On International Hot and Spicy Food Day, many of us will enjoy a meal that brings a familiar kind of heat. The sort that once felt overwhelming, but now barely registers. Over time, our tolerance builds, and what used to feel intense becomes manageable, sometimes even enjoyable. It’s a great example of how adaptable the human body is. But it also highlights something important about health, and about cancer in particular.
Why spicy food causes pain
The burning sensation from spicy food isn’t actually a flavour. It’s a pain response. Chilli peppers contain a compound called capsaicin, which activates pain receptors in the body that are usually triggered by heat or injury. These receptors send signals to the brain that something potentially harmful is happening, even though no real damage is being done. That’s why spicy food can feel so intense, especially at first.
Interestingly, research shows that with repeated exposure, the nervous system begins to respond differently. Studies using both behavioural testing and brain imaging have found that people who eat spicy food regularly often report lower everyday pain sensitivity, and show reduced neural responses to certain pain stimuli. In simple terms, the signal is still there, but the brain reacts less strongly to it.
This process is known as desensitisation. The body doesn’t stop detecting the stimulus, it just learns to live with it. Over time, spicy food feels less painful not because the heat has gone away, but because the nervous system has adapted. Some studies even show that people who enjoy spicy food begin to experience the sensation as more pleasant than unpleasant, highlighting just how much perception can change with familiarity and expectation - and this ability to adapt isn’t limited to food. People can also get used to physical symptoms.
A mild but persistent ache. A change in bowel habits. Ongoing fatigue. A feeling of being “off” that never quite settles. At first, these changes stand out. Over time, they become familiar, and familiarity has a way of quietening concern. Research into pain perception shows that how we experience sensations is shaped not just by what’s happening in the body, but by context, emotion and repetition. That means two people can experience the same symptom very differently, and it also means that symptoms which become part of everyday life can be easier to ignore, even when they’re still important.
Understanding persistent symptoms
Pain and discomfort aren’t just annoyances. They’re signals.
In cancer care, pain is one of the most commonly reported symptoms and remains an active area of research, both because of how often it brings people to medical attention and because of its impact on quality of life. Scientists are increasingly studying how the nervous system detects and communicates changes in the body, including those caused by cancer itself or by its treatments.
Many cancers are more treatable when they’re diagnosed earlier. But when someone becomes used to a symptom, they may delay mentioning it, sometimes without realising they’re doing so. The signal hasn’t disappeared, it’s just become easier to live with.
Recognising symptoms early
Early cancer detection doesn’t start with scans or tests. It starts much earlier, with noticing when something isn’t right for you. Noticing when a change doesn’t settle, when a symptom keeps coming back, or when “this is probably nothing” starts to feel like a familiar thought. Talking to a healthcare professional sooner rather than later can lead to reassurance, further investigation, or earlier diagnosis - all of which can make a real difference. Even when it turns out to be nothing serious, that conversation can provide clarity and peace of mind
So, on this International Hot and Spicy Food Day, we are asking you to remember that just like getting used to your favourite spicy food, it’s human to adapt, and it's normal to tolerate discomfort. But when it comes to health, especially when it comes to cancer, getting used to a symptom isn’t the same as it being normal. If something has changed, it’s worth noticing, and it’s worth discussing with a healthcare professional.
References
Bojun He, Min Shao, Junyu Wu, Junyao Wang, Zilong Wei, Lu Chen, Jing Meng, The analgesic effect and neural mechanism of spicy food intake, Social Cognitive and Affective Neuroscience, Volume 20, Issue 1, 2025, nsaf040, https://doi.org/10.1093/scan/nsaf040
Duan, G., Wu, Z., Duan, Z., Yang, G., Fang, L., Chen, F., Bao, X., & Li, H. (2020). Effects of Spicy Stimulation and Spicy-Food Consumption on Human Pain Sensitivity: A Healthy Volunteer Study. The Journal of Pain, 21(7–8), 848–857.
Haroun, R., Wood, J. N., and Sikandar, S. (2023). Mechanisms of cancer pain. Frontiers in Pain Research, 3, Article 1030899.
Mardelle, L., Saraiva-Santos, S., et al. (2024). From pain to tumor immunity: influence of peripheral sensory neurons in cancer. Frontiers in Immunology, 15, 1335387. DOI: 10.3389/fimmu.2024.1335387
Wang, W.-L., Hao, Y.-H., Pang, X., & Tang, Y.-L. (2025). Cancer pain: molecular mechanisms and management. Molecular Biomedicine, 6(1), 45.
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