BSE and CJD

Few events have had such a huge effect on farming, trade and consumer attitudes as the British BSE crisis:

     • An estimated 1.9 million British cattle were infected with BSE [109] and over 4.5 million destroyed, costing the government ?1.4 billion in compensation to farmers and ?575 million to dispose of the carcasses.

     • Between 117 and 705 people are believed to have died as a result of BSE, not including the number of farmers who committed suicide over the loss of their livelihoods. Families of CJD victims received ?55 million in compensation from the government.
     
      • Exports of British beef, once found on menus around the world, were devastated and have still not fully recovered. At the peak of the crisis, the EU imposed a worldwide ban on British beef exports, and beef consumption fell by 7 percent across the EU and 8 percent in the UK.

      • The blood of British citizens is now feared to be too dangerous to use in blood transfusions because it may be contaminated with CJD. The government was forced to spend ?50 million to buy a US plasma firm to secure a safe long-term supply for the UK, which has relied on American supplies since 1998. In 2000, the US and Canada prohibited blood donations from people who had lived in Britain for at least six months since 1980.

      • Plunging confidence in food safety caused many British consumers to stop eating beef or become vegetarian. The crisis undermined public trust in both the government and in food safety, and continues to shape consumer attitudes towards issues such as irradiation, genetic modification and organic farming.

BSE is a direct result of the intensification of agriculture. There have been no recorded cases of BSE in any animal born and reared organically, though cases have been recorded in organic herds where the animals originally came from a non-organic source. [110]

There are two main theories on the causes of BSE and CJD. Both of them involve the mysterious prion protein, and both could explain why there has never been a case of BSE in a born-and-bred organic cow.



TSEs and prions

BSE (Bovine Spongiform Encephalopathy) is an incurable disease which attacks the brain and nervous system of cows. An infected brain becomes filled with holes, like a sponge. Cows lose weight, become easily startled and find it increasingly difficult to stand. The disease is virtually 100 percent fatal.

BSE belongs to a group of diseases known as TSEs, which also affect sheep (scrapie), deer (CWD), cats (FSE) and humans. In humans, it is called Creutzfeldt-Jakob Disease (CJD), and there are several varieties. The symptoms of TSEs are similar in all species.

TSEs are thought to be caused by abnormal forms of prions. Prions are proteins found in healthy brains and nervous systems, but in BSE or CJD, these proteins become 'twisted' and cannot do their job normally.

Twisted prions are virtually indestructible - they cannot be destroyed by fire, freezing, disinfectants, solvents, bleaches, sterilization, incineration or intense radiation.

There are two possible ways that prions may become twisted:

     1. Prions might become twisted after eating infected meat. Twisted prions in the food start a domino effect, twisting healthy prions all the way through the food chain.

     2. Twisting is caused by pesticides and artificial mineral imbalances in the environment.
Both of these routes are prevented by organic farming practices.

Cow eat cow

In March 1996, 10 years after the first case of BSE was reported, the UK government made a humiliating u-turn on the safety of British beef. After 6 years of insisting that eating BSE-infected meat could not cause CJD, the government finally admitted a "probable link" between the two diseases.

Until the peak of the crisis, intensively farmed cows had been fed ground-up dead animals, including euthanized cats and dogs, road-kill, chicken litter, offal and parts of animals unfit for human consumption. [111] They were also fed the ground-up bodies of cows and sheep which had died of BSE and scrapie, the sheep version of BSE. As prions are indestructible, they can survive processing into animal feed, and cooking of burgers and steaks.

Government scientists agreed that prions in sheep infected with scrapie could infect cattle via their feed and twist the cow's prions. The domino effect continues when humans eat BSE-infected beef products, resulting in CJD.

The risk of contracting CJD from BSE-infected meat does stop with burgers and steaks. Cattle products can be found in wide range of processed foods and even medical products, including vaccines, cosmetics, human growth hormone, thyroid hormone, albumin, blood transfusions, vitamin and mineral supplements, gelatin in thousands of processed foods, corneal transplants, surgical instruments, estrogen, progesterone, cortisone, heparin, Vitamin B12, insulin, gelatin in pill capsules, yogurt, ice cream, butter, chewing gum, lard, margarine, shortening, egg substitutes, gravy mixes, cake mixes, whitener in refined sugar (from cattle bones), gelatin desserts, marshmallows, mayonnaise, sausages and sausage casings, medicines, pet foods, and many other products.

Cows are herbivores, not meat eaters. Their bodies have evolved to eat pasture and they cannot stay healthy when they are fed meat products, especially when the animals used for food died from disease.

The Soil Association banned the feeding of animal proteins to ruminants in its organic standards in 1983, three years before BSE emerged. Five years later, the British Government began to take similar action for all cattle, and cases of BSE fell dramatically. [110]



Creutzfeldt-Jakob Disease (CJD)

For many years, it was widely believed that BSE could cause a specific type of CJD called variant CJD (vCJD). Victims of vCJD tend to be young people, in their late teens or early twenties. The first symptoms of the disease include depression, introversion, memory loss, unsteadiness and weakness. As the brain becomes more filled with holes, victims lose control of balance, speech, movement and bodily functions. They become scared and anxious, suffer dementia and sometimes blindness. Death occurs 12 to 18 months after the first symptoms.

The disease is incurable. An estimated 117 people have died of vCJD to date and 11 sufferers are still alive, but no one knows what the final figure will be. The incubation period for the disease is unknown, but has been estimated at between 10 and 30 years. In 1999, EU scientists predicted as many as 500,000 deaths, but as the number of vCJD victims decreases every year, many had believed that the worst was over and that the number of human deaths would total around 200.


However, in November 2002, researchers at University College London announced that BSE may be responsible for another type of brain disease - sporadic CJD, a much more common type of CJD. The two types of CJD were previously thought to be unrelated, and the discovery re-ignited fears over the true scale of the problem. [112]

There have been 588 cases of sporadic CJD in Britain in the past decade. Professor Stan Prusiner, who won the Nobel Prize for his work on TSEs, told the Sunday Times that "a million cattle infected with BSE entered the British food chain… so almost everyone in the country will have been exposed to the infectious prion proteins." Professor Prusiner called for the entire British population to be screened for vCJD.

Cases of sporadic CJD have been recognized since the 1920s. The cause was previously unknown, but believed to be a spontaneous DNA mutation. [113]

Not everyone accepts the official government explanation of BSE and CJD. A second theory has been championed by Cambridge University prion biochemist David Brown and organic cattle farmer Mark Purdey, who are dismissive of the science behind the infectious theory of BSE. Brown insists that there is "no evidence an infectious agent is present in either meat or milk." [111]

How does manganese enter the food chain?

In 1984, two years before the first case of BSE was reported, the UK's Ministry for Agriculture, Forests and Fisheries (now called Defra) ordered the compulsory treatment of cattle with an organophosphate insecticide to control warble fly. The insecticide, (ICI's 'Phosmet') was applied along the spine of cattle, just millimeters away from prions in the spinal cord. The annual dose rate was four times higher than other countries that used this type of insecticide.[110]

The same geographical pattern that Purdey discovered between manganese/copper levels and TSEs has also been found between Phosmet use and BSE,[110] including an unusually high number of CJD victims downwind of a Phosmet production plant. [111]

A number of researchers have found that organophosphates can twist prions, though not in the same way as found in BSE. However, the pesticides have another disastrous effect on the prions - they can 'catch hold' of copper, keeping it away from prions and allowing manganese to its place.[116] Organophosphates thus make it easier for manganese to twist the prions and initiate the disease.

One formulation of the warble fly insecticide - Maneb, or Mancozeb - actually contains manganese in addition to organophosphate.[111]

Synthetic pesticides are prohibited in organic farming. Purdey took the British government to court and won the right not to use organophosphate on his organic cattle.

But organophosphates are not only used on farm animals. They are also found in flea products for pets and head lice and scabies products for children. It has been suggested that the use of organophosphates on children's' heads, millimeters from the prions in their brains, may 'prepare' the children for CJD in later life.