For those familiar with Ayurveda, one of the most surprising observations regarding modern nutritional science is that the relationship between taste and nutrition has been completely overlooked in Western investigations and conceptualizations. This is especially true when one considers that the sensation of taste is the primary and most obvious influence for every food that is eaten. The concept that taste may contain important clues to the biochemical actions of food is certainly an intriguing one, especially in light of the exquisite sensitivity of the taste receptors. Sweet taste can be perceived in a dilution of 1:200; salty, in a dilution of 1:400; sour, in a dilution of 1:130,000; and bitter, in a dilution of 1:2,000,000. According to the concepts of Ayurveda, this exquisite sensitivity of taste represents a communication mechanism to signal the physiology of the complex biochemical qualities of each food.
The sense of taste performs the dual role of informing the individual about the external world and connecting that perception with information about their internal environment. It is known from research into the sense of taste that molecules act on taste cells in particular areas of the oral cavity to trigger signals which are then transmitted to the cortex via afferent nerves, the caudal hindbrain, and the thalamus. The hypothalamus and limbic system are also reached by taste afferents. The taste of food is known to trigger physiological as well as behavioral reactions.
According to Ayurveda, when the taste buds first experience the different tastes and textural properties of food, an enormous amount of information is delivered throughout the body, triggering basic metabolic processes. These are held to reflect individual characteristics of the food as indicated by the taste. The influence on the physiology is then individualized according to the metabolic style determined by the individual’s Ayurvedic psychophysiological constitution and disturbances in the physiology.
Ayurveda describes six tastes: sweet, sour, salty, pungent, bitter, and astringent. Of these, the two that are not specifically recognized in Western nutritional science are ‘pungent,’ which refers to hot, spicy foods, and ‘astringent,’ which refers to foods with a drying, absorbent property (Table 1).
Table 1. The Six Tastes and Some Examples
- Sweet – Sugar, milk, butter, rice, wheat, bread, pasta, honey
- Sour – Yogurt, lemon, cheese, tomatoes, sour citrus fruits
- Salty – Foods with a high salt content
- Pungent – Hot spicy foods, hot peppers, ginger, cumin
- Bitter – Spinach, other green leafy vegetables, turmeric
- Astringent – Beans, lentils, apples, pomegranate, tannin in tea
Ayurveda recommends that all six tastes be represented in each meal, although the proportions of the six tastes will vary according to the individual’s psychophysiological constitution and physiological disturbances. When all six tastes are experienced, the appetite will be satisfied by this balanced intake. If any of the tastes are left out, the person will likely continue to eat even though they are full, in an effort to satisfy the body’s hunger for the missing tastes. Inclusion of all six tastes is easily accomplished by use of Ayurvedic churnas, which are spice mixtures tailored to different constitutional types.
Because of the gate-keeper role that the taste buds play, taste is considered central to the classification of foods. It should be noted however that the analysis of food in Ayurveda is more sophisticated and precise than the analysis of taste alone. In analyzing food, additional properties are also taken into consideration, including six major qualities of food that are identified as heavy, light, oily, dry, hot, and cold (Table 2).
Table 2. The Six Major Food Qualities and Some Examples
- Heavy – Cheese, yogurt, wheat products
- Light – Barley, corn, spinach, apples
- Oily – Dairy products, fatty foods, oils
- Dry – Barley, corn, potatoes, beans
- Hot – Hot (in temperature) foods and drinks
- Cold – Cold foods and drinks
Dietary prescriptions in Ayurveda are tailored according to individual need, based on determination of the individual’s Ayurvedic psychophysiological constitution and disturbances in the physiology.