What is circadian rhythm & how does it affect your health?

Life Extension, an alarm clock on a small table and a person next to a bed in front of a light window stretching

In our body, circadian rhythm regulates all aspects of our health from sleep to heart rate, blood pressure to hormone release, neurological function, lifespan, and even obesity. (1)

Researchers are discovering a new role for circadian rhythm to help foster longevity. They have found two compounds to help synchronize and restore youthful operation to our circadian rhythm. The priority is to enable older persons to regain control over this essential health- and longevity function.

The potential of this area of research is so promising that three American researchers won the Nobel Prize in Physiology or Medicine for their work on the mechanisms of circadian rhythm. (2)

Lab studies from MIT show that a robust circadian rhythm is correlated with a longer lifespan. Other MIT studies propose that it may soon be possible to prevent and treat the diseases of aging by enhancing circadian function. (3)

The urgency of this research cannot be overstated. Disruption of our circadian rhythms is increasing in modern societies.

While aging itself is a factor, exposure to blue light from cell phones and computers, jet-lag travel, and certain medications worsen it. One of the first signs of circadian disruption is poor sleep performance. (4)

Changes in sleep and circadian rhythm are now linked with aging at the molecular level, as well as with disorders of aging including neurodegenerative disease. (5,6)

Based on a continuing flow of confirmatory data, Life Extension® scientists sought to identify a way to help restore the body’s circadian rhythm to a more youthful state.

Circadian rhythm, sleep, and aging

Circadian rhythm and body clock:

Nearly every cell in our body has an internal “clock” that responds to changes in light perception and exposure, helping create our circadian rhythm and our own inner body clocks.

There is a central clock in the human brain that syncs with our circadian rhythm and regulates body functions such as wakefulness, sleep, body temperature, and hormone regulation according to the time of day.

Use of cellphones and other mobile devices exposes users to blue light, which suppresses melatonin levels.

In addition to the central clock in the brain, each of our cells in various organs contain a peripheral clock that takes its orders from the central clock. These peripheral clocks help regulate how our body functions, including our metabolism and myriad biochemical pathways.

Together, the central clock and the peripheral clocks regulate all physical functions in relation to circadian rhythm and the time of day.

Sleep and circadian rhythm:

One of the key functions of circadian rhythm is to regulate our sleep cycle. Taking cues from our outside environment, the body begins to release increased melatonin levels as light levels fall and lower melatonin levels as light levels rise with the start of a new day.

People with sleep problems almost always have disrupted biological clocks, which puts them at increased risk for cardiovascularneurological, and metabolic disorders (obesity, metabolic syndrome, diabetes). (7-14)

Regulating the central clock with melatonin:

The human body contains two types of clocks that respond to circadian rhythm. We function optimally when both types of clocks are harmoniously coordinated.

Life Extension scientists have found that we can keep our central clock in sync with melatonin and our peripheral clocks operating optimally with an extract from citrus peel called nobiletin. This unique nutritional approach targets both central and peripheral clocks to regulate circadian rhythm.

The central clock in the brain operates on light detected through the eyes. With the first light of day, our body turns on the systems, ready for activity. With the arrival of nightfall, our systems begin to shut down and prepare for sleep.

This activity is regulated in part through melatonin secretions from the brain’s pineal gland. This release of melatonin helps normalize hormone and neurotransmitter functions controlled by the brain and its central clock.

Science has shown that the hormone melatonin plays a critical role in keeping the central clock in sync with the environment and can restore our circadian rhythms through healthful sleep. (14,15) Melatonin also increases production of the longevity-promoting protein SIRT1. (16,17)

MIT scientists have shown that SIRT1 helps regulate circadian rhythm and protect against the diseases of aging. (3) So melatonin activates SIRT1 and SIRT1 helps regulate the central clock and potentially prevents degradation of circadian rhythm 

Melatonin tunes up and regulates the central clock so that it can better communicate with the body’s peripheral clocks.

The central and peripheral clocks need to be coordinated and talking to one another to manage all of the body’s systems. As circadian rhythm becomes dysregulated through age and lifestyle, this essential communication between the clocks becomes impaired and systems begin to fail. 

Regulating peripheral clocks with nobiletin:

In addition to the central clock in the brain, our individual cells contain a peripheral clock that regulates many critical biological functions including liver function, blood pressure, new cell growth, and the release of hormones. (8,18-21)

New research indicates that nobiletin, derived from citrus peels, regulates peripheral clocks, fostering natural circadian rhythm. (22)

Researchers at the University of Texas Health Science Center at Houston conducted a detailed animal study using nobiletin to modulate the peripheral clocks in mice. (22) 

This study in mice with metabolic syndrome demonstrated the impact of circadian clock regulation on weight gainResearchers fed mice a high-fat diet that was supplemented with nobiletin for 10 weeks.

The nobiletin-supplemented mice gained significantly less weight during the study compared with mice who received no treatment. 

Further, these researchers found that the lack of weight-gain was related to the beneficial effect on circadian rhythm rather than to any direct biochemical action of nobiletin. (22)

This animal study suggests that resetting biological peripheral clocks with nobiletin may have a beneficial impact on body weight and metabolism.

Supplements to promote circadian sleep

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  1. Available at: https://www.nigms.nih.gov/education/pages/factsheet_circadianrhythms.aspx. Accessed July 31, 2018.
  2. Available at: https://www.nobelprize.org/nobel_prizes/medicine/laureates/2017/press.html. Accessed July 31, 2018.
  3. Available at: http://news.mit.edu/2013/the-link-between-circadian-rhythms-and-aging-0620. Accessed August 2, 2018.
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  23. Original source from Life Extension®: https://www.lifeextension.com/magazine/2018/ss/circadian-rhythm-sleep-and-aging