Solar Rhythms in Ayurveda and Chinese Medicine
Introduction
The oldest Asian medical traditions are rooted in a worldview that recognizes the human being and the universe as a unified interdependent process. A fundamental etiological paradigm across these systems is the notion of disease as an “interruption” or “disconnection” from the larger functional, energetic, and spiritual context of our existence. It is for this reason that Ayurveda, Tibetan Medicine, and Chinese Medicine emphasize the need to live in harmony with the natural world and its cyclical laws. If we live in step with the rhythms of nature, we will remain in the flow of the universal life-force, and remain resilient. This understanding readily translates into dietary and lifestyle principles such as a seasonal and locally-sourced diet and a daily routine aligned to the cycles of day and night. While the three aforementioned systems share this understanding, they vary slightly in their application of these principles.
Mealtimes in Ayurveda and Chinese Medicine
For example, Ayurveda and Chinese Medicine offer differing perspectives on when to eat the largest meal of the day. According to Ayurveda, our digestive fire (agni) moves in tandem with the cycles of the Sun. The Sun reaches its peak at noon and so does our digestive power. Given this, Ayurveda advises that we eat our largest meal between the hours of 11am-1pm. I remember my teacher, Vaidya Mishra, saying that the digestive fire is like a low flame in the morning, but as the day (and Sunlight) progresses, the digestive flame increases enabling us to process more food, before waning again as dusk approaches.
Chinese Medicine also bases its lifestyle principles on the solar cycle of day and night, commonly known as the “Chinese clock” or “Meridian clock”. This biorhythmic clock divides the 24hr cycle of day and night into 12 divisions spanning two hours each. Each of the twelve meridians experiences peak energetic activity during a two-hour segment. The clock also maps the progression of the five phase-elements, with each consecutive 4hr division belonging to a single phase-element.
Within this schema, the Stomach meridian reaches its peak during the hours of 7-9am, followed by the Spleen from 9-11am. From the perspective of Chinese Medicine, during these hours the Stomach is more equipped than at any other time of day to receive and digest food. Once it does, the Spleen is able to transform and transport the energy derived from food throughout the whole system. If we eat too lightly in the morning, our energy levels will be compromised for the entire day and we might experience an afternoon crash. This is why breakfast is given unique importance in Chinese Medicine.
How to reconcile these views? Ayurveda and Chinese Medicine both share the same fundamental philosophy of unity and balance in the microcosm-macrocosm dynamic. Ayurveda and Chinese Medicine both classify the Stomach within the Earth element. And both systems agree that the solar peak occurs at noon. In the Chinese clock, noon is the mid-point of Heart’s hours (11am - 1pm). The Heart is associated with the Fire element and occupies the unique status of being the “Supreme Controller”. We see a similar emphasis in Ayurveda’s designation of agni as the root-intelligence of the body system. Despite this convergence, Chinese Medicine does not advocate we eat our biggest meal of the day during the solar peak. I believe some insight can be gained into this when we consider how energetic cycles wax, peak, and wane.
The paradox is that the apex of energy is the beginning of its declination. Therefore, the solar peak functions as a pivot. The apex of the Summer Solstice marks the beginning of the Sun’s waning cycle. However, during Spring, the solar energy is waxing and moving toward its maximum. In Vedic astrology, the Sun is considered exalted in the sign of Aries—the zero-point of the zodiac which coincides with the Spring equinox. The Sun is not exalted in Cancer, the sign it occupies at the Summer Solstice. In my view, the Chinese recommendation to eat the biggest meal at breakfast accords with the understanding that the solar energy is stronger on the arc toward the apex rather than at the apex itself.
Clock Time vs. Solar Time
Coincidentally, we need to remember the difference between clock time and solar time. Clock time is a stable unit of measurement that roughly coincides with the solar cycle, but not entirely. The modern adoption of daylight savings time complicates the issue, as does geographical location and seasonal variations. The time cycles referred to in traditional medicine are not “clock time” but solar time which describes the actual movement of the Sun in relationship to the Earth. Therefore, solar noon is not necessarily “12pm”, but is rather an astronomical reality when the Sun is directly overhead, otherwise known as “true noon”. In Hawaiian tradition, the solar peak is known as “lahaina” and is considered an auspicious time for certain rituals. Consider the very real difference between this and the convention of “12pm”. While we must live with the conventions of clock time, it is very important that we consider the realities of solar time as the true biorhythm informing our life. In clinical practice, practitioners have to be careful not to make meridian associations with the patient’s report (especially in regards to what time they wake up in the middle of the night or when their symptoms worsen). If we take clock time as the reality, we will often associate the wrong meridian with the patient’s symptoms. We need to convert the reported clock time to “meridian time”. This also applies, most importantly, to biorhythmic-based treatments (such as horary treatments in acupuncture).
No Absolutes
Ultimately, it is difficult to reconcile the contrasting views of Ayurveda and Chinese Medicine on this topic. In many ways, their views coincide, and in other ways they diverge. Neither one is more “correct” than the other. I have tested both approaches and know what works better for me, but that is how it is for me and not necessarily someone else. Those who want to follow the meridian clock approach should make sure they are actually eating between 7-9am solar time. For one following the Ayurvedic approach, eating while the Sun is still waxing towards its maximum, sometime between 11am-noon solar time (rather than at noon or after noon, when the Sun is beginning to wane) is recommended. It is worth noting that, in Tibetan Medicine, the Chinese approach of eating a large breakfast is adopted. Given the Tibetan’s significant incorporation of Ayurvedic and Chinese medical theories into their system, they were undoubtedly aware of both paradigms. I remember Menpa Wangmo saying the traditional recommendation is to eat breakfast like a king, lunch like a prince, and dinner like a pauper.
These biorhythmic considerations are becoming more of a challenge to implement amidst modern conventions. Society prefers a fixed measure of time around which to organize productivity, instead of following the natural cycle. Consider if our days were actually longer in Spring and Summer, and we worked more during the yang period of the year. If we work during the yang period of the year, we will have enough to store when the days shorten in Winter. Then we will have earned a much deserved rest. We would rejuvenate in the Winter and be prepared when Spring arrives again. Admittedly, such notions seem unattainable today, but that does not mean we should forget their value. Life becomes rich and simple when we realize that to heal is to live in the natural order, amidst the mysterious elegance of life’s radiant power.