While we’re all busy searching for the next superfood to increase blood flow and the latest diet to accelerate weight loss, we could be ignoring one of the most potent contributors to general well-being. All we have to do to find it is look upwards (providing you don’t live in the United Kingdom…!)
Ivy Cheung, a researcher at Northwestern University, describes natural daylight as ‘the most synchronising agent for the brain and the body’ while the World Health Organisation report that residents with inadequate natural light in their homes have greater risk for depression.
The research on the effects of natural sunlight in regards to mental health, sleep and general well-being is resounding, but the worry is that these findings often come as a surprise to people. After all, sunlight has played a huge role in the evolution of mankind, the way we eat, sleep and behave.
But through the invention of the light bulb and increased exposure to artificial light, we’ve largely forgotten about the simple benefits of the real light that lies beyond the four walls we often spend too much time lodged inside. This blog intends to re-stoke your relationship with the thing that keeps the world turning round.
Cancer, blood pressure and infection
We’re all well versed in the effects of too much sunlight on the health of our skin, but researchers at the Wake Forest University Baptist Medical Centre found that women with high sun exposure had half the risk of developing advanced breast cancer compared to those with low sun exposure.
High exposure was defined as having dark skin on the forehead. Exposure was measured as the difference between the skin tone of the forehead and skin colour of the underarm where tone was unlikely to be affected by sunlight exposure
There also seems to be a relationship between UV light exposure and blood pressure. Edinburgh University had 24 people sit under tanning lamps for two 20 minutes sessions. One group were exposed to UV and heat, while the other had the UV light blocked. Blood pressure dropped significantly for one hour following exposure to the UV light but not in the group only exposed to the heat. Researchers found that a compound called nitric oxide – a critical compound for blood flow – was released in the blood vessels when exposed to the UV light.
Have you ever thought about how much bacteria lives in household dust and how the sun could be affecting that, too? According to BioMed Central, 12% of bacteria were alive and able to reproduce in dark rooms compared to just 6.8% exposed to daylight and 6.1% exposed to UV light. Dust kept in the dark contained organisms related to respiratory diseases, suggesting natural sunlight has the ability to kill dust-dwelling bacteria.
Mood & Depression
You may be familiar with the fact that suicide and depression rates tend to be higher in extreme environments where there is either too little or too much sunlight.
It is well documented that suicide rates increase dramatically in Greenland during the summer where the sun doesn’t set between the end of April and August. The statistics are disturbing and show that in the very north of the country where sunlight is particularly extreme, 82% of suicides occurred in the daylight months. Researchers in Sweden summised that light generated imbalances in the turnover of serotonin may, with a lack of sleep, explain increased suicide rates.
Having lived in Sweden during the harsh winter months, I’m well aware of the dimming effects a lack of sunlight can have on the body. But is it the sun or just the weather? Brigham Young University potentially answered this question in 2016 when they found the answer lay in the amount of time between sunrise and sunset. They concluded that this was the most significant factor in leaving people vulnerable to emotional stress in a study that also considered rainfall, pollution and temperature.
There may be implications for child birth, too. Women in late pregnancy during the darker months of the year may have a greater risk of developing postpartum depression once their babies are born due to a lack of Vitamin D. Elsevier (2015) support this assumption, suggesting Vitamin D exposure plays a key role in creating a healthy environment within the womb prior to birth. Women born in the summer are more likely to be heavier at birth, taller as adults and start puberty later according to this study.
Sleep
I recommend a daily dose of natural sunlight to all my clients with the intention of improving their sleep. Researchers at the University of Manchester conclude that 10-15 minutes of exposure, preferably at midday when the sun is at its highest in the sky and emitting the highest concentrations of UVB radiation, is optimal for sleep quality and the synthesis of Vitamin D, but too much of it can have negative, sometimes fatal, consequences.
A little can go a long way. Northwestern University found that office workers with more light exposure within the office had longer sleep duration, better sleep quality and engaged in more physical activity than those who had no exposure to light.
Those who had windows in the office had 173% more white light exposure and slept an average of 46 minutes more per night. Statistics were measured using an actigraphy – a device worn on the wrist that measures light exposure, exercise activity and sleep.
Vitamin D
Vitamin D – one of the most important compounds for our bodies in terms of bone health, immunity and mood – is referenced in pretty much every study you’ll find relating to natural sunlight.
The problem is that unless you’re taking it in supplementary form each day it’s difficult to consume an adequate amount through food, and therefore adequate sunlight is needed for the body to synthesise it. Vitamin D deficiency is one of the most common deficiences in the world.
From the findings above we have learnt that the synthesis of Vitamin D has serious implication for the health of newborn babies, mental and phsyiological health. So how do we get enough of it?
Researchers in Spain have come up with a decent blueprint. They say with 10% of the body exposed in January, around 130 minutes a day is needed to synthesise the recommended 1,000 IU’s of Vitamin D. With 25% of the body exposed between April and July, just 10 minutes may be needed.
It’s not a lot to ask, but if exposing yourself to natural sunlight is a difficult task, a Vitamin D3 tablet from somewhere like Holland and Barrett or Healthspan isn’t a bad idea now you know just how important it could be.
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