Where there's no safe level

Posted by Andrew Wadge on February 9th 2007 in Science, safety and health

One of the real challenges for regulators in recent years has been how to respond to very low levels of genotoxic carcinogens in food.These are chemicals that have the potential to cause cancer by damaging the genetic material in the cell.This differs from the types of chemicals which exhibit a threshold below which any exposure is thought to have no effect on health.

Because experts are unable to identify a threshold for genotoxic carcinogens below which damage will not occur our regulatory response has been to keep levels as low as practicable by preventing their deliberate presence in food and by minimising unavoidable contamination and natural occurrence.

The European Food Safety Authority (EFSA) recently published its report on an international conference on risk assessment of compounds that are both genotoxic and carcinogenic.

The experts at this conference agreed with UK experts that it is not possible to identify safe levels of intake of these chemicals, or to identify a reliable estimate of the cancer risk at different intakes. All agree that if the doses causing cancer in laboratory animals are very much higher than the amounts that we are exposed to (referred to as the Margin of Exposure), then the risk is likely to be very small. However, there is not yet general agreement on the health significance of different sizes of Margins of Exposure.

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These substances ...

Posted by Andrew Wadge on 23/02/2007 - 16:55

Many of these substances exist naturally in the environment and so get into our food in small amounts during cultivation or processing. Some aflatoxins, for example, are genotoxic carcinogens and are produced by certain moulds growing on food crops such as cereals during production and storage. Acrylamide is a chemical that was found relatively recently in unexpectedly large amounts in starchy foods that had been cooked at high temperatures. These include crisps, chips, bread and crispbreads.

Given that these sorts of chemicals are not put in our food deliberately, they will not appear on the label. The Agency carries out regular surveys of different types of food to check that contaminants are kept as low as practical, given the nature of these chemicals. The Agency's advice is that you do not need to change your diet or the way in which you cook your food – but you should continue to eat a healthy, balanced diet.

genotoxic carcinogens

Posted by Val (not verified) on 21/02/2007 - 14:21

Can you give some examples of foods which may contain such substances, and also how they come to be present?

Are such foods labelled as containing substances which may be harmful?