Bacteria / Viruses / Who Gets It / Eating Meat / Chicken & Egg / Salmonella / Campylobacter / E. coli / Clostridium perfingens / Listeria / Botulism / Vibro vulnificus bacteria / Bugs & Drugs / Prevention or Poisoning / Cooking / Protection / References
Whether you eat to live, or live to eat, what you eat can determine how or even if you live.
Foods can nourish us or kill us, if they are poisoned. And with an alarming increase in frequency, food poisoning is on the rise in the United States and worldwide. Foods are poisoned by microscopic germs that get into them: viruses, bacteria, parasites, and even worms (which can grow large enough to see with the naked eye). Sometimes, it is the chemicals produced by these germs which cause us harm. In the following pages, you will learn about the major causes of food poisoning, what happens when you are poisoned, and the steps you can take to protect yourself and your family.
Almost all food poisoning today originates from animal agriculture and foods. Even the relatively few recent outbreaks of food poisoning derived from various fruits or vegetables have been traced to contamination and runoff from animal manure. The danger has been worsened by intensive factory farming methods used in animal agriculture. Thus, the simplest, most effective step you can take to protect yourself, and reduce the problem in society as a whole, is to avoid eating or serving animal products.
Modern life in the United States has many advantages. We have the benefit of technology making the most difficult tasks quick and easy. In one shopping trip we can buy enough foods for a month before the expiration date gets further and further away. Ready-made meals are becoming a part of everyday life, people eat out on a regular basis and take out and fast foods are readily available. However there is a price to pay for such "luxuries", and I don't just mean money. Food produced on a big scale leads to food poisoning on a big scale as there are many opportunities for bacterial and other infections. Food processing plants centralize the manufacture of meals so that one infected ingredient can spread to many products. What is food poisoning?
You know what happens when you eat something that disagrees with you? Well, food poisoning is more than a disagreement. It can feel like a full out battle between your body and the food you have eaten. Between 12 and 24 hours after eating the contaminated food you feel abdominal pain which is quite mild at first but it becomes stronger and stronger. The pain can be excruciating and may lead to explosive diarrhea. Your temperature may rise as high as 102ºF/39ºC. Vomiting may follow and dehydration (sunken eyes, a dry mouth and a rising pulse rate) may result. Usually the illness lasts for five to ten days, with a further one to two weeks before you feel well again. The loss of salt and water from the body can lead to heart attacks and strokes. Food poisoning occurs as a result of eating food that is contaminated by metal, chemicals or micro-organisms, such as bacteria and viruses.
What are bacteria?
Bacteria are the main cause of food poisoning. They are micro-organisms that exist everywhere; in the air we breathe, in the water we drink and in the food we eat. Some bacteria live on our skin, in fact there are on average one million per square inch. There are also bacteria which live in our guts protecting us against infection. Too many bacteria in our system can lead to illness and, because they can reproduce at a phenomenal rate, it is easy for them to get out of control. If bacteria are allowed to incubate in the foods we eat then problems will ensue. Sometimes people are not poisoned by the bugs themselves, but by the chemicals which they release into food.
What are viruses?
Virus is the term applied to a group of infective agents. Viruses are smaller and simpler than bacteria and cannot reproduce unless they are inside a host cell. Some viruses infect cells and destroy them and some co-exist with their host. The viruses that infect bacteria and destroy them are called bacteriophages and they are among the most complex viral particles known. They can cause infection by killing off healthy bacteria or by causing toxic substances to be released into cells during the virus life cycle.
Who gets it?
The following table shows us that eating animal products is a big risk in terms of food poisoning and is making over a million people ill - some very seriously - every year. Literature reports of the yearly incidence of foodborne illness range from 6.5 to 81 million people affected (1). Those most prone to food poisoning are the elderly, pregnant women and children under 1 year old, but anyone can get food poisoning. Ninety five percent of all food poisoning cases are caused by eating animal products. Five percent are from plant foods however much of this is from contamination by animal manure or from animal products. A diet free of meat, fish, milk and eggs is by far the safest, and one that I highly recommend.
Why does eating meat and animal products increase your chances of infection?
Food poisoning is becoming bigger, more complex and harder to control. Meat is a main culprit because bugs love it! Bacteria can multiply extremely rapidly given the opportunity, and meat, cheese, eggs and milk all provide the ideal environment for bacterial growth. From cradle to grave, or should I say from birth to plate, food poisoning bugs have six chances to infect meat:
- The conditions in which the animal lives:
Like us, animals are at their healthiest when they are happy. Those that are placed under stress are more susceptible to infection and illness. As farming has become more and more intensive, livestock are primarily selected for growth rather than disease resistance. Factory farming is at the root of the problem of food poisoning. Thousands of animals squeezed into cramped, dirty and unnatural habitats leads to problems. The main aim of intensive or factory farming is to have maximum output with minimum input or basically to make a lot of money. It is well known that when people are forced to live in camps, slums and other overcrowded and unsanitary places infection is inevitable.
Intensive farming involves crowding as many animals as possible into a limited space - making infection unavoidable. Bacteria and viruses thrive in this environment and can infect large numbers of animals within a very short time. Also, poor ventilation in buildings means that airborne bacteria spread easily.
Intensive farming means that every waking hour of the animal is manipulated to ensure a rapid and high yield. This is a strain on the animals involved and has its consequences.
E. coli O157 inhabits cattle in two forms. In its normal state in their gut, it is comparatively harmless. But when the animal is under pressure, like when cattle are subjected to the stress of being herded through the mass production process of a large modern industrial slaughterhouse, the bacterium breaks out into the bloodstream. This induces diarrhea and the potential for spreading the lethal infection becomes enormously greater (2). Add to this the safety problems which are increased because of a lack of testing, lack of controls, and lack of care at each stage of the food chain, and you have a recipe for disaster.
- The food that animals eat:
In Britain, cows were fed the brains of other cows and sheep which led to a fatal disease - BSE or mad cow disease. After years of government denial, it was finally acknowledged in 1996 that this disease can pass to people via infected meat, causing a lethal brain infection. This shows the dangers of forcing herbivores to eat the remains of other animals - a practice that happens in the US.
In intensive farming, the emphasis is placed on doing whatever it takes to lower production costs. This has led to even feeding animals the manure which they and other animals eliminate! The factories simply fill the feed troughs with manure, by itself or mixed with litter, and coat it with molasses or the like. This way, nutrients that were not extracted by animals digestive systems the first time, go through again. From a medical perspective, however, this unnatural process continually exposes the animals to harmful germs.
- At the slaughterhouse:
When an animal arrives at the slaughterhouse it may be covered in feces. This is a major source of contaminated meat because potentially fatal organisms such as E. coli O157 and salmonella can enter a meat processing plant on the skins of infected animals. Many slaughterhouses do not have a policy with regard to dirty stock.
For slaughterhouse costs to be kept to a minimum the animals are put through the system as quickly as possible. Speed is of great importance in the process and similar principles apply for the preparation of chickens, cattle, sheep and pigs. Automated slaughter and processing on a factory production line means that the bacteria and viruses can spread widely. The same implements are used to slaughter one animal after another with little washing in-between so the bacteria spread rapidly between carcasses. When the animal is split open its insides fall out along with the contents of the gut, which is often where the bacteria live. It is likely that the bacteria will spill onto the rest of the animal and infect the meat. If a living animal went into a slaughterhouse bug-free, there is a good chance that it would emerge as a disease-ridden carcass. And dont count on the government to stop contaminated carcasses from reaching the market: One investigation determined that meat inspectors in chicken processing plants have an average of two seconds per bird to check for signs of contamination (3).
- Butchering and processing:
A lack of hygiene can cause food poisoning bacteria to be spread. Processed meats tend to be more dangerous because cooked meats are the ideal breeding ground for bacteria.
- Restaurants/Food Service Industry:
A combination of poor food handling, inadequately trained staff and insufficient legal controls creates an environment which is highly conducive to outbreaks of food poisoning.
- In the home:
Cross-contamination from raw to cooked meat can spread bugs. There is also a chance of cross-contamination from raw meat to vegetables. Bad hygiene in the kitchen is a common cause of food poisoning.
The chicken and the egg
Intensive farming reaches its peak with chickens so it is not surprising that chicken meat and eggs are the most common source of food poisoning bacteria. According to Time Magazine, bad chicken kills at least 1,000 people in the U.S. each year - and thats a conservative estimate (4)! Broiler chickens (those reared for meat) are kept in appalling conditions and reared like popcorn - to be puffy, fluffy and produced quickly. Thousands of them are squeezed into a shed, fed constantly in artificial light, and not cleaned out once during their seven week lives. So not only do they live in their own excreta, they also live on top of the chickens that die in the process. Up to 20 per cent of broiler chickens don't survive the ordeal (5).
There are 2,000 different types of salmonella bacteria and the intestines of the chicken act like a reservoir and provide the potential for the spread of bacteria. In recent years, the amount of chicken eaten in the United States has risen dramatically, so it is not surprising that food poisoning is on the increase.
Battery/Layer hens are stacked in tiny cages in dim, stinking sheds. After an egg is laid it rolls into a collecting gully. Food and water are supplied automatically and lights are on for about 17 hours a day to promote egg laying. Up to 100,000 birds are kept in each of these sheds. The combination of a lack of fresh air, selective breeding and the caging of the birds in overcrowded conditions so that they cannot even exercise, has led to the spreading of disease and to distress and suffering.
Food poisoning bacteria can enter an egg by two methods.
- Ovarian infection - the infection is already in the egg when its laid. Bacteria get through the gut wall and into the internal organs including the blood. Therefore the eggs become infected via the ovaries.
- Transovarian - bacteria get inside the egg when the egg is washed (6). Both broiler and battery/layer chickens are often fed the infected remains of their own kind - allowing salmonella to spread like wildfire. You would not be able to tell by simply looking at a chicken or an egg whether it contains food poisoning bacteria. If you eat an infected egg that is not properly cooked, the salmonella may grow in you! It has been known for years that modern intensive methods of broiler and egg production are riddled with salmonella.
Types of food poisoning
Salmonella infections are most common in chickens but do occur in cows and pigs. An animal infected with salmonella excretes salmonella and therefore will cross-infect any other healthy animal with which it comes into contact - at the farm, to and from market and in the slaughterhouse. It would be difficult to devise a better, more efficient system for recycling salmonella than modern livestock farming. Its methods seem tailor-made to produce disease and spread infection among animals destined for human consumption. Salmonellosis is the infection of the intestinal tract. However, if the live bacteria penetrate the intestinal tissue and enter the blood stream the salmonella bacteria can colonize other tissues causing septicemia, meningitis, osteomyelitis and even death. According to the Center for Science in the Public Interest, infected chickens lay an estimated 2.3 million contaminated eggs each year, and a recent risk of assessment on eggs conducted by the United States Department of Agriculture (USDA) said that Salmonella enteriditis (SE) contaminated eggs have caused an average of 660,000 illnesses and 330 deaths annually. (7)
Campylobacter is the number one cause of food poisoning, with more than 2.5 million cases of Campylobacter diarrhea estimated to occur in the U.S. annually, according to the Centers for Disease Control (8). According to the U.S. Food and Drug Administration, one survey showed that 50% of Campylobacter infections are associated with either eating inadequately cooked or recontaminated chicken meat or handling chickens. It is the leading bacterial cause of sporadic (non-cluster cases) diarrheal disease in the U.S.(9) Infection is usually caused by eating chicken or turkey that is undercooked, or from drinking unpasteurized milk. Campylobacter infection occurs particularly in children and young adults often five to ten days after eating infected food. This is because it takes five to ten days for the bacteria to multiply to huge amounts in the gut and cause disease.
- E. coli:
E. coli is a normal inhabitant of the gastro-intestinal tract of humans and animals. However some strains have increased virulence and can cause illness. Today, the Centers for Disease Control estimates that there are 20,000 cases of E. coli O157:H7 infection in the U.S. each year associated with the consumption of contaminated beef, raw milk, and water. (10) Sub-groups of disease-causing E. coli are distinguished according to their method of attacking the host:
a. Sticking to the gut wall.
b. Invading the lining of the gut.
c. Producing toxins
The most serious form of E. coli is known as VTEC- verocytotoxin-producing Esherichia coli; the verocytotoxin is a poison and potent inflammatory. This toxin can cause severe hemorrhagic colitis (which usually presents as bloody diarrhea) and damage to the kidneys. Another name for the verotoxin-producing E. coli is E.coli O157. E. coli O157 has been of concern since1983 when a discovery was made: Gastro-enteritis can lead to Hemolytic Uremic Syndrome (HUS) which is a form of kidney failure. HUS is a complication of a VTEC bacterial infection. The bacteria adhere to the gut and release a chemical into the blood stream which causes kidney failure. It is most likely to affect the young and the elderly. VTEC is now thought to be the biggest cause of acute short term renal failure in children and farmed animals; cattle in particular, are thought to be the reservoir of infection. According to the CDC, "with intensive care, the death rate for hemolytic uremic syndrome is 3%-5%. About one-third of persons with hemolytic uremic syndrome have abnormal kidney function many years later, and a few require long-term dialysis. Another 8% of persons with hemolytic uremic syndrome have other lifelong complications, such as high blood pressure, seizures, blindness, paralysis, and the effects of having part of their bowel removed." (11)
In 1993 there was an outbreak of E. coli O157 which began in the Pacific Northwest in early January. Over 450 people were taken ill, 21 were put on dialysis and 3 died. The bacteria were traced to contaminated frozen beef patties served in a fast food shop in Washington State. One of the most recent E. coli outbreaks was near Albany, NY, in September, 1999. There were over 1000 people sickened and at least 122 confirmed cases including 65 hospitalized and 2 deaths (12). Health officials believe the source was cow manure from a nearby barn which washed into ground water, contaminating untreated well water used at a County Fair. E. coli food poisoning bacteria can be found in raw milk and undercooked or raw hamburger meat. E. coli O157 has been around for 15 years and has provided a test for the whole system of food production, showing up the weak spots. It has raised questions about whether the United States Department of Agriculture (USDA) is putting the interests of the food industry above those of the consumer.
- Clostridium perfingens:
These bacteria normally live in the human intestinal tract and generally do no harm. But if they are allowed to incubate in warm foods, they can cause problems. Infections due to Clostridium perfingens are most commonly reported in connection with beef and meat products, particularly soups and gravy. Outbreaks are linked to poor temperature control. Mass quantities of food left unrefrigerated for prolonged periods before consumption pose a risk. Clostridium perfingens bacteria are anaerobes, which means that they can only live without air and therefore in foods that are vacuum packed. They form spores, which multiply rapidly when food is cooling and heavy contamination occurs. Once ingested, the bacteria in the food produce an enterotoxin which leads to the food poisoning symptoms.
This is the infection of Listeriosis monocytogenes bacteria which has the unusual quality of being able to flourish at very low temperatures, i.e., refrigerators (13). Listeria is commonly found in feta cheese, delicatessen and other ready to eat foods, including hot dogs and sandwich slices (14). Contracting listeriosis produces flu-like symptoms and is a big risk for pregnant women as it can lead to blood poisoning, birth defects such as miscarriages and stillbirths and can produce abscesses, meningitis, septicemia, and death (15). In the United States, an estimated 1,100 persons become seriously ill with listeriosis each year; of these, 250 die, according to the Center for Disease Control (16).
This illness is relatively rare and brought on by eating improperly canned or preserved food contaminated with a toxin produced by the bacteria Clostridium botulism which is naturally present in the intestines of some animals and fish. The bacteria need certain conditions to thrive which are:
1. The absence of oxygen (e.g. vacuum packed food)
2. Nutrients and moisture (e.g. meat)
3. Absence of inhibitors
4. A suitable temperature - botulism bacteria can survive as low as 26ºF/-3.3ºC. Of the infected victims, between 20% and 50% die.
- Vibro vulnificus bacteria:
For those with more exotic tastes; according to the American Food and Drug Administration up to 10% of oysters and other raw shellfish contain this bacteria which can cause serious illness and has been known to kill people. Viruses are also emerging as an increasing cause of some outbreaks of food poisoning from shellfish (17). There is no way of sorting infected and non-infected shellfish, so its pot luck for the shellfish eaters.
Bugs and Drugs
Antibiotics have been the wonder drug of the last fifty years. It appears, however, that we have been taking them for granted. Most of today's doctors are willing to prescribe the drugs for almost any sign of infection, be it a sore throat, or a headache, or the virus-caused common cold, against which antibiotics are ineffective. If we take antibiotics for such minor ailments our body can forget how to defend itself against infection. Therefore our body's ability to strengthen its own immune system is reduced and we are more prone to illness. If the antibiotics used are broad spectrum (able to kill a lot of different kinds of bacteria) it is possible that useful bacteria will be wiped out along with the infectious bacteria. The body is then open to infection from other bacterial species, molds, viruses and other microbes which can colonize the bacterial wastelands.
The smaller and simpler a species, the faster it can evolve to survive environmental change. Micro-organisms are small and simple and therefore able to evolve rapidly to side-step our attempts at control. In fact antibiotics put selective pressure on bacteria to develop defense mechanisms and to become resistant. Thus the super-bug is born!
The National Academy of Sciences recently concluded that agricultural uses of antibiotics pose a risk to the public health. (18) The British Medical Association's chairman Dr. Sandy Macara has stated that "There is a real prospect that the majority of our antibiotics could become impotent for the purposes on which we have relied upon them for 40 years." This is a worldwide problem.
Modern animal farming depends to a large extent on antibiotics to produce cheap meat. Using antibiotics in animal feeds is a short term solution to the various diseases that occur during intensive farming. Antibiotics are used as a prophylactic - which means that they can prevent disease occurring in the animals. The antibiotics are also used as feed additives to ensure that the animals gain weight. For reasons no one fully understands, antibiotics promote the growth of animals but in the process they foster the growth of bacteria that can resist antibiotics.
Antibiotics in livestock feeds have given bacteria the upper hand in human illness and hence they have been named Super-bugs. Antibiotic resistant bacteria, or super bugs, are passed on to meat-eaters when they eat infected flesh. After all, you are what you eat and if you eat animals you also ingest their diseases and the drugs they have been given. Because the antibiotics given to animals are generally the same as those used for our medicine, a super-bug in your body is likely to defeat any antibiotic that your doctor can prescribe. According to Stuart Levy of Tufts University School of Medicine, former president of the American Society for Microbiology, estimates are that approximately half of the antibiotics produced in the U.S. today are used in agriculture, citing a 1998 Institute of Medicine report (19). As long as intensive farming continues with the extensive use of antibiotics, coupled with the over-prescription of antibiotics to humans, the problems can only get bigger (20).
The most recent example of this is salmonella DT104 which is resistant to antibiotics. Experts have linked this strain of food poisoning to pork, sausages, chicken, and sick farm animals. 25% or more of human salmonella infections are now resistant to drug therapy. If antibiotic-resistant salmonella are eaten in food they can remain dormant in the gut while being held in check by the normal intestinal bacteria. Then if antibiotics are used to treat some other illness they will kill off the normal gut bacteria and the salmonella can resist the antibiotic and overgrow. This leads to serious illness. Many experts believe that this antibiotic-resistant form of salmonella is a rising threat, and that cases of salmonella typhimurium have rocketed.
The problem is even worse than simply the antibiotic-resistant bacteria in the food animals themselves. Bacteria have the capability of rapidly transferring and spreading the antibiotic-resistance character to other bacterial species, including those which cause human diseases. Therefore, diseases which are not even related to food consumption may become resistant to antibiotics, and hence
a much greater threat. The use of antibiotics in animal feed, by selecting for the predominance of antibiotic-resistant bacterial species, is thus a global threat to human health for every individual on earth. This irresponsible misuse of antibiotics is unilaterally disarming our species from our precious last line of defense, and devastating epidemics may well be the legacy of the hunger for inexpensive meat.
The use of antibiotics has made intensive farming possible, but at what price? The meat may be cheap enough, but what about disease control? What about animal welfare? What about safety measures?
Prevention or Poisoning?
The choice is yours. Time and time again it has been proven that a meat-ridden diet can lead to health problems and that a diet which is high in vegetable intake can provide protection from such problems. The evidence is clear and the action to take is simple. Basically we need to turn more and more to a vegan diet if we want good health and a long life, and lets face it, who doesn't?
Will cooking kill the food poisoning bacteria?
Food which is left to sit for hours at room temperature provides the perfect conditions for staphylococci to produce a chemical toxin. This poison is called an enterotoxin and it is not destroyed by heat, so cooking the food will not prevent illness. Staphylococci thrive in meat products, cold meats, milk and egg products. Most bacteria can be destroyed by cooking food at a constant high temperature for a long time. However, there is no simple way for the consumer to tell if the bacteria and viruses have
can I do to protect myself and my family from food poisoning?
The individual alone is limited in what he/she can do to insure that food
is safe to eat. Because of factory farming, slaughterhouses and processors,
it is effectively out of our hands to control food poisoning. But we can
choose what we eat and serve. And the best way to avoid contamination
is by declining the dubious honor of being at the top of the food chain.
A vegan diet is by far the safest.
Goldman is Professor of Microbiology & Molecular Genetics. He has
a Ph.D. in Biochemistry and a Postdoctoral Fellow in Pathology from Harvard
Medical School. His outstanding career includes being a Consultant in
Pathology at Harvard Medical School; Assistant Research Microbiologist
at the University of California, Irvine, Medical School; full associate
Professor at the NJ Medical School-University of Medicine & Dentistry
of NJ; Guest Associate Scientist, Biology Department, Brookhaven National
Laboratory and Adjunct Professor, Ph.D. Program in Biochemistry, City
University of New York. He is also a scientific journalist; President,
UMDNJ chapters, of the American Association of University Professors (AAUP)
and a Member of the American Cancer Society Peer Review Group. He has
had his works published in 54 publications as well as having 63 abstracts
printed in conference proceedings.