Your Nose Can Taste Too?

Isabelle
Jul 2
3 min read

In school, most students are told that there are 5 distinct senses: sight, smell, hearing, touch, and taste. Although these senses are distinct, this generalization does not take into consideration that in order to perceive the world fully, multiple senses must combined at once. Perceiving taste is just one example. Flavor is most widely known to be perceived through tastebuds; however, smell actually contributes to 75-95% of the full sensation of taste (Wood, 2024).

The Basics of Tastebuds

There are five basic sensations that taste papillae (larger complexes that contain taste buds and detect taste) can pick up: sweet, salty, sour, bitter, and savory (AKA umami). Humans typically sense these basic tastes after saliva breaks down food into detectable compounds that bind to the taste papillae receptors on our tongue ("In Brief", 2023). These receptors then travel up nerves to our brain, which processes the taste stimulus. The problem, however, is that taste papillae are only capable of communicating to the brain these five basic tastes. The true nuance and distinction of different flavors is actually sensed by olfactory receptors in the nose (Rohland 2017).

The Role of Smell in Flavor Perception

The nose, being far more detailed in detecting and distinguishing between thousands of different odors, is the true hub of flavor detection. After food is broken down through chewing and chemical breakdown, volatile compounds, or odor compounds from the food, can travel up the rear junction of the mouth and nose (Rohland, 2017). These odor molecules are typically assisted up from the mouth to the nose during brief exhalations while eating. This concept is called retronasal olfaction (Ni et al., 2015). Examples of foods where smell highly amplifies flavor are chocolate and coffee (Wood, 2024).

Why Both Taste and Smell?

If our taste papillae evolved to detect taste, why is still such a strong contributor to taste? Taste and smell working in tandem actually results from evolutionary strategies for survival. To avoid consuming poisonous substances, smell helps our body detect potentially harmful foods. Recently, there has also been studies shown that smell helps regulate digestion. Olfactory receptors in addition to sensing different odors, also stimulates gastric juices, preparing our body to start digestion (Giduck et al., 1987 as cited in Wood, 2024). Smell also helps us distinguish calorie and nutrient rich foods from non-rich foods, which is beneficial in times of survival (Wood, 2024).

Interactive: Try Testing Yourself

To test just how much smell affects your perception of taste, quickly eat something but plug your nose when you chew. Notice how you can tell between the five different basic tastes (salty, sweet, sour, bitter, and savory) but not exactly pinpoint the full flavor? This is due to you limiting the olfactory signal to the brain! So cool!

Key Takeaways

Flavor is multifaceted, and it is extremely intriguing to see that our sense of smell is a huge component of taste. By understanding retronasal olfaction and the nuance behind different flavors, the you can enhance your eating experience and be more mindful about the wonderful world of flavors!

References

Fine, L. G., & Riera, C. E. (2019). Sense of Smell as the Central Driver of Pavlovian Appetite Behavior in Mammals. Frontiers in Physiology, 10, 1151. https://doi.org/10.3389/fphys.2019.01151
Giduck, S.A., Threatte, R.M. and Kare, M.R., 1987. Cephalic reflexes: their role in digestion and possible roles in absorption and metabolism. The Journal of nutrition, 117(7), pp.1191-1196
In brief: How does our sense of taste work? (2023). In InformedHealth.org [Internet]. Institute for Quality and Efficiency in Health Care (IQWiG). https://www.ncbi.nlm.nih.gov/books/NBK279408/
Ni, R., Michalski, M. H., Brown, E., & Shepherd, G. M. (2015, November 9). Optimal directional volatile transport in retronasal olfaction | PNAS. https://www.pnas.org/doi/10.1073/pnas.1511495112
Rohland, L. (2017). Taste bud. https://www.ebsco.com/research-starters/health-and-medicine/taste-bud
Wood, C. (2024, November 12). How does smell affect the way we experience food? https://www.foodunfolded.com/article/how-does-smell-affect-the-way-we-experience-food