Science in Society Archive

GM Ban Long Overdue

Dozens Ill & Five Deaths in the Philippines. Dr. Mae-Wan Ho

Unexplained sicknesses and deaths

In July 2003, a farmer living in a small village in the south of Mindanao Island of The Philippines, found himself and his entire family suddenly falling ill with fever and respiratory, intestinal and skin ailments. They were not alone; at least fifty-one residents of Sitio Kalyong (Barangay Landan, Polomolok, South Cotabato Province) had similar complaints at around the same time. They all lived within 100 m of a field planted with GM maize, and their illnesses coincided with the GM maize flowering time.

Another resident of Sitio Kalyong, said [1] that the GM-maize pollen made him dizzy, gave him severe headaches, chest pains and caused him to vomit.

The field in Sitio Kalyong belonged to a local official who bought five bags of Monsanto's Bt maize seed (Dekalb818YG with Cry1Ab from the soil bacterium Bacillus thuringiensis ), enough to plant 5 hectares. He paid 4 500 pesos per bag, which was more than twice as much as the non-GM variety at 2 200 pesos per bag. The premium price included the promise of a small vehicle if the harvest turned out to be good, as it was supposed to. In the event, the promise was broken on both counts: the harvest of 93 sacks compared poorly with the usual 150 sacks per ha, and the small vehicle was never delivered. The local official stopped planting the Bt maize after 2003.

As part of an investigation to determine what made the villagers ill, one of the farmers was “volunteered” to venture inside the Bt maize field in the presence of more than 10 witnesses, as he explained to me via an interpreter. “Within 5 minutes, I could not breathe and felt something extraordinary on my face,” he recalled. The others could see that his face had swollen up and remarked that it was “very dangerous”.

In fact, the farmer is ill to this day. Every now and again, he feels weak in his limbs and numb in his hands and feet. He held up the back of his right hand to show me the index finger. A yellowish-brown discoloration and thickening of the fingernail had developed since he was exposed to the GM pollen.

In October 2003, blood samples were taken from the affected villagers who still had symptoms, which were then frozen and analysed. Antibodies to the Bt toxin Cry1Ab expressed in the GM maize were found in all the blood samples taken from the 38 individuals.

Many if not all of the villagers exposed to GM-maize pollen in 2003 have remained ill to this day. Furthermore, there have been five unexplained deaths in the village. In total, 96 people got sick. In addition, nine horses, four water buffalos, and 37 chickens died soon after feeding on GM maize .

Denial and intimidation

The government's doctors had dismissed the illnesses as “influenza” and refused to investigate further. Meanwhile, without additional funding to proceed with independent studies, no follow up of any kind has been done, despite the continuing unexplained illnesses and deaths.

No more GM-maize has been grown in Sitio Kalyong after 2003, but further planting took place elsewhere in Polomolok, in Tupi, Tampala Tampakan and in Marbel and several other towns in South Cotabato. The harvested cobs were sold as food in the open market, even though the yellow maize is intended for animal feed, and yellow maize is generally not eaten as food in the Philippines.

MASIPAG (a farmers-scientists organisation) had asked the government to stop distributing Bt maize in March 2004, and warned farmers to be vigilant when buying seeds to avoid Bt maize [2]. They pointed out that Monsanto's Bt maize had been commercialised without adequate safety tests for health or the environment.

A concerned farmer travelled the country speaking of the plight of the villagers of Sitio Kalyong. This alerted people to further cases elsewhere in Mindanao (see below).

In November 2004, a Monsanto employee reportedly arrived in Sitio Kalyong accompanied by three large men on motorcycles that had no license plates. They asked for the activist farmer, indicating that they wanted to “negotiate” with him. Alarmed and intimidated, his neighbours said he wasn't home; telling off the gang at the same time. No such visits have occurred since. The incident has made me wary about naming any individual in this report.

More illnesses in 2004

More illnesses were reported in July 2004 when GM maize fields in four separate villages of Mindanao came into flower, I was told by a farmer who fell ill in 2003.

Thirty-two people in Tuka, Bagumbayan, Sultan Kudarat, suffered from headache, stomach-ache, dizziness, diarrhoea, vomiting and difficulty in breathing. About 30 ha were planted with Dekalb 818YG, but most of the residents affected were tenants, and hence not aware that what they planted was Bt maize, or even what Bt maize really was. Most farmers in Bagumbayan were aware of “Bt maize” based only on what Monsanto has told them. Bagumbayan is a “pet area” of Monsanto, after having won an award in 1999 for being the second biggest user of Power herbicide in the world.

In South Sepaka, Sto. Nino, South Cotabato, nine were reported sick, but 31 signed a petition circulated by a member of the Parish Social Action Center, claiming they fell ill during the flowering period of the Bt maize. Symptoms included red eyes, dizziness and weakness. Around two ha were planted with Pioneer 30Y 50, a Bt maize. The Bt maize belonged to a seed dealer who apparently failed to inform the village chairman that he had planted Bt maize. Most of the residents temporarily left their houses.

Around 20 children (aged 5-10 years) got sick during the flowering period of the Bt maize Dekalb 818YG planted near the elementary school in Magallon, M'lang, North Cotabato. They showed symptoms similar to those in other locations: cough, sneezing, asthma and difficulty in breathing. An authorized dealer had planted 10 ha without informing the community that it was Bt maize, but did say that the maize could not be roasted and eaten. One man ate a cob and got diarrhoea; the same happened to four goats that ate the maize.

Despite the unexplained illnesses and deaths, the Philippines government has failed to even initiate a safety enquiry, or set up post-market monitoring of health impacts. Instead it authorised commercial planting of Monsanto's Roundup Ready maize in February 2005, and later, a new GM maize variety with stacked Bt-toxin and Roundup tolerance; and approved the import of 19 GM products for food, feed and processing.

Feelings were running high in the Philippines as I began my lecture tour at the International Conference on Safe Food, 9-10 December, in Manila, Luzon. At the closing plenary, more than 250 participants from religious and farmers organisations, local government officials and academics from all over the Philippines called for a ban on GMOs in food, agriculture and fisheries.

Similar sentiments were expressed in Mindanao at the forum on Safe Food and Food Security, 12-13, in Davao City, and also at the International Forum on Genetic Engineering and Sustainable Agriculture on 15 December, Central Mindanao University, Musuan, and especially at Xavier University, 16 December, Cagayan de Oro. Farmer after farmer spoke from the floor, denouncing the government for approving the commercial release of Bt maize without safety tests, then failing to ban the Bt maize or to conduct a proper enquiry after it was implicated in serious health impacts including deaths, and instead giving approval to further releases of potentially more dangerous GM crops and products, including Roundup Ready soya (see below). Roundup Ready soya was approved for food, feed and processing only, not for field releases; but this is an artificial distinction as the soya seeds processed as tofu are the same seeds that the farmers plant.

Global ban and safety enquiry long overdue as more damning evidence accumulates

For years, the pro-GM lobby has been denying and dismissing all evidence pointing to the health hazards inherent to the GM technology. Meanwhile, more damning evidence has surfaced.

A research team led by Dr Irina Ermakova of the Russian Academy of Sciences reported in October 2005 that 36 percent of rats born to pregnant rats fed Roundup Ready GM-soya starting from before the rats conceived were severely stunted, compared with 6 percent of rats born to those fed non GM-soya. Within three weeks, 55.6 percent of the progeny of GM-soya fed rats died; a death rate six to eight times that of progeny from rats fed non-GM soya, or a diet without added soya [3].

When interviewed on BBC recently [4], Dr Ermakova said that she has now repeated the experiment three times with very similar results each time; the average death rate within three weeks of birth was 51 percent in the group fed GM-soya compared to around 6 percent in the two control groups. In addition, a third of surviving animals in the GM-fed group show markedly reduced body weight and lack normal internal organ development.

New research in Canberra Australia demonstrated that a previously harmless protein in bean when transferred to pea caused inflammation in the lungs of mice and provoked reactions to other proteins in the feed [5]. Immunological and biochemical studies carried out for the first time on the transgenic protein revealed that it is processed differently in the alien species, turning the innocuous protein into a strong immunogen. In addition, the transgenic protein promoted immune reactions against multiple other proteins in the diet. In other words, it provoked dangerous food sensitivities. As practically all the transgenic proteins involve gene transfer to an alien species, they will be subject to different processing. All transgenic proteins, therefore, can potentially cause serious immune reactions including allergies [6]. Yet, none of the transgenic proteins commercially approved for food and feed had received the regimen of tests now carried out on the transgenic pea protein. This omission is a most serious public health issue; and warrants an immediate ban on GM food and feed until proper assessment on the immune potential of all the transgenic proteins has been carried out.

These latest developments are the most dramatic and revealing in the light of previous scientific and anecdotal evidence that have been suppressed and dismissed, or simply not followed up (see Box). I should mention a series of reports from the Universities of Urbino, Perugia and Pavia in Italy that have also come to light. They document many changes in the cells of young mice fed GM soya. The acinar (secretory) cells of the pancreas showed a pattern of changes associated with a decrease in the synthesis of the digestive enzyme a -amylase in mice fed GM-soya compared with controls [7, 8]. In liver cells, however, the GM-soya fed mice showed a pattern of changes associated with an increase in metabolic rate compared with controls [9, 10] (“liver of mice fed GM soya works overtime”, SiS 20). Some of those changes could be reversed by a change of diet from GM-soya to non-GM soya; but equally these changes could be induced in adult mice by switching their diet from non-GM to GM-soya [11]. There were also alterations in the Sertoli cells (cells nurturing the developing sperms) and the sperm cells in the testes associated with a decrease in transcription in young mice fed GM-soya compared with those fed non-GM soya [12].

Damning evidence against the safety of GM food and feed

  • Pregnant female rats fed GM soya gave birth to severely stunted progeny and others in the litters that died within three weeks (see main article)
  • GM-soya affected cells in the pancreas, liver and testes of young mice (see main article)
  • Rats fed a Monsanto GM maize developed serious kidney and blood abnormalities [13]
  • Villagers in the south of the Philippines suffered mysterious illnesses when a Monsanto GM maize hybrid came into flower; antibodies to the Bt protein in the GM maize were found in the villagers, and there have been five unexplained deaths (see main article)
  • A dozen cows died after eating a Syngenta GM maize and more in the herd had to be slaughtered due to mysterious illnesses [14]
  • Dr . Arpad Pusztai and colleagues found young rats fed GM potatoes damaged in every organ system including an increase in thickness of the stomach lining to twice that in controls [15]
  • Scientists in Egypt found similar effects in mice fed another GM potato [16]
  • The US Food and Drug Administration had data dating back to early 1990s showing that rats fed GM tomatoes had developed small holes in their stomach [15]
  • Chickens fed Aventis' glufosinate-tolerant GM maize were twice as likely to die compared with controls [17]
  • New research demonstrated that a harmless protein in bean when transferred to pea caused inflammation in the lungs of mice and provoked reactions to other proteins in the diet (“Transgenic pea that made mice ill”, this series)

Commenting on some of the evidence presented here, Dr. Michael Antoniou, Reader in Medical and Molecular Genetics at King's College London, had this to say [18]: “ If the kind of detrimental effects seen in animals fed GM food were observed in a clinical setting, the use of the product would have been halted and further research instigated to determine the cause and find possible solutions. However, what we find repeatedly in the case of GM food is that both governments and industry plough on ahead with the development, endorsement and marketing [of] GM foods despite the warnings of potential ill health from animal feeding studies, as if nothing has happened. This is to the point where governments and industry even seem to ignore the results of their own research! There is clearly a need more than ever before for independent research into the potential ill effects of GM food including most importantly extensive animal and human feeding trials.”

A global ban on GM food and feed is long overdue. There must also be a comprehensive enquiry into the safety of GM food and feed, and into the systematic suppression and denial of the incriminating evidence.

Article first published 06/02/06


  1. “B'laans in South Cotabato exposed to Bt toxin, scientist says”, Mark S. Ventura, Catholic Herald 2004, 30 (8).
  2. “MASIPAG asks gov't to stop distribution of Bt corn” Davao Catholic Herald 2004, 30 (8).
  3. “Genetically modified soy affects posterity: results of Russian scientists' studies”, 25 October 2005, ;
  4. BBC4 Farming Today, 11 January 2006.
  5. Prescott VE, Campbell PM, Moore A, Mattes J, Rothenbrg ME, Foster PS, Higgins TJV and Hogan SP. Transgenic expression of bean a-amylase inhibitor in peas results in altered structure and immunogenicity. J. Agric Food Chem. 2005, 53, 9023-30.
  6. Ho MW. Trangenic pea that made mice ill. I-SIS Report. 28 November 2005.
  7. Malatesta M, Caporaloni C, Rossi L, Battistelli S, Rocchi MBL, Tonucci F and Gazzanelli G. Ultrastructural analysis of pancreatic acinar cells from mice fed on genetically modified soybean. J Anat 2002, 201, 409-415.L,
  8. Malatesta M, Biggiogera M, Manuali E, Rochhi MBL, Baldelli B, Gazzanelli G. Fine structural analyses of pancreatic acinar cell nuclei from mice fed on genetically modified soybean. European Journal of Histochemistry 2003, 47, 385-8.
  9. Malatesta M, Caporaloni C, Gavaudan S, Rocchi MBL, Serafini S, Tiberi C and Gazzanelli G. Ultrastructural morphometrical and immunocytochemical analysis of hepatocyte nuclei from mice fed on genetically modified soybean. Cell Structure and Function 2002, 27, 175-80.
  10. Ho MW. Liver of mice fed GM soya works overtime. Science in Society 2004, 21, 7.
  11. Malatesta M, Tiberi C, Baldelli B, Battistelli S, Manuali E Biggiogera M. Reversibility of hepatocyte nuclear modifications in mice fed on genetically modified soybean. European Journal of Histochemistry 2005, 49, 237-42.
  12. Vecchio L, Cisterna B, Malatesta M, Martin TE, Biggiogera M. Ultrastructural analysis of testes from mice fed on genetically modified soybean. European Journal of Histochemistry 2004, 48, 449-54.
  13. “French experts very disturbed by health effects of Monsanto GM corn” GMWatch, 23 April 2004.
  14. Ho MW and Burcher S. Cows ate GM maize and died. Science in Society 2004, 21, 4-6.
  15. Pusztai A, Bardocz S and Ewen SWB. Genetically modified foods: Potential human health effects. In Food Safety: Contaminants and Toxins , (J P F D'Mello ed.),
    Scottish Agricultural College, Edinburgh, CAB International, 2003.
  16. Fares NH and El-Sayed AK. Fine structural changes in the ileum of mice fed on dendotoxin-treated potatotes and transgenic potatoes. Natural Toxins , 1998, 6, 219-33; also “Bt is toxic” by Joe Cummins and Mae-Wan Ho, ISIS News 7/8, February 2001, ISSN: 1474-1547 (print), ISSN: 1474-1814 (online)
  17. Novotny E. Animals avoid GM food, for good reasons. Science in Society 2004, 21, 9-11.
  18. “New evidence of harm from GM food triggers call for immediate ban. UK government and EC accused of criminal negligence and wilful suppression of facts” GM Free Cymru Press Release 25 November 2005.

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