There are two steps in my personal skin care routine which I never miss on any day – moisturizer and sunscreen. I have been religiously using it even before I became a dermatologist, since I tan very quickly and used to travel nearly 3 hours every day in the sun during college. I read about it once and have been using it since then, switching from over-the-counter cosmetic products to pharmaceutical brands after I became a dermatology resident. Is there a difference? Yes, there is. Because in India, cosmetics industry is not regulated tightly and there are no fixed rules (whatever exists are very outdated) for combinations and strengths, unlike in western countries where sunscreen formulations are under strict radar, since sun induced skin cancers are common and sunscreens are a necessity and needs to prove that it works as it claims. I don’t mean that all cosmetic sunscreens are bad, as there as some very good formulations out there, just make sure you check and know what you are getting. Also, pharma sunscreens tend to be cheaper that cosmetic sunscreens with similar ingredients and formulation.
Why do we need it?
Sun induced skin cancers like melanoma and others, are uncommon (but does occur) in our country as our body and skin are accustomed to live in tropical weather and sun. But sun exposure can cause damage in other ways too, the most important being sunburn and tanning in the short term and accelerated ageing in the long term. There is a difference between physiological (intrinsic) ageing and extrinsic ageing – ageing compounded by external factors, the major one as far as skin is concerned is Sun.
Sun exposure increases melanin synthesis – the pigment responsible for darkening, in our skin. Melanin in turn absorbs UV rays and prevents free radical damage to cells to some extent, thereby protecting from skin cancer and skin damage – the reason why darker skinned people are more protected than fairer skin of western population. So, if melanin does that naturally then why do we need a sunscreen? Because melanin protection is not complete and melanin increase is not even. So, do we need uneven skin tone, sun spots, more pigmentation of existing blemishes and patches, earlier fine lines and roughness? No, right? Then sunscreens are the best first line of defense against all these.
How to choose one?
Check few things on the label of a sunscreen – Spf, UVA star rating, water resistance, ingredient list at the back, the formulation and base.
There are two major types of sunscreen – physical and chemical or inorganic and organic. Don’t right away assume that ‘chemical’ sounds bad and ‘organic’ seems better. They are both same. All substances are made up of chemicals and chemicals can be organic or inorganic (basic chemistry). So, in that sense even ‘herbal’ or ‘organic’ sunscreens are ‘chemicals’ too. The difference is based on the way they act. While physical or inorganic sunscreens, usually made of Zinc or titanium oxide act by leaving a physical layer on skin which reflects light and prevents absorption, chemical or organic sunscreens (avobenzone, uvinul A, octocrylene, Tinosorb and the list is long) absorb the light and turns it into harmless heat, protecting underlying structures. Both have some advantages and disadvantages that’s why they are almost always available in combination.
Spf (Sun protection factor)
Sun protection factor. It basically measures the percentage of protection you get from UVB sun rays (spectrum of UV which causes sun burns, tan and skin cancer). A spf of 30 blocks 97% of UVB rays going into your skin. An Spf 50 98% and spf 100 99%. So, u can see that above 50 its just a number with no real-world benefit of increasing protection. Spf 30 costs way less than 100 and is enough for a person who spends just few hours in the sun. A full blown sun tan with melanin filters 50% UVB rays amounting to Spf 2. So, u can see where sunscreens stand.
UVA protection star rating
Now don’t blindly compare sunscreens by Spf which measures only UVB protection. The star rating on your sunscreen tube tells about the UVA protection. UVA rays are responsible for ageing, skin damage and also cancer. UVA penetrates deepest and affects collagen under skin leading to skin sagging and wrinkles. Also, atmosphere is predominantly UVA. The star rating varies from 0 to 5. Generally physical and broad-spectrum chemical sunscreens are better against UVA.
Water resistance
It denotes the ability of sunscreen to withstand immersion or contact with water for a period of 40 to 80 minutes. Water and sweat resistant creams are formulated to stay for all day without reapplication for moderate sweating and rain. Though swimming and profuse sweating needs reapplication after about 1 – 2 hours.
Ingredients
A standard and cheaper combination is avo/oxybenzone (UVA) with octocrylene, octinoxate (UVB) and zinc to cover the entire spectrum. But avobenzone gets degraded under light into damaging molecules (so combined with octocrylene always to stabilise) and oxybenzone can get absorbed (though in negligible amounts) and has been shown to have theoretical risk of certain ill effects. Newer organic ingredients are Tinosorb S and M (UVA and B), Uvinul A, T, MC, Mexoryl SX (these may be available under their full chemical names too) are safer and have broader spectrum of coverage. Pure physical sunscreens used to be ideal for extended sports activity, since thick layer of zinc cream (like the one we used to see on cricketer’s face previously) can reflect all UV rays entering skin. But the white cast had to be dealt with. Enters an important technology in physical sunscreens – the nano zinc. Zinc in micronized form with size in nanometres so that they don’t clump and cause white tint. They are much more cosmetically elegant, suited for sensitive skins, extended sun exposure and safer in children and pregnant women.
Formulation and base
Sunscreens come in all bases and formulations in the form of lotions, creams, gel, stick, powder, tinted or matte. Tinted sunscreens also give a light coverage like a BB cream. Lotions and gels are better than creams for acne prone skin since they are lightweight and do not clog pores. But newer matte creams based on silicone stay for longer and doesn’t look oily (which is a common issue with sunscreens) and are non-comedogenic (it is mentioned in label). Powder and stick forms are not very popular in India but many foundation sticks, compacts and powders have added minerals like zinc, titanium and iron for tint which also gives sun protection ranging from spf15 to 30 depending upon coverage.
When and how to use it?
When? Always. 8 am to 4 pm. If you have an outdoor activity, then it doesn’t matter if it is cloudy or rainy or chilly. UV rays can penetrate easily through cloud cover, rain and shades. And UV rays are more in high altitude hilly areas (even if it feels cool and pleasant and you don’t ‘feel’ the sun) and most near snow and water due to reflection. How? The picture can give an idea about how much is ideal for complete protection of each exposed area. Generally 2mg/cm2 or for face about 1/2 – 1 teaspoon or 1 -2g. Apply 30 minutes before stepping out (purely physical sunscreens act instantly) and reapply after 2 to 3 hours, if you sweat profusely.
Controversies around sunscreen
I have to address this because my patients give ‘authentic’ internet references of the harm of sunscreens. There are many controversial claims, many are unproven but the one fact that’s proven is that protection from sunscreens is real and substantial and far outweighs the unproven or minor harms.
How do I get my Vitamin D?
The only valid question. Vitamin D is a sunshine vitamin with multiple health benefits. Usually about 10 minutes of sun exposure around forenoon is all that is needed for daily dose. But of late I do find many, especially women deficient in Vitamin D (also maybe we started testing more). Mostly home makers who rarely step out and sick who are confined indoors. But sunscreens leading to vitamin D deficiency is quite rare, the number one reason being, nobody uses it religiously in adequate quantity or frequency daily. Not even westerners who never step out without sunscreen. So, rest assured even if sunscreens filter UV rays some do go through and they are enough. If proven Vitamin D deficient, then you can consider an outdoor exposure for about 15mins without sunscreen.
What about allergies?
They were more common with older chemical ingredients like PABA, oxybenzone and octyl methoxy cinnamate which were unstable with UV rays, but extremely rare with present sunscreens. Still if you have very sensitive skin or have allergy to some preparations you can opt for pure physical sunscreens.
What about absorption of nano zinc particles/oxybenzone/octinoxate and side effects?
I have to say even in nano form, zinc cannot penetrate skin. Because even though individual particles are in nm they exist In clumps much bigger. Few chemical sunscreens are shown to have hormonal and other ill effects in lab settings. Not in actual humans on skin application as the penetration is negligible. These risks are mostly theoretical and confounded by numerous other contaminants in air, food and water we are routinely exposed to, which are in fact more damaging. So don’t investigate too much into it. Also, many older molecules are not used much in newer sunscreens.
Finally, can you live without sunscreens? In India if you have shade range from beige to medium to dark skin? Yes. You can, If, you don’t mind the cosmetic, pigmentation and ageing issues. Millions live that way. For us, Sunscreens are a necessity only in people with certain conditions which get aggravated by sun like genetic or allergic or autoimmune diseases. But if you want healthy, younger, even toned looking skin always, sunscreens should be the first product in your skin care basket.
