Written by Amber Walker, Owner of Origin Wellness
Amber Walker is a Doctor of Physical Therapy-turned author with a passion to empower others to heal from chronic illness. As the owner of Origin Wellness, Amber utilizes an approach based on a blend of functional/natural medicine, nervous system tools, nutrition, movement, and emotional healing to help patients move from surviving to thriving.
We spend approximately 93% of our lives indoors in Westernized countries. A study of Americans in the 1990s determined that we spend 87% of our time in enclosed buildings and about 6% of our time in enclosed vehicles. That was before the use of the internet and electronic devices became widespread. This number increases significantly if you live in northern locations, where daylight and air temperature reduce opportunities to be outside in natural light.
Fear of skin cancer and chemical-laden sunscreen products has been ingrained in many cultures and accepted as common knowledge. But have you ever stopped to look at what science says about sun exposure? The truth is that lifestyle and toxic burden cause cancer and inflammation in the body, not the sun. This article shares ideas for harnessing the healing power of natural light, the sun, and other circadian biology factors to optimize cellular function and health.
What is circadian biology?
Circadian biology is the cellular science of 24-hour cycles that are part of the body’s internal clock, running in the background to carry out essential functions and processes. The biggest factors that impact it are light signaling, body temperature, sleep habits, and nutrition. Circadian biology affects detoxification, glucose and lipid metabolism, insulin sensitivity and diabetes, obesity, appetite regulation, thyroid hormones, sex hormones, gut health, and emotional processing and release. Circadian optimization is emerging as a potent tool in reversing chronic inflammation and disease.
What are the major circadian hormones?
Leptin is the master circadian hormone. It gives directions to other downstream hormones and regulates energy metabolism via appetite modulation. It signals factors for fertility, thyroid and sex hormones, the glucose-insulin axis, and stored energy. Leptin reports to the brain every night and rises at bedtime, subduing the need to eat by reassuring the brain that energy reserves are adequate so that you can sleep more deeply. Leptin levels decrease with chronic sleep issues.
Leptin is produced by the body’s fat cells. When you eat, your body’s leptin levels rise proportionally, and when you fast, they decrease, signaling that you need to eat. Because individuals with obesity tend to have more fat cells, they also have high levels of leptin, which normally signals the body that enough energy is stored. However, with leptin resistance, the brain is less sensitive to leptin or fails to recognize the signaling process. This can perpetuate factors like obesity, insulin resistance, and metabolic disorders.
Melatonin eases you into sleep and helps you stay asleep, while cortisol, which normally spikes in the morning, helps wake you up and keeps you alert. Melatonin plays many roles in helping the body heal beyond sleep-wake cycles. Artificial light exposure and certain medications, such as beta-blockers, suppress melatonin, while infrared light boosts it.
Ghrelin acts on the hypothalamic-pituitary axis and other areas of the brain to stimulate hunger and promote feeding. It increases before mealtimes. Acute sleep deprivation raises ghrelin levels and, consequently, hunger. Getting less than 7.7 hours of sleep per night is associated with a higher body mass index (BMI) and abnormalities in leptin and ghrelin, signaling limited energy supply to the brain and leading to increased eating. Growth hormone is regulated by ghrelin and leptin and is influenced by light-dark signaling.
The truth about the sun
We don’t need synthetic vitamin D; we need the sun! The benefits of the sun go far beyond vitamin D. The amount and intensity of solar radiation depend on a variety of factors, including latitude, season, time of day, ozone levels, ground reflection, cloud cover, and altitude. Sunlight delivers proportionally more red and near-infrared light during the early morning or evening (closer to sunrise and sunset). It also provides blue light and ultraviolet light, which, in the right dosages, can be healing for the body.
Ultraviolet radiation
Stimulates anti-inflammatory pathways
Alters the composition of dendritic cells, T cells, and T regulatory cells
Induces nitric oxide synthase and heme oxygenase metabolic pathways
Mitigates disease progression and susceptibility
What causes us to burn?
Research from 45 years ago began to note mast cell degranulation, perivenular edema, elevated histamine levels, and increased prostaglandins when people were sunburned.
What are the upstream issues triggering these responses?
Nutritional issues, preservatives, seed oils
Contaminated drinking water
Toxins in the air and products
Improper light signaling to the eyes
Irregular sun exposure or improper dosage of light (e.g., spending all day at the beach in July with sunglasses on)
When people practice intermittent fasting, they notice less skin irritation, don’t tend to burn as easily, experience better wound healing and improved skin immune health, and show fewer signs of skin aging. What if burning was a report card for overall inflammation in the body – similar to how the menstrual period is a monthly indicator of overall health status?
Obviously, certain ethnic and genetic factors also play a role in a person’s sun tolerance. You can use the Fitzpatrick Scale to determine your skin type and decide how much sun exposure is appropriate. It’s recommended to get some direct sun exposure each day (without sunscreen) and then cover up after reaching a certain threshold to give your skin the right dosage.
Side note: Sunscreen is highly toxic – even the so-called “natural” and mineral versions. Ingredients in sunscreen have been linked to genotoxicity, cytotoxicity, neurotoxicity, cancer, allergies, birth defects, endocrine and sex hormone disruption, and lung inflammation.
What does the research say about light?
Skin cancer studies are often based on exposure to UV light bulbs, which lack natural blue, red, infrared, or near-infrared light. In other words, no natural light is studied. Much of the skin cancer research is funded by companies with conflicts of interest.
Research on artificial blue light shows associations with cancer (breast cancer, prostate cancer, and skin cancer), retinal damage, and age-related macular degeneration. Artificial blue light is what we are most commonly exposed to indoors.
A multitude of studies suggests increased rates of cancer, depression and mood disorders, obesity, cardiovascular disease, diabetes, gastrointestinal issues, and problems with fertility and pregnancy in shift workers. Melatonin and cortisol levels are often disrupted in individuals who work night shifts.
There’s also increasing research on the “sunscreen paradox,” which notes that while sunscreen usage has risen, melanoma rates have also increased.
Additionally, there are over 10,000 studies on red light therapy and its benefits. However, red light panels do not contain UV light – we need the sun too! Sun-based blue light regulates cortisol, one of our key stress hormones. Light signaling impacts the mitochondria, which play a role in healing virtually every disease.
Circadian optimization tips
What if we treated our light diet with the same level of importance as our food diet? This is an emerging focus in the holistic medicine world. Below are some tips to help optimize your circadian rhythm, hormones, and cellular function.
Light
Spend at least ten minutes outside around sunrise and sunset to absorb red and infrared light. If you live in a cold climate, bundle up or sit near a window while gazing at the horizon.
Get neuropeptide and neurohormone benefits by exposing yourself to a measured dose of midday sun.
Use red light therapy during daytime hours.
Wear blue light-blocking glasses at home and at night.
Avoid excessive sunglasses use. If you wear contact lenses, opt for daily lenses and avoid those that block light to the eye.
Nutrition
Eat more local and seasonal foods.
Maintain regular meal intervals.
Have your last meal at least two to three hours before bed.
If you practice intermittent fasting, skipping dinner instead of breakfast may offer additional benefits.
Drink filtered water to reduce your toxic burden.
Body temperature
Take a cold shower in the morning to increase core body temperature.
Take a warm shower in the evening to help lower core body temperature.
Exercise in the morning or midday to improve sleep and energy levels.
Sleep
Maintain consistent sleep and wake times. Aim to be in bed by 10 p.m. to support optimal detoxification and organ function. Rising earlier in the summer and sleeping later in the winter is fine – follow the sun’s natural rhythm.
Avoid shift work and excessive caffeine intake.
Limit screen time at night. Engaging with social media in the evening can alter dopamine levels and increase exposure to harmful blue light, negatively impacting sleep. Dim the lights in the evening and consider stopping all screen time two hours before bed.
Develop a relaxing evening routine and avoid consuming news, engaging in conflict, or working late in the day. Keep the bed as a sanctuary, free from devices and TV.
Reduce exposure to electric and magnetic frequencies (EMFs). Keep phones away from the bed and set them to airplane mode when near the body. Turn off Wi-Fi at night, check for dirty electricity near the bed, and avoid metallic bed frames.
These practices have a profound impact on circadian hormones and cellular function, ultimately leading to greater well-being and longevity. A great starting point is to incorporate short, sunscreen-free sun exposure each day. Increase your outdoor time relative to indoor time and observe how your health responds. Additionally, working with a foundational medicine practitioner to support detoxification and drainage pathways can help address upstream causes of inflammation, leading to better health and a reduced propensity for sunburn.
Read more from Amber Walker
Amber Walker, Owner of Origin Wellness
Amber Walker is a Doctor of Physical Therapy, author and the owner of Origin Wellness. She is passionate about a root issues approach to healing from chronic illness and has advanced training in functional medicine, nutrition, nervous system healing, Mind Body Spirit Release™ (MBSR™) and CranioBiotic Technique. With over 16 years of experience working with clients all over the world, Amber specializes in conditions such as mast cell activation syndrome, mold biotoxin illness, long Covid, POTS, Ehlers-Danlos syndrome, Lyme disease, autoimmune conditions, and chronic mysterious ailments. When not on a surfboard, she enjoys hosting telehealth groups, 1-on-1 care, and retreats in Mexico. Her mission: Help you go from surviving to thriving.
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