Can Moldy Cheese Cause Long-Term Health Issues?

December 21, 2025 •

4 min read

According to the World Health Organization (WHO), some mycotoxins produced by molds can have serious health effects. While many people have wondered, 'can moldy cheese cause long-term health issues?', the answer largely depends on the type of cheese, the mold, and the person's immune system, with serious risks often tied to mycotoxins.

Quick Summary

This article explores the health risks of eating moldy cheese, distinguishing between safe and harmful molds, explaining mycotoxin dangers, and advising on when to discard certain cheeses to prevent illness.

Key Points

Good vs. Bad Mold: Some cheeses, like Brie and blue cheese, are made with safe, intentional mold, while others develop harmful, spoilage mold.
Long-Term Mycotoxin Risk: Prolonged or frequent ingestion of toxic mycotoxin-producing molds can pose serious, long-term health risks like liver damage and cancer, though this is rare.
Different Cheeses, Different Rules: Soft cheeses with mold must be discarded, but hard cheeses can be salvaged by trimming 1 inch around the moldy spot.
Bacteria Risk: Spoiled, moldy cheese can also harbor dangerous bacteria like E. coli and Listeria, which can cause foodborne illness.
Most Accidental Ingestions are Harmless: For healthy individuals, a small, accidental bite of moldy cheese is unlikely to cause serious harm, as stomach acid helps destroy spores.
Immunocompromised Vulnerability: Pregnant women, the elderly, and immunocompromised individuals face higher risks and should avoid any potentially spoiled cheese.
Proper Storage is Key: Tightly wrapping and refrigerating cheese can prevent accidental mold growth and spoilage.

Understanding Mold on Cheese: The Good, the Bad, and the Ugly

Not all mold on cheese is a cause for concern. Many cheeses, particularly gourmet varieties, are intentionally cultured with specific types of mold to develop their unique flavors, aromas, and textures. However, the mold that grows on spoiled cheese is a different story and can pose health risks if ingested.

The "Good" Molds: Intentional and Safe

Some cheeses are deliberately inoculated with specific, food-safe strains of Penicillium mold. These molds are an integral part of the cheesemaking process and are perfectly safe for consumption by most people.

Penicillium roqueforti: This is the mold responsible for the distinctive blue or green veins found in blue cheeses like Roquefort, Gorgonzola, and Stilton.
Penicillium camemberti: This mold creates the thick, white, edible rinds on soft-ripened cheeses such as Brie and Camembert.

The "Bad" Molds: Accidental Spoilage

This is the fuzzy, green, or black mold that appears unexpectedly on cheese that is past its prime. This mold indicates spoilage and should be handled with caution. It's impossible to tell visually whether a particular spore is toxic, so it's best to be prudent.

Mycotoxins and Long-Term Health Risks

The primary long-term health concern from eating moldy food, including spoiled cheese, is exposure to mycotoxins. These are toxic secondary metabolites produced by certain species of fungi.

Carcinogenic Risks: Aflatoxins, a particularly dangerous type of mycotoxin produced by Aspergillus molds, are highly carcinogenic and can cause severe liver damage and tumor formation over long periods of exposure. While most dangerous mycotoxins are associated with moldy grains and nuts, they can contaminate cheese indirectly through animal feed.
Other Potential Effects: Mycotoxins can also contribute to immune deficiency and have mutagenic and teratogenic effects. While a single, small exposure is unlikely to cause serious harm in healthy individuals, prolonged or regular ingestion of contaminated products could lead to cumulative health problems.

Salvage or Discard: A Guide by Cheese Type

The fate of moldy cheese depends heavily on its type and moisture content. The rule of thumb is that the softer the cheese, the easier it is for mold to penetrate deep below the surface, spreading its harmful mycotoxins.

Hard and Semi-Hard Cheeses (e.g., Cheddar, Swiss, Parmesan): Mold spores cannot easily penetrate the dense, low-moisture structure of these cheeses. If you find a small mold spot, you can safely cut it off. The USDA recommends trimming at least 1 inch (2.5 cm) around and below the moldy area, being careful not to drag the knife through the mold. Re-wrap the remaining cheese in fresh packaging.
Soft Cheeses and Crumbled/Shredded Cheeses (e.g., Ricotta, Cottage Cheese, Cream Cheese, Crumbles): The high moisture content allows mold spores and potentially harmful bacteria like E. coli, Listeria, and Salmonella to spread throughout the entire product. If mold appears on these products, the entire item should be discarded immediately.

Comparison Table: Hard vs. Soft Cheeses


Feature	Hard Cheeses (Cheddar, Parmesan)	Soft Cheeses (Ricotta, Cream Cheese)
Mold Penetration	Difficult; mold typically stays on the surface.	Easy; mold spreads quickly and deep within the product.
Salvageability	Can often be salvaged by cutting away the moldy part.	Must be discarded entirely at the first sign of mold.
Mycotoxin Risk	Lower risk of deep contamination and mycotoxin spread.	Higher risk of widespread contamination, including harmful bacteria.
Example Molds	Often harmless surface mold, easily removed.	Potential for harmful bacteria and mycotoxins to contaminate the entire product.

What to Do If You've Accidentally Eaten Moldy Cheese

For most healthy individuals, accidentally eating a small amount of spoiled cheese is unlikely to cause serious long-term health problems. Your stomach acid is highly effective at destroying many mold spores. However, there is a risk of short-term digestive upset, allergic reactions, or foodborne illness.

Symptoms: Watch for symptoms such as nausea, vomiting, diarrhea, or cramping. If you experience an allergic reaction, symptoms might include sneezing, a runny nose, or a rash.
When to See a Doctor: Seek medical attention if you experience severe or persistent gastrointestinal issues, have trouble breathing, or develop a high fever. This is especially important for those who are pregnant, immunocompromised, or have underlying health conditions, as they are at a higher risk.

Preventing Mold Growth on Cheese

Proper storage is key to preventing unwanted mold. Tightly wrap your cheese in wax paper followed by plastic wrap or aluminum foil, and store it in the refrigerator's crisper drawer where the temperature and humidity are most consistent.

Conclusion: Can moldy cheese cause long-term health issues?

While the sight of unexpected mold on cheese is unappetizing, it doesn't automatically mean long-term health issues. The key takeaway is to differentiate between the safe, intentional mold on specialty cheeses and the harmful, accidental mold of spoilage. For hard cheeses, trimming is a safe option, but for soft, shredded, or crumbled varieties, immediate disposal is the only safe course of action. The true long-term risks are associated with chronic exposure to mycotoxins, which can be carcinogenic, but this is rare in sporadic, minor instances of eating spoiled cheese. Adhering to proper food safety and storage practices is the most reliable way to avoid these risks and ensure that your love for cheese remains a healthy one. When in doubt, it is always safest to throw it out.

USDA Food Safety and Inspection Service

Disclaimer: This article is for informational purposes and is not a substitute for professional medical advice. Always consult a healthcare provider for any health concerns.

Frequently Asked Questions

Safe mold is intentionally introduced during cheese production, as seen in the blue veins of Roquefort or the white rind of Brie. Unsafe mold is any unintended growth, often fuzzy and colored, that appears on spoiled cheese and can produce harmful toxins.

Mycotoxins are poisonous substances produced by certain molds. Some, like aflatoxins, are carcinogenic and can cause severe liver damage with long-term exposure. While not all molds produce mycotoxins, it's impossible to tell by sight alone.

For hard and semi-hard cheeses like Cheddar or Swiss, you can safely cut off the moldy part, trimming at least 1 inch around and below the spot. For soft, crumbled, or shredded cheeses, the mold may have penetrated deeper, so the entire product should be thrown out.

Most healthy individuals will not experience serious long-term effects from accidentally eating a small amount of moldy cheese. The most likely outcome is a bad taste or temporary gastrointestinal upset like nausea or diarrhea.

Individuals with weakened immune systems, pregnant women, the elderly, and young children are most vulnerable. For these groups, there is a higher risk of complications from mold exposure or foodborne bacteria that can grow alongside mold.

Spoilage mold can be a sign of the presence of other harmful bacteria, such as E. coli, Listeria, and Salmonella, which can cause serious food poisoning. The mold itself can also trigger allergic reactions in sensitive individuals.

To prevent mold, store cheese in the refrigerator, tightly wrapped in wax paper and then plastic wrap or aluminum foil, to regulate moisture. A clean refrigerator can also help prevent cross-contamination from other moldy foods.