Can I drink milk and eat eggs when I have a cold and fever? Food myths debunked.

Whenever you catch a cold, besides seeing a doctor and taking medicine, there are always a lot of dietary advice circulating. The two most widely circulated are: "Don't drink milk when you have a cold, it will produce phlegm and make your nasal congestion worse" and "Don't eat eggs when you have a fever, it will make your body temperature even higher."

Both of these statements are actually centuries old—not only found in traditional Chinese medicine texts, but even the 12th-century physician Moses Maimonides wrote that milk causes a "sense of blockage in the head." It sounds convincing, but what is the truth? This article will clarify two often-conflated studies, explaining "why drinking milk really does cause a feeling of phlegm," and also pointing out that when you have a fever, what you should really pay attention to is not eggs, but hydration and overall nutrition.

First, let's state the conclusion.

in other words:Milk and eggs are not inherently taboo during a cold.What we really need to pay attention to is...Lactose intolerance, milk allergy, and egg allergyThese three situations are completely different from "phlegm production".

II. Milk and Phlegm: What Two Studies Say

How prevalent is the claim that "milk produces phlegm"? Two sets of survey data can be used for reference:

• A 2004 surveyWe interviewed 300 parents who visited pediatric pulmonology clinics.58% believes milk increases mucus production.It is worth noting that,28% indicates that this statement was heard from a doctor.。
• A 1993 studyThe study found that nearly two-thirds of respondents believed that "drinking just one glass of milk increases the amount of mucus in the throat," and they used words like "thick," "blocked," "heavy," and "choking" to describe the feeling.

A common belief does not prove a claim. What has truly tested this issue are two differently designed experiments—they are often lumped together as one.

First method: Infect subjects with the common cold virus and then measure their secretions (1990)

A research team from South Australia recruited 60 healthy adultsvaccinate themRhinovirus-2 (one of the most common cold viruses)For the next 10 days, respiratory symptoms and the intake of milk and dairy products were recorded. Nasal discharge was not described by the participants themselves, but rather...Seal used toilet paper immediately and weigh each sheet.Weight is used as an objective indicator.

turn out:The intake of dairy products is not associated with nasal congestion symptoms in the upper and lower respiratory tracts, nor with the weight of nasal secretions.

One noteworthy detail from the study is that those who believed "milk produces phlegm" and who usually reduced their milk consumption due to colds...They reported significantly more cough and nasal congestion symptoms, but the actual amount of nasal secretions they measured was not particularly high.Beliefs affect how we feel, but they don't affect the amount of secretion.

Second item: Milk vs. soy milk, even the taste was matched (1993)

The same group of researchers then conducted another sensory experiment: 125 peopleDrink separatelymilk與Soy milkAnd heat it with cocoa mint.Eliminate the difference in taste between the two—The subjects had no idea which one they were drinking.

Results: Some people reported difficulty swallowing, thicker saliva, or a feeling of something stuck in their throat.However, the control group that drank soy milk also showed the same reaction.In other words, these sensations are not unique to milk.

Putting the two studies back into their respective titles, the conclusion becomes clear:Currently, no studies have found that dairy products increase the "amount" of respiratory secretions.It does indeed cause some people to "feel" something. A 2005 review also pointed out that milk intake does not lead to increased mucus secretion.

3. Why do I feel like I have phlegm after drinking milk?

If milk doesn't increase secretions, why do many people experience a "stuffy" feeling in their throat after drinking it?

The key point is:That sensation occurs in the mouth and throat, not in the respiratory tract.Milk itself is an emulsion in which fat is dispersed in water; mucins in saliva help to separate the tiny oil droplets from the milk.FlocculationThey aggregate into larger clumps, causing the mixture to...Increased volume and viscosityThis heaviness lingers in the oropharynx and can easily be misinterpreted as "more phlegm."

In a 2019 commentary, Balfour-Lynn, a pulmonologist at the Royal Brompton Hospital, wrote directly:"Milk does not produce a lot of extra mucus... Milk is an important source of calcium, vitamins, and calories for young children and should not be avoided."

It is important to distinguish between three things that are often confused:

The treatments for these three conditions are completely different: phlegm does not require treatment; lactose intolerance can be addressed by switching to low-lactose products or adjusting the way one drinks it; and milk allergy requires avoiding milk and dairy products altogether.

IV. Will eating eggs when you have a fever make your body temperature even higher?

Another common explanation is that when you have a fever, your body is already in a high-temperature state. Eating high-protein, high-calorie foods like eggs will increase the body's heat, but make it difficult to dissipate heat, thus worsening the condition.

Let's start with the correct parts.After eating, the body consumes extra energy during the digestion, absorption, and metabolism of food, and releases some of this energy as heat. This phenomenon is called…Thermic effect of food(Thermic effect of food, also known as the specific dynamic action of food). The differences are quite significant among different nutrients:

Protein is indeed the "most labor-intensive" of the three, which is the origin of the saying that "eating eggs will generate heat." But...The amplitude is very smallThis rise in body temperature caused by eating is a normal physiological phenomenon.It won't push a person into the range of fever.。

Let's talk about the parts that are wrong.Fever is not caused by "too much body heat that can't be dissipated," but rather...The body's thermoregulatory center (hypothalamus) raised the set temperature.This is a normal immune response to fight infection. It is driven by pyrogens.It has nothing to do with what you ate.You can still get a fever even if you don't eat.

More importantly, fever itself is a highly energy-consuming process. Physiological studies indicate that...For every 1°C increase in body temperature, the metabolic rate needs to increase by approximately 10¹¹TP + 12.5¹TP + 4T.During a fever, the bodyIt will increase the use of protein as an energy source, and accelerate muscle protein breakdown.In other words, what you really need when you have a fever is...Replenish sufficient protein, energy, and water.Instead of listing eggs as taboo.

The cooking method is the key.Egg protein has a significantly higher digestibility after cooking (approximately 511 TP4T for raw eggs and approximately 911 TP4T for cooked eggs). This is especially beneficial for those with poor appetite or gastrointestinal discomfort.Boiled eggs, steamed eggs, egg drop soupIt's better than frying or deep-frying eggs—not because eggs "generate heat," but because of the oil content and the burden on digestion.

To learn about the complete nutritional information and cholesterol content of eggs, please refer to the website's <Nutritional value of eggs and cholesterol myths〉。

V. Situations that truly require attention

One more thing: If fever occursPersistent high fever, difficulty breathing, chest pain, altered consciousness, seizures, or symptoms that do not improve after several days.Anyone experiencing these symptoms should seek medical attention as soon as possible. The elderly, children under five, pregnant women, and individuals with chronic health problems are at high risk of developing serious conditions and should not delay seeking medical attention.

VI. What can I eat during a cold?

Hong Kong Department of Health's Elderly Health Centre's "Nursing Influenza" recommendations are quite simple:Drink plenty of water and eat nutritious and easily digestible foods.For example, minced pork/beef porridge, oatmeal, rice noodles, and must haveSufficient sleep and rest。

• MoistureFever, sweating, and runny nose all lead to dehydration. The source of hydration doesn't have to be limited to plain water—soup, porridge, milk, and soy milk are all included (for a comparison of various plant-based milks, please refer to the website <...>).Soy milk and soy beverage selection and consumption guidelines〉）。
• proteinMilk contains approximately 3.4 grams of protein and 120 milligrams of calcium per 100 milliliters; a large egg contains approximately 6.3 grams of protein, 72 kilocalories, and also vitamins B12, riboflavin (B2), selenium, vitamin D, and choline. Both are convenient and readily available sources of nutrition during a cold.
• "Light" doesn't mean "only eating plain porridge and vegetables".Light and bland refers toLess oil, less sugar, less salt, and not spicy.Eggs, lean meat, and fish, when cooked properly (steamed, boiled, or stewed), are all considered light and refreshing ingredients.

To learn about the relationship between herbs and the upper respiratory tract, please refer to the information on this website.Natural Herbal Remedies for Upper Respiratory Tract Infections>; For an examination of evidence regarding the cough itself, see <Empirical Evidence on Chocolate and Cough〉。

VII. Frequently Asked Questions (FAQ)

Will drinking milk cause phlegm when you have a cold?

Studies have not found that dairy products increase the amount of nasal mucus or phlegm. Trials conducted on subjects with rhinovirus infection showed no association between dairy intake and nasal congestion or the weight of nasal secretions. If you want to drink milk during a cold, as long as it doesn't cause significant discomfort, moderate consumption is fine.

Why do I feel phlegm after drinking milk?

That's mostly a sensation in the mouth and throat, rather than increased respiratory secretions. Milk is an emulsion of fat dispersed in water; the mucin in saliva causes the small oil droplets to coagulate, increase in size, and become more viscous, creating a heavy feeling in the throat. In the same 1993 trial, a similar reaction occurred in the control group that drank soy milk, indicating that this is not unique to milk.

Will eating eggs when you have a fever cause your body temperature to rise even higher?

No. Eating does produce a thermic effect of food, with protein contributing approximately 20% of its calories (TP) to 35% (TP) to 4% (T), but the overall increase is minimal. Fever is caused by the body's thermoregulatory center raising its set temperature, and it has nothing to do with what you eat. During a fever, it's actually necessary to replenish sufficient protein, energy, and fluids.

How many eggs can you eat in a day?

For generally healthy individuals, one whole egg per day is a reasonable intake. During a cold or when appetite is poor, eggs can be eaten in smaller portions depending on appetite. If you have cardiovascular disease, diabetes, dyslipidemia, or an egg allergy, you should adjust your intake according to the advice of your doctor or registered dietitian. Related discussions can be found in the article "Nutritional Value of Eggs and Cholesterol Myths" on this website.

I am lactose intolerant. Can I still drink milk when I have a cold?

You can choose low-lactose or lactose-free milk, cheese, or hard cheese; you can also drink it in small amounts several times a day, avoid drinking it on an empty stomach, and eat it with other foods. Lactose intolerance is a digestive problem, which is different from milk allergy (an immune response). If symptoms persist or become severe, you should consult a healthcare professional.

Why do some people say you should "avoid certain foods" when you have a cold?

The traditional concept of "avoiding certain foods" largely stems from the idea of "trigger foods," which are generally common food allergens such as eggs, milk, beef, soybeans, and peanuts. For people without allergies, it's not necessary to avoid all of them; what they really need to avoid are the foods they are allergic to.

What should you eat when you have a cold?

The key is hydration and overall nutrition. The Hong Kong Department of Health recommends drinking plenty of water, eating nutritious and easily digestible foods, and getting plenty of rest. During a fever, the metabolic rate increases and protein breakdown accelerates, so adequate protein intake is essential; cooking should be done with less oil, sugar, and salt.

In what situations should you seek medical attention?

If symptoms persist or worsen, or if persistent high fever, difficulty breathing, chest pain, altered consciousness, or seizures occur, seek medical attention as soon as possible. Elderly individuals, children under five, pregnant women, and those with pre-existing health conditions are considered high-risk and should consult their doctor promptly.

Source of information

1. Pinnock CB, Graham NM, Mylvaganam A, Douglas RM. Relationship between milk intake and mucus production in adult volunteers challenged with rhinovirus-2. Am Rev RespirDis. 1990;141(2):352–356. PubMed Summary(60 people were vaccinated with rhinovirus-2, nasal secretions were weighed, dairy products were not associated with symptoms, and believers reported more symptoms but no difference in secretion volume.)
2. Pinnock CB, Arney WK. The milk-mucus belief: sensory analysis comparing cow's milk and a soy placebo. Appetite. 1993;20(1):61–70. PubMed Summary(125 people were compared between milk and soy milk, with cocoa and mint used to eliminate taste differences, and both groups showed similar sensations)
3. Arney WK, Pinnock CB. The milk mucus belief: sensations associated with the belief and characteristics of believers. Appetite. 1993;20(1):53–60. PubMed Summary(The feelings and characteristics of believers)
4. Lee C, Dozor AJ. Do You Believe Milk Makes Mucus? Arch Pediatr Adolesc Med. 2004;158(6):601. Original text (DOI)(Of the 300 parents, 581 TP4T believed that milk increased mucus production, and 281 TP4T said the information came from doctors.)
5. Wüthrich B, Schmid A, Walther B, Sieber R. Milk Consumption Does Not Lead to Mucus Production or Occurrence of Asthma. J Am Coll Nutr. 2005;24(6 Suppl):547S–555S. Original text (DOI)(Comprehensive review: There is no causal relationship between milk intake and mucus secretion or asthma)
6. Balfour-Lynn IM. Milk, mucus and myths. Arch Dis Child. 2019;104(1):91–93. PubMed Summary(An explanation of the "phlegm-like sensation" caused by oral mucoprotein flocculation; explicitly stating that milk should not be avoided)
7. Bartley J, McGlashan SR. Does milk increase mucus production? Med Hypotheses. 2010;74(4):732–734. PubMed Summary(Discussion on relevant mechanisms)
8. BBC Chinese — Who says you can't eat dairy products when you have a cold?(A popular science compilation of the history and related experiments of the milk and mucus claim)
9. National Center for Biotechnology Information (NCBI) — Physiology, Fever(For every 1°C increase in body temperature, the metabolic rate increases by 10–12.5%; protein breakdown increases during fever; fever is regulated by the hypothalamus.)
10. Hong Kong Department of Health Elderly Health Centre influenza(Nursing the flu: Drink plenty of water, eat nutritious and easily digestible food, get plenty of rest; high-risk individuals and prevention methods)
11. Hong Kong Centre for Health Protection — Seasonal influenza(Symptoms, transmission routes, incubation period, treatment methods, and high-risk groups)
12. MedlinePlus, U.S. National Library of Medicine — Lactose intolerance(The prevalence of lactase non-persistence in East Asians is 701 TP1T1001 TP4T)
13. The National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK) — Lactose Intolerance(Causes, Symptoms and Treatment)
14. The UK National Health Service (NHS) — Lactose intolerance 及 Food allergy(The difference between lactose intolerance and food allergy)
15. USDA-ARS — FoodData Central(Nutritional data for eggs and milk)

Note: The studies cited in this article each have their own ethnic groups, sample sizes, and design limitations. Some are observational or short-term trials and cannot be directly interpreted as causal relationships, nor should they be extrapolated to all people. Whether an individual needs to avoid milk or eggs should be determined based on their own allergies or tolerance and after consulting a healthcare professional.

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