A Romanian farmer shows genetically modified soybeans in the village of Varasti.

London - Eating a GM food diet over a lifetime can cause breast cancer, severe organ damage and early death, a breakthrough scientific study has revealed.

The first lifetime trials involving rats fed on GM corn found a raised incidence of breast tumours, liver and kidney damage.

Scientists said the results raised serious questions about the safety of GM foods and the assurances offered by biotech companies and governments.

Dr Michael Antoniou, a molecular biologist at King’s College, London, and an expert on GM foods, said: “It shows an extraordinary number of tumours developing earlier and more aggressively – particularly in female animals.

“I am shocked by the extreme negative health impacts.”

The research was carried out by Caen University in France, and has been peer reviewed by independent scientists to guarantee the experiments were properly conducted and the results are valid.

It is the first to look at the impact of eating a GM diet over a lifetime in rats, which is two years. To date, safety assessments of GM crops have been based on rat feeding trials lasting 90 days.

The corn was genetically modified to withstand spraying with glyphosate, the main chemical in the weedkiller Roundup, developed by Monsanto. The idea is that the corn can be sprayed without being damaged, while weeds are destroyed.

The tests looked at the impact of several scenarios including eating the GM corn (NK603), eating the GM corn sprayed with Roundup, and consuming Roundup at low doses in water.

The results were compared against those for a control group fed a “clean” diet without GM or Roundup.

The researchers found:

* Between 50 to 80 percent of female rats developed large tumours by the beginning of the 24th month, with up to three tumours per animal. Only 30 percent of the control rats developed tumours;

* Up to 70 percent of females died prematurely compared with only 20 percent in the control group;

* Tumours in rats of both sexes fed the GM corn were two to three times larger than in the control group;

* The large tumours appeared in females after seven months, compared to 14 months in the control group.

The team said the tumours were “deleterious to health due to a very large size”, making it difficult for the rats to breathe and causing digestive problems.

Significantly, the majority of tumours were detectable only after 18 months – meaning they could be discovered only in long-term feeding trials.

The study – led by molecular biologist Professor Gilles-Eric Seralini, a critic of GM technology, and published on Wednesday in US journal Food and Chemical Toxicology – said the GM corn and Roundup weedkiller “may cause hormonal disturbances in the same biochemical and physiological pathway”. The Daily Mail’s Frankenstein Food Watch campaign has long highlighted problems with the lack of rigorous safety assessments for GM crops and food.

Although GM corn is widely used in the US, British consumers have turned their backs on the technology because of concerns about its impact on human health and the environment.

Although it is not available in British supermarkets, it is fed to farm animals including chickens, pigs and dairy cows.

Mustafa Djamgoz, professor of Cancer Biology at Imperial College, London, said the findings relating to eating GM corn were a surprise. “We are what we eat,” he added. “I work at the molecular level on cancer. There is evidence that what we eat affects our genetic make-up and turns genes on and off.

“You could imagine it coming through the food chain all the way to us. I don’t think that, because there is an intermediary, you can rule the possibility out.

“We are not scaremongering here. More research, including a repetition of this particular study, is warranted.”

Patrick Holden, director for the Sustainable Food Trust and a supporter of organic farming, said it highlighted the need for a complete rethink of the way GM crops are assessed.

“The research exposes a critical deficiency in the regulatory process which, due to the short-duration of the required feeding trials, failed to identify the serious, long-term health consequences,” he said.

“To ensure that the public is protected against further exposure, there is an urgent need for a fundamental overhaul of the regulatory framework.

“In the meantime, in order to protect the rights of consumers all foods containing imported GM maize or its derivatives, should be clearly labelled.”

On Wednesday, the Agricultural Biotechnology Council, which speaks for the GM industry including Monsanto, insisted the technology was safe.

Chairman Dr Julian Little said: “The industry takes all health concerns regarding biotech food and feed very seriously and is committed to the highest standards of testing and safety.

“Biotech crops are among the most extensively tested foods in the history of food safety.

“Around two trillion meals containing GM ingredients have been eaten over the last 13 years without a single substantiated case of ill-health.”

Anthony Trewavas, professor of cell biology at Edinburgh University, questioned the way the research had been conducted, saying the number of rats involved in the study – 200 – was too small to draw any meaningful conclusions.

“To be frank, it looks like random variation to me in a rodent line likely to develop tumours anyway,” he said.

He also claimed Professor Seralini was an anti-GM campaigner and that previous studies questioning the technology’s safety had not withstood scrutiny.

On Thursday night, the French government ordered a safety review of the GM corn at the centre of the study. - Daily Mail