How to eat sunscreen.

How to eat sunscreen.

This month many of us will spend a lot more time in the sun, often in another country that is at a lower latitude in the summertime.

Living in the UK with a temperate maritime climate, apart from recent events, we can't guarantee a hot dry summer meaning many of us head south.

Anywhere above the equator will share the same summer as us but as we head south towards the equator the sun is closer to a 90-degree angle to the atmosphere meaning its radiation is travelling through less atmosphere before it reaches us and therefore has more power, this is combined with the fact we have more skin exposed and are outside for more hours of the day.

This year since travel restrictions are all but gone even more of us will be heading off for a few weeks of summer sun and the lighter-skinned of us will undoubtedly come back a different colour having allowed our skin to adapt to the increased ultraviolet radiation by getting a sun tan.

Every year at around this time we seem to be bombarded with messages, often mixed, about how we should or shouldn't approach this from a health perspective with being told sunlight is both good for us and a killer, so what's the truth and what can we do to maximise the benefits and minimise the risks

What is sunlight?

The Sun is the star at the centre of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy mainly as light, ultraviolet, and infrared radiation. It is the most important source of energy for life on Earth.

Of the energy that reaches us, it can be roughly classified into 3 parts, 

1 visible light, with wavelengths between 0.4 and 0.8 μm

2 ultraviolet light, with wavelengths shorter than 0.4μm

3 infrared radiation, with wavelengths longer than 0.8μm

μm - micrometre, also called micron, metric unit of measure for length equal to 0.001 mm, or about 0.000039 inches.


The UV component can be subdivided by wavelength and is comprised of: UVA, UVB and UVC.

UVA rays penetrate the skin deepest and contribute to premature ageing, such as sunspots, wrinkles and sagging.

There are two forms of UVA: UVA1 and UVA2; UVA1 rays penetrate the skin deeper than UVA2.

Of the three main types of UV rays, UVA accounts for 95% of UV exposure, of which UVA1 accounts for 75%.

UVB rays produce sunburns and are largely responsible for skin cancer.

The most dangerous type, UVC, is blocked by the earth’s ozone.

Sunburn is caused by UV radiation, mostly from our reaction to UVB. It is a reaction of the body to direct DNA damage from UVB light. This damage is mainly the formation of a thymine dimer.

Technical bit coming up!

Ultraviolet light is absorbed by a double bond in thymine and cytosine bases in DNA. This added energy opens up the bond and allows it to react with a neighbouring base. If the neighbour is another thymine or cytosine base, it can form a covalent bond between the two bases. The most common reaction is two thymine bases that have formed a tight thymine dimer, with two bonds glueing the bases together.

In other words......The damage is recognised by the body, which then triggers several defence mechanisms, including DNA repair to revert the damage, apoptosis and peeling to remove irreparably damaged skin cells, and increased melanin production to prevent future damage. Melanin readily absorbs UV wavelength light, acting as a photoprotectant.

Melanin is a substance in your body that produces hair, eye and skin pigmentation. The more melanin you produce, the darker your eyes, hair and skin will be, when UV radiation causes us to produce more melanin, we produce more of this pigment and we call this a suntan.

So what is sunburn?

In some ways, sunburn can be considered to be too much vitamin D!

When the ultraviolet rays of the sun hit the skin, it converts cholesterol in the skin into vitamin D (cholecalciferol).

One of Vitamin D’s mechanisms is to draw calcium into the blood, not only from the digestive system from the food we eat but also from other tissues in the body, like muscles, bones and skin. Too much vitamin D leads to rapid calcium removal from the skin which changes something known as the epidermal calcium concentration gradient. The gradient affects many skin functions, including skin cell development, barrier formation, and homeostasis. With less calcium, this leaves our cells vulnerable to burning, and even ulcers and cold sores. 

 - Above from

As explained above the sun can cause damage to our bodies but as with so many things, dosis sola facit venenum (Latin) 'only the dose makes the poison) a phrase credited to Paracelsus the C16th Alchemist, and indeed, it very much applies to sun exposure.

When your skin is exposed to sunlight, it makes vitamin D from cholesterol. The sun's ultraviolet B (UVB) rays hit cholesterol in the skin cells, providing the energy for vitamin D synthesis to occur. Vitamin D has many roles in the body and is essential for optimal health.

Vitamin D

Vitamin D has two forms: vitamin D2 (“ergocalciferol” or pre-vitamin D) and vitamin D3 (“cholecalciferol”). Both are also naturally occurring forms that are produced in the presence of the sun’s ultraviolet-B (UVB) rays, hence its nickname, “the sunshine vitamin,” 

Vitamin D promotes calcium absorption in the gut and maintains adequate serum calcium and phosphate concentrations to enable normal bone mineralization and prevent hypocalcemic tetany (involuntary contraction of muscles, leading to cramps and spasms). It is also needed for bone growth and bone remodelling by osteoblasts and osteoclasts. Without sufficient vitamin D, bones can become thin, brittle, or misshapen. Vitamin D sufficiency prevents rickets in children and osteomalacia in adults. Together with calcium, vitamin D also helps protect older adults from osteoporosis.

Vitamin D has other roles in the body, including reduction of inflammation as well as modulation of such processes as cell growth, neuromuscular and immune function, and glucose metabolism. Many genes encoding proteins that regulate cell proliferation, differentiation, and apoptosis are modulated in part by vitamin D. 

In other words, it's really important, even as much as some researchers consider it not to be classed as a simple vitamin but as a hormone or more accurately a prohormone.

Vitamin D is also essential for the production of serotonin as well as some of the sex hormones and can support higher levels of free testosterone in both men and women, this has been brought to light in recent years by the COVID-19 pandemic where low levels of D have been linked to greater health problems from the virus (study here)

Ok, so a little sun is good, too much can be bad, what can we do to not get burnt?

For most people the go-to method of not getting burnt is to use a chemical sunscreen, what is this, how does it work and should we be using them?

The evolution of sunscreen

We're so used to using it but in reality, it has only existed for a hundred years or so, here's a rough timeline:

The late 1920s — A South-Australian chemist by the name of H. A Milton Blake starts playing around with a sun-blocking cream. It’s not very good, but it’s a start. (After years of experimenting in his kitchen, he finally invents a sunscreen that works, and is still sold under the name Hamilton Sun and Skin).

1936 — L’Oreal founder Eugene Schuller develops his own version. Is sometimes credited as the man who invented sunscreen.

1938 — Franz Greiter, a Swiss chemistry student, gets sunburnt while climbing a mountain in Austria, of all places. He decides to create a sunscreen.In 1938 Franz Greiter, a Swiss chemistry student, gets sunburnt while climbing a mountain in Austria, of all places. He decides to create a sunscreen. 

Today sunscreens fall into two categories of action,  inorganic (mistakenly called 'physical') sunscreens (i.e., zinc oxide and titanium dioxide) and organic (also, mistakenly referred to as 'chemical') sunscreens (they are not made from organic ingredients!) Of the first category, these are sometimes called sunblock and are present on the skin as a white paste, most often used in extreme environments such as high altitudes where very little skin is exposed to intense sunlight as it would be both impractical (and weird) to cover your whole body with white paste!

Chemical sunscreen is what we are most familiar with and the principal active ingredients in sunscreens are usually aromatic molecules conjugated with carbonyl groups. This general structure allows the molecule to absorb high-energy ultraviolet rays and release the energy as lower-energy rays, thereby preventing the skin-damaging ultraviolet rays from reaching the skin. So, upon exposure to UV light, most of the ingredients (with the notable exception of avobenzone) do not undergo a significant chemical change, allowing these ingredients to retain the UV-absorbing potency without significant photodegradation.  A chemical stabilizer is included in some sunscreens containing avobenzone to slow its breakdown; examples include formulations containing. The stability of avobenzone can also be improved by bemotrizinol, octocrylene and various other photo stabilisers. Most organic compounds in sunscreens slowly degrade and become less effective over the course of several years even if stored properly, resulting in the expiration dates calculated for the product - From Wikipedia

Sounds great, right, cover yourself with sunscreen, enjoy being outside, get the right amount of UV and produce lots of Vitamin D, so what's the problem?

Sunscreen risks?


Of the two types of sunscreen we identified above inorganic UV filters in the white paste sunblock types like titanium dioxide and zinc oxide are broadly considered safe, they simply reflect and scatter UV radiation away from the skin.

Of the other kind, referred to as organic sunscreen, some of the organic filters are absorbed through the skin and into the bloodstream. This alone doesn’t mean sunscreen is unsafe, but there is a growing focus on the potential adverse effects of the most common UV filter worldwide: oxybenzone, also labelled as benzophenone-3 and sometimes Milestab 9, Eusolex 4360, Escalol 567, or KAHSCREEN BZ-3 - Look out for this!

Oxybenzone is an organic compound that is a benzophenone derivative, explains Jamie Alan, PhD, an assistant professor of pharmacology and toxicology at Michigan State University. “It’s also found in plastics, toys, and some flowing plants,”

However, it is a known hormone disruption in humans (Krause 2012, Ghazipura 2017) , affecting oestrogen production, particularly in women and testosterone production in men. At least one study showed oxybenzone exposure leads to lower testosterone levels in adolescent boys, as well as thyroid problems in both men and women. 

If that’s not scary enough, there’s mounting concern that oxybenzone causes skin cancer, the very thing it's supposed to prevent!

According to research groups such as the Environmental Working Group (EWG) and other leading toxicology experts. A team of researchers at the State University of New York and the National Institutes of Health found a link between a concentration of benzophenones (the categorization to which oxybenzone belongs) and poorer reproductive success in men. The same study found that oxybenzone exposure increased women’s risk of other reproductive diseases, like endometriosis.

But that's not all, the environmental impacts of this chemical can be devastating.


Oxybenzone and coral reefs

The sale of oxybenzone-containing sunscreens has been banned in popular ecotourist destinations such as Hawaii and Key West, FL, in the United States.

The bans followed earlier research that implicated the chemical in coral bleaching, though scientists were unsure about the possible mechanism.

In the new study, scientists at Stanford University in Stanford, CA, found that oxybenzone is converted from a UV blocker to a “phototoxin” inside the cells of anemone and coral.

A photoxin is a chemical that becomes toxic when exposed to sunlight.

Their experiments also suggest that algae that live in the coral provide some protection against the toxins. This may mean that bleached coral is more vulnerable to the chemicals.

The researchers argue that, in a warming climate, oxybenzone-containing sunscreens could accelerate damage to coral reefs and hinder their recovery.

From Medical News Today:

Ok, so there are genuine concerns for both human health and environmental health from using sunscreens, so what can we do?

How to avoid sunburn

The most obvious way to avoid sunburn is to limit your sun exposure. In the first few days of a holiday where you're exposed to increased UV radiation simply avoid direct sun in the middle of the day, sun yourself without sunscreen when the sun is lower in the sky in the early morning or late afternoon, and slowly increasing your exposure day by day as your skin reacts without burning, however, you can significantly increase your time in the sun without burning by taking care of your diet.

What happens if you do get a bit burnt?

The first and most obvious thing to do if you've overdone it is to get out of the sun and stay out until symptoms are significantly reduced but there are a few natural remedies that can help recovery.

1. Hydration - this is by far the most important, make sure to drink plenty of water until urine is alight straw colour, also, make sure you keep up your salt intake with this

2. Vinegar - Sounds weird but add 1 cup apple cider vinegar to a bath, apparently it can help restore the Ph balance of the skin and reduce symptoms

3. Essential oils. Peppermint, lavender, chamomile and tea tree oil can all reduce inflammation and cool your skin—but make sure to dilute the essential oils with a “carrier” oil such as almond oil, or add the essential oils to a moisturiser such as aloe vera.


How can you eat your sun protection?


The role of diet in sun protection

Instead of covering up, using chemical sunscreen and avoiding the sun what if we tweak our diet to give us natural protection....

It turns out we can eat ourselves a SPF.

A large part of natural sun protection is eating an anti-inflammatory diet. To make sure the body has the proper building blocks for healthy skin and to reduce inflammation, consume enough healthy saturated, monounsaturated, and omega-3 fats while avoiding polyunsaturated fatty acids and high omega-6 vegetable oils.

The role of Omega 6 oils in sunburn

Omega 6 fatty acids or Polyunsaturated Fatty Acids are mostly found in seed oils or common vegetable oil, this is the oil most used for frying foods, as salad dressings and in processed foods.

Effects of high-fat diets rich in either omega-3 or omega-6 fatty acids on UVB-induced skin carcinogenesis in SKH-1 mice - 

This study  (above) shows that consumption of a high-fat diet rich in omega-3 fats reduced skin inflammation and tumour incidence during UVB exposure when compared with an equivalent dietary level of omega-6 fats. The omega-6 corn oil-fed group had ∼6-fold greater increase in inflammatory markers, induced acute inflammation and increased UV cancer expression.

One huge problem is that when we're on holiday, many of us will eat a diet high in omega-6 oils when we're also being hit with hugely increased doses of UV. When on holiday, avoid fried foods, non-olive oil dressing, mayonnaise and other sources of Omega 6 as much as possible, as delicious as the calamari Romana (deep fried in batter) might be after a day in the sun a much better choice would be calamari la plancha (cooked on a griddle)

Avoid this.....

Swap for this!

Omega 3 fatty acids 

Apart from the cooking methods illustrated above seafood and pasture-raised meats are a great choice when exposed to increased levels of UV radiation, as they are all the time!

Omega 3 fatty acids in the form of DHA or EPA can significantly increase your natural sun protection. This study showed participants who consumed 4 grams of EPA for 3 months increased their resistance to sunburns by 136%, while no significant changes were observed in the placebo group.


Lycopene - a sunburn-protecting antioxidant

lycopene gives many fruits and vegetables their red colour and it is particularly rich in tomato and is really concentrated in tomato paste as well as being present in watermelon, pink grapefruit, pink guava, and papaya. Dried apricots and pureed rosehips contain relatively large amounts, too. Lycopene absorbs both UVA and UVB radiation, although it may take several weeks for the skin to become more photoprotective due to its turnover rate, according to a 2012 study so the best solution is to make these changes to your diet sometime before jetting off to the sun.

Beta Carotene - Precursor to Vitamin A sunburn protector

This study concludes an optimal supply of antioxidant micronutrients in the skin increases basal dermal defence against UV irradiation, supports longer-term protection, and contributes to the maintenance of skin health and appearance.

Our bodies convert beta carotene into vitamin A, which is vital for skin health. A 2007 meta-analysis found that beta carotene provided natural sun protection after 10 weeks of regular supplementation, so before you head off, make sure your diet is rich in foods containing this, great sources are: yellow, red and green (leafy) vegetables, such as spinach, carrots, sweet potatoes and red peppers, yellow fruit, such as mango, papaya and apricots.


Garlic contains a natural compound called allicin, which has strong antioxidant and healing properties. Antioxidants fight off free radicals that enter your body from sun exposure, so eat your garlic on holiday!

Red wine!

Here's some great news! Drinking wine can reduce the risk of sunburn, finds a study in the Journal of Agriculture and Food Chemistry. Wine flavonoids, a nutrient found in grapes, protect skin cells from sun damage.


So the foods and nutrients listed above can reduce our likelihood of burning, which foods should we avoid?

In general when exposed to increased radiation we should avoid inflammatory foods as much as possible, this includes most processed foods, refined grains and refined sugars but by far the most important thing is to drastically reduce your intake of omega 6 rich seed oils, especially those used for frying which are likely oxidised.

What should we eat more of? 

Pasture-raised meats and sustainable local seafood high in omega-3s

Lots of leafy greens

2+ tablespoons of tomato paste daily (add this in for the lycopene and skin protection)

A little red wine

Things cooked in garlic and olive oil 

If this kind of sounds like a Mediterranean diet, could this be a coincidence? Probably like the locals, not like a tourist, sleep well, exercise a little,  leave your phone at the hotel and breathe!

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