Saturday night I went out to dinner with two friends, one who does not have children and one whose daughter just celebrated her first birthday. The former suggested that I might want to order a certain salad, but the new mother said, “No, she can’t have feta! You can’t eat soft cheese when you’re pregnant.” Sheepishly I thought of the occasional salads with pasteurized feta I had been enjoying at home and asked, “Isn’t it okay if it’s pasteurized?” Granting that her doctor is very conservative, she said she had been told to avoid soft cheeses like feta altogether. The week before at a dinner party, another friend (who is a little farther along in her pregnancy than I am) had mentioned her doctor’s opinion that anything pasteurized was safe.
Understanding what is and is not likely to give me listeriosis has been vexing. There’s a lot of conflicting information out there because there aren’t "safe foods" and "unsafe foods"—just relative levels of risk. My two biggest questions have been, "Can I eat pasteurized soft cheeses? And can I eat raw milk cheeses if they are hard and aged, like Parmigiano Reggiano and Gruyère?" I think I’ve finally worked it out, at least well enough for myself.
Listeriosis is an infection caused by bacteria called listeria, which are all around us but don’t cause any trouble unless they make it into our food supply. Even then, most healthy adults can fend off infection without even noticing; it is elderly people, pregnant women, and people with compromised immune systems who are at risk. A pregnant woman herself is unlikely to be seriously harmed by listeriosis, but it could do devastating harm to her fetus, leading to miscarriage or stillbirth.
How to Prevent Listeriosis
The Centers for Disease Control estimates that every year 2500 Americans are seriously sickened by listeria infection; 500 die. Pregnant women are twenty times as likely to contract listeriosis as other healthy adults. How can they (and other at-risk populations) avoid it? According to the CDC, everyone should cook meat and poultry thoroughly, wash fruits and vegetables well, keep a very clean kitchen, eat perishable foods as soon as possible, and avoid raw milk and foods made with raw milk. The CDC’s recommendations for people at risk (emphasis mine) are:
- Do not eat hot dogs, luncheon meats, or deli meats, unless they are reheated until steaming hot.
- Avoid getting fluid from hot dog packages on other foods, utensils, and food preparation surfaces, and wash hands after handling hot dogs, luncheon meats, and deli meats.
- Do not eat soft cheeses such as feta, Brie, and Camembert, blue-veined cheeses, or Mexican-style cheeses such as queso blanco, queso fresco, and Panela, unless they have labels that clearly state they are made from pasteurized milk.
- Do not eat refrigerated pâtés or meat spreads. Canned or shelf-stable pâtés and meat spreads may be eaten.
- Do not eat refrigerated smoked seafood, unless it is contained in a cooked dish, such as a casserole. Refrigerated smoked seafood, such as salmon, trout, whitefish, cod, tuna or mackerel, is most often labeled as "nova-style," "lox," "kippered," "smoked," or "jerky." The fish is found in the refrigerator section or sold at deli counters of grocery stores and delicatessens. Canned or shelf-stable smoked seafood may be eaten.
So, you see, the CDC says pasteurized soft cheese is okay. I should be able to enjoy my pasteurized feta in peace, right?
Unfortunately, a product’s having been pasteurized is not an absolute guarantee against listeria contamination (just as there is no guarantee that a raw milk product will make you sick). Since listeria bacteria are everywhere, they do sometimes end up in food between pasteurization and packaging. (In fact, contaminated pasteurized milk killed three older men and caused one miscarriage in Massachusetts just last December. The bottling plant had previously received high marks for compliance with food safety guidelines. You can read about this incident and other listeria outbreaks and product recalls at Listeria Blog, which, please keep in mind, seems to be maintained by a trial lawyer.) It doesn’t happen often—if my research is correct, there have been only three outbreaks of listeria in pasteurized milk in the past twenty-five years, in 1983, 1994, and now in 2007—but it does happen.
Don't Fear Your Food
Instead of living in fear of milk and hot dogs, you should follow best-practice guidelines for cleanliness, storage, and cooking; discard any food that has been hanging out in the refrigerator for a few days and now seems iffy; and, perhaps most importantly, only buy food from stores and people you trust. Yes, it is common for pregnant women in Europe to continue to eat raw milk cheeses. They are probably closer to and more knowledgeable about the sources of their cheese than are many (but not all) of us here in the United States. If I were willing to put in the time to find a source of feta, pasteurized or not, that I felt good about, I would go for it; but it isn’t my top gastronomic priority, frankly, so I think I’ll just skip the pasteurized supermarket feta I’m used to and try some different hard cheeses in my salads instead. Though it isn’t at all likely that my old feta would make me sick, I’m not devoted enough to it to take even a small risk, and the prospect of trying new cheeses is always fun, anyway.
As for hard raw-milk cheeses like Parmigiano and Gruyère, they are less likely to give me listeriosis than fruits and vegetables, if I am reading this chart from the FDA correctly, as long as I don’t eat massive quantities on a regular basis (which I can’t afford to do anyway, so there’s one problem solved). And if I haven’t given much attention to deli meats and hot dogs here, it’s because I almost never eat them—maybe once a year. But now that I know that I can’t eat a hot dog unless I carefully prepare it myself, I’m filled with longing every time I pass Gray’s Papaya. Go figure.
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