Food Safety: What Are the Real Issues?
Manfred Kroger, Ph.D.
The American food supply is abundant, affordable and appealing. And contrary to pop-nutritionist claims, it’s nutritious when the right dietary choices are made. As things stand now, Americans certainly enjoy the safest and most wholesome food in the history of mankind. We should be proud of that achievement and have faith in our food system. Yet many are worried that our food supply is dangerous.
Actually, unsafe food has bothered people since time immemorial. It took thousands of years to understand how contamination and spoilage can cause discomfort, illness or death. These insights developed slowly through a process of trial and error. Today’s scientists are trying to determine what relationships—if any—exist between diet or specific foods and such problems as cancer, heart disease, allergy, and disorders of mood and behavior. As a modern technological society, it behooves us to address food safety as thoroughly as we address military efforts, space research and other endeavors of science—but it also behooves us to maintain a realistic perspective.
In 1979, a committee of the U.S. Department of Agriculture set out to identify and rank areas of food safety and nutrition that deserve further research. After two years of study that included input from 134 food research administrators from industry, government and universities nationwide, the committee listed the following food hazards in the order of their importance. Note that this ranking is quite different from that generated by the media and held by much of the public.
1. Mycotoxins. Little is known about fungal toxins since only about two decades have passed since the discovery that aflatoxins (produced by the common mold Aspergillus flavus and other molds) can kill and are carcinogenic. Since both human food and animal feed tend to become moldy, consumption of mold toxins is almost inevitable. Even livestock can pass them on in modified form to consumers. History tells us much about ergotism (once called “St. Anthony’s Fire"), alimentary toxic aleukia and other problems related to fungal contamination. Are naturally occurring mold toxins in our diet actually making people ill? We don’t know, but it seems prudent to be cautious about molds and moldy foods. Agricultural practices are now closely monitored to minimize mold contamination. And products such as peanuts, tree nuts, corn and oilseeds are closely monitored to detect aflatoxins. Not all molds are harmful. Most people clean up or throw out mold-contaminated food. The less affluent seem to be the ones most exposed to mold toxins because they cannot afford to throw spoiled food away. History shows that ergotism often appears when there are food shortages.
2. Bacterial toxins. These include the death-dealing neurotoxins produced by Clostridium botulinum and the debilitating enterotoxins of several other species. There is reason to believe that many unrecognized toxin-producing bacteria exist and contribute to food hazards. Most of our efforts with home and restaurant hygiene are directed at preventing food poisoning due to bacterial toxins. Sanitation procedures and proper food treatment have helped keep populations healthy. Understanding the principles, food handler education, and respect for hygiene will continue to be the major factors in reducing disease and death from food poisoning.
3. Food-borne bacterial infections. Salmonellosis is the best known, with thousands of cases reported annually in the United States. This is only the tip of the iceberg, since most cases of food poisoning are not reported to the Centers for Disease Control and Prevention. There is still much to be learned about how people get sick from bacteria in food. All of us are familiar with “stomach upsets,” “intestinal flu” and "travelers’ diarrhea,” but relatively little is known about the actual disease mechanisms. Experts would probably agree that of all human misery in the world, now and before us, there has never been a cause bigger than the wrong kind of tiny bacteria within us. (It would be a mistake, however, to conclude that all bacteria are bad. Those used in food fermentation are safe and useful, and various bacteria normally living within the human intestinal tract are essential for life.)
4. Chemical residues. This category includes pest control substances, biologicals used in animal agriculture, and industrial chemicals appearing as chronic or sporadic environmental pollutants. Modern technology is blamed for the presence of all of these unwanted chemicals in our food; so it is important to fully understand the risks and benefits of the substances that human ingenuity has conjured up to work for us. The risk-benefit balance of agricultural chemicals tilts heavily towards benefit. Some countries that don’t use pesticides lose up to half their food to insects and other pests. Washing fruits and vegetables removes most of the surface contaminants; the tiny amounts that may remain represent no threat to human health. Those who speak of the “chemicalization of our food” do not fully understand the realities of agriculture. Nor do they have proper appreciation of our technological heritage. “Technological” and “chemical” have come to define modern life, mankind and progress. We merely require the wisdom to effectively harness technology and chemistry. Food became "technological” and “chemical” centuries ago because more of it was needed to feed ever increasing populations. At the same, concern was generated to keep unhealthy chemicals out of our diet. Continuing awareness will assure us of a “clean” food supply.
5. Naturally occurring toxicants and allergens. Many people believe that anything coming from Mother Nature must be benign. That simply isn’t so. If man’s actions leave some chemicals in our foods, nature contributes the rest. Every bit of every piece of food is composed of chemicals. A cup of milk contains thousands of chemicals and so does a bite of bread or a whiff of coffee. Nutrients are chemicals. Most of the hundreds of thousands of chemicals are neutral in character, some (quite a few) are toxic. Of course, we know about poisonous mushrooms, but to what extent are toxic alkaloids in potatoes or sulfur compounds in onions hazardous to consumers? Questions of this type should be explored further but kept in perspective.
6. Process-induced toxicants. The value of technology—including such developments as refrigeration, pasteurization, and canning—is obvious. There is still cause for concern about possible chemical interactions and toxic products formed during food processing—such things as nonenzymatic browning reaction products, or the secondary effects of chlorine in meat processing.
7. Viral infections. About 25% of the reported outbreaks of food-borne disease cannot be attributed to known bacterial agents and may be due to undetected viruses. Food animals are susceptible to a wide variety of viruses—which may be transmittable to humans. These areas are not well understood. Our knowledge about the significance of virus-induced cancers is slimmer still.
8. Food additives. Promoters of “organic” foods and a number of so-called consumer advocates have succeeded in making this the number one food safety issue in the mind of the general public. Although vigilance is in order, the fact is that food additives have been extensively studied—probably more so than the other categories listed here.
9. Toxicants formed in the body. The fact that cancer-causing nitrosamines can form in the human digestive tract should certainly be studied further. What else is going on inside us that is food-related and might precipitate harm? Do we harbor a diet-related “self-destruct” mechanism?
10. Parasitic infections. This was a big problem in Europe and North America until about 50 years ago, and it still is a problem in many other parts of the world. Food is a major vector for human parasites, particularly the organism that causes trichinosis. In 1940, some 16% of the U.S. population was infected with trichinae, generally from meat products. By 1985, largely due to government regulation of meat processing, the number of reported cases had dropped below 100 per year. In 2000 only 15 cases were reported.
During the 20+ years since the USDA survey was done, no such “official” ranking has been repeated, but professional publications continue to reflect far more concern about microbial toxins and infections than about food additives. Since 9/11, there has also been much concern about possible terrorist attacks, by chemical or microbial means, aimed at the food supply. Other subjects worthy of study include food interactions, foods that prevent toxicity, and even foods that prevent cancer.
Totally synthetic food restricted to the 40 to 50 nutrients essential for life might eliminate all the hazards mentioned above and provide perfect food safety. Can you imagine eating such a diet?
This article was posted on June 6, 2005.