by Danielle Knight

Washington,22 Oct 99(IPS) -- A new scientific study, suggesting that
genetically modified foods may be harmful to health, underscores the
need for government testing of such products before they are marketed,
say US public health researchers.

About 40 genetically modified (GM) crops appear in a variety of
food products now available on the US market. But only a handful
of studies have examined the long-term health and environmental
impact of these foods because government regulatory bodies do
not require such testing.

Health experts point out, however, that the few peer-reviewed
scientific studies that have been carried out indicate there is
a need for further monitoring and study - despite the claims of the
bio-tech industry that their products are safe.

[According to postings on some of the internet list-servers on
this question, at least in the case of the Bt-corn, the toxicity
tests were done and considered safe for use, not on the relevant
protein extracted from the Bt-corn, but from the plants with Bt-
genes which expel a natural protein that is toxic to pests.]

[The adequacy of these tests have been challenged by critics who
point out that the protein expelled from the Bt-corn is much more
concentrated than the natural protein expelled by the plants that
have a natural Bt and which affect pests. And unlike the natural
Bt expelled by the plants or even organic pesticides prepared
from them, the corn containing the Bt-gene is ingested by humans
and animals, and the toxic protein is more concentrated.]

"What we are seeing is that there are, in fact, new effects
created (by GM foods)," says Paul Billings, a medical
geneticist, who is a board member of the Council for Responsible

"But we don't have the monitors in place to decide if these
impacts are, on the whole, better or worse for human health,"
says Billings, who has co-authored laws and policies to protect
the public against having their genetic information used against

Scientist Arpad Pusztai published a study the leading British
medical journal 'The Lancet' this month which underlined public
concern - especially in Europe - over eating GM food.

He found that rats fed with genetically engineered potatoes
suffered adverse health effects - a thickening of stomach walls
and other changes in their intestines.

The potatoes had contained an implanted gene to produce lectin,
a type of chemical found in nearly all plants that act as a

While other types of GM potatoes are currently on the market, the
kind used in the study are still in the testing phase and not
yet freely available.

Health officials here concede that, while Pusztai's study is in
a preliminary phase, the research is important because it is the
first study to link health problems with GM foods.
Last May, health and environmental experts also became alarmed
with the results of another peer-reviewed study, conducted by
Cornell University. Researchers there found that half the
butterflies that ate milk weed - a main food source commonly
found near cornfields - that had been dusted with pollen from
genetically modified corn, died. Others grew to only half the
normal size.

While few in number, such emerging studies prove that regulatory
agencies need to conduct tests to prove the products are safe
for humans, says Michael Hansen, a senior researcher at the
Consumers Union, a Washington-based advocacy organisation.

"These products have been in use for too short a time and our
regulatory framework is too fragmented, too reliant on industry
self-regulation, to say that either experience or the government
assures safety," he says.

The US Food and Drug Administration (FDA) and the Department of
Agriculture test for immediate safety of GM products.

But they, as most other countries' regulatory agencies, do not
require long term testing health and environmental impact
testing of GM foods because the agencies have determined GM food
to be essentially the same thing as non-GM food.

Erik Millstone, science and technology policy researcher for
Sussex University in Britain, says this policy, known as
"substantial equivalence," is "tantamount to pseudo-science."

Current policy "should be replaced with a practical approach that
would actively investigate the safety and toxicity of GM foods
rather than merely taking them for granted," wrote Millstone,
in the Oct. 7 edition of the scientific journal Nature.

In response to the growing outcry against GM foods, the USDA
announced recently it will hold several public forums across the
country next month to discuss its regulatory process for the

One public health concern over human consumption of GM foods is
that some percentage of the public may be allergic to a certain
protein introduced by a gene that is not present in the non-
engineered variety, says Hansen.

Allergies may also develop only after repeated exposure to a
substance. "Unless the new substance undergoes long-term
clinical testing, there cannot be certainty as to the safety of
the new variety," he says

Since GM foods are not labelled in the United States, consumers
with certain food allergies would not even be able to choose to
avoid GM foods, Hansen adds.

Researchers also worry about the possible health impacts of the
anti-biotic "marker gene" that are commonly used to trace gene
transfers. All genetically engineered products have anti-biotic
marker genes.

After GM food is absorbed into the human digestive trace, these
anti-biotic genes could move from what we have eaten into the
blood stream or into the bacteria in the intestines, says

"Such transfers might alter our health directly or change the
beneficial symbiosis between people (the bacteria that inhabit
our intestines)," he warns.

It could also help further spur resistance to antibiotic
pharmaceuticals, one of the major emerging public health
threats, adds Hansen.

While the British Medical Association and Consumers Union both
recommend a ban on the use of antibiotic markers in GM foods,
the FDA says there is a "vanishingly small" risk that antibiotic
marker genes will be transferred to disease- causing bacteria.

The above article by the Inter Press Service appeared
in the South- North Development Monitor (SUNS) .