INTERNATIONAL FOOD SAFETY CONSULTANCY
DR WILLEM MARSMAN
Mad Cow Disease is the layperson’s name for Bovine Spongiform Encephalopathy (BSE), a transmissible,
Slowly progressive, degenerative, fatal disease affecting the central nervous system of adult cattle. There is no evidence to date of BSE affecting American cattle.
BSE is a disease that affects cattle. However, there is a disease similar to BSE called variant Creutzfeldt-Jakob Disease (CJD), or bCJD, which is found in humans. There have been a small number of cases of vCJD reported, primarily in the United Kingdom, occurring in people who consumed beef contaminated with an infective agent. (As of February 2001, there have been a total of 92 cases of vCJD worldwide – including 88 in the U.K., three in France and one in Ireland). There is strong scientific evidence (epidemiological and laboratory) that the agent that causes BSE in cattle is the agent that causes vCJD in people. There are no reported cases of vCJD in the United States.
The disease, vCJD, which primarily affects younger persons, is very hard to diagnose until the disease has nearly run its course. In its early stages, the disease may manifest itself through neurologic symptoms but it is not until the latter stages of the disease that brain abnormalities detectable by xray or MRI can be seen.
The disease, vCJD, has been associated with the consumption of foods produced from BSE infected animals. Because BSE has never been found in the U.S., it is unlikely that food purchased in the US such as at a grocery store or restaurant would be contaminated. The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service has restricted the importation of live ruminants, such as cows and sheep, and food products from these animals from BSE countries since 1989, and from all European countries since 1997. Thus it is highly unlikely that a person would contract vCJD today by eating food purchased in the United States. It is important for consumers to know that:
No meat products from the 31 countries identified as having BSE or at risk for having BSE are allowed in the U.S. This includes meat products used in human, animal and pet foods. Milk and milk products continue to be imported into the US from these countries because milk and milk products are not believed to pose any risk for transmitting BSE to humans. Experiments have shown that milk from BSE infected cows has not caused infections in the same species or in other test animals.
FDA requires that gelatin-containing products such as candy or capsules imported from the 31 countries identified as having BSE or at risk for having BSE be manufactured under specific guidance and certified as such to ensure they are safe for American consumers. FDA guidelines require gelatin to be made from non-BSE herds and use only specific parts of BSE-free animals in the rendering process.
Dietary supplements and certain cosmetic ingredients containing bovine materials from animals originating in the 31 countries where BSE has been found or is at risk for being found, are excluded from the US.
With heightened concern about vCJD in Europe, the Centres for Disease Control and prevention have enhanced their vCJD surveillance in the U.S. To date, there have been no cases of vCJD identified in the United States.
In the United Kingdom, the current risk appears to be extremely small, perhaps about 1 case per 10 billion servings of beef. In the other countries of Europe, the current risk, if it exists at all, would not likely be any higher than that in the United Kingdom, except possibly in Portugal. In the 12-month period ending June 15, 2000, Portugal had about half the reported incidence of BSE cases per 1 million adult cattle as that reported in the United Kingdom; however, Portugal has only recently implemented BSE-related public health control measures.
According to the Centres for Disease Control and Prevention, the current risk of acquiring vCJD from any specific country cannot be precisely determined because cattle products from one country might be distributed and consumed in others.
For travellers concerned about reducing their possible risk of acquiring vCJD from food, CDC suggests:
Milk and milk products from cows are not believed to pose any risk for transmitting the BSE agent because experiments have shown that milk from BSE-infected cows has not caused BSE in cows or other test animals.
BSE has been of great concern since 1986, when it was first reported among cattle in the United Kingdom. At is peak, in January 1993, almost 1,000 new cases per week were identified. The outbreak in the United Kingdom may have started from the feeding of scrapie-contaminated sheep meat-and-bone meal to cattle. Scrapie is a disease of sheep that is related to BSE in cattle. There is strong evidence that the outbreak in cattle was amplified in the United Kingdom by feeding rendered bovine meat-and-bone meal to young calves.
The nature of the transmissible agent in BSE is not known. Currently, the most accepted theory is that the agent is a modified from of a normal cell surface component know as a prion protein, which is a pathogenic form of the protein. Why or how this substance changes to become disease-producing is still unknown. Prions are resistant to common treatments, such as heat, to reduce or eliminate its infectivity or presence.
These countries are: Albania, Austria, Belgium, Bosnia-Herzegovina, Bulgaria, Croatia, Czech Republic, Denmark, Federal Republic of Yugoslavia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Liechtenstein, Luxembourg, Former Yugoslavia Republic of Macedonia, The Netherlands, Norway, Oman, Poland, Portugal, Romania, Slovak Republic, Slovenia, Spain, Sweden, Switzerland and United Kingdom (Great Britain including Northern Ireland and the Falkland Islands).
There are no known cases of the BSE in the United States due to the active surveillance and import measures taken by the Food and Drug Administration and the U.S. Department of Agriculture over the past ten years. These and other federal and state agencies and industry groups have taken a series of actions to prevent the introduction of BSE into the US food supply.
For example, to prevent BSE from entering the United States, firm restrictions were placed on the importation of live ruminants and ruminant products including meat, meat-and-bone meal, offals, glands etc., from countries where BSE was known to exist. These restrictions were later extended to include importation of ruminants and certain ruminant products not only from BSE-positive countries but also countries thought to be at high risk for BSE, even if the disease hadn’t been identified in those countries.
In addition, FDA prohibits the use of most mammalian protein in the manufacture of animal fees given to ruminants because this kind of feeding practice is believed to have initiated and amplified the outbreak of BSE in the United Kingdom.
BSE is a disease of cattle. However, a related disease, Chronic Wasting Disease (CWD), does occur in a small number of American elk and deer in certain parts of the country, particularly Colorado and Wyoming. FDA is working closely with other government agencies and the public health community to address CWD in wild and domesticated herds. Wildlife officials in Colorado and Wyoming have advised individuals not to harvest, handle, or consumer any wild deer or elk, especially in those states, that appear to be sick, regardless of the cause.
We get all kinds of messages about food and food safety everyday. Sometimes the messages are warnings. Sometimes they conflict with the information in a previous report. You might feel confused. Following are a few hints to help you sort through the message maze.
Where does the message come from? Is the source reliable? Be sceptical of sources that have something personal to gain by convincing you to believe the information. Reliable sources use scientific expertise to back up their claims. Often reliable resources, like the FDA, have authority. Information from reliable sources is usually backed up quickly by other reliable sources.
Who is affected by the problem or information? Are only people of a certain age, such as newborn babies, affected? What about the amount consumed? Are you likely to consume close to that amount? Certain potent substances – like pesticides – can be used to help produce foods without harming consumers as long as dangerous amounts of the chemicals don’t remain on the food. The FDA helps make sure safe limits are maintained. Is the problem confined to a certain area of the country? Is it possible that you have food shipped from that area? Is there a problem with only a specific batch of a product? If so, you need to throw out or return only those items with the affected lot number.
Most research questions take years to investigate. Before something is taken as fact, the results of an investigation must be repeated by others. Science controversies do exist. Different scientists interpret data differently. Food safety messages based on research can change as scientists discover new information. Researchers draw broad conclusions from studies of large groups of people. Their conclusions about the risk of eating or not eating something are guidelines to individuals, not guarantees.
Here are some tips:
Be wary if immediate, effortless or guaranteed results are promised.
Look for telltale words and phrases such as “breakthrough,” “miracle,” “secret remedy,” “exclusive,” and “clinical studies prove that…..”
Beware of promotions for a single product claim to be effective for a wide variety of ailments.
Don’t forget that, unlike scientists and health professionals, quacks do not subject their products to the scrutiny of scientific research. The quack simply thrusts a product onto the market in order to get your money.
Be cautious of money-back guarantees, for a guarantee is only as good as the company that backs it.
If it sounds too good to be true – it probably is.
Washing fresh produce before eating is a healthful habit. You can reduce and often eliminate residues if they are present on fresh fruit and vegetables by following these simple tips:
Wash produce with large amounts of cold or warm tap water, and scrub with a brush when appropriate; do not use soap.
Throw away the outer leaves of leafy vegetables such as lettuce and cabbage.
Trim the fat from meat, and fat and skin from poultry and fish. Residues of some pesticides concentrate in animal fat.
Supermarkets, as a rule, don’t wash produce before putting it out, but many stores mist it while its on display. Misting keeps the produce from drying, but surface residues drain off also, in much the same way as from a light wash under the kitchen faucet.
A 1990 report in the EPA Journal by three chemists from the agency, Joel Garbus, Susan Hummel, and Stephanie Willet, summarised four studies of fresh tomatoes treated with a fungicide, which were tested at harvest, at the packing house, and at point of sale to the consumer. The studies showed that more than 99 percent of the residues were washed off at the packing house by the food processor.
A 1989 study reported by Edgar Elkins in the Journal of the Association of Official Analytical Chemists showed the effects of peeling, blanching and processing on a number of fruits and vegetables. For example, in the case of benomyl, 83 percent of the residues found on fresh apples were removed during processing into applesauce, 98 percent of residues from oranges processed to juice were removed, and 86 percent of residues from fresh tomatoes processed to juice were removed. Another study in 1991 by Gary Eilrich, reported in an American Chemical Society Symposium, showed similar results.
The Food Allergy Network’s Anne Munoz-Furlong suggests keeping a food diary as a first step, writing down everything you eat or drink for a one or two week period. Note any symptoms and how long it took for such symptoms to develop.
But Furlong and other experts agree that those who suspect food allergies also need to be evaluated by a physician with intensive specialty training in allergy and immunology. Be use to discuss what diagnostic and treatment plan is anticipated, and the costs.
Ask if the tests have been proven effective by accepted standards of scientific evaluation.
“Go to a board-certified physician who is an allergy expert,” advise Paul C. Turkeltaub, M.D., associate director of the division of allergenic products and parasitology at FDA’s Centre for Biologics Evaluation and Research. “Be very wary of claims of food allergy to explain chronic, common complaints.”
The diagnosis of food allergy requires a careful history, physical exam, appropriate exclusion diet, and diagnostic test to rule out other conditions. Tests can include direct allergy skin tests, blood tests, or “elimination and challenge” tests for suspected foods.
The most accurate kind of test is a controlled challenge test, often done in “blind” or “double-blind” fashion to eliminate psychological factors. In a blind challenge, the patient is given either a sample of the food, without being told what it is, or a placebo, an inert substance used as a control in the test. The observer, ( a doctor or assistant), however, knows what the substance is. Both patient and observer record any symptoms of allergic reaction. In a double-blind challenge, neither the patient nor the observer knows if the patient is given the food (allergen) or the placebo.
In recent years, unproven tests such as “food cytotoxic blood tests” and “sublingual provocation food testing” have been promoted as supposed “diagnostic” tools to detect food allergies. FDA believes that food cytotoxic blood tests are not supported by well-controlled studies and clinical trials.
In food cytotoxic testing, a test tube of blood is taken from the patient. The white cells (leukocytes) are mixed with plasma and sterile water and placed on microscope slides coated with dried extracts of a particular food. The reaction of the cells is then examined under a microscope; if they change shape, disintegrate, or collapse – or the person examining them says they do – the patient is supposedly allergic to that particular food. Test results may be interpreted by a “nutritional counsellor” working on commission, who recommends vitamins and minerals (often available on site) that the patient needs to corrects his or his “allergic condition”. But FDA and other experts emphasise there is no evidence that such tests are valid in diagnosing food allergies.
Sublingual provocation food testing dates back to 1944. The test consists of placing three drops of an allergenic extract under a patient’s tongue and waiting 10 minutes for any symptoms to appear. When the doctor is satisfied he has determined the cause of the symptoms, he administers a “neutralising” dose, which is usually three drops of a diluted solution of the same allergenic extract. The symptoms are then expected to disappear in the same sequence in which they appeared. Advocated claim that if the neutralising dose is given before a challenge test (for instance, eating a meal contained the offending food), the person will not have symptoms.
But after careful study of existing data, The American Academy of Allergy and Immunology says no controlled clinical studies demonstrate either diagnostic or therapeutic effects of sublingual provocation food testing. The academy concludes that use of the tests should be reserved for experiments in well-designed trials.
If you are diagnosed with a food allergy, scrutinize food labels to detect potential sources food allergens. When eating out, ask about ingredients if you are unsure about a particular food; ask to talk to the manager of the restaurant about ingredients in specific dishes.
Keep epinephrine with you and know how to administer it. If you do experience a reaction, seek medical attention immediately, even if the symptoms are mild or seem to subside. Mild symptoms may be followed 10 to 60 minutes later by the onset of severe problems.
To answer the numerous questions regarding bio-engineered foods received from the industry and the public, the FDA issued comprehensive guidelines in 1992 to cover traditional and bio-engineered fruits, vegetables, and grains. This guidance establishes a standard of care under the Federal Food, Drug and Cosmetic Act to assist developers in evaluating the safety of new substances in food (e.g. proteins), the nutritional content, the levels of native plants toxins, and the potential for allergenicity. FDA requires that bio-engineered foods be as safe as other foods.
Allergenicity is an important consideration for bio-engineered foods because there is some possibility that a new protein in a food could be an allergen. Developers must evaluate this possibility. This is especially true for genes derived from foods that commonly cause food allergy because they contain allergens. These foods include milk, eggs, fish, crustacea, molluscs, tree nuts, wheat and legumes (particularly peanuts and soybeans). These foods account for ninety percent of food-allergic reactions.
Scientists report that only a fraction of the thousands of proteins in the diet have been found to be food allergens. Therefore, it is unlikely that most proteins introduced into food through bio-engineering will be allergens. Additionally, scientists can determine whether a transferred protein has characteristics of known food allergens. To date, all new proteins in the bio-engineered foods that will be sold in grocery stores have been shown to lack the characteristics of food allergens.
To alert sensitive customers, FDA will require labelling for a food that contains a new protein with characteristics suggesting that it may be a food allergen. If we find that labelling will not adequately protect consumers, we will take steps to prevent marketing of the product.
We are following advances in bio-engineering, and developers are working with FDA to ensure that safety questions are resolved. We are confident that the bio-engineered foods that are currently approaching the market do not pose a safety concern for you or your family.
The hazardous substance lead was banned from house pain in 1978. U.S. food canners quit using lead solder in 1991. And a 25 year phaseout of lead in gasoline reached its goal in 1995.
Critical to prevention is focusing on the important lead sources. Dealing with sources of lead means recognizing them in your family’s environment, knowing which ones contribute significant exposures, and eliminating or avoiding those exposures.
The greatest source of lead poisoning in young children is deteriorating lead paint in older housing. But lead poisoning is preventable. If your house was built before 1978, follow this advice from the National Lead Information Centre.
Wash floor, windowsills, and other surfaces weekly with warm water and detergent.
Wipe soil off shoes before entering the house. Cover soil with grass, mulch or other barrier.
Immediately clean up paint chips.
Ask your doctor or health department whether your children should be tested for lead, even if they seem healthy.
If you suspect your water pipes are leaching lead, use cold water for drinking and cooking, running it 30 seconds before use. Ask your state health agency about testing your drinking water for lead.
Remove lead foil capsules from wine bottles before pouring. Before removing the cork, wipe the bottle neck and rim and the cork top with a clean cloth.
Never use ceramicware that gets chalky after washing. Avoid storing acidic foods like juice and vinegar in ceramic holloware. If pregnant, avoid daily use of ceramic mugs for hot beverages like coffee and tea. Stick to commercially made items. If you buy a craft piece, ask if it’s lead-free. If you’re unsure whether a food serving item is made from lead-based materials, you can check with the manufacturer. Test antiques with a kit from a hardware store. And never use items marked “decorative” for food.
If your occupation exposes you to air-borne lead, change clothes and wash before coming home.
In homes with young children, make sure cartons of imported vinyl mini-blinds have terms like “non-leaded formula” or “no lead added”. Discard blinds you’re unsure of. Blinds with lead may form lead dust as they deteriorate.
Children and pregnant women should avoid frequent use of crystal glassware.
Never feed babies from crystal baby bottles.
Keep all hair dyes, especially those with lead acetate, away from children.
Never expose children to the Middle East eye cosmetic dyes kajal, kohl or surma or to the foreign remedies Alarcon, Azarcon, Coral, Creta, Liga, Maria Luisa or Rueda.
Many health experts agree that using a process called irradiation can be an effective way to help reduce food-borne hazards and ensure that harmful organisms are not in the foods we buy. During irradiation, foods are exposed briefly to a radiant energy source as gamma rays or electron beams within a shielded facility. Irradiation is not a substitute for proper food manufacturing and handling procedures. But the process, especially when used to treat meat and poultry products, can kill harmful bacteria, greatly reducing potential hazards.
The Food and Drug Administration has approved irradiation of meat and poultry and allows its use for a variety of other foods, including fresh fruits and vegetables and spices. The agency determined that the process is safe and effective in decreasing or eliminating harmful bacteria. Irradiation also reduces spoilage bacteria, insects and parasites, and in certain fruits and vegetables it inhibits sprouting and delays ripening. For example, irradiated strawberries stay unspoiled up to three weeks, versus three to five days for untreated berries.
Food irradiation is allowed in nearly 40 countries and is endorsed by the World Health Organisation, the American Medical Association and many other organisations.
Irradiation does not make foods radioactive, just as an airport luggage scanner does not make luggage radioactive. Nor does it cause harmful chemical changes. The process may cause a small loss of nutrients but nor more so than with other processing methods such as cooking, canning, or heat pasteurisation. Federal rules require irradiated foods to be labelled as such to distinguish them from non-irradiated foods.