In South Asia, seasonal diseases (respiratory, allergic, gastrointestinal, vector-borne, and dermatological) make up a significant proportion of morbidity and Ritucharya (Ayurvedic seasonal regimen) is said to play a preventive role against these types of diseases, but the evidence for the role of prevention has never been systematically synthesized. In an attempt to identify the sources, a non-interventional narrative-systematic review was carried out by applying pre-designed inclusion and exclusion criteria to the classical texts of Ayurveda (Charaka Samhita, Sushruta Samhita, Ashtanga hridayam, and major commentaries), PubMed/MEDLINE, Scopus, Google Scholar, DHARA/indmed, institutional MD dissertations, and Indian government/WHO surveillance reports, extracting data on season, Dosha dynamics, prescribed Ahara-Vihara-Shodhana, target diseases and reported preventive outcomes and grading preventive effect on a 0–3 scale with significance threshold of p< 0.05 as reported in the primary sources. Of 80 records identified, 62 met inclusion criteria (14 classical primary texts, 18 clinical/observational studies, 9 systematic reviews/meta-analyses, 8 epidemiological surveillance reports, 7 pharmacological studies, 6 institutional dissertations) and seasonal dynamics were consistent across all three classical primary texts, while five of six classical seasonal disease predictions showed complete concordance with national surveillance data, with Ritusandhi (transitional vulnerability) showing only partial concordance. The five to six seasons where the compliance was measured directly showed biologically plausible, statistically significant effects on objective biomarkers when applied in the appropriate season (e.g., Virechana reduced PASI by 42.3% in psoriasis, p < 0.001; Basti reduced CRP by 31.4% and ESR by 28.6% in Amavata, p < 0.01), with five of six seasons graded 3 (significant preventive effect), and Grishma was graded 2–3, indicating comparatively limited, but biologically plausible, dedicated trial data. The evidence reviewed does not support the null hypothesis that Ritucharya has no significant preventive effect on seasonal disease, and presents strong support for the alternative hypothesis that adherence to Ritucharya is associated with a significant decrease in the incidence and severity of seasonal disease, though this support is mainly from observational and single-institution studies, and prospective, well-designed, multi-centre studies with standardised compliance and outcome measures are needed for Ritucharya to be included in evidence-based preventive health policy.
Dr. Nishant Bhatnagar* (2026) studied this question.