Fasting in Sync with the Moon: Decoding Ekadashi with Modern Lens

Modern science has finally recognized what ancient wisdom long understood: that human body is guided by lunar rhythms, now identified as the circalunar clock.

Significance of Ekadashi-

More than a million people observe fasting on Ekadashi worldwide and today we will explore the science behind this practice. The word "Ekadashi" means "eleven" in Sanskrit, referring to the 11th day of the lunar cycle and hence there are 2 Ekadashi in a month. All Ekadashi are associated with the worship of Lord Vishnu and aim to gain control over mind and senses for spiritual growth. Nirjala Ekadashi, through its rigorous nature, particularly intensifies this spiritual progression. Nirjala means fasting without water or waterless fast which is very rigorous and can be done only by well-experienced fasters. Because it requires a complete water-less fast it is said to grant the same virtue as observing all 24 Ekadashi of the year.

Besides its spiritual significance it also offers health benefits like body detoxification and mental clarity, promoting spiritual growth by reducing worldly distractions and fostering a connection with one's higher self.  This day is ideal for fasting because the Moon's gravitational influences bodily fluids and observing fast is believed to balance these lunar effects, leading to purification, detoxification, and improved physical and mental well-being.

The fast begins at sunrise on Ekadashi day & the fast is broken on the following day (Dwadashi) after sunrise, often after prayers. If a full fast is not possible, allowed foods often include fruits, dairy products, nuts, certain flours (buckwheat, amaranth, water chestnut), and vegetables like potatoes and gourds.

Foods to Avoid: Grains (like rice and wheat) and pulses are typically avoided during the fast.

Ekadashi is the eleventh lunar day (tithi) of both the waxing (Shukla Paksha) and waning (Krishna Paksha) phases of the moon in a Vedic month and this explains why there are 2 Ekadashi in a lunar cycle (length of 1 lunar cycle is 29.5 days).

Shukla Paksha (Waxing Moon): Starts after the new moon (Amavasya) and ends with the full moon (Purnima). The Ekadashi in this phase is the 11th lunar day after the new moon.

Krishna Paksha (Waning Moon): Starts after the full moon (Purnima) and ends with the new moon (Amavasya). The Ekadashi in this phase is the 11th lunar day after the full moon.

What happens in our body during Ekadashi-

The gravitational force of the moon influences the Earth's bodies of water, causing ocean tides. Proponents of Ekadashi fasting believe this same gravitational pull influences the fluid within the human body, which is composed of 70–80% water.

This is the reason why grains and lentils are avoided during Ekadashi time because they tend to absorb water in our body and worsen the water tides inside making our digestion difficult and tremulous. But for those who cannot fast then fruits, juices and nuts are best options because they absorb less water.

Ekadashi Impact on the mind and body:

 The atmospheric and gravitational effects of the lunar cycle are said to increase more strongly in the days following Ekadashi, peaking during the full and new moons. By fasting on Ekadashi, the body is thought to be prepared for the increased gravitational stress in the coming days.

This effect occurs on the 11th day of both the waxing phase (leading to a full moon) and the waning phase (leading to a new moon), of each monthly calendar leading to 24 Ekadashi in a year. Because the moon influences water, it also affects the Swadhisthana chakra (sacral chakra) meaning women’s fertility and childbirth are deeply connected to lunar cycles.

Science still has a long way to go, but here’s what modern research and technology have revealed so far regarding Lunar cycles–

1. Lunar cycles profoundly affect Earth's tides and the behavior of some marine animals indicating that water elements have a crucial role to play.

2. Several studies suggest that people sleep less and go to bed later in the days leading up to a full moon.

3. A 2018 study of 17 patients with rapid-cycling bipolar disorder found that their depressive-to-manic mood shifts coincided with lunar cycles.

4. It is possible that humans still possess a "circalunar clock"—a biological mechanism that once governed behavior in response to lunar cycles, much like a circadian clock (which runs every 24 hours).

5. Research suggests that animals may use variations in the Earth's magnetic field, which are influenced by the moon, to maintain their biological calendars.

6. A study on Holstein cows found that the timing of spontaneous deliveries was significantly influenced by the moon phase, suggesting that remnant physiological effects may persist even after domestication.

7. The well-known correlation between the lunar and human menstrual cycles is widely considered a coincidence. A 2021 study, however, revived the discussion by suggesting that the human monthly oscillator may still be influenced by the lunar cycle, though light pollution (from modern desynchronization. This may help explain why women’s monthly cycles, as well as the natural rhythms of pregnancy and childbirth, have become increasingly unpredictable.

8. Circalunar (in humans) and circa tidal rhythms (in marine animals) are controlled by dedicated molecular mechanisms, though they can borrow elements from the circadian clock, such as the Bmal1 gene.

9. A study in 2013 on sleep patterns found that around the full moon, participants took longer to fall asleep, slept for shorter periods, and had reduced deep sleep. This was associated with lower levels of melatonin, a hormone regulated by light-sensitive cryptochrome proteins, which are encoded by circadian clock genes.

10. Future research-Some scientists hypothesize that certain individuals might have a greater genetic predisposition for sensing lunar influences due to "more ancient markers". While no specific human genes have been identified, the complex nature of genetic regulation means that a link cannot be completely ruled out, even if it is not a dominant factor in human biology.

Conclusion

It’s fascinating that Ayurveda and yoga recognized the deep connection between lunar cycles and the human body thousands of years ago. To balance this influence, fasting rituals were introduced—not as superstition, but as a way to correct water imbalances in the body. Since it was difficult for the rishis and maharishis (ancient day scientists in India) to explain the science behind it, they taught simple practices like fasting and spiritual observances, making them accessible even to uneducated village communities. Without telescopes, they not only named the different moon phases but also discovered the power of specific spiritual practices aligned with them.

Today, as modern science delves deeper into circalunar rhythms, we’re uncovering how they affect our body at the genomic level, particularly in relation to the swadhisthana chakra. Who knows, further research may hold answers to irregular cycles, recurrent miscarriages, and many challenges in women’s reproductive health. “The timeless wisdom of fasting laid down thousands of years ago provides a powerful foundation, one that modern science can now build upon to drive innovation and guide us toward true wellness.”