We don’t often get it, but when we do, us Irish really do strange things in the sun . With temperatures reaching a balmy 19 degrees last week, the shorts were out and the nostalgic smell of freshly-cut grass mixed with the soft fragrance of B.O from those who just ‘can’t handle this heat’ were back. The sandals with white socks got their annual outing and HB ice-cream sales rocketed. After a harsh winter this sunshine is welcomed and has lifted the spirits of an entire country. The ancient Greeks recognised Apollo as the god of medicine and healing as well as of sun and light, but Apollo (the sun) could cause illness as well as offer cure. Medicine today has a similarly divided acknowledgement that exposure to the ultraviolet radiation (UVR) in sunlight has both beneficial and harmful effects on human health (Mead, 2008; van der Rhee et al., 2013).
Australia has the highest skin cancer rate on Earth, which inspired the nation’s famed Slip! Slop! Slap! campaign. Launched in 1980, it advised Australians to slip on a shirt, slop on the sunscreen, and slap on a hat. This was an attempt to battle a steep rise in skin cancer. The southern hemisphere tilts toward the sun and in an Australian summer the sun beats down more directly than above the equator. It is harsh on the pale, blonde and redheaded European immigrants and their descendants. The Slip Slop Slap campaign was hugely successful, but Australia now face an epidemic of vitamin D deficiency. Vitamin D is made in our skin following exposure to sunlight. The required sunlight has to fall on bare skin for 20 to 30 minutes. Two to three exposures of sunlight per week during spring and summer months is enough to achieve healthy amounts of the vitamin in our bodies. The main action of vitamin D has long been known to help absorption of dietary calcium and phosphorus, which is essential for bone structure and strength. Vitamin D deficiencies leach calcium from muscles and bones, causing pain, weakness, fractures, osteoporosis, and osteomalacia. Called rickets in babies and children, the bone-deforming illness not seen since the mid-20th century has begun cropping up throughout the developed world including Ireland (Spiro & Buttriss, 2014). Appropriate Vitamin D levels can also lower disease rates for cancers including breast, prostate, and non-Hodgkin’s lymphoma, along with autoimmune diseases(van der Rhee et al., 2013).
In 2007 there were an estimated 60 to 70% of people with Vitamin D deficiencies in Australia. So after nearly half a century Australia is welcoming back the sun. The move follows this new understanding of skin cancer and vitamin D. In 2003, a landmark eight-year study of 106,379 Scandinavian women linked melanoma to sunburns (not tanning), blonde or red hair, and numbers of moles on the legs (Veierod et al., 2003) . A second article showed that people regularly exposed to daily sun actually have a lower risk of getting melanoma and also have a higher survival rate if they do because regular sun exposure protects against burning (Berwick et al., 2005), a finding later confirmed by a landmark 2008 World Health Organization (WHO) International Agency for Research on Cancer report.
Runners have a love hate relationship with the sun. Running in warm weather can be hard but soaking up the warmth and energy from the sun is lovely , especially after a winter of too many frigid, freezing wet and cold miles. Our bodies churn out vitamin D when the skin is exposed to sunlight. But that’s not the only role the sun plays, the skin houses large amounts of nitric oxide, a compound that dilates blood vessels to reduce blood pressure and lower the risk of heart attack and stroke. Sunlight activates those nitric oxide supplies and releases them into circulation (Liu et al., 2014). But more importantly spending time in the sun may lead to faster race times, The large stores of nitric oxide released from the skin help more blood and oxygen flow to working muscles helping runners go harder and longer (Muggeridge et al., 2015).
So get out in the sun, but don’t get burned, and remember its actually still only April and white socks and sandals never look good!
Berwick M, Armstrong BK, Ben-Porat L, Fine J, Kricker A, Eberle C & Barnhill R. (2005). Sun exposure and mortality from melanoma. J Natl Cancer Inst 97, 195-199.
Liu D, Fernandez BO, Hamilton A, Lang NN, Gallagher JMC, Newby DE, Feelisch M & Weller RB. (2014). UVA irradiation of human skin vasodilates arterial vasculature and lowers blood pressure independently of nitric oxide synthase. J Invest Dermatol 134, 1839-1846.
Mead MN. (2008). Benefits of sunlight: a bright spot for human health. Environ Health Perspect 116, A160-167.
Muggeridge DJ, Sculthorpe N, Grace FM, Willis G, Thornhill L, Weller RB, James PE & Easton C. (2015). Acute whole body UVA irradiation combined with nitrate ingestion enhances time trial performance in trained cyclists. Nitric Oxide 48, 3-9.
Spiro A & Buttriss JL. (2014). Vitamin D: An overview of vitamin D status and intake in Europe. Nutr Bull 39, 322-350.
van der Rhee H, Coebergh JW & de Vries E. (2013). Is prevention of cancer by sun exposure more than just the effect of vitamin D? A systematic review of epidemiological studies. Eur J Cancer 49, 1422-1436.
Veierod MB, Weiderpass E, Thorn M, Hansson J, Lund E, Armstrong B & Adami HO. (2003). A prospective study of pigmentation, sun exposure, and risk of cutaneous malignant melanoma in women. J Natl Cancer Inst 95, 1530-1538.