07 Aug Everything on SPF and UV protection in Natural Oils, Herbs and Foods
Since I am going all-natural, I am making my own sunscreen for my holidays. Before making it, I wanted to make a research on the natural sunscreens, SPFs and trace where the information on the SPF in the natural oils came from. Keep reading if you want to know which information across the web is correct, which is misleading and what is missing; I even made a couple of Tables from which this information is easily visible. In addition, in this post you’ll find all the basics about SPF, sunscreens and sunblocks, which oils to avoid when exposed to the sun (phototoxic and photosensitive) and above all, the tables I’ve made where I gathered all the surveys and the info they provided about the natural oils, including their SPF and which UV protection they can provide. There’s something for everyone; if you don’t wish to read the long preface, just scroll down to the Tables and enjoy all the researched info about the natural oils that can protect you while on the sun. Have fun 🙂
I had a few second thoughts about making my own sunscreen, since I am not used to taking a natural-all-the-way to the point where society and everyone seems to be terrified of the sun causing you cancer. Despite reading countless blogs, articles and books on how the sun is good for you and that the sunscreens are just a consumer propaganda that want to earn money and on top of that, they are often the ones causing you skin cancer, I am trying to be objective about this and always look on the both sides of the story, even if I prefer just the one. So, will avoiding the application of the mainstream sunscreen give me a possible skin cancer in the future or will the opposite do so? I hope not. I don’t really know what’s gonna happen, do you?
We do need to protect our skin and find a balance between complete and utter exposure to the sun and blocking the sun completely. But that doesn’t necessarily mean we have to apply (only) the chemicals onto our skin. Often either (1) the chemicals of the sunscreens and sunblocks are causing you cancer or (2) we don’t apply the sunscreen correctly, thus we’re exposed to the sun for much longer periods of time, without the proper protection and/or knowledge. I stop to think and wonder when on earth did we start being so terrified about everything? Don’t expose yourself to the sun, hide in the shade, it’s gonna give you skin cancer! If not now, maybe in 10, 20 or 30 years, who knows. Better stay away and just keep nibbling Vitamin D in capsule form, it’s safer. We seem to have every excuse based on the “it’s safe” method.
Despite not fully knowing the ingredients and its side effects in the sunscreens, I base my knowledge on the other skin and hair care products and I honestly go with the method: whatever is (1) XY and I don’t understand it, (2) can’t pronounce it and (3) need a chemistry dictionary to understand it’s content, I won’t apply it on my skin. Despite customer service being very nice and reassuring that “this product doesn’t contain any harsh chemicals that could hurt you”, I am not falling for these kinds of explanations.
On one occasion I asked a representative of Jason (you’ve heard of this brand right?) what is the process of Potassium Hydroxide in their products and how does it just disappear after saponifying. Do you know what I learnt? Nothing, they didn’t know the answer. I am doing my own homework regarding this. The chemicals may not be very harsh, however … Why would I want to put something that “is ok and probably won’t do me and my skin any damage”, on my skin when I know I can make my own, for instance, shower gel that includes no XYs and contains only coconut butter, lavender and Calendula infusion together with lavender essential oil (for more info, check post on Coconut Shower Gel)? This way I know exactly what I’m putting onto my skin, on a longer run into my body, and the funny thing is that it does the job. It does the job; my skin is soft, I smell nice (even my feet and arm pits!) and all without any chemicals. It can actually be done in the natural way 🙂 A bit out of the topic, but hopefully you get my point.
Sunscreen, sunblock, Titanium dioxide and Zinc Oxide
What is the difference between the first two? Sunscreen is what I want to do: it allows the sun rays to penetrate our skin and at the same time it doesn’t go in the deeper layers of the skin. Sunblock, on the other hand, reflects the light away so it doesn’t reach the deeper layers of the skin at all. If you remember the 90s and the thick white creams, that was it, the sunblock. Those contained Titanium dioxide or Zinc Oxide and these can be purchased and are often combined with the sunscreen (look only for the Nano free one). Nowadays you can find more natural sunscreens that are called mineral sunscreens and they usually contain only these two. However, beware of the harsh chemicals that are always in these products.
I am considering if I should add some sunblock to my sunscreen, however, first I want to make a thorough research on these two ingredients (I’ll be posting my variations of sunscreens later on and you’ll see if I included them in my sunscreen). For a very brief info; I’ve learnt that Zinc Oxide is very toxic if overdosed and can cause gastrointestinal problems if ingested (severity of the side effects depends on the quantity of the Zinc Oxide in the product). Titanium Dioxide is used thoroughly as a natural sunscreen, aka mineral sunscreen. The nanoparticles are used in a sunscreen and as long as they represent around 25% of concentration in the sunscreens, they can be considered safe for the humans on the skin since it absorbs around 70% of incident UV. Some scientists are concerned about this nanoparticles being absorbed and its possible side effects. Furthermore, if you inhale these nanoparticles you risk lung inflammation, there are even some test that show that this can lead to cancer. In addition, the nanoparticles can act as a photo catalyst, meaning that they can accelerate a photoreaction and thus generating hydroxyl radicals which result in toxic effects. Not all nanoparticles have this property, if they are appropriately managed. Most importantly, the products containing mineral sunscreen are often labelled as a “natural sunscreen” and, as we often discover, this is not the case. The titanium dioxide is supposedly pitch black with a lot of lead in its natural form. Therefore, this product is refined and probably processed and not pulled out of the earth and into the lotion.
To sum up, Zinc Oxide and Titanium Dioxide can be safe to use, but as many ingredients in very small amounts, however, the opinions on the possible side effects still vary and on top of that, they are usually refined and processed, therefore not really natural.
UVA, UVB and UVC
So, after my research I’ve learnt once again that the sun IS in fact a crucial member of our lives and we do need it. Our skin, hair, nails and above all, our bones need the vitamin D. However, the ultraviolet radiation (UV) can be damaging. There are UVA, UVB and UVC radiation that we need to pay attention to. The UVC is absorbed by the ozone layer and is a potentially the most harmful one. I remember how sun lotions used to say that they protect from the UVB radiation and only later on you could see on the Nivea lotions sign of “protects from UVA and UVB radiation”. I’ve tried to learn more about different radiations, but I got many contradictory information, such as that UVA mainly leads to skin cancer and that UVB is responsible for skin tanning and then another research I found that said that UVB and UVA (in a lesser extent) can lead to skin cancer. So basically, just to be safe, try to find a protection for the UV spectrum and reduce the ones that have the protection from the UVB only.
Initially I wanted to publish the article as it is, but since I do want this information to be as thorough as possible, I was digging up deeper and wanted to know more about the wavelength since this expression kept showing up in the literature. Now that we know what is UV I can explain it further and it is easier to understand the whole concept of the UV. I do need to add that here I found many contradictory information on the wavelength between the UVA, UVB and UVC. They are the wavelengths that you can’t see.
UVA is the longest one at 320 – 400 nanometres (nm) and is further on divided into two ranges; UVA I which measures 340 – 400 nm and UVA II which has the range of 320 – 340 nm. UVB‘s range is 290 – 320 nm and UVC has the shortest rays with 100 nm – 290 nm and the most of it is absorbed by the ozone layer. After learning more about wavelength I discovered that the research (Pharmacognosy Res. 2010 Jan-Feb; 2(1): 22–25.) that I’ve been very excited about, only measured UVB and not the UVA. So basically to sum it up, the efficient sunscreen should have the absorbance between 290 and 400 nm, thus covering UVA and UVB. If you want to be really safe, try to find the protection in the range between 100 and 400nm and you’ll be protected against UVA, UVB and UVC.
So what is SPF?
It stands for Sun protection factor and it basically tells us how strong our sunscreen is. The higher the SPF, the more protection you’ll get against the UV radiation that can cause skin burn. That being said, differences between SPF’s are not as big as you may think. Many people buy the really high numbers just so they can stay exposed to the sun for longer periods of time without the need to re-apply too often (or so they think). I remember reading that no matter if the SPF is 50 or 100, it won’t protect you for much longer. Below you can see the differences between various SPF’s and their protection.
SPF 15 protects 93% (that means that 7% of the UVB rays get through to our skin)
SPF 30 protects 97%
SPF 50 protects 98%
SPF 100 protects 99%
As you can see, especially with the SPF 50 and above, the difference is so small that the next time you’ll find yourself buying insanely expensive sunscreen just because of the really high SPF, think again. I couldn’t find the information on how much does the SPF 20 protects from, but I would assume it’s between 93% and 97%, therefore cca. 95%.
Surveys on the natural oils
Here I’ll very briefly explain the researches I could find and further below are the tables I’ve made which are based on most of these surveys.
I came across one wonderful blogger and she made a table of natural oils and their SPF based on the research by the Kapoor and Saraf (2009), however, there was no info which oils protect from the UVA and UVB, so I decided to put this and another research of the same Institute together. The study found that all of the herbal products are stable in the UVB range and 71% of them are also stable in the UVA range (Table 2).Bear in mind that only two ingredients were of sole use, others were paired together, making it more difficult to obtain the information on their exact SPF and whether or not they do or don’t protect from both, UVA and UVB. Another research, from the same university Kaur and Saraf (2010) had a wonderful outcome and their results are also included in the Table 1 below. However, they only measured the UVB range.
Furthermore, another short research by Teressa, Kumar & Sampath (2004) showed that coconut, groundnut, castor and olive oils have transmission above 70% in the UVB region and that neem-seed, sunflower, sesame and cod liver oil have transmission level below 60% in the UVB range. If I am correct when interpreting this, it basically means that if you’ll apply for instance, olive oil on your skin, you could have reduced exposure to UVB.
Red raspberry oil, I’ve heard and read so much about you! I wanted to get to the bottom of it since it seemed to be the best one. In every article I came across, it said it protects form both UVA and UVB and has a factor between 28 and 50. I found the research by Oomah et al. (2000) (summarised in the Table 1 below) and the info on the websites is both correct and wrong. The research showed that raspberry oil has some absorbance in the UVC and UVB range. It can also shield against UVA (320 – 340 nm) induced damage by both scattering and by absorbing the UV. The shielding power depends mainly on the scattering effect. Therefore, the red raspberry oil can act as a broad spectrum of the UV. Another interesting thing that was written in the report was that its transmission was comparable to that of a titanium dioxide with SPF 28 – 50 for UVB and 6.75 – 7.5 for UVA, if I understood that correctly. I don’t think the SPF was the purpose of this survey, however, these results offer us some great information about the red raspberry oil and its protection against the UV radiation. However, the survey mainly relies on the statements that this oil protects against UVB and UVC, and CAN be used as a broad spectrum against UV radiation, therefore everyone that claims its protection against UVA is somewhat misinterpreting these results. To interpret it, it isn’t exactly 100% positive that it will protect you against the UVA as well. But after reading all of the researches, I believe that this is as close as you can get to the confirmed-by-science natural sunscreen that offers you a possible UVA and UV spectrum protection.
SPF and UV protection in Natural Oils, herbs and foods
In this paragraph you can see the Tables containing the info on the surveys, some other oils that weren’t included in the researches. In addition, you’ll learn about some herbs that can help you protect against the UV and some foods that have amazing properties when exposed on the sun. Enjoy the reading! 🙂
Tables of Natural Oils and their SPF & UV protection
Below are the promised Tables in which I’ve gathered the accessible surveys. I hope you find them useful and that it’ll make your next vacation enjoyable. A bit of a legend: you have listed ingredients, their SPF, measured UV protection and further below the ingredients are the references of the surveys. The empty spaces mean that there’s no information about whether or not the ingredient protects from these UV; most of the surveys presented the info on the protection in the UVB range only. Below the Table 1 and 2 I also presented Table 3 which includes the information about other oils that are found on the most of the websites and I wanted to check whether the sources are traceable or not. In some cases I’ve found the sources, in others I couldn’t find them; be it because the information is inaccessible or because source was untraceable.
Summary of the Tables
I will briefly summarise some of the best and most surprising results. As you can learn from above Red Raspberry Oil is one of the best ones so far, in both the SPF and the protection against UV spectrum. In addition, both Coconut and Olive oil have the SPF of cca 7 and Peppermint (essential) oil surprised me with its 6.7 SPF. One of the biggest surprises, given the fact that the surveys were mainly concentrated on the oils was the finding that the Aloe Vera alone has the SPF of 19.9 (but it does protect only from the UVB). In addition, Water melon (I know right?) has the SPF of 10 and showed some absorbance of the UVA. There are many other amazing oils mentioned and researched in the surveys and showed in the Tables above, but they are paired with many others (Table 2) and this makes it difficult to obtain their exact SPF.
While reading the above tables and learning more about the oils, keep in mind:
- That there are very very few researches in this area and that even though we are trying to base our opinion on a couple of them, it’s always good to be a bit of a sceptic.
- In addition, two of the researches were done by the same Institute.
- Furthermore, in order to protect you from misinformation, I also added the list of the oils that can be found on every single blog/article/website regarding natural sunscreens and kept repeating. Unfortunately, the sources haven’t been always checked by many of the authors, therefore some information can be misleading. For instance, the article on the e-how claims that in the research of Kapoor and Saraf (2009), the carrot seed oil was found to have the SPF of 38 – 40. However, if you read the article and check the survey results (see Table 2 above), it is clear that Carrot was tested together with Symplocos and Wheat germ and altogether, the SPF was 40.6. Therefore, Carrot hasn’t been tested alone and we don’t know it’s SPF. At least not in this research.
- I wasn’t able to access some references, especially books. I traced some of the researches, however, on many occasions I wasn’t able to do so, due to the (1) inability to access the source because it’s not accessible on the internet or (2) I couldn’t trace the source.
Other oils and herbs that can protect your skin
While browsing through the literature I’ve read about many other oils that either weren’t included in the surveys I’ve presented or were paired with others. I haven’t done much research on these oils since they were written in the book of Neal’s Yard Remedies (Reference is below) and wanted to post this article before Christmas 🙂
There are some oils that confirm findings of the research. For instance, Almond oil (Table 1, research 2) is also included in the book where they confirm that it has a low SPF and there is a mentioning of the Red Raspberry Oil (Table 1, research 1) confirming my findings that this oil helps to absorb the UVB and UVC (could be the same research as the one I’ve gathered the info from). Another oil that I’ve noticed three times in the surveys but hasn’t been tested alone is the Sandalwood (Table 2, research 3) oil. They claim there are scientific test where this oil demonstrated the ability to prevent skin cancers caused by UV and toxic chemical exposure. Makes you run into the store, buy it and add it to your sunscreen doesn’t it? Furthermore, Wheat bran extracts are supposedly capable of some protection against the UV. In the surveys and generally in the web there’s a lot written about the Wheat Germ oil. So is this the same? Wheat bran is the outer layer of the seed whereas the germ is the part of the seed that grows, the embryo of the grain.
Comfrey (Symphytum officinale) contains rosmarinic acid which has various properties that help protect the skin from the UV damage. Another oil that can contribute greatly to not only your skin, but your hair as well is Avocado Oil with its properties to boost protection during sun exposure. Sunflower oil can for instance help to both repair and protect the sun-damaged skin. Last, but not least is the Lemon balm (Melissa officinalis) which have caffeic and ferulic acid that help to penetrate in the deeper layers of the skin and protect it from the UV skin damage. I’ve checked and this oil is not photosensitive, so go for it. More on the phototoxic and photosensitive oils (oils to avoid in natural sunscreens) read the last chapter.
How can you protect yourself from the sun with foods?
When researching this topic I started to think how did people let’s say 200, even 500 years ago did it? How did they protect themselves against the exposure of the UV? I don’t know the statistics for those times on the skin cancer and whether the lack of our knowledge on this matter is because (1) there was almost no examples of skin cancer at that time, (2) there was actually no skin cancer because they didn’t have millions of creams and therefore millions of chemicals or (3) they just didn’t have a name for the skin cancer. Anyway, why don’t we go with the nature hand in hand and make it work?
I’ve read in several places that it’s a good idea to boost yourself up on Vitamin C since it can reduce the effects of the sun exposure. There has been a research that mainly researched the positive effects of the green tea against the UV damage and the green tea was ingested in combination with Vitamin C. As mentioned, it is great contribution to your skin protection if you drink Black, Green or/and White tea every day. Even if they are applied topically, they can provide some sun protection against the UV radiation. In addition, there has been a study in the British Journal of Nutrition saying that if you drink as little as two cups of tea per day (along with 50mg of Vitamin C) it can protect you from the sunburn. According to this survey green tea offers protection against sunburn inflammation and potentially long term UV damage. Hooray for us tea lovers! 🙂
Pomegranate can provide some protection against the sun due to the bioactive compounds. You can add it in your sunscreens be it the extract, oil or juice. Another good food that is a must on your plate while you’re on your holiday is Tomatoes. The research at the University of Newcastle and Manchester revealed that the tomato paste has the SPF equivalent to SPF 1.3. They discovered that it is a very good compound and addition to sunscreens and that you can easily manage it if you like eating tomato-based meals. The tomato based diet boosted the level of procollagen in the skin which is suggesting anti-ageing properties in the skin which is a great addition in reduction of sunburn.
That is all I found and don’t forget that eating these foods alone won’t protect you from sun damage. They are an incredible addition to the protection and go hand in hand with the natural sunscreen and wise exposure on the sun.
Phototoxic and photosensitive oils: the oils not to be included in the natural sunscreen
When making your own blend of sunscreen, you can choose from variety of different oils. The above mentioned oils that were researched and have some validation on their SPF and UV protection can be a very good choice for anyone in search for something natural. However, when making your own blend, a lot of us will want to add some essential oils to make it smell nicer, some even have a great SPF! Please bear in mind, that some of the oils are phototoxic and photosensitive and as such can cause various unpleasant skin conditions.
Phototoxic oils are, in our example, essential oils that can make our skin more sensitive to the UV light and therefore they can damage our skin (we can get more sunburn or allergy reaction). Do not understand me wrong, these oils won’t cause you any harm if you apply them on your skin while diluted with the carrier oil and when you’re not on the sun. However, don’t expose yourself on the sun afterwards (around 12h after the application) or you can risk everything from sunburn, blistering to oedema.
- Bergamot (Citrus Bergamia)
- Bitter Orange (Citrus x aurantium)
- Grapefruit (Citrus x paradisi)
- Lemon, cold pressed (Citrus limonum)
- Lime, cold pressed (Citrus aurantifolia)
- Opopanax (Commiphora guidotti)
- Angelica (Angelica archangelica)
- Petitgrain (Citrus aurantium)
- Rue (Ruta graveolens)
Photosensitive oils aren’t toxic to your skin, however, they can cause various unpleasant reactions to your skin. These oils can be:
- Cumin (Cuminum Cyminum)
- Lemon Verbena
- Cedarwood (Cedrus atlanticum)
- Cinnamon (Cinnamomum zeylanicum)
- Clary Sage (Salvia sclarea)
- Elecampane (Inula helenium)
- Ginger (Zingiber officinalis)
- Lovage (Lovisticum officinale)
- Patchouli (Pogostemon patchouli)
There is much information that is of complete opposite, such as that Lemon (steam distilled), Lime (steam distilled), Mandarin, Sweet Orange, Tangerine and Bergamot (furanocoumarin/bergapten free) are in fact safe, whereas other websites claim they are either phototoxic or photosensitive. In addition, various websites have completely opposite information on the oils (some are considered phototoxic on one website and on the others you can find that they are listed in photosensitive oils), so keep that in mind. Therefore, bear in mind that I’ve just put all the pieces from various websites onto one place and if you need more info, you have all the references below. Either way, it is always the best thing to try it out yourself beforehand and see how your skin reacts. You should always make a test before exposing yourself to the sun in order to avoid the damage on your skin (sunburn, allergies etc.). I know I am more of a safe player, therefore I won’t be putting any of these in my sunscreen.
To sum up, we’ve learnt about the basics of the sunscreens, sunblocks and what the Zinc Oxide and Titanium Dioxide are good and bad for. If you didn’t know which oils have been actually researched or not on their SPF and UV protection, all the info is in one place now. In addition, beware for the phototoxic and photosensitive oils that you are putting in your DIY sunscreens. Hopefully I’ve broaden your perspective on the natural protection from the sun and as you could see, you can protect yourself from overexposure not only with a sunscreen and re-applying it every couple of hours, but with a rich diet of various nourishing foods as well as common sense of the length of time you spend exposed on the sun. I’m sure a lot of you will include the teas, water melon and tomatoes into your diets while on the sea side 🙂
Things to remember:
- The quality and legitimacy of the research and the body who conducted it. For instance, have you checked the research method, do you know if it’s valid and actually of use? Have you checked the university/research institute that conducted this research and what is their reputation and recognition in the contemporary scientific area? In addition, why is there such a small amount of surveys in this field? I am not trying to turn you away from the natural way, just always keep in mind a shred of doubt in the researches, be it in natures’ or chemicals’ favour.
- Natural medicine, cosmetics and herbs are based on the traditional use only. This being said, it is however true that when applying natural medicine, herbal remedies and natural cosmetics, the organic products/herbs are based on the traditional use only. Therefore, if you are all about nature and would only listen to the scientists, you would have probably given up by now and return to the so called “shelf life” and chemicals.
- Type and origin of the oil you are using for the sunscreen. You and me, we probably won’t be using the same type of oil. So I am quite certain that the SPF also depends on the quality of oil (organic or non-organic), whether it is virgin, cold pressed, unfiltered, unrefined and where it’s been stored (is the packaging recyclable and non-plastic) etc.
- Be aware of the photosensitive and photo toxic oils. When mixing up your sunscreen/sunblock you can always add the essential oils of your choice. However, most of the citrus oils are NOT OK to put on your skin when you’re exposed to sun. Check this thoroughly before exposing yourself to the sun and make a test beforehand.
- Red Raspberry oil. I traced the claims back to the original article, have read it through and found that mistakenly everyone seems to be claiming that it protects against UVA and UVB radiation, whereas the conducted research actually discovered that it does absorb UVB and UVC radiation and it has a potential to absorb UV spectrum and that it can shield against the UVA. Meaning, it is possible that it offers protection from various UV radiation, however, only UVB and UVC were proved so far. That being said, it is still a wonderful contribution to the home made sunscreen and one of the very few ones that can shield you against UVA as well. I will definitely be including it in my DIY sunscreen recipe.
- Carrot seed oil seemed to be right after the raspberry seed oil given the popularity, high SPF and the UV protection across the web. I’ve tried to trace the source and unfortunately I couldn’t find any research claiming that it actually has the SPF of 38 – 40 which I’ve also written down in the Table 3. In addition, in one of the researches (see Table 2), by Kapoor and Saraf (2009) it was indeed tested but with many other oils (2 in one case and 4 in the other), therefore, there is no information whatsoever on the SPF of the carrot oil alone in this survey.
Remember: it is up to you what kind of substances you are putting onto your skin and what suits you best. Making a 100% natural sunscreen that will protect you against the UV radiation is do-able! Nature is amazing 🙂 I hope you found this post/article useful and if you have any information on the sources/researches, I’d love to hear it (together with some comments, opinions, your experiences with the DIY sunscreens etc). I’ll be making my own variations of the DIY natural sunscreen(s) and will be sharing it in one of the next posts since my holidays are almost here 🙂
“Nature doesn’t hurry, yet everything is accomplished.” – Lao Tzu
*Illustrations by Luka Arh. Potrfolio: http://arhluka.weebly.com/
Copyright © 2015 WorldNaturelle. All rights reserved.
Curtis, S., Johnson, F., Thomas, P. (2015). Neal’s Yard Remedies: Beauty book. London: DK.
Dunford, R., Salinaro, A., Cai, L., Serpone, N., Horikoshi, S., Hidaka, H. & Knowland J. (1997). Chemical oxidation and DNA damage catalysed by inorganic sunscreen ingredients. 418(1 – 2), pp. 87 – 90.
Kapoor, S. & Saraf, S. (2009). Efficacy Study of Sunscreens Containing Various Herbs for Protecting Skin from UVA and UVB Sunrays. Pharmacognosy Magazine, 5(19), pp. 238 – 248. Available on: http://www.phcog.com/article.asp?issn=0973-1296;year=2009;volume=5;issue=19;spage=238;epage=248;aulast=Kapoor
Kaur, C.D. & Saraf, S. (2010). In vitro sun protection factor determination of herbal oils used in cosmetics. Pharmacognosy Research, 2(1), pp. 22–25. Available on: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3140123/#!po=45.8333
Oohman et al (2000). Characteristics of Raspberry Seed Oil. Food Chemistry, 69, pp. 187 – 193. Available on: http://mail.lotioncrafter.com/reference/oomah.pdf
Teressa, Kumar & Sampath (2004). Ultraviolet Transmission through a few Edible Oils in the context of changing Solar Insolation. In J. Ind. Geophys. Union, 8(4), pp. 267 – 271. Available on: http://www.igu.in/8-4/4Shohana.pdf
University of Newcastle and Manchester. Available on: http://www.ncl.ac.uk/medicalsciences/news/item/tomatoes-found-to-fight-sun-damage