Shining a LIGHT on Thyroid Activity

Updated: Apr 13



The Circadian Thyroid Thyroid activity is fundamentally related to our biological need to 'act'. Transversely, it is also implicated when our body does not act, as this too will affect the thyroid function.

In Western Medical terms, the thyroid

  • Regulates our metabolic functions

  • Provides our cells with Energy


Even when our body is at rest we know that it requires energy to keep our essential functions running smoothly. Our heart beat, our lungs, our CNS, our brain, our digestive system, our rest and repair mechanisms are all being fueled and continue to do essential activities whilst we either rest or sleep.


The World has a natural balance - day follows night, as night follows day. Each is important and has a function, profoundly influencing and affecting how all life develops upon the Planet.


Similarly, our biology has a natural balance. Our cells and our biological systems did not evolve in isolation, but in symbiotic harmony with the cycles of the Earth itself.

There is a time for all things, and that timing is reflected in the development and regulation of our body, as we move through different times of the day, the month, the quarterly seasons of the year and the life cycle of years themselves.

The Traditional Chinese Medicine Body Clock

In Traditional Chinese Medicine (TCM) the body clock is classified as being relative to 12 divisions. These 12 divisions are all connected to the 'Meridians' of the body (a circuitry of energetic pathways which carry life-giving 'qi' to every part of the body).


These meridians are classified by the main organs that they traverse on their pathway through the body, although in reality the meridians are not 12 separate pathways, but one energetic pathway that is completely joined together. (We divide and separate the energy pathways into 12, in order to assist our understanding and the practical applications of each meridian).


As each Meridian channel moves through a main organ of the body (such as the liver, the large intestine or the heart), the organs themselves are regulated by the amount of 'energy' required for each organ and its system function (what its main function is within the overall body). Therefore the meridian clock indicates to us which of the channels and/or organs are at their 'zenith' point, and are receiving the greater concentration of 'qi' as it moves through the body throughout the daily (or seasonal cycle).


This makes complete sense, when we consider that within the natural cycles of the Earth. the body has need of different functions at different times of day or night. Therefore we see the overall regulation of energy requirement across the whole body system is guided by this natural cycle.

We can see how uncomplicated biological requirements are fulfilled by the rise and fall of the meridian energy flow throughout the 24 hour hour cycle in this illustration:




The Pineal Gland & Light The Pineal gland is a small endocrine gland in the brain that modulates sleep patterns and therefore has an affect upon our circadian rhythms and how our body adapts to the cycles of the seasons, particularly through the influence of 'light'.

The relationship between the pineal gland and thyroid hormones was explored, and this test showed that thyroid hormone levels vary throughout the daytime, depending upon the levels of light. Although it sits almost in the very centre of the brain, in its deepest, most protected part, it is in fact a 'photoreceptor'. A sensor of the light.

Within esoteric wisdom, this tiny gland, hidden deep in our brains is associated with our ability to 'see the light', to become 'awakened', or indeed to become 'super-conscious'. It is akin to a tiny lighthouse in our mind, that not only has a very biological function in regulating our body patterns in response to the affects of light and dark, but also in regulating our deepest conscious responses to becoming personally 'enlightened'.


I think it is interesting to reflect on the pineal gland and its influence over the thyroid in relation to this aspect of its functionality.

We might individually spend some time reflecting on where in our life we "need to see the light", or indeed if there is a deeper reason to our situation, one which may be providing us with an opportunity to 'awaken' to a different level of awareness, of our own conscious evolution or 'enlightenment'...?


Thyroid Hormones & Circadian Rhythms

The Thyroid Circadian Rhythm precedes the circadian body temperature rhythm by 2 hours.

In the journal of Pineal Research, Jerry Friend published the results of a study (1984) that explored the influence of the pineal gland on thyroid hormones. Thyroxin (T4) and triiodothyronine (T3) were measured by radioimmunoassay at 4-hr intervals throughout the daily light-dark cycle (14L/10D). Both T4 and T3 concentrations increased significantly during the 'light' (L) period of the daily cycle and decreased during the 'dark' (D) period of the cycle; A.M. versus P.M. differences in free thyroxin indices (FTI) were also studied and was significantly greater in serum samples at 7 P.M. than at 7 A.M. (with lights on at 6:30 A.M.). Serum taken at 7 P.M. had less unsaturated binding sites than serum taken at 7 A.M.

The influence of light on these rhythms is clear. The same experiment also used blind subjects. There were no significant changes in levels between L & D cycles for the blind subjects, although their T4 and FTI's were significantly lower in general. This blind group was used as a comparison, with the differentiation being 'sight' and the 'eyes' being defined as the main source of light into the brain (and therefore the pineal gland itself.

In a separate research article published by Elsevier, E. Decuypere and E. R. Khun showed the effects of fasting and feeding on thyroid hormonal activity. This article concluded "Shifts in time of meal-eating were paralleled by shifts in circadian rhythms of glucose, rectal temperature, and serum T4 and T3 levels...serum rhythms of T3 and T4 are totally or partly due to meal-time-related shifts in 5′-monodeiodinase activity."


Therefore we can see that both eating times and daylight influences have an effect upon circadian rhythms, which in turn have an effect upon thyroid hormone activity.

To conclude these include:

  • 5' - monodeiodinase activity (controlled by mealtime shifts)

  • T3 & T4 Levels being variable in light or dark time periods

  • Hormone binding ability (AM/PM variations)

  • Lowered T3 levels in periods of fasting

  • Higher T4 levels in periods of fasting