FOODBORNE ILLNESS: POISONS AND THE PERILS OF PROCESSING FOR PROFIT
by Andrew T. Fisher
How large is the risk to you from foodborne illness? Nobody really knows! Estimates of cases of food poisoning range from 6.5 million to 81.4 million cases annually. The United States Centers for Disease Control and Prevention (CDC) estimate deaths from these illnesses at more than 9,000 annually and more than 80,000,000 cases of foodborne illnesses the United States each year! These figures may be underestimations; some are not reported, others are misdiagnosed. The CDC have not taken an actual count of foodborne illnesses and deaths since 1983. This is changing, with a National Molecular Subtyping Network for Foodborne Disease Surveillance, a collaborative effort by the CDC, Food and Drug Administration (FDA), United States Department of Agriculture, and some state health departments.
Due to modern agricultural practices using pesticides and chemical fertilizers, soils, plants, and animals have become depleted in beneficial lactic-acid producing bacteria, which used to be prevalent in the natural environment, and in the past have balanced and often destroyed disease-causing micro-organisms. Humans may be experiencing more infections these days because of a dramatic decline in these lactic-acid producing bacteria. Also, the overuse of antibiotics in agriculture kills off mild pathogens and allows more virulent ones to proliferate.
Several widely used food processes contribute to foodborne illness:
Also, many current farming practices are risky. With monoculture, far greater quantities of toxic pesticides, including insecticides, herbicides, and fungicides, are used on fields. With intensive rearing of livestock, sometimes as many as 100,000 head of cattle may share one feed lot, or tens of thousands of chickens may be crowded into one hen house. With such crowded conditions, often the entire herd or flock can be contaminated rapidly by only a few animals. A practice to multiply egg production compounds the Salmonella problem. In involves manipulating light patterns to increase egg laying. Also, more than a billion pounds of dead chickens and turkeys are recycled each year into poultry feed! Another problem involves supplementing animal feed with the nutrient selenium. With an incubation period as brief as 24 hours, the organisms can multiply a million-fold in this medium.
Current techniques used in processing, shipping, and storing foods also increase risks of foodborne illnesses. In addition to the well-known inadequacies of fish, meat, and poultry inspection, there are many other risks. Defeathering machines pound any contaminants present into the carcasses of chickens. Contamination is spread further when microbial-containing spray lands on nearby carcasses and/or workers. Poultry carcasses are then dipped in what has been dubbed a "fecal bath" of chilled water where many other antibiotic-resistant bacteria, Aeromonas hydrophlia may reside. In larger animals, whose food is withheld before slaughter, E. coli may colonize more readily. Another widespread problem known as "biofouling" occurs when microorganisms accumulate on many of the surfaces of food processing equipment. Microorganisms seek solid surfaces with nutrients for sufficient growth, and food processing equipment is ideal. These biofilms of microorganisms and nutrients have become pervasive with machine processing of foods, especially Staphylococcus aureus with poultry, Listeria monocytogenes with meat and dairy, and Bacillus cereus on dairy equipment. Centrifuge egg-breaking machines, used by many bakeries and food services as a convenience to separate the liquid from the shell, also increase contamination risks when minute bits of shell carrying bacteria are expelled along with the liquid. In the past decade, many state and federal health agencies have sought to have such machines banned from use, but the practice continues.
Ironically, the "healthy" practice of eating low-calorie foods actually increases the risk of food poisoning. Low-fat butter replacers may have a higher water content than regular butter, making them susceptible to bacterial growth. Similarly, the fat in whole milk inhibits bacterial growth more readily than in skim milk lacking the fat. Processed low-calorie and low-acid foods, such as mayonnaise, are much more hospitable to disease-causing bacteria such as Salmonella and Listeria.
Use of ground meat has become very popular, but in its handling it becomes more susceptible to contamination than whole chunks of meat. Bacteria find it easier to grow on meat surfaces without burrowing inside, but when the meat is ground, the surface bacteria become mixed throughout the entire batch. In forming patties, the bacteria are spread even further. A new practice of shipping coarsely ground beef to the supermarket where it is ground more finely, increases the risk of microbial contamination.
Many other "convenience" practices have increased the risk of food contamination. Skyrocketing sales of these "carry-out" pre-prepared foods have greatly increased the use of high-tech packaging (with slow contamination to the food), often toxic preservatives, hydration used in the produce sections of supermarkets to increase shelf life, and the handling and pre-processing of foods at restaurants. All these practices increase the risks of foodborne illness.
Adequate intake of food fiber can reduce the risks of foodborne illnesses. Fiber can increase the amount of mucin (a secretion from the intestinal cells). Mucin is one major defense mechanism against pathogens. Also, rat tests have shown that a low-fat diet is important for maximum mucin production (yet another reason to avoid high-fat "junk" food!)
*Source: adapted in part from "Overlooked Threats of Foodborne Illness," by Beatrice Trum Hunter, Consumer’s Research, Inc., pages 14-18, October, 1995.
Article from NOHA NEWS, Vol. XXII, No. 4, Fall 1997, page 2.