In India, choices of food among the people at large are still derived from the Ayurvedic worldview and understanding. This is an area where the local communities abound in various do’s and don’ts, which often appear to be not incomprehensible to the modern investigator. This is perhaps one of the reasons why there is a poor understanding of the nutritional value of many substances that were traditionally valued very highly, such as rice.
The characterisation and description of rice that is found in the texts of Ayurveda use terminologies which are entirely different from the modern medical and nutritional terminologies. The gap is quite wide on these matters between the modern and the traditional, and there have only been a few scattered and sporadic efforts to bridge this gap. In fact, concepts such as hot and cold are not only not understood, but also dismissed as superstition.
Consider the following question, which appeared in a journal published by the National Institute of Nutrition. “It is true that there is a widespread belief that some foods are ‘hot’ and others ‘cold’. However, there appears to be no scientific basis for such classification. It is not desirable to limit the choice of food based on such beliefs.” There has been an attempt to directly understand and assess the concepts of traditional medicine, such as hot or cold employing modern nutritional laboratory techniques.
At the outset, it may appear that the concepts of traditional medicine such as hot and cold are completely outside the scope of understanding of modern medicine, and few would think that there is any kind of dialogue possible. However, it is interesting to note that in the late 1960s an attempt was made by a scientist from the National Institute of Nutrition, Hyderabad, to try and understand the biochemical basis for the Ayurvedic understanding of hot and cold foods.
A list of food items that are believed to produce either heat or cold when consumed, was prepared, and from among these, two diets were formulated. The first consisted mainly of hot foods and the second cold foods.
Hot foods were generally those that, when consumed, produced a subjective feeling of burning eyes, burning micturition, and a feeling of warmth all over the body. Four normal healthy adult subjects from the laboratory staff were selected for the metabolic study.
Protein, fat, and calorie intakes were adjusted according to the Nutrition Advisory Committee recommendations. The subjects were first placed on a diet comprising mostly of the hot foods for a period of 10 days followed by the second period of 10 days when they were given a diet consisting mainly of cold foods. The period of intake of each of these types of foods was 10 days.
When the subjects were consuming hot foods, the acidity of the urine was much higher than when they were consuming cold foods. The high acidity of urine may be the possible cause for the burning sensation during micturition. Urinary excretion of sulphur was also found to be higher in hot foods than in cold foods, indicating a possibility that the high sulphur content of urine may be the cause for the high acidity of the urine.
Nitrogen retention was found to be lower in hot foods than in cold foods, although the total nitrogen content was the same in both the diets. Surprisingly, this remains the only research report in India where such an effort has been made to comprehend Ayurvedic parameters through a laboratory exercise.
Laboratory studies show that Karungkuruvai rice variety is rich in iron and has a low glycemic index. This is consistent with the very high value which Siddha physicians attribute to this variety. The glycemic index of Karungkuruvai, Kullakar, Kovuni, Mapillai Samba, Neelam samba, Kudaivazhai are low compared to market varieties such as White Ponni. This is consistent with the traditional view that these are good for diabetes.
Although nutritional properties in modern medicine are described using terms such as protein, caloric content and vitamins, traditional medicine uses entirely different terms.
Among the basic terms used, some of the key concepts are as follows:
- Rasa – This literally refers to the taste of a substance. It is believed that different tastes impart or correspond to different nutritional qualities. For example, a substance that is bitter in taste is likely to have properties that are Krimigna (it controls Krimi, “deworming”) and a substance that is sour in taste can increase the intensity of Agni (capacity to digest).
- Guṇa – This refers to a large number of specific qualities.
- Vīrya – This refers to the potency of a substance, which may be Uṣna (hot) or Sita (cold). This indeed refers to the overall impact or feeling in the human after ingesting/digesting the substance.
- Gaṇa-s – Charaka, another classic Ayurvedic authority, classified drugs into 50 groups or Gaṇa-s according to their action. Various other authors have added more terms to describe the action of all substances, be it food or medicine.
Folk Knowledge
The body of knowledge and practices related to nutrition exist both in the classical and the folk forms. Although this is a subject that merits a detailed investigation, a brief overview is provided below. There is a vast body of textual literature in Saṁskṛit and various other Indian languages (such as Tamil, Telugu and Kannada), which not only have detailed and rich descriptions of the properties of foods but also provide a theoretical framework for this knowledge. Linked to this understanding, there is rich folklore and traditional knowledge that still strongly influence and govern the choice of food by the people of India. This includes the understanding of what is healthy food, what is a balanced diet, which foods are appropriate or inappropriate during various seasons, incidence of illness and various stages of life and growth such as infancy, women attaining puberty, pregnant and lactating mothers and old age.
Some of the Hot and Cold Foods are given below:
List courtesy: Banyan Botanicals
Source: CIKS, Dr Vijayalakshmi
