Slip Slop Slap – Have We Got It Wrong?
Sunlight provides many more benefits beyond the effect on the SCN and our circadian rhythms. In Australia we are taught to fear the sun, due to the ‘risk’ of melanoma, skin, and eye damage. Most everyone my age remembers the introduction of the ‘Slip, Slop, Slap’ campaign that was released in the 80’s and drummed into us to ‘Slip on a shirt, slop on some sunscreen, and slap on a hat’, and boy did it work.
Over the years, kids have gone from being able to play at lunch time in the clothes they arrived in, to being made to wear hats, and now sunblock is compulsory for parents to pack. I cringe when I walk past playgrounds and see children covered head to toe, even fighting with their oversized hats to see properly, and reeking of toxic chemicals that prevent them from ever absorbing the many benefits of sunlight on your bare skin. Not to mention the sunglasses…
So, what benefits can you get from “having as much skin in the game as possible”, as Dr. Jack Kruse always says?!
Vitamin D synthesis: Sunlight contains ultraviolet B (UVB) radiation, which stimulates the production of vitamin D in the skin. When UVB rays penetrate the skin, they interact with a precursor molecule called 7-dehydrocholesterol, converting it into vitamin D3 (cholecalciferol). Vitamin D plays a crucial role in calcium absorption, bone health, immune function, and numerous other physiological processes.
Mood regulation: Sunlight exposure triggers the release of endorphins, which are neurotransmitters that promote feelings of happiness and well-being. Endorphins have analgesic properties and can help to reduce pain and stress, leading to improved mood and relaxation.
Nitric oxide release: Sunlight exposure stimulates the production of nitric oxide (NO) in the skin. Nitric oxide is a signaling molecule that helps to dilate blood vessels, improve blood flow, and lower blood pressure. Increased NO levels contribute to cardiovascular health and may have anti-inflammatory effects.
Skin health: Skin cells, like many other cells in the body, have their own circadian clocks. Exposure to natural light, particularly in the morning, helps synchronise these peripheral clocks with the master clock in the suprachiasmatic nucleus (SCN) of the brain. Proper synchronisation of circadian rhythms is essential for maintaining and controlling skin health including the regulation of skin cell proliferation, repair, and immune responses like eczema and psoriasis. Exposure to sunlight triggers the production of melanin, the pigment responsible for skin color. Melanin acts as a natural sunscreen, absorbing and dissipating harmful UV radiation to protect the skin from damage. Increased melanin production helps to reduce the risk of sunburn and skin cancer associated with excessive UV exposure.
Wound healing: Certain wavelengths of sunlight, particularly near-infrared (NIR) radiation, have been shown to promote wound healing and tissue repair. NIR light penetrates deep into the skin, stimulating cellular metabolism, increasing blood flow, and enhancing the production of collagen and elastin, which are essential for skin regeneration.
Breast health: Sunlight exposure can help reduce inflammation in the breast tissue. The production of vitamin D, stimulated by UVB radiation from sunlight, has anti-inflammatory properties. Balanced hormone levels are crucial for maintaining breast health and reducing the risk of hormonal-related breast conditions.
Gut health: UVB radiation, can positively impact the gut microbiota. Research has shown that sunlight can alter the composition and diversity of gut bacteria, promoting the growth of beneficial bacteria and suppressing harmful ones. Sunlight on the gut maintains the integrity of the gut lining and reduces gut inflammation, which can prevent or alleviate conditions such as inflammatory bowel disease and other gastrointestinal disorders.
Cardiovascular health: Sunlight can influence the production of cytokines, proteins that play a role in the immune response. Balanced cytokine levels can reduce systemic inflammation, lowering the risk of inflammatory conditions that affect the heart. Sunlight exposure can enhance the body’s production of antioxidants, which help neutralise free radicals that can cause cellular damage, including to cardiac cells. Reducing oxidative stress is essential for preventing heart disease and related complications. Sunlight exposure may influence lipid metabolism, potentially improving cholesterol profiles. Adequate vitamin D levels have been linked to lower levels of low-density lipoprotein (LDL) cholesterol and higher levels of high-density lipoprotein (HDL) cholesterol, which are beneficial for heart health. It also lowers triglycerides.
Working in an office or a WFH set-up seriously restricts our access to sunlight, but we really need to prioritise our health and make time to get as much sun exposure in over our working days as possible. 10 min ‘sun breaks’ every hour is a good start, and if you can, a longer sunning period during lunch time. Try downloading MyCircadianApp to see when UVA and UVB is present in your area and make an effort to increase your Vitamin D levels without supplementation.