Spicy foods are painful to eat but around 80% of us enjoy them. This fact has caused scientists to investigate the mechanisms involved in ‘tasting’ heat and why we enjoy it when, rationally, we should be driven to avoid it.
The science of spiciness - Rose Eveleth
While some experts theorize that the health benefits derived from consuming hot food (such as lowering blood pressure) are behind our motivation to seek out spice, others argue that these benefits are not significant enough to explain why humans enjoy chili-spiced food.
Increasing evidence is emerging that suggests our love of spicy foods may be linked with the analgesic effects triggered by our brain when it believes we are in pain. The reward of the euphoric and mood-enhancing effect of endorphin release is thought to spur on our love of spicy food.
Why does spicy food taste hot?
The active ingredient in spicy food, capsaicin, binds to VR1 receptors inside our mouth, causing the sensory neuron to depolarize and send a signal to indicate that the food we are eating is spicy. However, VR1 receptors did not evolve to detect capsaicin, the binding between the two is an accident, VR1 receptors evolved to detect heat to prevent us from consuming food that will damage our mouths and tongues.
When these receptors are accidentally triggered by the presence of capsaicin in spicy foods, we interpret them as tasting hot because this is what VR1 receptors signal for, heat. Technically, spicy food is not hot, it is our neurons being tricked into thinking we are consuming something hot that may cause us harm.
Even though we are not truly being hurt by spicy foods our brain believes that we are. Scientists have pondered why this should be the case and have found the answer in the natural pain relief that is triggered by the brain when it thinks we are hurt.
Spicy foods release endorphins and make us feel good
When we eat spicy food, because our brain is being fooled into thinking that we are hurting ourselves, we release the body’s natural pain killers, endorphins, in the same way we would if we had actually been injured.
Endorphins, as well as diminishing the perception of pain, are also known to induce feelings of wellbeing and euphoria, can reduce stress and enhance our feeling of pleasure, and can have a sedative effect. Scientists believe that these pleasurable effects of endorphin release are why we enjoy spicy foods. When we consume them, even though we perceive them as mildly painful, we are being rewarded by triggering the release of endorphins, which make us feel good.
Rather than being addicted to pain, as some may theorize, it seems we are addicted to feeling good.
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Spicy food and pain relief
Due to their ability to trigger an analgesic effect, scientists have been investigating how capsaicin may be developed into new therapeutic approaches to pain relief. Throughout history and across cultures, capsaicin has been used to treat a variety of ailments, including fevers, nausea, vomiting, malaria, and different pain conditions.
In some communities in Peru, leaves containing capsaicin are burned to produce steam to cure headaches. In the Dominican Republic, these leaves are eaten to treat painful menses, and in the Philippines, capsaicin-containing fruit is used to treat arthritis. More modern applications of capsaicin to treat pain include topical creams with capsaicin.
Much research has focused not only on how to utilize capsaicin, but how to exploit the VR1 receptors that bind with capsaicin to develop new therapies for pain relief. VR1 receptors are considered to be a good target for developing small-molecule antagonists. Future studies will likely help to further develop the use of capsaicin itself, as well as agents that act on VR1 receptors in the treatment of various types of pain.
Spicy food and mortality
Interestingly, as well as being an area of development for pain management, spicy food is being explored for its health benefits. A recent study revealed that the frequency that spicy food is consumed is inversely linked with mortality. These findings suggest that spicy food provides some benefit that helps prevent death in some way.
Studies have also found that frequently consuming spicy food is specifically linked with lower death rates of cancer, ischemic heart diseases, and respiratory diseases.
Currently, scientists do not fully understand how spicy food generates these impressive health benefits and seemingly protects the body from disease, although some studies have suggested that capsaicin likely plays a role.
While more research is needed to fully uncover the biochemical mechanisms via which spicy food reduces overall mortality and disease-specific mortality, recent evidence has indicated that it could be related to the antibacterial effect of spicy food and its effect on gut microbiota populations which have been linked to the risk of developing various diseases including cardiovascular disease, cancer, diabetes, and liver cirrhosis.
Sources:
- Lv, J. et al., 2015. Consumption of spicy foods and total and cause specific mortality: Population based Cohort Study. BMJ. https://www.bmj.com/content/351/bmj.h3942
- O'Neill, J. et al., 2012. Unravelling the mystery of capsaicin: A tool to understand and treat pain. Pharmacological Reviews, 64(4), pp.939–971. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3462993/
- Yang, F. et al., 2015. Structural mechanism underlying capsaicin binding and activation of the TRPV1 ion channel. Nature Chemical Biology, 11(7), pp.518–524. https://www.nature.com/articles/nchembio.1835
Further Reading