opinions prepared by the Scientific Panels. The Scientific Committee focuses on developing harmonised risk assessment methodologies in fields where EU-wide approaches are not already defined.

[1] OECD Guideline for the Testing of Chemicals – Repeated Dose 90-day Oral Toxicity Study in Rodents (OECD TG 408)
[2] EU Directive 2010/63 on the protection of animals used for scientific purposes

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