The Healing Power of the Sun – Should You Use Sunscreen?

Do you run for cover as soon as the sun comes out or do you slap on the suntan lotion? Do you think it is dangerous to be out in the sun? Have you considered that it might be more dangerous to avoid the sun and that your sunscreen may actually be harming you? 

We often feel we need to protect ourselves from the sun with lots of sunscreen but in this two-part series I will discuss why the sun is good for you and is not to be avoided, despite the skin cancer scare propagated by the health authorities. In this post I will discuss what to look for in a sunscreen if you really do need one and in the second part of the series I will explain how nutrition can help protect you from the inside out.

You may think that you need to protect yourself from the sun because it ages you, causes skin cancer and can certainly cause painful sunburn. The sun can indeed damage protein in your skin (1) and can cause oxidative stress and inflammation in your skin which can contribute to ageing (2), but we also evolved with a certain amount of sun exposure so can it really be so harmful as to warrant avoiding it altogether?

The main message we have been hearing from the health authorities is that sunshine increases the risk of malignant melanoma, the form of skin cancer that contributes to the most deaths, since the more common basal cell and squamous cell carcinomas are rarely lethal (3).

Yet in 1998 29 studies on sun exposure and 21 studies on sunburn were analysed and although they do show an increased risk of melanoma with intermittent sun exposure and with sunburn, they actually show a significantly reduced risk with high levels of occupational exposure (4). It seems that sunbathing may be protective as long as you do not burn (5).

So part of the aim of this two-part series is to give you advice on how to reduce your risk of burning, but even so let us put the risk of malignant melanoma into perspective. In 1995 the number of deaths in England and Wales from malignant melanoma was less than 1,400 and the number of deaths from ischaemic heart disease was over 133, 000 (6). Sunshine enables you to make vitamin D which has been associated with a reduced risk of cardiovascular disease (7). So even if avoiding sun exposure did have some overall effect on reducing mortality from malignant melanoma that effect is likely to be small in comparison to the increase in mortality from cardiovascular disease as a result of sunlight deprivation simply because the death rate is close to 100 times greater for cardiovascular disease than for malignant melanoma. Furthermore there are other health benefits of sun exposure that are likely to further reduce mortality that I will discuss in the next post.

Now I use the word ‘deprivation’ because sunbathing is pleasurable and relaxing for many people and seems to improve mood (8) as can be seen by the very existence of Seasonal Affective Disorder which is treated with light boxes when sunlight is scarce in the winter (9). This effect is more related to the light coming in through the eyes and I will discuss some more ways in which sun exposure can improve mood and wellbeing later in this series.

So is suntan lotion a good idea?

Some ultraviolet B (UVB) radiation exposure is necessary for producing vitamin D (10) and this is important since there is very little vitamin D in food sources (11) so that most individuals get 90% of their vitamin D from the action of sunlight on their skin (12). Suntan lotion can block or at least reduce vitamin D production (13).

Vitamin D benefits bone health (14) and prevents rickets (15), improves immune function (16), is anti-inflammatory (17, 18, 19) and may reduce the risk of heart disease, autoimmune disease and cancer (20). Vitamin D may improve both male and female fertility (21).

Vitamin D might be partly responsible for the mood boosting effects of sunshine since it increases brain serotonin (22). Low levels of vitamin D, both in the mother when pregnant and in the child, are associated with an increased risk of autism which may be in part because vitamin D is important for forming myelin sheath which insulates your neurons (23), but also because brain serotonin has been found to be low in autism and vitamin D also activates the receptor for oxytocin (24), which reduces stress and promotes social bonding (25).

Type 1 Diabetes rates went down in sun-deprived Finland after milk was fortified with vitamin D in 2006 (26). Low vitamin D levels may be a driver of multiple sclerosis since rates of this autoimmune disease are higher at higher latitudes (27).

Vitamin D is associated with reduced cancer risk (28) and protects mice from skin cancer (29) so reducing production of vitamin D by using sunscreen may be counterproductive. It may also be counterproductive for ageing since vitamin D is associated with longer telomeres in white blood cells in women (30), and longer telomeres are considered to be a sign of reduced ageing (31). The prevalence of vitamin D insufficiency has been found to be 65.9% in the USA and 86.4% in Europe (32) showing that we do not get enough sunshine exposure.

Expensive suntan lotion has been touted as protecting against skin cancer but some research actually shows sunscreens are associated with an increased risk of melanoma (5), especially at latitudes greater than 40 degrees (33), which would include most of Europe. Since higher factor sunscreens became popular in the 1970s rates of melanoma have risen steeply and this may be because suntan lotion reduces burning by blocking UVB radiation but not UVA radiation (34). Sunscreen that blocks out UVA and UVB radiation might prove to be more effective in a few more decades (35) if you are willing to be part of that experiment. Blocking out UVA may also reduce some of the ageing effects of sunshine (36).

However there is also the question of the toxicity of the active ingredients in sunscreen (37), some of which are absorbed and can be found in human breast milk (38) and some of which are not absorbed but can potentially damage the skin (39). Some of these toxins are xenooestrogens which not only disrupt your sex hormones (40) but also end up polluting rivers, lakes and seas and accumulating in the food chain (41) effecting the reproductive capacities and the development of different organisms (40) and causing coral bleaching (42). One of these hormone disruptors, BP-3, has been found in 85% of Swiss breast milk samples and in 96% of urine samples in the USA and yet little research has been carried out to determine the effects of these compounds on human subjects (43). UV filters do also impact thyroid function in rats (44). Ultraviolet filters can also impact the expression of genes that code for detoxification enzymes, thus reducing the capacity to deal with other toxins (45).

Many sunscreens use zinc oxide or titanium dioxide as their active ingredient. Nanoparticles of zinc oxide can damage DNA and inhibit mitochondria in keratinocytes (46), the cells in your skin that produce keratin, and titanium dioxide nanoparticles also cause oxidative stress that can lead to the keratinocyte cell death (47). When these nanoparticles absorb UV radiation free radicals are produced that could potentially cause DNA damage, though according to most of the available evidence the skin is not deeply penetrated by these particles even if you already have some sunburn when you apply the sunscreen (48). Perhaps the safest UV filters are larger particles of zinc oxide and titanium dioxide, although they may block pores and thus exacerbate acne and rosacea (49) and they are not transparent if that is important for you. Zinc dioxide is more effective for UVA protection and titanium dioxide is more effective for UVB protection so a combination of the two would provide fuller protection but as you make the particles smaller UVB protection is increased at the expense of UVA protection (50). As a result the larger particles of zinc dioxide and titanium dioxide combined will offer protection over a wider spectrum of radiation.

Please be aware that the SPF number relates to UVB that causes more of the burning and not to UVA which can contribute to photoageing and melanoma risk (51). Overall if necessary I would suggest using a combined large particle zinc oxide and titanium dioxide sunscreen, and if you really need it to be transparent the larger particles will need to be replaced by nanoparticles, which may carry less risk than other UV filters according to current evidence.

If you do need to use a sunscreen you also need to be aware of toxic additives other than the UV filters such as BPA, phthalates and parabens (52) as well as aluminium that may actually cause more oxidative damage to your skin (53). Vitamin A, often labeled as retinyl palmitate, is often added to sunscreen but is not very stable in the presence of ultraviolet radiation and can then cause damage to your skin (54) so is best avoided.

Sunscreens do not protect from radiation in the infra-red range which can also cause free radical damage (55).

As we go deeper into the complexity involved in this fight against the sunshine that we would be naturally exposed to during aeons of our evolutionary history I am reminded of the complicated battle we have waged against the bacteria that we evolved with, rather than strengthening our own natural defences such as our own gut flora. It seems that all of the antibacterial lotions and sprays and antibiotics in the world will not succeed in wiping out such an ubiquitous perceived enemy. Many of us might wish that sunshine were equally ubiquitous and we may be asking ourselves if the battle against the sun is also doomed to failure no matter how many new chemicals we can come up with to block different frequencies of sunlight. Perhaps strengthening our antioxidant system might confer some more natural protection against sun-induced free radical damage? There’ll be more on this in the next post.

When our dietary patterns, stress levels and level of exposure to toxins are so at odds with what we evolved to deal with it is hard to tell how much of our sensitivity to the sun is due to diminished antioxidant defences. Clearly those Caucasians of fair skin, red hair and blue eyes are more at risk of sunburn (56) but you might expect we would have evolved to thrive in the climate of our ancestors. So why do so many people here in the UK burn so easily in their own country of origin? Is this down to the poor dietary habits, high stress levels and toxic exposure in the industrialised West?

It is melanin production that results in darker skin both due to tanning and due to racial heritage (57). Melanin also reduces vitamin D production by blocking UVB radiation (58). So perhaps fair skin is an evolutionary compromise to increase vitamin D production at the expense of a reduction in protection from UV radiation (59) and it is interesting that women tend to have lighter skin thus enabling increased vitamin D production which is so essential for healthy pregnancy and breastfeeding (60).

Therefore just as antibiotics are sometimes necessary some individuals may need to sometimes use suntan lotion no matter how careful they are to follow the advice I will give in the next post to protect themselves, although it may well be that the problem of burning so easily is compounded by poor diet, high stress levels and toxic exposure.

The Environmental Working Group gives some further advice on sunscreens and the toxins you should avoid.

SUMMARY:

• • Sun exposure can improve mood and has many health benefits because it increases vitamin D production which probably reduces overall mortality significantly more than malignant melanoma would increase mortality.
  • Sunscreens contain many toxic compounds that can disrupt your hormones.
  • The safest suntan lotion to use if needed would be based on larger particles of zinc oxide and titanium dioxide which protect from both UVA and UVB radiation.
  • Make sure if you use a sunscreen there are no other toxic additives such as aluminium, BPA, phthalates, parabens or even vitamin A.

In the next post, Sun Protection from the Inside Out: The Nutrition Perspective, I will give you even more reasons to enjoy the sunshine and the health benefits it brings and I will also talk about ways you can protect yourself other than sunscreen, such as foods and supplements to protect you from the inside out.

I hope this information will help you to safely enjoy the sun and benefit from its mood-lifting and health-giving properties.

I personally find that the sun relaxes me and boosts my mood. Do you enjoy the sunshine or do you feel it is too risky? Please leave your comments below.

Read Part 2, learn more about my work in London and Totnes, or find out about online consultations.

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Related posts:

Sun Protection from the Inside out – the Nutrition Perspective