By Jenny Livanos, Optometrist & Nutritionist
Summer 2011/12 True Natural Health Magazine
The sun is essential to life and highly beneficial for physical and mental health. Visible and invisible portions of the light spectrum, especially ultraviolet, act as the ignition system for many of our biological functions. Life on Earth evolved under the sun – prehistoric tribes and ancient civilisations worshiped and used sunlight for its healing powers.
Sunlight exposure has been found to reduce cancer risk, especially that of the prostate, breast, lung and colon. Chronic skin conditions, diabetes, cardiovascular disease, and hypertension can be assisted with sunshine. Light also helps the immune system and may benefit multiple sclerosis, viruses, measles and tuberculosis. Anxiety, depression, learning difficulties, behaviour, jetlag and mood are positively affected by sunshine. It’s the perfect, free and easy treatment for a healthy life! Without light, growth and repair of our bodies would be impossible.
Dr John Ott was a pioneer in light research and inventor of time-lapse photography and full-spectrum lighting. He coined the term ‘malillumination’ to describe sunlight deficiency and the harmful effects of indoor living, sunglasses and normal fluorescent light on learning, behaviour, health and longevity. He found that artificial lighting produced increased levels of the stress-producing hormones, ACTH and cortisol, contributing to changes in mental and physical health. Full-spectrum light including infra-red and ultra-violet was found in his experiments to be most beneficial for humans, animals and plants.
Vitamin D is a group of hormones, with its best source being sunlight exposure. It is not a vitamin but a pro-hormone that our body makes from cholesterol. It has recently been gaining popularity as a nutritional supplement to support overall health.
Our body can synthesize vitamin D when sun exposure is sufficient. It helps regulate the concentration of calcium and phosphate in our blood and promotes healthy bone growth and remodelling. Vitamin D is also beneficial for healthy hair growth, diabetes, peripheral vascular disease, some cancers, immunity, multiple sclerosis, hormone regulation, pre-eclampsia in pregnancy and Parkinson’s disease.
Testing for deficiency of vitamin D is now part of a routine blood examination. A recent study found that much more than 40% of tested patients were lacking vitamin D. Levels above 75 nmol/L are being proposed as desirable for achieving optimum health. The TGA’s recommended daily dose is 1000 IU. For therapeutic use, doses would be higher.
As an optometrist, I am often asked about what is appropriate eye wear to protect the eyes from the sun. I do advocate regular and careful sun exposure. If you are outside for long periods of time or work outdoors, wrap-around UV-blocking sunglasses are recommended to reduce excessive light exposure. Excessive exposure may contribute to cataracts, pterygia and macular degeneration. Age, health and nutritional status are the biggest risk factors for eye disease. The negative effects of sunlight are magnified by poor dietary and lifestyle choices.
BENEFITS OF LIGHT THROUGH THE EYES
Full-spectrum light influences your entire body, not only through the skin, but also when it enters your eyes. The resulting nerve messages not only go through to the brain’s visual centres, enabling us to see, it also go to our hypothalamus. The hypothalamus controls body temperature, hunger, thirst, water balance and blood pressure. Additionally, it controls the master gland, the pituitary, which secretes many essential hormones.
Certain brain regions that control emotions, pleasure, our body clock and cognition become underactive when deprived of light. Seasonal Affective Disorder (SAD), or ‘the winter blues’, is a type of depression that occurs during autumn and winter when sunlight is limited. Mood-lifting serotonin levels are low in people with depression. UV light entering the eyes helps regulate serotonin levels via the pineal gland and hypothalamus. Exposure of the eyes to special light boxes can assist in depression, eating disorders, PMT and sleep disorders.
Proper exposure to sunlight can prevent children from becoming near-sighted. Researchers have found that the amount of time children spend outdoors is critical. A comparison of children in Singapore and Sydney showed that the myopia rate in Singaporean children is 10 times higher. But the children in Sydney spent significantly more time in near-work activity such as reading, which has long been held to be implicated in myopia progression. However, the Sydney-based children were also outdoors almost four times longer than their Singapore counterparts.
We have evolved to adjust to patterns of light and darkness in a physiological cycle known as the circadian rhythm. This depends on adequate sunlight exposure at the appropriate times during the day to function properly. Long hours of work, insufficient sunlight, over-exposure to artificial lights and less sleep can all contribute to a disruption in pineal gland functioning and melatonin production.
Melatonin is a hormone secreted in the brain only at night and is triggered by the absence of light. Melatonin’s immediate precursor is the neurotransmitter, serotonin. Insufficient melatonin can lead to decreased immune function, seasonal affective disorder, tumour growth, blood pressure instability, increased brain plaques (as in Alzheimer’s disease), osteoporosis and diabetic blood vessel disease.
Exposure to light pollution during the night can disturb sleep patterns and exacerbate insomnia. The proliferation of glowing gadgets like computers and Ipads can trick your brain into thinking that it’s still daytime after the sun has set. These devices are more likely to disrupt than is a TV or lamp, which are further away from the eyes.
Suggestions for minimising artificial light exposure at night:
- Install thick curtains to ensure complete darkness in your bedroom.
- Eliminate night lights. Recent studies found that keeping a night light on for children increased their risk for short-sightedness.
- If you get up during the night, try to avoid turning on a light.
- Minimise your exposure to computers and gadgets at night.
- Don’t watch TV late.
- Try to get to sleep before 10pm, when it’s dark outside, and rise when the sun is up at 6am or thereabouts.
LIGHTING AT WORK
Studies have also shown that poor lighting in the workplace can trigger headaches, visual stress and fatigue. Indoor workers also have a higher rate of melanoma – on covered skin areas – than outdoor workers! I always recommend allowing yourself a lunch break outdoors, going for a walk, and, as an eye exercise, shifting your focus from near to far and back again and side to side in the distance. Try to spend more time outdoors on weekends.
HOW TO SUN
At the time of writing, the Cancer Council recommends regular sun exposure to help get enough vitamin D. In summer 10 minutes per day exposure to face, arms and hands; in spring 15 – 20 minutes; and in winter 30 mins is recommended. You need to expose about 15% of your body. The best time is on either side of the UV peak which is 10am to 2pm. (Updated guidelines can be found here Vitamin D | Cancer Council)
Other authorities recommend having maximum skin exposure between these hours, that is, in the middle of the day when UVA and UVB are relatively equal. If these recommendations seem too opposed, rest assured that all sides agree that sunburn must be avoided – this is critical.
At risk of insufficient light exposure are elderly people, those convalescing, office workers, infants and people with darker skin (melanin pigment can block UV absorption). Natural health advocates support these guidelines as a minimum, with dietary adjustments and supplementation when vitamin D levels are low.
We need sunlight exposure every day to optimise our physical and mental health. It is one of the greatest healing remedies found in nature, ensuring a healthier, happier and longer life for each of us.
Jenny Livanos is a wholistic optometrist/nutritionist with over 20 years experience practising in North Strathfield, Sydney. She considers how environment, nutrition, visual habits and lifestyle factors affect visual health and focus. She can be contacted on 02 8765 9600.