Highlights on the Efficacy of "Ayurveda "and it Importance to Human Health

Background: Ayurveda is an ancient medicine system of the Indian subcontinent. The word Ayurveda is a conjugation of two Sanskrit words 'ayus', meaning 'life' and 'veda', meaning 'science', thus ayurveda literally means the 'science of life'. Moreover, Moreover, Ahara vidhi literally means method of taking diet. It includes diet and dietary guidelines. The concept of diet in Ayurveda has a broader view beyond ingestion of food, unlike modern dietetics which is restricted to concept of calorie consumption, Ayurveda recommends methods of taking food, its quality and quantity based upon individual’s capacity to digest (Agni). Materials: Questionnaire on the basis of Literature available in Ahara vidhi -Dietary Guidelines in Ayurveda Classics was developed. Methods: Proper guideline of development of questionnaire has been followed. Results: After the Development of Dietary Questionnaire the questioner sent to the expert to check the face validity and content validity of the Questionnaire with proper concept of statistical Analysis. Discussion: In this article, various aspects of concept of diet in Ayurveda are discussed. Conclusion: Ayurveda diet practices and principles are helpful to improve the human health.


INTRODUCTION
The researchers observe that when food enters in to mouth and passes through the digestive system, it send the interacting signals to the brain, loaded with sensory, nutritive, and other information. Thus, the digestion and metabolism is not limited to ingestion of food only; but it is affected by how the brain and nervous system receives and processed the information too. This article describes classification of food, quantity of food, dietary guidelines and important factors influencing digestive health. Classification of food and development of questionnaire are based on following points. Purpose to Assessment of proper quantity of food and create eating awareness in the society.

Development of Questionnaire: Based on Dietary Guidelines
Proper quantity of food: One must take food in proper quantity. The actual Matra/Quantity of food changes as per the individual and depends on the strength of Agni (digestive power). It is the proper quantity of food, which is digested in time without disturbing the Dhatusamya [1].
Dietary guidelines advise to take food according to energy requirement based upon age, gender, physiological conditions like pregnancy, lactation and level of physical activity. The goal is to maintain ideal body weight and optimal nutrition status [2].

Proportion of Heavy and light to Digest Food
The Proper quantity always depends upon the substance itself. It is based on the food-article itself, it is advised that heavy to digest articles should be taken up to one third to one half of the satisfaction of capacity of stomach; The remaining proportion shall be filled with light to digest food. Neither heavy to digest not light ones should be taken in surfeit in order to maintain the strength of Agni [3].

Eating Variety of Food (Sarva Graha) or Single Substance (Parigraha)
The healthy eating pattern includes taking all types of foods together (sarva graha) and not a particular substance (parigraha) at one time. This affects the digestion and metabolism of food [4]. For example, eating a dish containing all food items like roti, curry, dal, rice together has a different effect than eating only rice at one time. This also affects the overall nutrition status.
Divisions of stomach: The total capacity of stomach can be divided in three functional parts for deciding the proper quantity of diet. One part of solid, one for liquids and third part can be left empty for movement of dosha.) Therefore, one shall fill stomach up to maximum of two third of its capacity with equal proportionate ingestion of solid foods and liquid beverages. This preserves health and prevents diseases [5].

Assessment of Proper Quantity of Food
The assessment of proper quantity of food can be done by observing following signs after consumption of food:

Benefits of Proper Quantity Diet
The food taken in right quantity certainly provides strength, complexion, happiness and longevity to the person; without disturbing the normalcy [7]. It maintains equilibrium of dosha, normal digestion and metabolism (Agni), easily passes down through the bowels, and gets digested without discomfort. If food is taken in excess quantity, it leads to disorders due to over nutrition and vice versa, A large number of disorders including obesity, cardiovascular diseases including coronary artery disease and hypertension, diabetes, cerebrovascular stroke are caused due to over nutrition. Malnutrition results in Kwashiorkor/Marasmus, iron deficiency anaemia, stunting, wasting especially in children.

Sequence of Eating Food Items
The food with sweet taste shall be taken in the beginning followed by those with sour and salty taste. The food with other tastes like pungent, bitter and astringent shall be taken at last. According to the source of food, fruits should be taken in the beginning followed by liquid gruel (peya). Then the variety of solid eatables (bhojya and bhakshya) can be taken. The best fruit to be taken at the beginning is Indian goose berry (amalaka) [8]. This sequence of taking food is based upon the status of digestive factors (Agni) and post digestive effects (vipaka) of food. The sweet food items are generally heavy to digest and can be digested easily when taken at first in the presence of peak strength of digestive power (Agni). The first phase of digestion after taking meals is dominated by effect of sweet taste (madhura avastha paka), followed by sour taste (amla avastha paka) and ended by pungent taste (katu avasthapaka). This sequence is applicable only in person with normal digestion capacity (Agni). In case of abnormal digestion, the sequence can be changed according to the disease condition. The recent researches showed taste like cells in the gut. These cells play an important role in integrating physiological responses during digestion. These taste receptors also influence eating pattern. The relation between sequence of eating food and its impact on taste receptors in gut need more studies.

Food Articles for Regular Consumption and Preservation of Health
One should regularly consume shashtika rice (Oryza sativum), shali rice (varieties of Oryza sativum rice), Green gram (mudga, Vigna radiata), rock-salt, Indian-gooseberry (amalaka, Phyllanthus emblica), barley (yava Hordeum vulgare-), water, milk, ghee, flesh of animals of arid habitat (jangala) and honey [9]. Those food items, which maintain health as well as prevent onset of diseases should be included in daily regimen [10]. One should always take food of all tastes [11].

Forbidden Food Articles for Habitual Consumption
One should not have the habit of taking dried meat, dried vegetables, tuber of lotus (Shaluka, Nymphaea alba Linn.) and stalk of lotus (Bisa, Nymphaea alba Linn.) as these are heavy to digest. One should never eat meat of emaciated animal [12]. Regular consumption of coagulated milk, cream-cheese, pork, meat of cow and buffalo, fish, curd, black-gram and wild-barley should be avoided [13]. Accordingly, one should never eat such heavy to digest articles as preparations of flour, rice, flattened rice etc., on top of a meal. Even while hungry one should take them in right quantity [14]. Salt, saturated fats, and excess sugar are disease causing. Excess consumption of animal products leads to premature ageing, increased risk of chronic diseases and higher cause of mortality. Refined carbohydrates including white rice, white bread, sugar, honey, maple syrup, agave nectar lead to overweight, diabetes, dementia, mental illness and cancer. The fast and processed food includes chips, soda, cookies, candy, breakfast cereals, bars, French fries, burgers, pizza, white flour baked goods, and all other high-calorie, lownutrient foods that people often eat multiple times per day. These food items contribute to obesity, diabetes, heart attacks, strokes, dementia and cancer. This has resulted in decreased longevity. The fast food, processed food, commercial baked goods, and sweets may also be linked to destruction of brain cell and a lowering of intelligence. Candy and sweetened baked goods may even stimulate the brain in an addictive fashion, which can lead to more serious illnesses. Hence they shall be avoided. One should never eat food which is not sacredly prepared (achoksha), contaminated, with stone particles, grass or hair etc. The food which causes aversion, kept overnight, foul smelling and stale shall be avoided. The food which does not have its natural taste, hardened due to passage of time, cold, re-heated, with oozing and moisture, burnt shall not be taken [15]. Reheated foods cause more oxidative stress through formation of aldehydes and increase the risk of degenerative illness and artherosclerotic disease. Reheating of cooking oils like corn, soyabean, and sunflower oils produces toxin named 4-hydroxy-trans-2-nonenal (HNE). This is responsible for increased risk of cardiovascular disease, stroke, Parkinson's disease, Alzheimer's disease, Huntington's disease, various liver disorders, and cancer. Therefore reheating of food shall be avoided. On should not be habituated to consume food having a single taste, foods of inferior quality, unsuitable to human being and sour foods [16].

The Suppression of Urge of Hunger and its Treatment
One shall not suppress the natural urge of hunger for a longer duration. It leads to emaciation, weakness, change in body complexion, generalized body ache, aversion (to food) and dizziness. Such cases are treated by unctuous, hot and light (easily digestible) food is advised [17]. These effects are observed after starvation for a longer time due to depletion of glucose, then fatty acid break down and formation of ketone bodies. The treatment is done with sips of water mixed with glucose, fruit juices to avoid refeeding syndrome.

Personal Well Being
One Should eat after washing hands, face, mouth and feet and dressed appropriately.
Reciting mantras, offering oblation to God, departed ancestors, guests and dependents is good practice. Wearing of precious stones while eating has been the practice in the past, is being followed in some societies [18]. It is important to maintain personal hygiene, prevent negative effect of metaphysical powers while eating.

Effect of Sound on Health
Reciting mantra before eating is observed in some societies. Mantra is a sacred utterance, a numinous sound, a syllable, word or phonemes, or group of words in Sanskrit believed by practitioners to have religious, magical or spiritual powers. Hymns and sacred chants are observed in all religious scripts. The term mantra in Sanskrit means "to think". Since ancient times, mantras have been used to calm the mind and produce a sense of peace. Recently, scientists have confirmed this calming effect and have discovered the causal factors within the brain/mind that bring it about.Mantra (prolonged repetitive verbal utterance) showed psychological calming effect by reducing the blood oxygenated level dependent signals in brain.The structure of Gayatri Mantra is in perfect tune with the science of cosmic sound. Chanting of mantra can enhance spiritual energy, increase selfawareness, cognizance level. On the other side, ample evidence shows that exposure to environmental noise has adverse effects on the health of the population. A report from the world health organization showed evidence on the relationship between environmental noise and health effects, including cardiovascular disease, cognitive impairment, sleep disturbance, tinnitus, and annoyance.

Influence of Mental Status on Digestion
One should eat with a stable and pleasant state of mind. The wholesome food, though taken in the right quantity, does not get digested properly, if the mental state of the person is riddled with anxiety, grief, fear, anger, or restlessness and irritability due to lack of sleep [19] One should not take food with greed, ignorance, passion/desires, greed, infatuation, envy, bashfulness, conceit, excitement and fear in mind. The negative mental factors can harm the digestion process leading to formation of ama (undigested food) and a number of metabolic disorders [20].
One should eat with utmost concentration on the food and avoid mental distractions like watching television, reading newspapers, checking emails and working. One should avoid talking or laughing during meals. This can lead to the same defects as by eating too fast discussed later in this article [21]. The mental distractions showed overeating leading to obesity. While paying attention to a meal was linked to eating sufficient meal and lesser chances of gaining weight. Thus, paying attention to meal is directly linked to satiety and weight gain. A concept of mindful eating is originated on these practices.

Pleasant Surroundings
One should eat in pleasant surroundings with soothing fragrance around. Facing towards the north direction while eating is said to have beneficial positive effect on health. According to ancient Indian architecture (vastu shastra), the north direction is full of divinity and spiritual energy. However scientific research is needed to study effect of direction while eating.
The attendants serving food shall be loyal, disciplined, clean and devoted to impart pleasant surroundings [22]. Utensils made up of metals shall be used to process and store cooked food [26]. The hygiene at the place of eating is of utmost importance to avoid microbial contamination of food and its diseases. The utensils used for cooking, preparing and storing food shall not possess antagonistic properties to that of food. The interaction can cause harmful effects on health.

Duration of Taking Meals
One should not eat too fast to avoid entry of food particles in nasal passage. By eating with normal speed, the person is able to ascertain the qualities and taste of the food or even detect any defects in the food [27]. One should not eat too slow. Eating too slow can affect satiety and lead to eating in excess quantity. As the time passes, the cooked food becomes cold and is not digested properly [28].
A research on eating speed shows that eating quickly (within 9 minutes) leads to poor digestion, increased weight gain, and lower satisfaction. However, slow eating for 29 minutes showed better digestion, better hydration, easier weight loss or maintenance, and greater satisfaction.Mindful eating has suggested ideal eating time as 20 minutes with complete attention on meals.

GUIDELINES AFTER MEALS
Taking water: Water shall be taken in suitable quantity during meals and after meals [29]. Drinking suitable quantity of water during meals assures proper passage of food in alimentary canal, mixing in stomach and digestion.

Mouth Cleaning and Mouth Freshener
To prevent decaying of teeth and bad smell (halitosis), mouth should be thoroughly cleaned after eating [30]. Kapha is aggravated after taking food and produces discharge in oral cavity. One shall take mixture of areca nut (puga), cubeb (kankola), camphor (karpura), clove (lavanga) or fruits of pungent, astringent taste with betel leaf as mouth freshener [31].

Lifestyle
After taking food, one should sit comfortably like a king (rajavat) till the drowsiness due to food is over. After that, one should walk slowly for hundred steps and rest by lying on the left side. One shall observe those measures which soothes, nourish senses and feels good [32]. After meals, sleeping and sitting for longer time, excess liquid diet, exposure to heat, swimming, travelling, riding shall be avoided [33].

Faulty Dietary Habits
The improper dietary habits disturb process of digestion and metabolism (Agni), lead to formation of ama (undigested food and toxins) and cause severe diseases of various body systems [

Multi-Factorial Effect of Food and Diet in Health and Diseases
A person who eats healthy food is not affected by disease. Intake of nutritious foods, on the other hand, is not the only cause of disease or can help to avoid disease. Aside from unwholesome diet, there are a variety of other etiological elements that contribute to disease, including seasonal changes, intellectual errors, unwholesome contacts, and excessive, incorrect, and over-use of the senses of hearing, touch, vision, taste, and smell.

CONCLUSION
Despite a healthy intake of tastes (rasa) and nutrition, these etiological factors might induce diseases in an individual. As a result, it has been noticed that someone who eats healthy food can become ill. Similarly, eating an unhealthy diet does not instantly result in negative consequences. All unwholesome foods are not equally destructive, all doshas are not equally powerful, and all bodies are not capable of disease prevention.Depending on the habitat, season, combination, potency, and excessive consumption of unwholesome food, it can be more dangerous. When the dosha is related with several variables, treated with incorrect therapies, becomes deep rooted, chronic, vitiated in one of the ten seats of vitality (prana), and afflicts vital centres within the body known as Marma, the dosha becomes acute and exceedingly difficult to manage.Individuals who are severely obese, emaciated, with depleted muscles, blood, and bones, who are physically very weak, who are accustomed to eating unwholesome foods, who consume insufficient amounts of food, and who have a very weak mind are unable to withstand infections. Individuals with the opposite attributes to those listed above, on the other hand, are capable of resisting diseases. As a result, diseases of moderate, severe, acute, and chronic nature are caused by unwholesome diet, dosha, and bodily constitution factors.

CONSENT
It is not applicable.

ETHICAL APPROVAL
It is not applicable.