MadSci Network: Neuroscience |
Dear Nils, Your question basically relates to genetics of taste sensitivity. It actually has been known for a long time that genetics does appear to influence our ability to taste certain substances. For example, about 15-30% of all people are unable to taste the bitter flavor of thiourea compounds like phenylthiocarbamide (see AC Guyton, Textbook of Medical Physiology, p. 640, 1971). The molecular basis for this ability to taste thioureas has only recently been discovered. A family of membrane associated proteins located on taste cells of the taste buds have been identified that appear to bind to taste molecules and stimulate the sensations of taste. One of these proteins is specific for thioureas (see H. Matsunami, et al., "A family of candidate taste receptors in human and mouse" in the journal Nature, vol. 404, pp. 601-604, 2000.) Probably, genetic variations in this protein are responsible for the varying abilities of people to taste these molecules. Spices do seem to prevent spoilage in hot climates, so perhaps one reason why spicy foods are often adopted by cultures of people in hot climates is that the taste becomes associated with a feeling of safety and security in eating the food. It seems likely to me that these food preferences arise from long traditions and learning, rather than from any genetic differences between peoples. Great genetic differences between people in Thailand and Mexico, for example, exist, but both cultures like highly seasoned food.
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