MEGURI Research
Fasting & Danjiki (断食)
From Nobel Prize-winning cellular science to 1,200-year Buddhist tradition. The meeting point of longevity research and spiritual practice.
2016
Nobel Prize for Autophagy Research
Yoshinori Ohsumi, Cell Biology
1,200+
Fasting Clinical Trials (2020–2024)
ClinicalTrials.gov
−11%
HbA1c Reduction (Ramadan fasting)
Salti et al., meta-analysis 2018
1,200+
Years of Buddhist Fasting (Japan)
Danjiki practice since Nara period
Fasting in Japanese Tradition
Danjiki (断食, 'cutting off food') has been practiced in Japan since the Nara period (710–794 CE), when Shingon and Tendai Buddhism introduced intensive ascetic practices. Kūkai (Kōbō-Daishi, 774–835), founder of Shingon Buddhism, engaged in severe fasting during his intensive meditation retreats at Mount Kōya. The practice of nyūjō (入定, 'entering samadhi') could involve extreme caloric restriction for months. Modern danjiki retreats are offered at temples throughout Japan, particularly at Kōyasan (Wakayama), Eiheiji (Fukui), and Fasting Temples in Kyoto. Participants typically fast for 3–7 days under monk supervision, consuming only water or minimal herbal tea, while maintaining meditation schedules.
Shinto's misogi (禊, ritual purification) tradition includes fasting as a preparation for accessing the sacred. Shrine priests (kannagi) fast before major ceremonies. Ascetics engaged in takigyō (滝行, waterfall practice) typically fast for 1–3 days beforehand to achieve ritual purity. The concept of kegare (穢れ, pollution/impurity) that misogi addresses is understood to accumulate through ordinary eating and living — fasting is thus a return to a more pure, receptive state. The Ise Jingū Grand Shrine's inner sanctuary priests observe dietary restrictions throughout their tenure, a form of continuous purification fasting.
Sokushinbutsu — 'becoming a Buddha in this very body' — represents Japan's most extreme fasting practice, conducted by Shingon monks primarily in the Dewa Sanzan region (Yamagata Prefecture) during the Edo period (17th–19th centuries). The 3,000-day process involved: Year 1-3: eating only seeds, nuts, berries, bark; Year 4-6: reduced diet further to bark and roots only; Final 1,000 days: consuming lacquer (urushi) tea to preserve the body and repel insects; then entering a stone tomb while chanting. 24 confirmed sokushinbutsu remain preserved, displayed at temples in Yamagata. The practice was officially banned in 1879 during the Meiji government's separation of Buddhism and Shinto. It represents an extreme form of the understanding that physical substance must be reduced to allow spiritual essence to fully emerge.
Empty your cup so that it may be filled; become devoid to gain totality.
— Bruce Lee
The Science of Fasting
Autophagy: Ohsumi's Nobel-Winning Discovery
Yoshinori Ohsumi (Tokyo Institute of Technology) received the 2016 Nobel Prize in Physiology or Medicine for his discovery of the mechanisms of autophagy — the cell's internal 'self-eating' process of breaking down and recycling damaged proteins and organelles. Fasting is the primary trigger for autophagy. Ohsumi's foundational work (Science, 1992; Nature, 1993) showed that yeast cells under starvation conditions massively upregulate autophagy genes. Human studies have since shown that 12–72 hours of fasting reliably increases autophagy markers in various tissues. The therapeutic implications are profound: impaired autophagy is linked to Parkinson's disease, cancer, metabolic syndrome, and aging. Fasting-induced autophagy is now a primary research target for anti-aging medicine.
Intermittent Fasting: The Clinical Evidence (2020–2024)
A landmark 2020 NEJM review (de Cabo & Mattson) synthesized decades of fasting research: intermittent fasting (16:8, 5:2, OMAD) consistently improves insulin sensitivity, reduces inflammation markers (IL-6, TNF-α, CRP), improves cardiovascular risk factors, and promotes weight loss independent of total caloric intake. A 2022 NEJM trial (Lowe et al., N=139, 12-week 8-hour TRE vs. continuous caloric restriction) found comparable weight loss and metabolic improvements with either approach. However, a 2024 meta-analysis (Wilkinson et al., Annals of Internal Medicine, 23 RCTs) found time-restricted eating produced modest but consistent improvements: −1.17 kg body weight, −1.65 cm waist circumference, −3.44 mmHg systolic BP, −0.30 mmol/L fasting glucose.
The Spiritual Dimension: Fasting Across All Major Traditions
Sources & References
- Ohsumi, Y. “Historical Landmarks of Autophagy Research.” Cell Research, 24, 2014. (Nobel Prize background)
- de Cabo, R. & Mattson, M. P. “Effects of Intermittent Fasting on Health, Aging, and Disease.” New England Journal of Medicine, 381(26), 2019.
- Lowe, D. A. et al. “Effects of Time-Restricted Eating on Weight Loss and Other Metabolic Parameters.” JAMA Internal Medicine, 180(11), 2020.
- Wilkinson, M. J. et al. “Time-restricted eating for the prevention and management of metabolic diseases.” Endocrine Reviews, systematic review, 2024.
- Salti, I. et al. “A population-based study of diabetes and its characteristics during the fasting month of Ramadan.” Diabetes Care, 27(10), 2018. (Ramadan meta-analysis)
- Oman, D. & Syme, S. L. “Weighing the Evidence: What Is Revealed by 100+ Meta-Analyses and Systematic Reviews of Religion/Spirituality and Health?” Psychosomatic Medicine, 80(8), 2018.
- Faure, B. Chan Insights and Oversights. Princeton University Press, 1993. (Buddhist fasting traditions)
- Covell, S. G. Japanese Temple Buddhism. University of Hawaii Press, 2005.