Blue cheese, a soft, mold-ripened cheese, is a source of common concern for people who are pregnant. Its characteristic blue veins and creamy texture require careful consideration during this period. Safety is conditional, depending entirely on the cheese’s production methods and preparation before consumption. Understanding the specific food safety risks helps in making informed dietary choices.
Understanding the Listeria Threat
The main concern with soft cheeses like blue cheese is the potential presence of a bacterium called Listeria monocytogenes. This organism is responsible for listeriosis, a foodborne illness that poses a unique and serious threat during pregnancy. Pregnant people are approximately 10 to 20 times more likely to contract listeriosis than the general population due to changes in the immune system that naturally occur during gestation.
While a listeriosis infection in the pregnant person may manifest as mild, flu-like symptoms such as fever, muscle aches, and headache, the consequences for the fetus can be severe. The bacteria can cross the placenta, potentially leading to grave outcomes for the developing baby. These risks include miscarriage, stillbirth, premature delivery, or severe, life-threatening infections in the newborn. The severe risk of fetal infection is why health authorities recommend strict adherence to food safety guidelines for this vulnerable population.
Pasteurization Determines Safety
The presence of Listeria monocytogenes is not inherent to the mold used in blue cheese production, but rather a risk associated with the environment and the milk used. The high moisture content and lower acidity of soft, mold-ripened cheeses create an ideal environment for the bacteria to survive and multiply, even at refrigeration temperatures. This is why pasteurization is so important for safety.
Pasteurization involves heating milk to a specific high temperature for a set period, a process designed to kill harmful microorganisms, including Listeria. Blue cheese that is explicitly made with pasteurized milk is generally considered safe for consumption. However, even cheeses made with pasteurized milk can become contaminated if they are produced in unsanitary conditions or if the bacteria is introduced after the pasteurization step.
To determine if a blue cheese variety, such as Gorgonzola or Stilton, is safe, it is necessary to check the product label for the word “pasteurized”. If the label indicates the cheese was made with “raw milk” or “unpasteurized milk,” it should be avoided entirely. If the pasteurization status cannot be confirmed, especially in a restaurant setting, it is safest to assume the cheese poses a risk and choose an alternative.
Safe Preparation and Alternatives
If a pregnant person wishes to consume a blue cheese of uncertain pasteurization status, or one known to be soft and mold-ripened, the risk of listeriosis can be eliminated through cooking. Heating the cheese thoroughly until it is steaming hot will kill any present bacteria. This means blue cheese can be safely enjoyed when melted into a sauce, baked into a quiche, or incorporated into a hot casserole.
For this method to be effective, the internal temperature of the cheese must reach 165°F (74°C). This temperature ensures that any Listeria bacteria is destroyed, making the dish safe to eat. This preparation method allows for the enjoyment of the distinct flavor while mitigating the risk associated with soft, chilled varieties.
When a cold, cheesy flavor is desired without the risk, many safe alternatives exist that are made from pasteurized milk and have a low moisture content.
Safe Cheese Alternatives
- Hard cheeses like Cheddar, Parmesan, and Swiss are safe options because their low moisture and high acidity create an environment where Listeria cannot thrive.
- Other safe choices include cream cheese, cottage cheese, and processed cheese slices, which are almost always made with pasteurized milk.
Following general food safety practices, such as preventing cross-contamination and refrigerating leftovers promptly, also helps ensure a safer diet throughout pregnancy.