What regulates circadian rhythms and its impact on skin health

Since circadian rhythms reached mainstream discourse thanks to the 2017 Nobel Prize, the question on how to regulate circadian rhythms has been at the center of many innovative health approaches and treatments. 

More recently, groundbreaking cosmetic science efforts are discovering the implications of circadian rhythms for skin health, thus opening the door for revolutionary treatments. More specifically, research around the bodies’ internal clocks is unveiling opportunities for a new science for well-aging, while also opening the door for better understanding the link between circadian rhythm disruptions and a host of skin problems, including premature aging and reduced skin barrier function. 

In this context, understanding the scientific basis behind what regulates circadian rhythms is key to incorporating natural skincare products that are able to support a healthy skin cycle.

Understanding the circadian rhythm

The circadian rhythm is a 24-hour cycle that influences human beings’ sleep-wake cycle, as well as hormone production and metabolism. 

Often referred as the body’s internal clock, this cycle is primarily regulated by the suprachiasmatic nucleus (SCN), a region of  the brain that receives light and dark signals: when the SCN detects light, it triggers the production of cortisol, a hormone that promotes wakefulness; as darkness falls, the SCN signals the production of melatonin, a hormone that promotes sleep. 

Research around what regulates circadian rhythm has focused on issues related to this cycle’s disruption. Sudden changes in sleep cycles or disruption in sleep patterns cause melatonin to be released without alignment with natural light cues. The consequences have been associated with a host of issues, from metabolic disease, to cognitive malfunction and a compromised immune system (Zisapel, 2018).

Regulating the circadian cycle thus has far-reaching consequences in terms of overall health, with implications also involving skin and muscle repair. Regarding this, recent scientific findings on two complementary research articles (published simultaneously in the journals Science and Cell Stem Cell by a team of scientists from the UPF and IRB Barcelona) reveal that central and peripheral circadian clocks coordinate to regulate the daily activity of skin and muscles. The coordination between the two clocks (central and peripheral) guarantees 50% of the circadian functions of tissues, including vital processes such as the cell cycle, DNA repair, mitochondrial activity, and metabolism. As such, synchronization between the central brain clock and peripheral ones prevents premature muscle aging and improves muscle function. This research proves particularly fascinating in suggesting new strategies to tackle age-related decline through circadian rhythm modulation.

Three FAQs about circadian rhythm, explained

What part of the brain regulates circadian rhythm?

The suprachiasmatic nucleus (SCN), which comprises 20,000 nerve cells and is located in the hypothalamus, serves as the main system that regulates the circadian rhythm.

Which hormone regulates circadian rhythms?

Melatonin, secreted by the pineal gland, is the main hormone related to circadian rhythms. This hormone is secreted at night driven by the brain’s circadian centers, and its dysregulation is related to disorders related to sleep and circadian rhythms. Melatonin is also related to immune regulation and modulation of pituitary and adrenal hormones (Malhotra et al., 2004).

How do I reset my circadian rhythm?

The question around what regulates circadian rhythms is at the center of innovative treatments looking at the body’s internal clocks and their effects on health. This is also true of those looking at how to reset circadian rhythms as part of holistic skincare treatments.

In addition to using natural skincare products, there are some key lifestyle choices that help regulate circadian rhythms:

• A consistent sleep schedule, that is, going to bed and waking up at the same time each day, even on weekends. 
• Limiting screen time before bed, as blue light emitted by electronic devices can interfere with sleep. It’s precisely in this context where blue light skincare is also emerging as a key trend. 
• Creating a relaxing bedtime routine, engaging in calming activities like reading or taking a warm bath before bed.
• Practicing stress-reduction techniques (such as meditation or yoga), as chronic stress can disrupt the circadian rhythm.
• Exposing yourself to natural light and spending time outdoors during the day, providing the right cues for the suprachiasmatic nucleus (SCN).

How does circadian rhythm affect skin? What the science says 

As well as the effects on overall health described above, disruption of the circadian clock also has several implications for skin health. 

Research initiatives have analyzed the relationship between circadian rhythms and transepidermal water loss and keratinocyte proliferation (Matsunaga et al., 2014); or its impact on skin barrier function, finding that skin permeability is higher in the evening and night than in the morning (Yosipovitch et al., 1998).

When looking at the effect of circadian rhythms and skin health, there are two major areas to be considered: 

• Cellular repair.

Understanding skin damage repair and circadian rhythms lies at the heart of circadian rhythm skincare. Put simply, skin cells are most active in repairing damage during the night, when melatonin levels are high. That is the time when cellular detoxification takes place, the process by which cells remove harmful substances, toxins, and cellular by-products. 

Because cellular detoxification displays rhythmic patterns of activity that are tightly regulated by the circadian clock, addressing the circadian cycle is a key move to promote cellular detoxification, therefore supporting the processes that ensure cells can maintain their normal function and overall health.

• Antioxidant activity

On the one hand, the body’s antioxidant defenses can be influenced by the circadian rhythm and, consequently, vary throughout the day.

Behind these mechanisms is melatonin, which has been found to be “uncommonly effective in reducing oxidative stress under a remarkably large number of circumstances” by both “direct detoxification of reactive oxygen and reactive nitrogen species and indirectly by stimulating antioxidant enzymes while suppressing the activity of pro-oxidant enzymes” (Reiter et al., 2016).

Circanblue™: the natural ingredient to resynchronize the skin’s circadian rhythm

Provital’s commitment to innovative natural cosmetic science is behind the launch of Circanblue™, a biotechnological vegan solution that is capable of regulating the skin’s circadian clock.

Circanblue helps resynchronize the skin’s natural biorhythm in order to counter digitally-induced desynchronization of the circadian cycle for healthy skin well-aging.

A postbiotic natural active, it has shown efficacy in enabling chrono-protective activity against blue light, as well as in supporting the skin’s natural repairing and detoxifying capacities linked to cellular repair and circadian rhythms.

More specifically, testing protocols showed: 

• Keratinocytes treated with Circanblue™ restored the expression rhythm of both genes CLOCK and CRY1 closer to non-irradiated cells, returning gene expressions to basal levels after 24 h. 
• The ingredient’s cellular detoxification activity via the activation of cellular pathways related to the circadian rhythm (Nqo-1 and Hmox1).
• The modulation of genes related to the skin’s circadian cycle, including a melatonin receptor (MTR1) and a repairing enzyme (SIRT1), which suggest the ingredient presents antioxidant activity through ROS scavenging, thus promoting mitochondria homeostasis and anti-inflammatory activity.

As such, Circanblue™ stands at the forefront of skincare innovation looking at circadian rhythm regulation, all through the prism of natural skincare that aligns with consumers preferences for holistic health and beauty.