Objective
Carcinogens are chemicals that can increase the occurrence of tumours; the carcinogens that can damage DNA are referred to as genotoxic. Improved analytical methods are capable of detecting very low concentrations of chemicals. This has revealed that foods can contain low levels of genotoxic carcinogens, including man-made chemicals such as ethyl carbamate, nitrosamines or heterocyclic amines, but also natural chemicals like methyleugenol in basil.
There is no international consensus on how to evaluate the risk of genotoxic carcinogens in food. In Europe, the former Scientific Committee on Food (SCF) has advised on the assessment of genotoxic carcinogens in the diet on a case-by-case basis using a graded "weight of evidence". In the USA, however, a quantitative hazard characterisation is performed by mathematical low-dose extrapolation of animal data.
The Risk Assessment of Genotoxic Carcinogens in Food Task Force aims to improve quantitative assessment of cancer risk from low dietary exposure to genotoxic carcinogens. The results may contribute to the prevention of diet-related cancer.
Activity
Application of the Margin of Exposure (MOE) Approach to Genotoxic Carcinogens in Food
In 2005, the EFSA/WHO international conference with support of ILSI Europe on “Risk Assessment of Compounds that are both Genotoxic and Carcinogenic: New Approaches” concluded that, in order to better define the level of health concern associated with a certain MOE (or range of MOE), it would be informative to calculate MOEs for more examples. Therefore, the task force decided to set up a new Expert Group that works in close collaboration with WHO/IPCS and EFSA to carry out this work.
The task of the Expert Group is:
- To choose 10-12 examples to calculate the MOE (e.g. by taking the substances evaluated by JECFA and EFSA/SCF in the last 10-15 years)
- with a range of low and high carcinogenic potency,
- with limited and with large amounts of relevant data
- To evaluate carcinogenicity data including dose response, as available at the time of the assessments (data quality, uncertainties and limitations), also considering the duration of exposure in relation to the carcinogenicity
- To select the appropriate cancer data for mathematical modelling
BMD and BMDL to be calculated on the 1%, 5% and 10% level; T25 only to be calculated if needed
- To evaluate human exposure data as available at the time of the assessments (data quality, uncertainties and limitations):
- characterise exposure by different scenarios, e.g. general population, subgroups
- select the appropriate exposure value(s)
- include some examples for exposure with the same subset of data
- To provide a narrative on the assumptions and uncertainties in a consistent way for each of the examples.
The manuscript developed by the expert group will be discussed at a workshop held on 1-3 October 2008, Rhodes, Greece. The overall objectives of the workshop will be:
- To critically appraise the MOE approach in the light of these assessments,
- To provide guidance on the application of the MOE approach, and
- To further characterise the interpretation of the numerical value of the MOE (e.g. banding).
The revised manuscript will then be submitted to Food and Chemical Toxicology.
Task Force Collaborators
The scientists below participate in the task force and expert groups:
Experts from supporting member companies
Dr. Peter Cadby, Firmenich (CH)
Dr. Philip Carthew, Unilever (UK)
Dr. Myriam Coulet, Nestlé (UK)
Dr. Brett Jeffery, Mars (UK)
Mr. Hervé Lafforgue, Groupe Danone (FR)
Dr. Gladys Ouédraogo-Arras, L’Oréal (FR)
Dr. Jürgen Schnabel, Givaudan (CH)
Dr. Benjamin Smith, Firmenich (CH)
Dr. Gunna Würtzen, Coca-Cola European Union Group (DK)
Experts from public institutes
Dr. Diane Benford, Food Standards Agency (UK) - Participation costs covered by the Food Standards Agency
Dr. P. Michael Bolger, U.S. Food and Drug Administration - FDA (USA)
Prof. Alan Boobis, Imperial College London (UK)
Mr. Bernard Bottex European Food Safety Authority - EFSA (IT)- Observer
Mr. Michael Dinovi, Food and Drug Administration (USA)
Dr. Ada Knaap National Institute of Public Health and the Environment - RIVM (NL)
Dr. Jean-Charles Leblanc, French Food Safety Agency - AFSSA (FR)
Prof. em. Andrew G. Renwick, University of Southampton (UK)
Dr. Josef Schlatter, Swiss Federal Office of Public Health (CH)
Dr. R. Woodrow Setzer, U.S. Environmental Protection Agency - EPA (USA)
Prof. Wout Slob National Institute of Public Health and the Environment - RIVM (NL)
Dr. Angelika Tritscher, World Health Organization - WHO (CH) - Observer
Prof. Gary Williams, New York Medical College (USA)
Publications
J. O'Brien et al. Approaches to the Risk Assessment of Genotoxic Carcinogens in Food: A Critical Appraisal. Food and Chemical Toxicology 2006;44(10):1613-1635
Annex: Introduction to Genetic Toxicology.
S. Barlow et al. Risk Assessment of Substances that are both Genotoxic and Carcinogenic. Food and Chemical Toxicology 2006;44(10):1636-1650
For more information contact info@ilsieurope.be.