It is a strange phenomenon of the modern world that many of the things we should be enjoying we are told that we should avoid. Most of the time, not only are these things enjoyable, but they are immensely healthy too. Meat, saturated fats, fats in general, eggs, and dairy have all been proscribed, and nigh on prohibited, by various government bodies and health authorities. Each has turned out, in reality, to be perfectly healthy. Being out in the fresh air and sunshine seems to be another to be added to that list, particularly of late.
Locked away from the light …
Amazingly, the average American spends 93% of his life indoors, this includes time in the office, in the house or flat, and time in the car. Doubtless, the figures would be much the same for people in the UK or Canada, if they were available. American children spend, on average, a mere 4-7 minutes a day in unstructured outdoor play. Such a sedentary lifestyle is deeply unhealthy, leading to our children being relatively unfit compared to previous generations. It has also led to a childhood obesity problem. These are not good outcomes …
We need natural light, particularly sunshine, for a large number of essential functions if we are to thrive as human beings. Sequestered away inside four walls, we are like plants left in a dark corner of a room. We may survive but we will not thrive.
In this time of pandemic, we have been advised to stay indoors and social distance. Whilst the latter makes a lot of sense, the former may actually be making the situation worse. We need to be exposed to daylight every day and for a goodly period of time to promote many of the functions that will help protect us from the worse of the virus.
The Benefits of Sunshine
The benefits of sunshine are numerous, perhaps even too numerous to innumerate in a single blog. Because of this, we are going to concentrate on the indisputable and the well-known, with maybe just a mention or two of other theories that indicate even more positives than previously thought.
Sunshine helps us produce Vitamin D
This is perhaps the most commonly understood benefit of light exposure. Specifically, it needs to be UVB from sunlight, if at all possible. Hence it is much easier to achieve decent levels of vitamin d from daylight in countries closer to the equator than those in more northern climes such as Canada, the US, or the UK.
UVB triggers the process that enables our skin to produce vitamin d. Having sufficient amounts of vitamin d comes with a large range of benefits. Getting our vitamin d direct from sunlight is so much better than supplementation. The best-known benefit of vitamin d is promoting the absorption of calcium in your gut, hence helping to protect you from osteoporosis and generally being very good for the health of your bones.
Beyond your bones, vitamin d also helps strengthens muscles, an important factor to prevent vulnerability as we age. Vitamin d plays a vital role in our immune system, something that is particularly relevant right now, given the situation with the pandemic at the time of writing.
The list of vitamin d benefits just goes on and on … (1).
Sunshine can help our Immune System
Our body’s T cells are fundamental to our immunity system. They are white blood cells that play a crucial role in tracking down invading pathogens and eliminating them. They can perform this function far better when they are enabled to become more mobile. Exposure to sunlight helps boost the mobility of T cells.
Perhaps this discovery that sunlight boosts T cell mobility helps explain, at least to some extent, why people who are exposed to more sunshine are less likely to develop autoimmune diseases and cancer
We rely on our T cells as the immune system’s first line of defence. The longer we sit around indoors, the more that we are likely to experience a drop in our immunity. It is believed that in order for our T cells to function properly then adequate amounts of vitamin d are required, hence the need to spend time outdoors, hopefully in the sunlight.
Sunshine helps Fight Depression
The Japanese have a concept of being in the forest that they call ‘shinrin-yoku’. Roughly translated, this means ‘forest bathing’. The notion is that time spent outside, particularly in natural surroundings like a forest, is good for you in and of itself. This is not only true physically but psychologically as well.
As with many other areas that affect our wellbeing, the psychological need to be outside probably goes back deep into our ancestral roots. If we can experience being outside in a natural surrounding then so much the better. Just being in such a situation can help lift depression, increase energy levels and leave you feeling healthier and more mentally positive. Studies have found that those of us who take our exercise outside, whether that be running or cycling, or even simply going for a walk, have much better mental health than those who stay indoors and take their exercise within four walls, such as in a gym or at home.
Sunshine Strengthens our Skeletal Structure
When we are younger we tend to have a blithe disregard for our skeletal health. As we age, thought, such factors assume a greater and greater importance. Unfortunately, the overwhelmingly sedentary lifestyle that many of us adopt in the modern world is immensely unhealthy for our muscular and skeletal integrity.
We tend to spend an awful lot of time indoors or sitting in care or on transport. Because of this, there is a twofold attack on our skeletal health. Firstly, the muscles that support us become weaker and weaker over time if they are not actually engaged in the act of supporting us. In simple terms, they atrophy. Secondly, a sedentary lifestyle puts a lot of pressure on our spines and disc tissue, hence the ubiquity of back problems in recent times.
Sitting down can put up to 600 lbs of discal pressure on our spines. This is more than twice the pressure that would be the case if we were standing. We need to stand, we need to move, we need to be in open spaces.
If you add these effects to the damage that poor levels of vitamin d and calcium can do to our bones, you can readily understand how we are creating an almost perfect storm in regards to skeletal health.
Avoids Indulging Poor Habits
The mere fact of staying indoors tends to lead us to spend more time indulging poor and unhealthy habits. Smoking, drinking, taking drugs, endless computer games, or meaningless TV bingeing – all are much more difficult to indulge in if we spend more time in the open air.
This is perhaps particularly true for those in their teenage years. At this stage of life, we are often easily influenced into beginning such nihilistic habits. This is the prime time for our bodies to grow and strengthen into adulthood. This process is not helped by spending hours in front of a TV or playing computer games. In recent years, there has been a notable increase in reports of teenagers suffering lower back pain.
In some ways, these reports are the canary in the coal mine. They belie the underlying problem of more and more teenagers spending huge amounts of time in front of screens. In pre-pandemic days, I would sit in the local coffee shop writing and would occasionally watch groups of teenagers who seemed almost incapable of conducting conversations face to face and instead would all be busily texting away on social media. A sad indictment of our times.
Sunshine can help reduce some Cancer Risks
Many times, one hears that it is sensible to stay indoors, out of the sun, because of the risk of skin cancer. Interestingly, the likelihood of many types of cancer actually seems to be reduced for those spending more time outdoors. This is true for breast, colon, and rectal cancers for example. People who had high blood levels of vitamin d when diagnosed have nearly double the rate of survival compared to those with the lowest levels (2).
The sun, because it interacts with cholesterol layers beneath the skin, promotes the production of vitamin d. Another beneficial effect of sunshine is helping the body to produce serotonin. This neurotransmitter helps to improve mood and lifts depression, helping us fight against the psychological effects of serious illness (3).
Excellent for Eye Health
Obviously, and this shouldn’t need saying, don’t go looking directly into the sun. Beyond that, though, sunshine has gotten quite a bad rap for its affect on the eyes. Allowing the eyes to be exposed to natural outdoor light, rather than through lenses or glass, is actually quite good for the eyes.
The retinas in our eyes contain photosensitive cells. These connect directly to the pituitary gland in our brains. These retinal cells need the stimulation that comes from sunlight. This is particularly the case with blue light with all the concomitant implications for our circadian rhythms (4).
Other photosensitive cells in our eyes are also directly connected to the hypothalamus region in the brain. This connection is vital for regulating biorhythms within us. If these are well coordinated with daylight they will have positive effects on the quality of our sleep, hormone regulation, and general mood. Many of the cells in our bodies are cyclic in nature, hence being out of time with the day’s rhythm can lead to all manner of problems. We need daylight exposure to adequately coordinate our bodies with the world we live in.
Fights Obesity by Improving Metabolism
There is a fundamental truth that many people seem intent on avoiding. If you spend a lot of time sitting on your bottom (for want of a better word) or laying on your back, locked away indoors, your metabolism and general health will suffer.
On another level, a recent study connected regular exposure to sunshine with alterations to the metabolism of itself. This is mostly achieved by its effect on nitric oxide levels in the body. The study examined how sunshine may induce nitric oxide production via its effect on converting nitrates already stored within the body(5).
The study concluded that exposure to sunshine can significantly affect metabolic function. This has implications for how the changing of the seasons can affect our metabolism. It’s difficult to get enough vitamin d in a British or Canadian winter simply because of the lack of exposure to sufficient sun. The same goes for nitric oxide levels. This may help to explain why the winter brings increases in strokes and heart attacks.
The takeaway again is: get out into the daylight whenever you can but maybe particularly in the colder months. It is easier to be tempted to go out on a lovely summer’s day but it may be at least equally important to get yourself out into the fresh air during the colder months of the year.
Lowers Blood Pressure
What we refer to as blood pressure is simply a measure of the resistance to blood flow in the arteries. The resistance, to some extent at least, is caused by the stiffness of the arteries. The stiffer the arteries, the higher the measured blood pressure will be.
Hypertension, the medical name for chronically high blood pressure, can cause damage to the walls of the arteries. If this continues over a period of time, it can eventually lead to heart failure. There are also a range of other problems attached to hypertension such as arrhythmia of the heart, strokes, and kidney diseases.
Hypertension is very common in our modern world. It is a major cause of mortality. Often people are unaware of the danger until it is too late. Getting out into the fresh air, particularly the sunshine, can help us to reduce blood pressure. One study demonstrated a very significant decrease in both systolic and diastolic blood pressure immediately after exposure to UVA light. The change lasted for an hour during which blood flow increased by 68%, not an insignificant amount (6).
Another study from China adds support to the idea that sun exposure helps to lower risk. China has particularly high numbers of people suffering from hypertension. The study took residents from Macau in the South of China and examined lifestyle factors for their effect on blood pressure. They found that being exposed to the sun for just half an hour a day, as opposed to none, was enough to predict a 40% reduction in the risk of hypertension (7).
The Dangers of Sunshine
Although the aim of this blog is to get people to go out more and benefit from a healthier lifestyle, there are still risks that should be considered when we are exposed to the sun. Most of these negatives are avoidable with some relatively simple measures, but care should be taken nevertheless.
Short term skin damage
It can take just a mere 15 minutes to get sunburn. This is the result of overexposure to ultraviolet (UV) rays. Such sunburn usually comes with blistering and pain. If strong enough, it can even lead to second-degree burns. However, such effects are easily avoided by simply being sensible and introducing yourself to the sunlight gently and over a period of days as you build up your level of acclimatisation.
One thinks of the classic British holidaymaker arriving for his first day on the Costa del Sol. On the first day of his vacation, he charges out to the beach and fries himself for the next three or four hours. He then wonders why he has to avoid the sun for the next ten days as he attempts to recover from a bad case of sunburn.
Be intelligent, be sensible, and such problems are easily avoided.
Long term skin damage
More seriously, long-term extended over-exposure to UV rays over the years can cause your skin to age considerably. The skin will tend to lose its elasticity and be subject to more wrinkles and sagging. You may also see age spots on the surface.
In extreme cases, such damage can even lead to skin cancer. These may occur in such common forms as melanoma, basal cell carcinoma, and squamous cell carcinoma. According to the Skin Cancer Foundation, suffering more than five episodes of sunburn in childhood increases lifetime melanoma risk by 80%.
Given this degree of risk being the case, it is obvious that one should be respectful of the dangers. This doesn’t mean, however, that one should avoid sunlight altogether. Far from it. Simply it is a reminder that we have to be respectful of direct sun rather than cavalier in our attitude. If the sun is really strong, don’t spend time roasting but seek shade instead.
Dehydration is another potential danger when we are out on very hot days. Most people drink too few liquids in any case (other than the contra-indicated alcohol). It is not enough, however, to simply chug back massive amounts of water on a hot day.
Such a simplistic approach can lead us to a situation where we will continuously be losing electrolytes through our sweat and urine but not replacing them if we are only drinking water. Effectively, our electrolytes will become more and more diluted. To avoid this, make sure you drink something that contains adequate salts (sodium, potassium, calcium, and magnesium). Such drinks can easily be made easily and cheaply at home, though they tend to be quite costly if purchased in a store.
Tell-tale signs of dehydration are increased thirst, decreased urine, dizziness and weakness, dry mouth and the inability to sweat. More serious symptoms are heart palpitations, fainting, and confusion. If you become aware of any such symptoms in yourself or your children, then immediately seek to rehydrate, preferably with electrolyte-containing liquids.
Heatstroke can be quite a dangerous phenomenon. Untreated, it can even lead to brain or organ damage. In extremis, it can even be fatal. Having said that, it is a fairly rare event in the UK, Canada, or in the northern US, to experience days that are that hot, but care should still be taken nevertheless.
I have had some experience of this myself about a decade ago in Chiang Mai, Thailand. The temperature was around 40 degrees Centigrade (104 degrees Fahrenheit) and had been for several days. The first signs in my case were a splitting headache and a degree of delirium. Fortunately, I was aware enough to understand what was happening and sequestered myself away in my air-conditioned hotel room for a couple of days, only going out to purchase copious amounts of drinks. Still, I must admit, it was a fairly unpleasant experience.
Other symptoms may include nausea (sometimes with vomiting), muscle cramps, a general feeling of enervation, accelerating heart rate and shallow breathing.
In my travels, which have included many searingly hot countries, the incident in Chiang Mai was the only occasion that I have suffered heatstroke. With sensible precautions, it should be relatively easy to avoid. As ever, an ounce of prevention is worth pounds of cure.
UV radiation comes in three forms. UVA ( from 315-400 nm), UVB (from 280-315 nm), and UVC (from 100-280 nm). The latter can effectively be disregarded though, as they do not penetrate the earth’s atmosphere.
Ultraviolet radiation can be a threat, particularly UVA because it is the variation that we are most commonly exposed to. Skin cancers have generally increased in number in the last 30 years. This may be due, in part at least, to the depletion of ozone in our atmosphere.
Fortunately, for most of us in the northern hemisphere, UV exposure reduces the further you go from the equator. This does not mean that we can be completely relaxed about exposure to the effects of such radiation, however. The same warning applies here, a sensible approach is worth taking in such matters.
Dangers of Indirect Sunlight
It is curious to note just how incredibly paranoid most of the information relating to sun exposure is, hence the advice to stay in and avoid direct sunlight. Glass actually blocks UVB, the shorter wavelength of ultraviolet light. On the other hand, it allows something like 75% of UVA light through. Excessive UVA, even if through glass, still poses a significant risk but comes without the benefits of being out in the fresh air.
How And When To Get Enough Sunshine
For the vast, vast majority of people, it is probably the case that we need to get outside far more often than we actually do. Of course we need to be conscious of the dangers of excessive direct sun exposure. On the other hand, those of us living in the Northern States of the US, the UK, or Canada may be thinking ‘chance would be a fine thing!’. For the most part, the danger in such northerly climes is too little exposure to sunlight, and all the problems that come with that, rather than too much.
Because of the effects of blue light at the start of the day, it is wise, whenever possible, to get out in the early morning. This allows your circadian rhythms to respond to light clues and will result in better sleep that night. Experiencing light indirectly, through the glass windows of your house, conservatory, office, or car is simply not good enough.
The other side of this is to avoid blue light in the evening, especially within two hours of bedtime. Electric lights, TVs, smartphones, and computer screens all give off blue light and can easily upset your circadian rhythms. Blue light will provoke the production of hormones that signal to the brain that now is the time to be awake. In particular, high levels of cortisol can be a problem. It is wise to avoid activities that expose us to blue light as we get closer to bedtime. Failing that, at least use blue-blocking glasses to filter out the worst of the effects (8).
Not too little, not too much
On the other hand, it may not be wise to be exposing ourselves to direct sunlight in the middle of a sunny afternoon in the height of summer. Far too commonly, this is exactly what many people from northern climes do when on holiday further south. There is an odd notion out there that if something is good then lots of it must be better. We see people making this error in many areas (over-exercising, over-eating, over-drinking, etc.). Being exposed to sunlight, and simply being outside, is a good thing. Baking in the early afternoon sun is probably not …
It is also wise to wear appropriate clothing. Far too many people seem to feel the need to cover themselves from head to toe, thus stopping the skin from being able to produce sufficient vitamin d. Lightweight clothes, T-shirts, skirts, shorts and other such clothing are appropriate and helpful if one wants to benefit from exposure to light and the open air.
Those of us with darker skin may need to be particularly aware of the dangers of not getting enough UVB via sunlight. Melanin is the substance that makes darker skins dark. Melanin competes with the substance in the skin that triggers the body’s vitamin D production. Very dark pigmented skin, at the levels commonly found in people of African origin, abrogates more or less all ultraviolet-induced vitamin d3 synthesis. This indicates that darker-skinned people require more UVB exposure than those with lighter skin to produce similar amounts of vitamin D. Failing this, then supplementation may be a wise move if such folks are living in the north of Europe or the US (9).
As may be obvious by now, sunlight is something of a double-edged sword. It comes both with benefits and dangers. As a culture, we seem to have become progressively more and more frightened of simply being out in the open air. In recent decades, we have spent more and more time indoors. Such an indoor and sedentary lifestyle has led to a huge range of problems. This is nowhere more obviously the case than with the painfully restricted lives of modern youth and children. In bygone days, youngsters would spend the vast majority of the day out in the open air. Now, because of a range of sociological factors, this is no longer the case. This change has directly affected the physical and mental health of children in a range of deleterious ways. Much the same goes for the rest of us though. A healthy lifestyle needs the willingness to be out in the open air, out in nature, and out enjoying the sunlight.