Recent evidence points to the increased need for this in our modern society as a way to ensure your children are protected from the risks of myopia (or short-sightedness). The American Academy of Ophthalmology heard from researchers who had found a clear link between time spent outside and decreased levels of myopia – this link could even be quantified as for each additional hour spent outside, the chance of myopia dropped by 2 percent.

The reasons for this protective effect are not as yet clear with research efforts focusing on:

• increased use of distance vision,

• reduced use of near vision,
• natural ultra violet light exposure or
• physical activity.

While the reasons are being uncovered it could well be a good time to remind your children (and yourself) that today is a good day to go play outside.

Related posts:

1. Exposure to daylight may prevent myopia
2. Anaemia and Vitamin D
3. Vitamin D Deficiencies At Epidemic Levels

While their study was focused on Vitamin D supplements, we believe the findings can be applied to Vitamin D generated through sunlight exposure.

Their findings showed that 18 of the 167 children who received supplements subsequently contracted influenza, while 31 of 167 children who had only a placebo went on to get ill.

An unplanned finding showed that of children with a previous diagnosis of asthma, asthma attacks as a secondary outcome occurred in 2 of the children in the supplement group and 12 in the placebo group.

We believe this study shows the value of adequate Vitamin D levels. If you have the opportunity – get your Vitamin D from sunlight. And if you’ve wondered how much sunlight is the right amount – we explored this issue in a previous article – you can find this here.

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C3H mice are chosen for these studies as they are prone to tumor development. 98% of males and females will typically develop breast carcinoma.

The following results were seen:

• A: 30 pairs of mice were exposed to pink fluorescent light. 29 female mice developed cancer. Females died 1 month earlier than those in Group B. 1-2 offspring per litter, instead of 6-15.

• B: 30 pairs of mice were exposed to daylight-white fluorescent light. 24 female mice developed cancer.
• C. 8 control pairs were kept exposed to daylight through windows into basement room. They developed cancer 3 months after group A and 2 months after group B.

Source: S.L. Gabby (1961), Observations on the effects of artificial light on the health and development of mice, cited by J.N. Ott (1982), How to Stay Healthy, Devin-Adair (1982), ISBN 0-8159-61 21-9.

An additional study was completed by J.N. Ott in the 1970s using the same type of mice to look at the relationship between light and mortality rates. Over 2,000 C3H mice were used in that experiment. The following results were seen:

• A: Mice kept under pink fluorescent lived an average of 7.5 months

• B: Mice kept under daylight white fluorescent lived an average of 8.2 months
• C: Mice kept under full-spectrum plastic glazing lived an average of 15.6 months
• D: Mice kept under natural outdoor daylight lived an average of 16.1 months

Source: J.N. Ott (1973), Health and Light: The Extraordinary Study That Shows How Light Affects Your Health And Emotional Well-being, Ariel Press, USA, ISBN 0-89804-098-1.

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The background notes to the meeting state:

Humans have evolved over millions of years and adapted to a solar day of approximately 12 hr of light and 12 hr of dark, latitude and season permitting. Our ability to artificially light the night began about 250,000 years ago when we discovered how to use fire. Candles were introduced about 5,000 years ago, and gas street lighting was possible beginning in the mid-1700s. However, only in the last 120 years has environmental illumination begun to change on a pervasive scale for the masses of people through the introduction of electric lighting.

 

One of the defining features of the built environment in the modern world is this artificial lighting. Electricity has made it possible to light the inside of large buildings and light the night for work, recreation, and security. The benefits of this lighting are obvious and enormous. It has become apparent, however, that although of obvious benefit, it may not be completely innocuous.

 

Light, including artificial light, can be potent in regulating human physiology and behavior and can therefore alter human physiology when inappropriately timed. One example of potential light-induced disruption is the effect of light on circadian organization, including the production of several hormone rhythms. Changes in light–dark exposure shift the timing of the circadian system such that internal rhythms can become desynchronized from both the external environment and internally with each other, impairing our ability to sleep and wake at the appropriate times and compromising metabolic processes. Light can also have direct acute effects on neuroendocrine systems, for example, in suppressing melatonin synthesis or elevating cortisol production that may have untoward long-term consequences.

The meeting concluded that maintenance of these circadian rhythms is important to health and well-being. And that the participants needed to focus on creating studies to advance our understanding of the impact of circadian disruption from lighting, and what then can be done to minimize or eliminate the adverse consequences for human health.

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1. Circadian disruption and breast cancer.
2. Circadian rhythms and how to check yours
3. Best of 2011 – Sleep

For some the answer is a chicken coop in the backyard with three-four chickens kept for egg production. Knowing that the mileage on your breakfast is around 10m can be very satisfying indeed!

In terms of keeping chickens happy and healthy, what can the backyard farmer learn from the current state of research into light and how it effects birds?

Chickens can perceive UV light that humans can’t and are sensitive to its absence. A widely quoted Wall Street Journal article of 1987 reports that chickens in the study kept under full-spectrum light bulbs lived twice as long, were calmer and less aggressive, and produced eggs 25% lower in cholesterol.

This study was backed up by an article in Animal Behaviour (Volume 62, Issue 5, November 2001). The article found that corticosterone levels were higher in chickens kept under standard artificial light, than in chickens kept under full-spectrum light. Production of corticosterone is typically an indicator that the body is under stress. Living in a persistent state of stress is damaging to the body.

The ideal would be to keep chickens in conditions where they have good access to natural lighting. But given that chickens started in the jungles of South East Asia but are now kept all over the world – they may be being kept in areas where they simply can’t get the light they need from natural sources. In these cases, supplementing with a full-spectrum bulb will reap benefits.

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1. Raising healthy chickens – why light matters.
2. Best of 2011 – Care of Chickens and other birds
3. Light quality and the relationship to fertility

Anaemia occurs when the body has too few oxygen carrying red blood cells. Mild anaemia symptoms include fatigue, lightheadedness and low energy. Severe and prolonged anaemia can damage organs through oxygen deprivation.

The study looked at 9400 children between the ages of 2 and 18. The lower the vitamin D levels, the lower the hemoglobin and the higher the risk for anemia, the researchers found.

While the findings show a clear link between low vitamin D levels and anemia, they do not prove that vitamin D deficiency causes anemia, the investigators caution. It does however suggest strong avenues for study in future research.

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The experiment covered in the article showed that laboratory-grown gingival cells treated with vitamin D boosted their production of an endogenous antibiotic, and killed more bacteria than untreated cells.

The article suggests this means vitamin D can protect gums from bacterial infections that lead to gingivitis and periodontitis.

In addition to the antibiotic mentioned above, the researchers found that the cells treated with Vitamin D produce another protein, called TREM-1. While this protein has not as yet been well-studied, it is thought to be made by white blood cells and boosts production of pro-inflammatory cytokines.

While as yet unresearched this may be the means by which Vitamin D protects against autoimmune diseases.

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1. Anaemia and Vitamin D
2. Vitamin D Deficiencies At Epidemic Levels
3. Vitamin D and Pneumonia

Several recently published articles have looked at the relationship of light to the female ovulation cycle. From the anecodotal description of the Burnett Park Zoo in Syracuse installing sunlight-simulating bulbs to reduce vandalism and then discovering the subsequent increase in animal birth rate to more formal studies.

The theory behind this relationship is that humans developed living in bright light during the day and full darkness at night – except for the few days surrounding a full moon. According to this theory – Lunaception – by ensuring that sleep takes place in full darkness, followed by exposure to full light in the morning and a dim night light for the few days of full month, a woman’s cycle will reset to it’s optimal timing.

Subsequent research to support this theory was conducted by Centre for Chronobiology, Institute of Internal Medicine, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, Russia.

Objective
Studies have shown a shortening of the menstrual cycle following light exposure in women with abnormally long menstrual cycles or with winter depression, suggesting that artificial light can influence reproductive hormones and ovulation. The study was designed to investigate this possibility.

Findings
Morning exposure to bright light in the follicular phase of the menstrual cycle stimulates the secretion of hypophyseal reproductive hormones, promotes ovary follicle growth, and increases ovulation rates in women with slightly lengthened menstrual cycles. This might be a promising method to overcome infertility.

While still an alternative school of thought, paying attention to quality of light can be a non-invasive safe proceedure for those wishing to conceive.

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1. Chickens, food miles and light quality.
2. What is the relationship between sunlight and breast cancer?
3. Blue-enriched white light in the workplace improves self-reported alertness, performance and sleep quality

The study completed at Waikato Hospital looked at blood samples of the 112 patients hospitalised with pneumonia. They found that the death rate was 29% for those with very low levels of Vitamin D compared to only 4% amongst those with normal or slight deficiencies. While this was an observational study, it suggests avenues for research on whether Vitamin D is a viable treatment option for respiratory diseases.

The article continues on to look at other studies that have found relationships between vitamin D deficiencies and other diseases – type 1 diabetes, multiple sclerosis and cardiovascular disease.

Vitamin D is produced in the skin after exposure to ultraviolet light from the sun or artificial sources, and occurs naturally in fish amongst other foods.

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1. Vitamin D Deficiencies At Epidemic Levels
2. Why are we Vitamin D deficient?
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The main findings of this study were:

1. the students in full-spectrum light were healthier and attended school 3.2 to 3.8 days more per year;
2. libraries with superior light resulted in significantly lower noise levels;
3. full-spectrum lighting induced more positive moods in students; and
4. because of the additional vitamin D received by the students in full-spectrum light, they had 9 times less dental decay and grew in height an average of 2.1 cm more (over the two year period) than students attending schools with average light.

The full study can be review here.

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2. New fluorescent lamps awakens sleepy students
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