Food, Sex and Salmonella. David Waltner-Toews

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СКАЧАТЬ against them. The next time you eat shrimp, your body, thinking that a pre-emptive attack is called for, attacks the shrimp molecules even before they get down the gullet. Each time you are exposed, the reaction is stronger, as if your body has been stockpiling nuclear weapons in the interim. Before you know it, you are gasping for breath or dead.

      In the early 1990s, I had a buffet meal with my family at a great local restaurant in St. Jacob’s, Ontario. For dessert, I chose a piece of custard pie. Within minutes, I was kneeling before the butt-throne and throwing up. When I told the sweet girl behind the counter that the pie was bad, she was flustered and offered me another piece. “No,” I told her. “It is really bad. It will give lots of people food poisoning. Probably Staphylococcus aureus.” She probably thought I was swearing and suggested that I wouldn’t have to pay for the pie.

      In the end, the restaurant gave me a free meal, but it was what came afterward that changed my life. The gut damage had allowed some larger molecules of egg to breach the intestinal walls and challenge my body’s immune system to a lifelong fight. I have always loved making and eating foods with eggs in them: Spanish omelettes, huevos rancheros, chocolate cakes, soft-boiled eggs with a bit of butter and salt, waffles, crepes and pancakes, banana cream pie, chocolate cream pie, cheesecakes of all sorts, paska (traditional Mennonite Easter bread) with fresh orange frosting—the list is almost endless. At first, when I got queasy after eating eggs, I didn’t think much of it. Then it was cakes.

      One time my wife, Kathy, and I came home from the market with a piece of Greek layer cake. “This cake is bad,” I said, running for the bathroom.

      “It is?” said Kathy, reaching for a second piece.

      Then I had scones at a restaurant that said they didn’t have eggs in them. I cured that by emptying my stomach into the plumbing system and making myself some chicken noodle soup. That was when I discovered that the noodles in chicken noodle soup have eggs in them. The last two times I reacted was when someone at Tim Horton’s assured me that their bread had no eggs in it and I just about died in the parking lot as my lungs filled with water, and on a trail in Bruce County, after having some homemade chocolate from a local store. From the Tim Horton’s episode, I learned that baking prepared in a donut-making factory probably has some egg in it. From the chocolate episode, I discovered that lecithin, an emulsifier used in some chocolates, may be from vegetable (usually soy) or other (sometimes egg) sources.

      I now carry an EpiPen (injectable adrenaline) and have to go through long explanations in airports to people who understand as much about foodborne diseases and allergies as the girl behind the restaurant counter did. I also carry antihistamines, which, if I use them as soon as I suspect there might be a problem, can head off the worst effects. Once, in Addis Ababa, I was worried about the ingredients of the food I had eaten, so I took some of the bright pink Benadryl pills I had in my pocket. I had a rough-and-tumble stomach all night. The next morning, I discovered that the pink pills I had swallowed were not antihistamines but a cathartic (an antidote to constipation). I guessed that there had been no eggs in what I had eaten, or I would not have survived the night.

      I could likely sue the restaurant owner, but he’s an acquaintance, so I haven’t even told him. Which is probably irresponsible of me. Instead, I have my students prepare public dissemination projects and hammer into them the public part of public health. And I write books like this one.

      At least one kind of food intoxication mimics an allergic reaction. Sometimes, in scombroid fish such as tuna and in some cheeses, bacteria may partly digest the food (some might call it spoilage, but I am trying not to be judgmental). When eaten in large amounts, such spoiled foods cause symptoms that may be confused with those of true allergies: a burning in the mouth and throat, flushing, and dizziness.

      In early March of 1981, a young, organized British Columbia woman bought two cases of canned tuna. She opened a can from the first case and ate the contents, despite their strange, bitter taste, on March 15. About half an hour later, she felt nauseated, her throat was swelling, and she felt hot; she also developed what appeared to be a rash on her chest and back. On March 22, probably thinking about fiscal responsibility and the large investment she had just made in tuna, she tried again, with the same results. Almost exactly nine years later, three people in downtown Toronto tried out a local luncheon special of mahimahi fish. Within the next hour, all three felt as if they had a sudden sunburn. Peppery taste, headache, dizziness, diarrhea, and flushing are recognized symptoms of food allergies.

      At one time, scombroid fish poisoning was thought to be a kind of allergy. Now we know that it is neither an allergy nor restricted to scombroid fish such as tuna, mackerel, and other dark-fleshed fish, like mahimahi. Scombroid “fish” poisoning has also been reported from eating Swiss cheese. Some bacteria will digest foods containing the amino acid histidine, such as fish that have not been cleaned and chilled quickly enough. The product of the bacteria’s labor is histamine, the same compound made by our own bodies during an allergic reaction—hence the similarities in clinical picture. The big difference, however, is that our bodies learn from a food allergy. One encounter, however benign, enhances the seriousness of the next. Scombroid toxicity is more like a predictable aunt, with unchanged irritability from visit to visit.

      In both neurological and allergic-type reactions, ordinary citizens might ascribe their state to a stimulating dinner companion, were it not followed so inconveniently by more serious gastrointestinal or neurological complications.

      Foodborne illnesses may also result from food intolerances, in which case your body does not have the enzymes necessary to digest certain parts of certain foods. Milk intolerance is a common problem among some ethnic groups, which results in frothy diarrhea and cramps. Many of us can recall stories of poor villagers in some developing country using powdered milk to whitewash their houses. One might view this use as a form of ingratitude in the face of our obvious generosity, but such generosity is not much different from their sending us skewered cockroaches to solve our food problems. Another food intolerance, this one found in many people of Mediterranean origin, is called favism. These people can develop an acute hemolytic anemia if they eat fava beans.

      The large intestine is mostly a place where fluids and electrolytes get sucked back into your body. Being less acidic than other parts of your gut, the large intestine is generally hospitable to bacteria, many of which normally make their home there and don’t cause illness. In fact, one might suggest that the only ecological and evolutionary justification for the human race is to serve as a living area for large numbers of anaerobic (air-intolerant) bacteria. This perception is not as heady as thinking of ourselves as the brains of evolution, but in ecologically recessionary times, when millions of species are going extinct for lack of a working niche, it is at least a job. The total number of bacteria excreted by an adult each day ranges from a hundred billion to a hundred trillion.

      If pathogenic agents do manage to get a foothold in these nether regions, we feel lower abdominal cramps and can develop bloody diarrhea. Red blood in the feces is a sign that the destruction must be quite low down, because blood entering the intestines higher up turns black through partial digestion.

      Finally, high-fiber foods such as bran will draw water into the large intestine and smuggle it away to the great outdoors in what is called an osmotic diarrhea.

      The foregoing are the acute effects of foodborne diseases. These diseases may also have long-term effects, sometimes called sequelae. Reactive arthritis develops in more than 6 percent of people who get salmonellosis and in probably 1 percent of those with Campylobacter infection. Campylobacter infections can be followed by Guillain-Barré syndrome, in which people develop burning sensations and paralysis; 15 percent of them die. There is also some evidence that foodborne infections may contribute to plaques in blood vessels and hence to cardiovascular disease. Diseases caused by E. coli O157:H7 (so-called hamburger disease) can lead to chronic kidney failure or chronic bowel diseases. Some kinds of fish and shellfish СКАЧАТЬ