The Importance Of Sun Exposure For Your Health

This is a long one! Grab a cuppa ..

More and more research is highlighting why sun exposure IS important for our health, and that avoiding it altogether could actually cause us more problems! Research is now showing that sun worshippers are more likely to OUTLIVE those who avoid sun rays!

This is a topic I have been exploring for years, each summer I experiment with my nutrition, skin care routine, sun exposure and use of sun cream. I'm essentially doing my own mini trial based on my research and knowledge.

What Have I Found Out So Far?

- What I eat makes a difference to whether my skin burns or tans (depending on length of time in the sun, of course!)
- My body tells me the sun has done it's job, and it's time to get some shade
- How effective zinc oxide based sun creams are in protecting from burning
- That I don't need to bake in the sun for hours to get nice tan, sensible sun exposure does this for me
- Ditch the sunglasses!
- That sensible sun exposure is supporting my longevity, not causing harm!

The Importance Of Sun Exposure

Sun exposure is important for our circadian rhythm, it influences your sleep cycle, body temperature, eating habits, mood, immune cells and hormone synthesis.

“Our biology is set up to work in partnership with the sun”

- Linda Geddes

When your eyes make contact with dusk your brain starts to produce melatonin to signal sleep, reducing certain neurotransmitters like serotonin and histamine reduce whilst GABA and adenosine rise to take us into our sleep onset. Melatonin also reduces anxiety, which helps stabilise mood, appetite and routine.

Morning and daytime light exposure encourages an earlier shift in melatonin by supporting the natural decline of cortisol throughout the afternoon.

Cortisol is often referred to as your stress hormone, but it's also responsible for waking you up. It promotes alertness, peaking at wake time through to midday, then declines throughout the afternoon, triggering the rise in melatonin.

This is why morning sun exposure is shown to promote productivity and concentration throughout the day, it's supporting your natural skeep wake cycle and the hormones that facilitate this.

If you want to learn more about this then I recommend a book called "Chasing The Sun" by Linda Geddes

But what does sun exposure have to do with your hormone health?

A great deal!

Cortisol and melatonin are both hormones that rely on sunlight for optimal function.

Lack of sunlight is instrumental in producing more melatonin which actually works AGAINST thyroid hormone and shuts down the ability to use energy efficiently and lowers core temperature. This makes sense, as melatonin is your sleep hormone, and a lower core temperature and reduced energy expenditure is protective whilst we sleep.

It's shown that optimal light exposure throughout the day supports thyroid hormone conversion and overall metabolic health.

It's important to mention the potential damaging impact of sunglasses here. Sunglasses block 75-90% of natural light to the eyes. When exposed to sunlight, the retina stimulates production of suprachiasmatic nucleus to let the brain know it's daylight so it can organise your hormones as above. Lack of sunlight from sunglasses could encourage higher melatonin production at the wrong time of day, lowering thyroid function and disorganising the natural circadian rhythm.

This shouldn't be too much of an issue in a healthy person if sunglasses are worn now and then, but if you struggle with digestion, mood, immunity and hormonal health then removing sunglasses and exposing your eyes to natural light throughout the day could lead to health improvements.

Another consideration is the production of melanin, a hormone that protects and controls pigmentation of your skin. The more melanin you produce, the darker your skin. Melanin is also protective of the suns UV rays. When your eyes meet sunlight, the pitutiary gland releases a Melanocyte Stimulating Hormone (MSH). which is responsible for producing melanin to protect us from the rays. When you are wearing sunglasses, melanin isn’t produced and instead of getting tanned, your skin is more likely to get sunburned!

Sunlight to bare skin is also important, as you may know when sunlight hits the skin your body produces vitamin D, or hormone D as it should be known as!. But what many people don't know, is that skin connection to sun rays also produces progesterone which is the most protective hormone to both male and female physiology. If you've watched The Female Hormone Masterclass then you will appreicate the importance of progesterone production!

Sun Exposure Safety

So how do you get the above benefits without causing any damage to your skin? This comes down to the length and time of sun exposure, what you're eating AND what you're putting on your skin/wearing!

UVB rays (which make vitamin D) can only penetrate our bodies in the midday sun rays. This is due to the angle of the sun at that time of day. Morning and evening sun will not provide sufficient exposure yet will still allow your body to penetrate UVA rays, which are known to be the most damaging. Just to be clear, both UVA and UVB rays are shown to be damaging to the skin in excess exposure, and UVA rays are still very strong midday so it is important to be sensible with your exposure.

This is where mother nature is very clever, she has given us an optimal amount of time to absorb the health benefits of the sun our individual body needs without causing harm. If we exceed this that is where the risk factors start - too much of a good thing!

I've read a few resources that suggest the tingling of your skin is your bodies natural timer, letting you know to cover up or find shade. I've personally used this approach to head inside or put on sun cream, and slowly built up the length of time my skin bare skin can be exposed to the sun without burning. This is dependant on your melanin production, nutrient intake and your genetics. Fairer skin people may only require 10 minutes, whereas darker skin may need 20 minutes or more.

There is an app called “dminder” which calculates your vitamin D intake using your personal parameters like age, weight, skin colour etc. It gives you an idea as to how long you can safely be in the sun - I've never used it my self, but let me know if you have!

Nutrition

Nutrients DO play a very important role in protecting your skin. Some nutrients also play a key role in skin damage, too!

Polyunsaturated fats are a big concern for me. In the presence of heat, oxygen and light (the human body, in the sunlight), these fats turn rancid and exacerbate free radical damage. A higher rate of free radical damage leads to ageing and metabolic diseases such as diabetes, heart disease and cancer. This is a concern for skin health as the fatty acids we eat are expressed through your skin, contributing to healthy skin maintenance and growth ... or contributing to skin damage, ageing and even burning.

This also includes the oils we use on our skin topically, PUFA's such as rapeseed, sunflower, grapeseed and almond oils are often found in 'natural' products. But don't worry, I have a homemade sun protective moisturiser recipe coming to The Hormone Club very soon!

This moisturiser is made with saturated fatty acids such as shea butter and coconut oil. This is because saturated fats actually offer some SPF protection whilst nourishing our bodies at the same time. You see, our cells are saturated with saturated fatty acids as they remain stable in our 37 degree, oxygen rich body. Each of our cells has a fatty acid membrane that relies on saturated fats from grass fed animal foods as well as coconut oil and cacao butter.

UVB and UVA rays from the sun can also heighten free radical damage, it's a normal by product of a living, breathing human! However, food offers us something called antioxidants, which essentially mop up the free radicals and protect us from long-term damage! The problems occur when free radical damage out weighs antioxidant intake!

Because nature is clever, summer foods offer us plenty of antioxidants, whether it's berries, stone fruit, cucumber, beetroot, carrots, fennel, radish etc. the rule is the deeper the colour, the richer the antioxidants!

Polyphenols are a particular type of antioxidant that are shown to protect the skin from sunburn! Many plant foods are full of polyphenols (including DARK CHOCOLATE AND COFFEE!).

Vitamin E has super antioxidant capabilities. In fact, it is the first line of defence against the oxidation of polyunsaturated fatty acids. This is why vitamin E is found in PUFA rich food like nuts and seeds (again, nature ... clever), but it needs the shell to keep it stable, so by the time that handful of almonds reach your mouth there's no vitamin E in sight!

Vitamin C also has to be mentioned here, another key antioxidant that is abundant in berries and fruit over summer (nature ... clever). It also works with vitamin E in mopping up the oxidation from free radical damage.

Here is a list of sun protective foods to include in your diet either daily or weekly, and you can find it under the resources section.

Sun Cream

Unfortunately, a lot of sunscreens on the market have a number of chemicals that are shown to have damaging effects to our overall health, throwing our hormones out of balance, increasing skin allergies and potentially contributing to some cancers!

It is important to check the ingredients of your personal care products, especially sunscreen as it is shown to be the worst offender when it comes to chemical overload! The Environmental Working Group provides more detail on this with a list of ingredients and the concerns they raise.

European sun care products are shown to have tighter regulations, which is something we currently benefit from in the UK. However, it is still important to check for ingredients in the above link as well as certain forms of vitamin A like retinol (acetate, palmitate, linoleate) and retinoic acid which have been shown to speed up the development of malignant cells in skin cancer!

Obviously there is a risk vs protection element to conventional sunscreens when being used for a week or so whilst abroad, but we are advised to cover up all day everyday throughout the summer months!

The good news is that there are brands out there we can trust! Mineral based sunscreens containing zinc oxide or titanium dioxide are shown to provide strong sun protection with fewer health concerns as very few of the mineral based particles penetrate the skin to living tissue - unlike chemical based sunscreen!

But how much do sunscreens really protect us?

When the EWG tested 8 of the most common ingredients for sun protection, including octocrylene and homosalate which are widely used in the UK, only 1 came back with meaningful broad spectrum protection - Zinc Oxide.

Since UVA and UVB are both harmful, you need protection from both kinds of rays. UVB is the main cause of sunburn, whilst UVA plays a major part in long lasting skin damage, contributing to and potentially initiating skin cancers. So whilst your sunscreen is protecting you from burning, high chances are it isn’t protecting you from long lasting damage!

My Top Tips:

Considering all of the above (which is a lot, I know!), here are my five top tips for safe sun exposure throughout the summer:

- Ditch unnecessary PUFA's in your food and body products. Swapping things like margarine, rapeseed and sunflower oil, mayonnaise and other PUFA rich condiments for saturated fats such as block butter, tallow, shea, coconut oil and olive oil will not only protect your skin from sun damage, it can improve your overall metabolic function!

- Eat saturated fat and antioxidants together. Polyphenols such as lycopene and fat soluble nutrients like vitamin E are require saturated fat for optimal absorption and function. This months parmigiana recipe is perfect as it's rich in lycopene from the tomatoes and saturated fats from the parmesan and mozzarella!

- Find your sun tolerance by getting some bare skin exposure for 10 minutes each day, slowly working up towards 15-20 minutes. Remember, the darker your skin the more melanin you produce and can therefore withstand longer sun exposure with less risk. Whilst midday sun is important for hormone synthesis, it is also the strongest so just be cautious of your skins tolerance and cover up or take shade when necessary!

- Prioritise surface protection with saturated oils such as cacao, shea butter, coconut oil and tallow. What I haven't mentioned is that sun cream blocks the body's natural communication with sunlight which shuts down those signals to burning such as going red and tingling! Saturated oils can provide a small amount of natural SPF to protect the skin barrier without shutting down this communication (because it’s surface level), so using this as a daily body butter can give you a bit of extra support.

- If you're out all day or on holiday soaking up the sun (which is 100% what I will be doing!), then a mineral based sun cream is a MUST. Here is my guide to sourcing a zinc oxide based sunscreen with minimal to 0 PUFA - it's not easy so I've done the work for you!

There’s no doubting that spending too long in the sun can create sunburn and damage, the mechanisms suggested here should help to lower a susceptibility to burning so you can benefit from the health promoting factors the sun has to offer, safely!