Pregnant? Guess what — everyone is about to tell you what you can and can't eat. And, let's face it, it's mostly gonna be what you can't eat. Alcohol, sushi, cold cuts, and cantaloupe all get the boot for the sake of that fetus. And then it really starts hurting when you get to that one little word: cheese.
Cheese? Really? What's so bad about pregnancy and cheese? Do you actually have to avoid all cheese, as some extremely cautious friends have been known to do? Or is some of the cheese avoidance an unnecessary precaution? Let's bust the myths and see what's true — for you or that pregnant friend craving a slice of Havarti right now.
Why Is Cheese a (Potential) Pregnancy Problem?
But first: Why is our beloved cheese even a problem at all? Like many of the other foods on the watch-out list for pregnant women, cheese has been linked to outbreaks of Listeria monocytogenes, a foodborne pathogen that causes an illness that can, at its worst, cause miscarriage, stillbirth, or death of a newborn.
And unlike most food hazards, which are just as problematic if you're pregnant or not (E. coli is an equal-opportunity hazard), pregnant women are actually more susceptible to listeria. "Listeria is one of the few foodborne illnesses that can harm both the pregnant woman and baby," says Dr. Tamika August, a Washington, DC-based OB/GYN. "It's the most common of the rare diseases, but one that can cause the most serious damage."
For that reason, avoiding cheese is on her short list of tips for her patients. Even so, there's some misinformation out there. Here are five common beliefs — and the real story — about pregnancy and cheese.
1. All pasteurized cheeses are safe. (Not true!)
The first question to ask before you decide if you can eat a particular cheese is: Is it pasteurized? Pasteurization is the process of heating the milk used to make cheese at a high temperature long enough to kill pathogens, listeria among them. Federal regulations specify that some cheese sold in the U.S. — like mozzarella and cottage cheese — can only be made with pasteurized milk, while other varieties do not necessarily have to be made with pasteurized milk.
That being said, it's not the only question to ask. "Pasteurization does not protect against post-pasteurization contamination of milk or cheese," says Dr. Dennis D'Amico, a professor in the Department of Animal Science at University of Connecticut. While all cheeses, whether domestic or imported, sold in the United States must meet FDA safety standards, contamination can happen in the processing environment.
At that point, the risk is correlated to the kinds of cheese: High-moisture, low-acidity, and low-salt cheese (like brie or camembert) are more hospitable to bacteria than their low-moisture, higher-acidity, higher-salt counterparts. "I generally tell my patients to stay away from the fancy cheeses," says Dr. August.
2. You might accidentally buy unpasteurized cheese. (Not exactly true!)
While many grocery stores carry both pasteurized and unpasteurized cheese, federal regulations require cheesemakers to clearly label the ingredients in their cheese, including specifying whether the milk they used is pasteurized or unpasteurized. Also, check the age of the cheese: If a cheese is less than 60 days old, it must be made with pasteurized milk. Older cheeses can be made with pasteurized or unpasteurized milk (the aging allows for enough time for any potentially harmful bacteria to be killed).
"It is important to remember that all cheese sold at the grocery store, pasteurized and unpasteurized, should meet FDA food safety requirements and guidelines, whether imported or produced domestically. These cheeses can be produced by producers large or small, local or from far away," says Dr. D'Amico.
A caveat: That being said, the rules for intrastate sales like those at farmers markets can differ by state and or even by town. It is possible that cheeses sold at these markets were produced without the benefit of FDA oversight and interstate regulations — so it's best to avoid them, for now.
3. You'll know right away if the cheese is bad. (Not true!)
Unfortunately, cheeses contaminated with pathogens, especially Listeria monocytogenes, do not show signs of spoilage. Listeria symptoms are similar to flu symptoms: nausea, vomiting, fever, muscle aches, and the like. But symptoms of listeriosis don't show up immediately; in fact, it can take from two to 60 days after exposure for these symptoms to show up.
If you have these symptoms, contact your healthcare provider right away; they can give you a blood test to determine if you're suffering from listeriosis or another less-worrisome ailment.
4. Mexican-style cheeses such as queso fresco are especially dangerous. (True!)
The CDC has found that Hispanic women are 24 times more likely than the general population to get a listeria infection. For that reason, they recommend avoiding Mexican-style cheeses like queso fresco, queso blanco, queso blando, queso cotija, queso panela, queso ranchero, and cuajada en terrón.
"The main issue related to some Mexican-style cheeses like queso fresco is that this style of cheese is typically high in moisture, low in acidity, and can be low in salt. These conditions are comparatively more hospitable to microbial growth if contamination does occur," says Dr. D'Amico.
5. All cheese is out. (Not true!)
Cheese safety is more linked to the style of cheese as opposed to the type of milk used. "All else being equal, harder cheeses are less supportive of pathogen growth and survival," says Dr. D'Amico. In general, hard or firm cheeses made with pasteurized milk are less likely to allow for the growth of unwanted bacteria.
So if you can't imagine all those months without cheese, look for cheeses like Swiss, Gouda, Parmesan, and provolone made with pasteurized milk.