Replies to LegCo questions

LC Q15: Genetically-modified ingredients of food products

Following is a question by the Hon Fred Li and a written reply by the Secretary for Health, Welfare and Food, Dr Yeoh Eng-kiong, in the Legislative Council today (June 18):

Question :

Last month, the Consumer Council released the results of the tests for genetically-modified ("GM") ingredients it had conducted on a number of food products in the market. One of the findings revealed that three snack food products contain a GM corn ingredient known as Maximizer (also known as Bt176), which contains a gene that confers resistance to Ampicillin, an antibiotic commonly used to treat pneumonia, bronchitis, diphtheria, scarlet fever, whooping cough and other infectious diseases. Some environmentalists are thus concerned that for people who frequently consume such snack food, the effectiveness of the antibiotic for treating these diseases may be undermined. Besides, the Codex Alimentarius Commission ("Codex") has issued a guideline that food products should not have ingredients which contain genes that encode resistance to clinically used antibiotics. In this connection, will the Government inform this Council whether:

(a) it will consider banning the sale of food products which contain the above ingredient; if it will, of the details; if not, the reasons for that;

(b) it will, in accordance with the guideline of Codex, demand distributors to recall food products which contain such ingredient; if not, of the rationale; and

(c) it will conduct a comprehensive survey on other food products for such ingredient; if it will, of the timing of the survey; if not, the reasons for that?

Reply:

As stated by the World Health Organisation (WHO), genetically modified (GM) foods currently available on the international market have passed risk assessments and are not likely to present risks to human health. This also applies to Maximizer corn (Bt-176). According to the WHO and the Codex Alimentarius Commission (Codex), the probability of transfer of antibiotic resistance gene from GM foods to the body cells or bacteria in the gastrointestinal tract of humans is extremely low. It is because the presence of novel DNA in a GM food consumed in the human diet represents only a very small amount of the total amount of DNA consumed in the dietary intakes. In addition, the transfer of plant DNA into microbial or mammalian cells under normal circumstances of dietary exposure would require all of the following complex events to occur consecutively:

* the relevant gene(s) in the plant DNA would have to be released, probably as linear fragments;

* the gene(s) would have to survive nucleases in the plant and digestive enzymes in the gastrointestinal tract;

* the gene(s) would have to compete for uptake with dietary DNA;

* the recipient bacteria or mammalian cells would have to be competent for transformation and the gene(s) would have to survive their restriction enzymes; and

* the gene(s) would have to be inserted into the host DNA by rare repair or recombination events.

In the very unlikely event that all of the above occur and the gene was incorporated into a bacterial genome, it would still need the specific bacterial promoters to initiate translation in order to produce the enzyme that confers bacterial antibiotic resistance.

Before marketing internationally, the Maximizer corn has been thoroughly assessed by a number of overseas regulatory authorities including authorities from member countries of the European Union, the USA, Canada, Japan, Australia and New Zealand. These overseas regulatory authorities have evaluated, among others, the health impact arising from the presence of antibiotic resistance gene in the Maximizer corn. Results of safety assessments reveal that even if such highly unlikely transfer should occur, the health impact to humans would be negligible because the gene is already commonly carried by bacteria found in the environment as well as in the human gastrointestinal tract.

While Codex recommends that alternative technologies that do not result in the presence of antibiotic resistance gene in foods should be used in the future development of GM plants, it does not imply that GM foods currently available on the market which contain antibiotic resistance gene are unsafe for human consumption. Codex has not recommended a ban on the sale of these GM foods. Safety assessments conducted by the overseas regulatory authorities concluded that Maximizer corn was considered to be as safe as its non-GM counterpart. Given the above considerations, we do not intend to prohibit the sale of or to recall food products containing Maximizer corn. As other GM foods currently available on the international market have also passed risk assessments and are not likely to present risks to human health, we do not intend to conduct a study on the presence of antibiotic resistance gene in those foods.

End/Wednesday, June 18, 2003
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