Disease microbes, nutrient shortages and lack of access are greatest threats, not biotechnology. Contamination of fish and meat with parasites, or grains with mold toxins, are also significant food health hazards.
By Professors Bruce Chassy, Ph.D., and David Tribe, Ph.D.
The safety of food components obtained from genetically modified crops is part of a much bigger issue of food safety. Food safety is a complex but fascinating topic to discuss, because food is itself is both chemically very complicated and absolutely essential for human survival. Food’s wonderful flavors, colors and aromas all come from an extraordinarily large chemical palette that we all delight in savoring when taking a delicious mouthful.
Any particular food component such as a fruit, vegetable or spice may contain hundreds of different chemical compounds. The food we eat can be contaminated by many different natural toxic chemicals, artificial chemicals, and disease-causing organisms. These are the sources of most of the risks we face when we eat food.
It is important to keep a sense of proportion when thinking about the safety of genetically modified food, because wasting our attention on risks that are minuscule will distract us from the important job of keeping our communities free from the most likely sources of food-based harm globally, such as these:
- Disease-causing microbes
- Dietary shortages of vitamins and minerals such as iron
- A lack of access to food, leading to starvation and malnutrition
Scientists are using genetic manipulation of crops in an attempt to prevent much of this harm.
Food scientists have given, and continue to give on a daily basis, lots of attention to managing food hazards. There is a considerable body of expert knowledge about food risks (e.g, Adams and Moss 2008, Kotsonis and Burdock 2008, Murano 2003, Omaye 2004 ). A top priority is to make sure the public is protected from infectious agents such as food-borne viruses and bacteria that, taken together, are the No. 1 source of food-borne illness. Experts believe that food-borne illness may make more than one billion people ill every year, and causes the deaths of millions.
Because large numbers of people can be affected by illness – such as diarrhea, which can spread widely in the commercial food chain – attention to ensuring the absence of pathogenic bacteria such as E. coli 0157 and Salmonella in commercially produced produce is one of the more important food-safety priorities. Unfortunately, there have been large outbreaks of food-borne disease caused by hamburger patties, spinach, peanuts and tomatoes contaminated with disease-causing bacteria in recent years, and tragically, too many deaths caused by inattention to food microbe-related safety.
Contamination of fish and meat with parasites, or grains with mold toxins, are also significant food health hazards. A large portion of the liver, kidney and esophageal cancer in the world, as well as many birth defects and organ failures, can be traced directly to natural toxicants in our foods. These are produced by molds that grow naturally on our food if we do not prevent them from doing so. It has been concluded that the impact of naturally occurring mycotoxins (mold toxins) has been greatly underestimated and that these compounds may be adversely affecting large numbers of people each year (Wild and Gong 2010).
The safety of chemicals present naturally in foods or applied as additives is also a complicated and challenging issue. This is because the average diet contains literally hundreds of thousands of different types of chemical substances. Some of these natural plant chemicals are toxic because they are natural pesticides that are produced by plants themselves to protect them against insects and other animals that want to eat them.
Millions of years ago, plants began to compensate for their inability to flee from predators (in this case, herbivores) by adapting to contain compounds that would discourage them from being eaten. This is probably why many vegetables and fruits such as cassava, bitter almonds, cherry and apple contain the deadly poison cyanide. Many members of the pea family of plants contain other toxic chemicals. One of them, grass pea (Lathrus sativus) is an important food source in India and Ethiopia, but consumption of this food for long periods gives rise to the dreadful nerve and muscle disease known as lathyrism. Interestingly, human’s aversion to bitter tastes also probably evolved as a defense mechanism since the bitter components of food are very often toxic.
Because of these basic realities of food complexity and the natural presence of potential hazards, assurance of food safety is not a black-and-white issue. It is complicated still further by the fact that one organisms’ poison (like theobromine to dogs) can be another’s delight (put another way, chocolate). It is not possible to give absolute assurance of safe food and to guarantee absence of any chemicals that are potentially able to cause harm. It is important to remember that any chemical can cause harm if it is present in excessive quantities; even relatively harmless chemicals such as water, table salt, or baking soda, if taken excessively, can cause death.
As the ancient poison expert (and the father of the science of poisons, toxicology), Paracelsus (1493 to 1541) said: “What is there that is not a poison? All things are poison and nothing without poison. Solely the dose determines that a thing is not a poison.” This applies directly to the chemicals found in foods. The dose makes the poison, and our daily diet contains many poisons naturally present in doses that are usually below the level that causes harm.
This background level of chemical exposure is unavoidable. For example, 99 percent of all the pesticides in our diets are natural chemicals produced by plants, and 99 percent of the carcinogens in our diets are also chemicals found naturally in foods.
Microbiologists know that foods can harbor food pathogens. The harvesting of food from soil or from the sea is subject to the uncertainties of natural events that make attaining absolute safety impossible—put another way, when it comes to food, there is no such thing as zero risk.
Regulatory agencies such as the U.S. Food and Drug Administration (FDA), the European Food Safety Authority (EFSA), and Food Standards Australia and New Zealand (FSANZ) provide systems and laws that are able to keep these infectious-disease problems under control if food-safety systems are properly followed by food companies, food retail outlets, and families. Food safety depends upon implementing a proactive risk-management plan, using good manufacturing practices and standards, and in many cases, working out that the food is safe by balancing a lot of different sources of evidence.
If food safety required elimination of every compound that might, under some circumstances, cause harm, virtually no food would be declared fit for consumption. In practice then, food safety is a balancing act of making sure that new foods are at least as safe as what we eat already—without requiring guarantees of absolute safety in all circumstances. This is the approach scientists use when determining the safety of our food supply. It is also the approach food scientists and safety specialists use when determining the safety of genetically modified foods: Are they at least as safe as what we already eat?
Applying these standards, the record shows that crops and foods produced through biotechnology have been scrutinized for safety – in advance, in depth and in detail – more than any other foods in human history. Their remarkable record of safety reflects the conclusion of expert bodies around the world that have considered this issue and found, as the European Commission did, that:
Indeed, the use of more precise technology and greater regulatory scrutiny probably make them even safer than conventional plants and foods; and if there are unforeseen environmental effects – none have appeared as yet – these should be rapidly detected by our monitoring requirements. On the other hand, the benefits of these plants and products for human health and the environment become increasingly clear.
Adams MR and Moss MO (2008) Food Microbiology 3rd Ed. RSC Publishing UK. An excellent overview of food microbes and food borne infectious diseases.
Kotsonis FN and Burdock GA (2008) Food toxicology, Chapter 30 in Casarett & Doull’s Toxicology. Ed. CD Klaassen, McGraw Hill Medical, USA. An advanced, authoritative and concise review of current knowledge on food toxicity. This chapter provides good access to the scientific research literature.
Murano PS (2003) Understanding Food Science and Technology, Thomson. A college level general course on food technology with chapters devoted to food safety issues.
Omaye ST (2004) Food and Nutritional Toxicology CRC Press. A readable but comprehensive coverage at advanced college level of the diverse chemicals present in food that may cause harm. Omaye’s book explains the major concepts needed to understand food borne intoxification, safety management, and government regulation.
Wild CP Gong YY (2010) Mycotoxins and human disease: a largely ignored global health issue. Carcinogenesis vol.31 no.1 pp.71–82, 2010; doi:10.1093/carcin/bgp264; Advance Access publication October 29, 2009.
Filed Under: News