Experts unsure of long-term effects of Bt brinjal

The approval to genetically modified (Bt) brinjal seems to have been been given without adequately assessing long-term health risks, although with a stipulation that surveillance and long-term follow up should be conducted — two conditions that experts are aware have not been fulfilled even in the case of some critical drugs.

Health experts in the Genetic Engineering and Approval Committee (GEAC), the statutory body responsible for approving its cultivation, agreed, while talking to Business Standard, that they were not sure about the long-term health effects of a genetically modified food on humans and qualified their approval with the present understanding of science and their insistence on surveillance and long-term studies.

"Our collective wisdom is limited on recombinant technology. Therefore, we are treading carefully. Decisions have been based on current evidence in science. But, we must have a system of post-marketing surveillance to assess health impacts," retired senior deputy director general at the Indian Council of Medical Research and a member of GEAC expert committee, Vasantha Muthuswamy, said.

Those familiar with health systems know that post-marketing surveillance, even in the case of medicines, is poor and overall surveillance is virtually nil, despite several efforts since the outbreak of plague in 1994 to put a comprehensive system in place.

"Brinjal is not a staple food for anybody. Unless the product is in use, how can we say?" Muthuswamy said. "What will happen in the future is anybody's guess," she added. In any case, she said, the Bt (or Bacillus thuringiensis) gene may already have become a part of the food chain, as Bt cotton cakes are being used in animal feed and fodder.

Some of the other health experts on GEAC were not willing to talk on record but agreed that there is no long-term data and approvals given are based on current knowledge of science. "There is no safety concern at present. But, long-term studies of the toxin gene are not available. We don't know how it may interact with the human body 20 years hence," said another member.

Even though this member had given his approval, he is not sure if the pest will not develop resistance to the Bt gene after a few years. However, Muthuswamy disagreed strongly with this contrarian view. "People develop resistance to antibiotics. Does it mean we stop giving them? These are presumptions," she added.

Speaking strictly as a scientist, M K Bhan, secretary, department of biotechnology, said, "There were no concerns on safety. The Bt protein has no mechanism to process in a mammalian system. It is like eating grass."

Bhan said assessment of safety is a scientific question, whereas commerce is a public policy issue and the two issues should not be confused in the current debate. "My personal view is the safety assessment is based on evidence provided," said Bhan and later added, "When we create a system, we must learn to trust it." 

Activists have been calling for a revamp of the entire regulatory processes. "We have been recommending that the regulatory system should be reviewed," said convenor, Gene Campaign, Suman Sahai, a geneticist.

The GEAC announced approval for large-scale field trials for Bt brinjal in September 2007, and its commercialisation by early 2009. It also cleared proposals for biosafety studies for other food crops such as okra (lady's finger), rice, and tomatoes.

Bt brinjal is a transgenic brinjal created out of inserting a gene from the soil bacterium, Bacillus thuringiensis (Bt) into brinjal. This is said to give the brinjal plant resistance against insects such as the Brinjal Fruit and Shoot Borer It is reported that upon ingestion of the Bt toxin by the insect, there would be disruption of digestive processes, ultimately resulting in the death of the insect. Bt Brinjal is being developed in India by Maharashtra Hybrid Seeds Company, Mahyco. India is the centre of origin for brinjal. Brinjal has been cultivated in India for the last 4,000 years or so and has many historical references in various languages.