| + | <div style='text-align:justify;'>Three causes viz. improper union of senses with objects (asatmendriyartha samyoga), intellectual defect (prajnaparadha) and time (parinama) are responsible for manifestation of diseases. Among these, parinama or kala plays an important role in the health of the individuals. The excess (atiyoga), deficient (ayoga) and improper (mithya yoga) of kala results in dosha vitiation. As a part of normal seasonal variation also, doshas get vitiated in the individuals. A proper management of the environmental determinants of health is essential for the promotion of positive health and thereby preventing diseases. Recognition that human health can be affected by a wide range of ecological disruptions, consequent upon climate change, is a recent development in modern scientific world. But the idea that human health and disease are linked to climate probably predates written history. The Greek physician Hippocrates (about 400 BC) related epidemics to seasonal weather changes, stating that physicians should have “due regard to the seasons of the year, and the diseases which they produce, and to the states of the wind peculiar to each country and the qualities of its water”. He exhorts them to take note of “the water which people use, whether they be marshy and soft, or hard and running from elevated and rocky situations, and unfit for cooking,” and to observe “the localities of towns, and of the surrounding country, whether they are low or high, hot or cold, wet or dry and of the diet and regimen of the inhabitants”<ref>Hippocrates. Airs, waters and places. An essay on the influence of climate, water supply and situation on health. In: Hippocratic Writings. Lloyd G.E.R. ed. London, UK, Penguin, 1978.</ref> |
| + | All these facts are well studied and presented by Ayurveda scientists along with the management protocol. More over recent studies have shown changes in the biochemical parameters along with seasonal variations. The physical health impacts of climate change, especially infections, allergies, respiratory and cardiovascular diseases are now well recognized. These objective evidences can be considered as a reflection of the physiological imbalance occurring in the equilibrium of tridoşha due to seasonal variations, progressing to a pathological state as a result of unhealthy diet and regimen. So, in order to prevent seasonal outbreak of diseases, a regimen should be designed, including currently available facilities. For that a thorough knowledge of the physiological imbalances occurring in various seasons in terms of dosha vitiation, status of agni and bala are very essential.<br/>The season is a variation for a particular time which includes environmental factors which consist of nature of land, water, atmospheric temperature, humidity, wind, rain, clouds and atmospheric pressure. All these factors undergo a continous change and at a time, when no two movements are exactly alike in a given place.<ref>Jangid C, Vyas HA, Dwivedi RR. Concept of Ritus and their effect on Bala. AYU Int Res J Ayurveda. 2009; 30:11–5).</ref> <br/>Some studies are carried out to eshtablish the influence of seasonal changes on the development of opportunistic diseases. These show the effect of photo period on immune function and hormone synthesis has a positive result. It also showed that time of the year is important in changing the glucocortcoid concentrations in unstressed and stressed animals.<ref>Nelson RJ, Demas GE. Seasonal changes in immune function3. Q Rev Biol. 1996; 71:511–48.</ref><ref name="ref6">Romero LM. Seasonal changes in plasma gluco-corticoid concentrations in free-living vertebrates. Sci Direct. 2002;9:1147–51</ref><br/>A study was conducted to assess the biophysical, and biochemical changes and provocation of tridosha in ritusandhi. It shows that there was a increasing and decreasing pattern in biochemical changes within normal variations, but the changes were not remarkable. The study is also evident of occuring jwara (fever), pratishyaya (rhinitis), alasya (tiredness) frequently with dominance of vata and kapha provocation.<ref name="ref7">Mallika KJ. Critical study of Swastha-Catuska w.s.r. to Biophysical and Biochemical changes in Rtusandhi. MD (Ayu) Thesis. Jamnagar: Gujarat Ayurved University; 2002.</ref></br>Based on the principles of ritucharya, a study has been conducted on healthy volunteers to assess the bala (physical strength) in different ritus (seasons). The study showed that maximum bala was seen during winter (hemanta ritu), moderate bala during spring (vasanta ritu) and minimum bala during rainy season (vaasha ritu).<ref name="ref6"/> Other systems of medicine also considered the effect of seasons on health. For instance, father of modern medicine, Hippocrates says that whoever wishes to investigate medicine properly should proceed thus in the first place to consider the seasons of the year and what affects of each of them produces. Tibetian system also believes that seasonal regimens are powerful instruments in prevention of diseases.<ref name="ref7"/> </br>Variation in state of dosha in different ritu results in diseases if the prescribed regiment is not followed. For example, increased occurrence of flu, dry skin in winter, heat stroke in summer, pollen allergy in spring, high incidence of air and water borne diseases in rainy season and skin diseases in autumn are observed.<ref>Valiathan MS. Towards Ayurvedic Biology ,Bangalore: Indian Academy of Sciences; 2006.</ref> Few studies show positive correlation between attack of asthma in winter season. Contemporary science also have evidences regarding seasonal affectective disorders (SADs).<ref>Tabers Cyclopedic Medical Dictionary. 18th ed. New Delhi: Jaypee Brothers Medical Publisher (P) Ltd; 2000</ref> <br/>Understainding of Ayurvedic concept of seasonal divisions (ritu vibhaga) is mainly based on specific characteristic features of seasons (lakshanas), based on the hindu calendar months (masa) and stars (rashi). In present scenario, the characteristic features of classically mentioned characteristic features are not uniform all over the geaographical areas. But still specific features during seasons based on biological and external environmental changes during the each seasons are observed. In this connection, a few reviews eshtablish the relation between ritus and gut microbial changes and their effect on health. The food habits and lifestyle changes during each season (ritu) changes the free living microorganism in gut. This increases individual susceptibility to inflammatory as well as metabolic diseases such as non- communicable diseases. Adopting a proper seasonal regimen including seasonal purification enhances the gut acclimatization, thus prevent the pathological manifestation of seasonal diseases and maintain health.<ref>Deppti R, Vandana Rani .M, Delvin T Robin, Anushree Dilip. Adopting seasonal regimen (Ritucharya) to modulate the seasonal variation in gut microbiome. Journal of ethics food : 2-2021</ref> <br/>A seasonal change in immune function has also been observed by researchers during animal studies. Immunological parameters like spleen mass, white blood cells, cellular immunity, IgG and IgM levels showed seasonal changes. Cellular immunity was found to be high in winter than in summer.<ref>De Li Xu,Xiao Kai Hu, Yufen Tian. Seasonal variation in cellular and humaoral immunity in male striped hamsters, Biology, open 2018,7 bio038489,doi- 10.1242/bio 03848</ref> </div> |