The Truth: Why are we not supposed to drink cold water?

October 5, 2025 •

3 min read

According to some traditions, drinking cold water is a bad habit that can slow down digestion and harm your health. However, a growing body of scientific evidence suggests that for most healthy individuals, the potential risks associated with water temperature are minimal and often linked to pre-existing conditions. This article explores the question, “Why are we not supposed to drink cold water?”, by examining both historical beliefs and modern research to provide a balanced perspective.

Quick Summary

Examine the beliefs surrounding why drinking cold water is discouraged and compare them with modern scientific understanding. Discuss potential effects on digestion, heart rate, and headaches, and address when water temperature truly matters for your health.

Key Points

Most Myths are Unfounded: For most healthy people, drinking cold water is not harmful and can be beneficial during exercise, especially for cooling down.
Digestion is Not Significantly Affected: While cold water causes temporary vasoconstriction, the body rapidly normalizes its temperature, and it does not block digestion in healthy individuals.
Migraines and Headaches are a Risk: Certain individuals, especially those prone to migraines, may experience a cold-stimulus headache from rapidly consuming very cold liquids.
Conditions May Worsen: People with specific issues like achalasia, sensitive teeth, or respiratory illnesses may find their symptoms aggravated by cold water.
Listen to Your Body: The ideal water temperature for hydration is often a matter of personal preference and health conditions; pay attention to what feels comfortable and encourages consistent intake.
Traditional Beliefs Exist: Traditional systems like Ayurveda and Chinese medicine suggest warm water to support digestive 'fire,' a belief based on balancing bodily elements.

The belief that drinking cold water is harmful has been passed down through generations in various cultures, including traditional Ayurvedic and Chinese medicine. These traditions often advocate for drinking warm or room-temperature water to maintain the body's natural balance and 'digestive fire'. While these ancient practices provide valuable historical context, it is important to scrutinize them through the lens of modern science.

The Effect on Digestion

One of the most common claims against cold water is that it slows down or impairs digestion by constricting blood vessels.

Scientific Perspective: The body efficiently warms cold water to core temperature, minimizing impact on blood vessels. Older studies noted a temporary slowdown in stomach contractions, but not a significant issue for healthy individuals.
The Exception: Cold water can worsen symptoms for people with achalasia, a swallowing disorder, where warm water is more soothing.

Impacts on the Cardiovascular and Nervous Systems

Cold water can have temporary effects on the nervous and cardiovascular systems.

Vagus Nerve Stimulation: The vagus nerve can be stimulated by cold water, temporarily decreasing heart rate. This is generally mild in healthy people.
Cold-Stimulus Headaches: Rapidly drinking cold water can trigger a "brain freeze" headache, especially for those prone to migraines, due to effects on spinal nerves.

Respiratory Concerns

For those with respiratory sensitivities, cold water can have temporary effects.

Thickening Nasal Mucus: A 1978 study suggested cold water can thicken nasal mucus, potentially increasing congestion during illness, while hot liquids may help.

How Cold Water Affects Nutrient Absorption

Traditional beliefs that cold water hinders nutrient absorption are not scientifically supported. The body's absorption processes are not significantly affected by water temperature.

Hydration is key, and cold water can be more palatable, encouraging greater intake and better hydration, particularly in warm conditions or during exercise.

Comparison: Cold Water vs. Room-Temperature Water


Feature	Cold Water	Room-Temperature Water
Digestion	Temporary vasoconstriction, generally not significant for healthy individuals. Can worsen achalasia.	Gentle on digestion; aligned with some traditional practices.
Heart Rate	May temporarily lower heart rate via vagus nerve stimulation.	No temperature-related effect on heart rate.
Headaches	Can trigger cold-stimulus headaches in susceptible individuals.	Less likely to cause temperature-related headaches.
Respiratory	May temporarily thicken nasal mucus.	Can be soothing for sore throats; may not thicken mucus.
Exercise Performance	Palatable and aids body cooling during intense activity.	Less effective for rapid internal cooling.

Who Should Be Cautious?

While most people can safely drink cold water, some individuals should be cautious:

People with Migraines.
Individuals with Achalasia.
Those with Sensitive Teeth.
Individuals with Respiratory Illnesses.
People with Circulatory Issues (consult a doctor).

Conclusion: The Best Approach to Water Temperature

For most healthy people, the concerns about cold water are largely unfounded; effects are temporary and not harmful. Cold water can even be beneficial during exercise. However, those with specific health conditions should consider warmer water if it causes discomfort. The most crucial factor is consistent hydration, and the best water temperature is often the one that encourages adequate intake.

For additional information on drinking cold water, refer to resources like Healthline's expert-reviewed articles.

Disclaimer: The information provided is for educational purposes only and is not a substitute for professional medical advice. Always consult with a healthcare provider for any health concerns.

Frequently Asked Questions

For most healthy people, no. Your body quickly warms the water to core temperature, so any effect on digestion is very temporary and not a cause for concern.

Yes, a rapid intake of very cold water can trigger a "brain freeze" or cold-stimulus headache, particularly in individuals susceptible to migraines.

Ingesting cold water can stimulate the vagus nerve and slightly lower heart rate, but this is a mild response and not harmful for most healthy individuals.

Some older studies indicate that drinking cold water can temporarily thicken nasal mucus, which may feel unpleasant during a cold or flu.

Yes, individuals with this rare swallowing disorder may experience worsened symptoms, such as chest pain and difficulty swallowing, when drinking cold water.

Traditional Ayurvedic practice suggests that cold water dampens 'Agni' or digestive fire, recommending warm or room-temperature water instead to maintain balance.

Cool water (around 16°C or 60°F) is often recommended for exercise, as it can be more palatable, encouraging higher intake and more effectively cooling the body.