Understanding the Risks of Unpasteurised Cheese
Unpasteurised, or raw milk, cheese is made from milk that has not been heated to a high enough temperature to kill potentially harmful bacteria. While many artisanal cheese enthusiasts value the complex flavours that raw milk can impart, the health risks for certain populations are a serious concern. The most significant danger comes from foodborne pathogens like Listeria monocytogenes, Escherichia coli (E. coli), and Salmonella. For most healthy adults, an infection might only cause mild, flu-like symptoms. However, for vulnerable individuals, the consequences can be severe or even fatal.
Who Is Most at Risk?
Pregnant Women
Pregnant women are strongly advised to avoid unpasteurised cheese due to the risk of listeriosis, an infection caused by Listeria. A listeria infection during pregnancy can lead to severe complications, including miscarriage, stillbirth, premature delivery, or life-threatening illness in a newborn. Even a mild case in the mother can have devastating effects on the baby. The hormonal changes of pregnancy can also compromise the immune system, making expectant mothers more susceptible to this infection. Safe alternatives, such as hard cheeses or pasteurised soft cheeses, should always be chosen.
Young Children and Infants
Children under the age of five have developing immune systems that are not yet robust enough to fight off many foodborne pathogens. Consumption of raw milk products can expose them to dangerous bacteria, potentially causing severe illness, kidney failure, or other long-term health issues. Health authorities consistently recommend that young children only be given pasteurised dairy products to minimise these risks.
Older Adults (Over 65)
With age, the immune system naturally weakens, making older adults more vulnerable to severe infections. Like pregnant women, seniors are at a higher risk of developing listeriosis and other foodborne illnesses. What might be a minor stomach upset for a younger person could lead to serious, life-threatening complications for an elderly individual. Experts recommend that older adults avoid all unpasteurised cheeses, particularly soft and mould-ripened varieties.
Individuals with Weakened Immune Systems
Anyone with a compromised or suppressed immune system is at a significantly higher risk from unpasteurised cheese. This includes people with conditions such as HIV/AIDS, cancer (especially those undergoing chemotherapy), kidney disease, diabetes, or those who have undergone organ transplants. For this group, a listeria infection can be particularly dangerous, with a higher likelihood of invasive and severe illness.
Hard vs. Soft Cheeses: A Critical Distinction
While all unpasteurised cheeses carry some risk, the type of cheese plays a role in the potential for bacterial growth. Soft cheeses, which have higher moisture content and lower acidity, provide a more hospitable environment for harmful bacteria like Listeria to thrive. This is why soft cheeses such as Brie, Camembert, Feta, and certain Mexican-style soft cheeses (queso fresco) are particularly risky when made from raw milk. Hard cheeses, on the other hand, have lower moisture and higher salt content, which generally inhibits bacterial growth, making them safer, even if unpasteurised. However, health authorities still advise high-risk groups to exercise extreme caution with any raw milk product.
Identifying Unpasteurised Cheese
It is crucial to check the label for clear indications of pasteurisation. In many regions, food labeling laws require producers to specify if a product is made with raw milk. Look for phrases such as "unpasteurised milk," "raw milk," or the French equivalent, "au lait cru". If the label does not explicitly state that the milk is unpasteurised, it can generally be assumed to be pasteurised. When purchasing cheese from a cheese counter or a farmers' market, always ask the vendor about its pasteurisation status. If in doubt, it is always safest to choose a clearly labeled pasteurised product, especially for vulnerable individuals.
Comparison of Unpasteurised vs. Pasteurised Cheese
| Feature | Unpasteurised Cheese (Raw Milk) | Pasteurised Cheese (Heated Milk) |
|---|---|---|
| Flavour | Often more complex, intense, and varied due to natural milk bacteria and enzymes. | Flavour is more consistent and milder, as heating removes most natural flora. |
| Safety Risk | Higher risk of carrying harmful bacteria like Listeria, E. coli, and Salmonella, especially in soft cheeses. | Lower risk of bacterial contamination due to the heat treatment process. |
| Target Consumers | Best for healthy adults who are not pregnant or immunocompromised. | Safe for all consumers, including vulnerable populations like pregnant women, children, and the elderly. |
| Typical Cheeses | Traditional Brie, Camembert, Roquefort, artisanal goat cheeses, some aged hard cheeses. | Most commercial soft and hard cheeses, including mass-produced Mozzarella, Cheddar, and cottage cheese. |
| Labeling | Explicitly labeled as "raw milk" or "au lait cru" in many regions. | Generally labeled as "pasteurised" or, if unmarked, is likely pasteurised. |
Safe Alternatives and Preparation Methods
For those who love cheese but fall into a high-risk group, there is no need to avoid it entirely. Safe alternatives include all hard cheeses, as well as any soft or semi-soft cheeses clearly labeled as pasteurised. Additionally, cooking can be an effective way to mitigate risk. Heating cheese to a steaming hot temperature (at least 74°C or 165°F) for a minimum of two minutes can kill harmful bacteria. This makes dishes like baked Camembert, pizza, or mac and cheese generally safe, as long as the cheese is thoroughly heated.
Conclusion: Prioritising Health Over Culinary Curiosity
While unpasteurised cheeses offer a distinct and rich flavour profile, they carry a potential health risk that is too significant for certain segments of the population. Pregnant women, young children, the elderly, and immunocompromised individuals must prioritise safety by avoiding raw milk products. By understanding the risks, checking labels diligently, and choosing safe alternatives or ensuring thorough cooking, these vulnerable groups can still enjoy cheese without compromising their health. The CDC provides further guidance on the safety of raw milk and dairy products for at-risk populations.
For more information on food safety, you can visit the official website of the CDC: https://www.cdc.gov/food-safety/foods/raw-milk.html.
