Does Eating Cheese Make Phlegm Worse? Separating Fact From Fiction

October 26, 2025 •

3 min read

Despite the widespread belief that dairy products, including cheese, increase phlegm production, multiple scientific studies have found no concrete evidence to support this claim. This article explores the origins of this persistent myth and the true reasons behind the sensation of thickened mucus after eating cheese.

Quick Summary

Scientific evidence largely debunks the myth that cheese or other dairy products cause increased phlegm production. The creamy texture of dairy can temporarily thicken saliva, creating a perception of more mucus without increasing its actual quantity. For most, cheese does not worsen respiratory symptoms.

Key Points

The Scientific Consensus: Multiple studies confirm there is no link between dairy consumption and increased mucus production.
Perception vs. Reality: The creamy texture of cheese mixes with saliva, creating a temporary sensation of thickened mucus in the throat.
It's Not an Allergy: For most people, the sensation is not caused by a dairy allergy, which involves an immune response and more severe symptoms.
Other Causes Exist: Infections (colds, flu), allergies, and environmental irritants are the actual causes of excess phlegm.
Myth Perpetuation: The belief is often fueled by personal anecdotes and historical misconceptions, rather than physiological fact.
Effective Management: Stay hydrated and avoid known irritants to effectively manage phlegm and congestion.

The Scientific Verdict: Busting the Myth

For decades, the idea that dairy products, especially cheese, increase phlegm has been a common belief. However, medical research consistently shows this is a myth. Studies, including those on individuals with the common cold, have found no significant link between consuming milk or dairy and increased nasal secretions or mucus. The sensation people experience after eating dairy is due to its texture, not increased phlegm production. The fat and texture of dairy can mix with saliva, creating a thicker feeling in the mouth and throat that may be mistaken for excess mucus.

Origins of the Persistent Belief

The belief that dairy increases mucus is also influenced by psychological factors. People who hold this belief often report more respiratory symptoms, even when objective measurements show no increase in mucus production. This myth's history can be traced back to early medical texts from the Middle Ages, which advised avoiding dairy during illness. These early observations, made without modern scientific methods, contributed to a misconception that continues today.

Dairy Intolerance vs. Dairy Allergy: The Crucial Difference

It's important to distinguish between general cheese consumption and specific medical conditions. While cheese doesn't affect mucus for most, those with a true dairy allergy might experience respiratory issues. A milk protein allergy, an immune response to proteins like casein and whey, can cause symptoms like wheezing and hives. This differs from lactose intolerance, a digestive problem caused by difficulty digesting lactose, the sugar in milk. Lactose intolerance typically causes digestive symptoms and not increased phlegm. Individuals with a confirmed dairy allergy should avoid cheese. However, for the majority, the idea that cheese causes phlegm is not physiologically accurate.

What Actually Causes Excess Phlegm?

If cheese isn't the cause, what is? Phlegm is a natural defense mechanism against inflammation or infection. Common causes include:

Infections: Colds, flu, and sinus infections often lead to increased mucus as the body fights pathogens.
Allergies: Reactions to allergens like pollen or dust can trigger immune responses that increase phlegm.
Environmental Irritants: Exposure to smoke or pollution can irritate airways and increase mucus production.
GERD: Stomach acid can irritate the throat, causing a sensation of phlegm.
Dehydration: Lack of fluids makes mucus thicker and harder to clear.

Comparison: Common Causes of Perceived Phlegm Worsening


Factor	How it Affects Phlegm	Scientific Evidence	Impact on Respiratory Health
Eating Cheese	Creates a temporary sensation of thickened saliva in the throat, not increased production.	Numerous studies show no link. Sensation is due to mouthfeel, not physiology.	Negligible, unless you have a true dairy allergy.
Colds/Flu	Triggers the body to produce excess mucus to trap pathogens.	Extensively documented. A primary cause of increased phlegm.	Significant, direct cause of congestion and phlegm.
Allergies	Causes the immune system to react, leading to inflammation and mucus production.	Well-established link. A common trigger for respiratory symptoms.	Significant, direct cause of congestion and phlegm.
Dehydration	Causes existing mucus to become thicker and harder to move.	Widely accepted. Proper hydration thins mucus.	Significant, makes clearing phlegm more difficult.

What You Can Do if You Experience Phlegm

Effective ways to manage phlegm include:

Stay Hydrated: Drinking water, broth, or tea can thin mucus.
Use Humidifiers: Moist air soothes airways and prevents mucus from thickening.
Practice Saline Irrigation: Saline sprays or neti pots help clear nasal mucus.
Avoid Irritants: Reduce exposure to smoke and pollution.
Consult a Professional: If you suspect a food issue, a doctor or dietitian can supervise an elimination diet.
Consider Dairy Alternatives: Plant-based milks might offer sensory relief if the creamy texture is bothersome.

Conclusion

Scientific evidence does not support the myth that cheese worsens phlegm. The sensation is typically a temporary effect of the creamy texture mixing with saliva, not increased mucus production. For most people, cheese is safe for respiratory health. True dairy-related respiratory issues are usually linked to milk protein allergies. Instead of avoiding dairy, focus on hydration, avoiding irritants, and treating underlying infections or allergies. The National Asthma Council Australia also debunks the milk-mucus myth and states dairy rarely triggers asthma.

Frequently Asked Questions

Your throat feels thick because the creamy texture of cheese briefly mixes with saliva, creating a coating sensation. It is a change in the physical properties of the mucus and saliva mixture, not an increase in the amount of mucus produced.

The myth is based on sensory perception, not physiological fact. There are historical roots for this belief, and for those who believe it, the perceived symptoms are stronger, even when there's no actual increase in phlegm.

Yes, you can eat cheese if you have a cold. It does not increase the amount of phlegm your body produces. However, if the mouthfeel of dairy is bothersome, you can choose to avoid it for comfort.

For most people with asthma, cheese does not worsen symptoms. A true dairy allergy could trigger asthma-like symptoms, but this is an immune response, not a general effect of cheese on mucus production.

Lactose intolerance is a digestive issue and does not cause phlegm. A milk protein allergy is an immune reaction that can cause respiratory symptoms, but this is a specific medical condition, not a universal effect of dairy.

Spicy foods can cause a temporary increase in mucus, and processed foods or excessive sugar can trigger inflammation. Also, dehydration makes existing phlegm thicker and harder to clear.

You can use plant-based milks like almond, oat, or soy milk. Warm broths and herbal teas are excellent for hydration, which helps thin mucus. These can provide comfort and nutrition without the creamy mouthfeel of dairy.