The question of whether mozzarella on pizza is safe during pregnancy is a common and understandable concern, given the general guidance to avoid certain cheeses. The short answer is that mozzarella on pizza is almost always safe to eat, provided a few basic food safety principles are followed. The safety of the cheese depends on how it was produced and, crucially, the high temperatures it reaches during the cooking process. For expectant parents, understanding these factors helps clarify which dairy products are safe choices throughout pregnancy.
The Role of Pasteurization in Dairy Safety
The primary concern with consuming dairy products during pregnancy revolves around the presence of the bacterium Listeria monocytogenes. This organism can cause an infection called listeriosis, which poses a serious threat to pregnant individuals and their developing fetus. Pregnant people are estimated to be about ten times more likely to contract listeriosis than the general population, primarily because pregnancy temporarily weakens the immune system’s ability to fight off this particular pathogen.
Listeriosis can lead to severe complications, including miscarriage, stillbirth, preterm labor, or serious illness in the newborn. The process designed to eliminate this risk is pasteurization, which involves rapidly heating milk to a specific temperature for a set time to destroy harmful bacteria like Listeria. The heat treatment effectively neutralizes the threat, making products made from pasteurized milk safe to consume.
While healthy individuals might experience only mild flu-like symptoms from listeriosis, the risk to the fetus is significant. Therefore, any cheese or dairy product consumed during pregnancy should be made from milk that has undergone this heat-treatment process.
Low-Moisture vs. Fresh Mozzarella: Assessing the Risk
Mozzarella comes in two common forms. The most frequently used type for pizza is low-moisture, part-skim mozzarella, which comes in shredded form or solid blocks. This commercial product is almost universally made from pasteurized milk and is considered safe to eat, even before it is cooked. Its lower water content and slightly higher salt concentration also make it a less hospitable environment for bacteria compared to softer cheeses.
Fresh mozzarella, typically packed in water or brine, has a higher moisture content. While the majority sold in North American and European supermarkets is made with pasteurized milk, certain artisanal or imported varieties, such as traditional Buffalo mozzarella, may use unpasteurized milk. Consumers must check the product label for the word “pasteurized” before purchasing. If the label does not explicitly state it was made with pasteurized milk, the cheese should be avoided unless it is going to be thoroughly cooked.
How High Heat Neutralizes Risk
The cooking process provides a layer of safety that mitigates risk. Listeria monocytogenes is easily killed by heat. The bacteria are destroyed at temperatures above 65°C (149°F), though an internal temperature of 74°C (165°F) is often recommended for safety.
Standard pizza ovens operate at temperatures ranging from 350°F to 500°F, which is far hotter than necessary to eliminate the pathogen. The cheese on the pizza, even if made from unpasteurized milk, reaches a temperature high enough to destroy any potential Listeria contamination. The mozzarella should be heated until it is visibly bubbling, melting, and steaming hot throughout the entire pie. This visual confirmation ensures the cheese has reached the required internal temperature to neutralize any harmful bacteria.