When it comes to spicy food, you either love it or hate it. Spice excites the taste buds in a way that no other flavor comes close to, providing some with satisfaction while also turning their mouths into fiery cauldrons of pain. So what is it that defines our preference, could it be simply an acquired taste, or is there a genetic factor to it?
What is Spiciness, Exactly?
To start off, ‘spicy’ isn’t an actual taste per se, because it doesn’t trigger the receptors (sensory equipment on your cells) that are associated with taste. This is because the term ‘taste’ is reserved for sensations that we perceive through receptors specialized to pick up chemosensory cues.
Rather, the molecule largely responsible for spiciness, capsaicin, activates a receptor known as Transient Receptor Potential cation channel subfamily V member 1 (or just TRPV1)1. The TRP family of receptors is unique as it is responsible for the sensation of hot and cold, much like microscopic thermometers. When you bite down on that chili, the capsaicin released binds to TRPV1 and activates it, which happens to be the ‘hot’ switch, causing the familiar burning sensation.
Taste evolved as an important feature of animal survival because it helps us decide what foods should or shouldn’t be consumed, especially if we’ve never tried them before. A bitter or sour taste usually signals toxic substances, sweet means energy in the form of carbohydrates, while umami (activated by the amino acid L-glutamate) might indicate the presence of protein. The role of taste has played a key part in the evolution of species, as seen in how pandas lost their umami receptors as they became vegetarian.
Fun fact: salty and sour tastes are detected by ion channels while sweet, bitter, and umami tastes are detected by G protein-coupled receptors; all of this machinery resides on cells in areas known as taste buds2!
You Are What You Eat
And there might be a little truth in the old saying, after all, judging from studies that have shown how your personality can affect your views on spicy. One theory suggests that the consumption of chili is linked to certain thrill-seeking behaviors such as taking roller coasters or consuming alcohol; although they provide a rush to the individual, these activities are rather low-risk, much like eating a hot chili pepper3.
Studies were carried out with participants ranked on a certain Sensation Seeking Scale (SSS), where a strong positive correlation was established between liking spicy meals and sensation-seeking4. Sensation-seeking behavior is defined by an individual’s need for varied, novel and complex sensations and experiences, combined with the willingness to seek them out on impulse.
But you’re not popping Mexican chilies into your mouth for fun! Okay, maybe you are, but from an evolutionary perspective, there is a tangible benefit to this kind of ‘fun’. Sensation-seeking behaviors are actually quite a useful trait, as humans have time and again taken on great risks to discover, explore and colonize the entire world5. The higher the risk, the larger the reward. Because of this, a certain degree of risk-taking is wired into our genome—to inhibit our response to the fear that usually accompanies risky business.
Furthermore, sensation-seeking behavior is considered attractive to women, as they are usually exhibited by men who are in good physical condition and can afford to pursue such behavior6. Of course, as with all variations in evolution, there exists an optimal level of sensation-seeking that provides an individual with the best chance of survival, as chronic high-risk behavior would surely decrease his/her lifespan.
Location, Location, Location
What’s better than hot stew and mulled wine to warm your belly on those cold, winter nights? What about tearing into some sambal (spice paste) or spicy jalapeño peppers? But hang on a minute, sambal is from Indonesia, while jalapeños are mainly used in Mexican cuisine. And those regions don’t exactly have a cold season, sitting so close to the equator.
An international study showed that in fact, countries with hot climates used spices more frequently, compared to countries in cooler regions. Interestingly, as the mean annual temperature of a country increases, so too does the proportion of recipes containing spices, the number of spices per recipe and the total number of spices used7. What a strange correlation!
Many spices possess antioxidant properties due to the presence of phenolic compounds and hence, can scavenge free radicals by quenching singlet oxygen species. These include gingerol (in ginger), piperine (in black peppers) and capsaicin (in chilis), all of which have been extracted, purified and shown to prevent food spoilage in vitro8.
Furthermore, many of these spices have the ability to inhibit or destroy bacteria, fungi and viruses. They work through a wide range of different processes, from disrupting the cell membrane, affecting enzyme function, to even altering the genetic material of these food-borne pathogens.
As a result of these two factors combined, it could well have been an evolutionary advantage to enjoy spice, because that meant an extended shelf life for food and decreased ingestion of these pathogens. This is especially true of hot and humid tropical climates, where the conditions accelerate food spoilage as well as pathogen spread, thereby explaining the real reason why we equator-dwellers have always enjoyed our spicy meals!
Reference
- Tominaga, M., & Julius, D. (2001). Capsaicin receptor in the pain pathway. The Japanese Journal of Pharmacology, 83(1), 20-24.
- Bachmanov, A. A., & Beauchamp, G. K. (2007). Taste receptor genes. Annu. Rev. Nutr., 27, 389-414.
- Rozin, P., & Schiller, D. (1980). The nature and acquisition of a preference for chili pepper by humans. Motivation and emotion, 4(1), 77-101.
- Byrnes, N. K., & Hayes, J. E. (2013). Personality factors predict spicy food liking and intake. Food quality and preference, 28(1), 213-221.
- Zuckerman, M., & Kuhlman, D. M. (2000). Personality and risk taking: common bisocial factors. Journal of personality, 68(6), 999-1029.
- Jones, B. C., DeBruine, L. M., Little, A. C., Conway, C. A., Welling, L. L., & Smith, F. (2007). Sensation seeking and men’s face preferences.Evolution and Human Behavior, 28(6), 439-446.
- Billing, J., & Sherman, P. W. (1998). Antimicrobial functions of spices: why some like it hot. The Quarterly review of biology, 73(1), 3-49.
- Gottardi, D., Bukvicki, D., Prasad, S., & Tyagi, A. K. (2016). Beneficial effects of spices in food preservation and safety. Frontiers in microbiology, 7, 1394.
About the Author
Sean is a consultant for clients in the pharmaceutical industry and is an associate lecturer at La Trobe University, where unfortunate undergrads are subject to his ramblings on chemistry and pharmacology.
