Experts share tips on sunscreen and its effectiveness

Mar 24, 2015, 08:05 IST | Soma Das

The mercury is rising. Now's time to dab sunscreen and block the menacing sun. the guide invites experts to spell out the importance of applying sunscreen and also picks out the best buys in the market

Different types of sunscreen
There are two types of sunscreens: chemical sunscreens (also called sunscreen) and physical sunscreens known as sunblocks. Chemical sunscreens absorb the sun's harmful ultraviolet rays while physical sunscreens reflect them.
Physical sunscreens act as a shield and reflect both UVA and UVB light and contain ingredients such as titanium dioxide and zinc oxide while the chemical sunscreens have avobenzone and benzophenone. Chemical sunscreens often contain UVB-absorbing chemicals only; however, there are some chemical sunscreens that contain both, UVB and UVA absorbers.

Which sunscreen should you use?
>> It depends on how sensitive your skin is, how dry/oily your skin is, history of previous skin diseases, and activity undertaken.
>> If you have fair skin that burns easily, choose a sunscreen that covers UVA and UVB with a higher SPF-30+.
>> If you have skin that tans easily, a broad spectrum of sunscreen with an intermediate SPF-15-30 works.
>> If you have dark pigmented skin and don't have sensitivity to sunlight, sunscreen with a lower SPF is suitable.
>> If you have dry skin, choose sunscreen with a moisturising base. If you have oily skin choose sunscreen with an aqueous base.
>> If you plan to have an activity outdoors, choose a water resistant sunscreen.
>> Patients with oily skin or conditions such as acne should avoid products containing preservatives or fragrances, as well as those containing PABA or oxybenzone. Oily skin types may find gel formulas (which contain alcohol) more drying and less likely to aggravate acne.
>> Acne-prone patients should avoid greasy sunscreens, thick emulsion-based sunscreens or high SPF sunscreens, since they exacerbate breakouts.
>> Dry skin can benefit from moisturising sunscreens or thick emulsion-based sunscreens.

skin care

What is SPF?
>> SPF or Sun Protection Factor is the measure of effectiveness of the sunscreen. Higher the SPF, greater the protection against ultraviolet light.
>> SPF is the amount of UV radiation required to cause sunburn with sunscreen on. Many people believe that the numbers mentioned (like SPF 25) are the number of hours the skin is protected, which is untrue as SPF is related to the amount of exposure and not time.
>> SPF is a measure of how well the sunscreen deflects UVB rays and not UVA rays. Manufacturers calculate SPF based on how long it takes to sunburn skin treated with sunscreen.
>> If not applied thoroughly, it might be washed off during swimming. Rather than looking at SPF, choose a broad-spectrum sunscreen that protects from UVA and UVB rays.

Do sunscreens affect Vitamin D absorption?
>> Sunscreen use does not affect Vitamin D absorption or production in daily routine. This is mainly due to inadequacies in their application to the skin. Most individuals apply only on the sun-exposed areas and not the full body area daily. Further, no sunscreen provides absolute protection and some UV rays still pass through.
>> Vitamin D is not absorbed through the skin; rather the UV rays from the sun when absorbed through the skin help in the production of Vitamin D. Only a short duration of sun exposure in the range of 30 minutes is needed to produce enough Vitamin D. Moreover, casual exposure to sunlight before 10 am and after 5 pm can provide sufficient UV rays for stimulation of Vitamin D production.
>> When having prolonged sun exposure, especially between 10 am-5 pm, it is suggested that sunscreen is used as the chances of sunburns are higher.

The importance of sunscreen
>> Sunlight has UVA and UVB rays that act differently on the skin.
>> UVA does not cause sunburn but causes changes in DNA of cells; that can cause cancer like Melanoma.
>> UVB damages the superficial level of the skin causing sunburns and can cause cancer. Ingredients in the sunscreen absorb high-energy ultraviolet rays and release the energy as lower-energy rays, thereby preventing sun damage.
>> On exposure to direct sunlight, skin produces a brown pigment called melanin, which creates a suntan. This is already present in pigmented skin (darker people). Melanin has the same effect as that of a good sunscreen. Lighter skinned people have less of melanin and are prone to use sunscreen of higher SPF.

Dos and don'ts

>> Look for the presence of zinc, titanium dioxide and avobenzone that are powerful UVA blockers, do not get absorbed and remain on the skin surface.
>> Use a sunscreen with SPF 15-30+ daily. You should use SPF 30+ only if you plan to stay in the sun for an extended period.
>> Choose a sunscreen that has a broad-spectrum of protection from both UVA and UVB rays and lasts longer.
>> Get a test dose of a small amount of sunscreen on little children and infants.
>> Apply generous amounts of sunscreen to dry skin 30 minutes before you go outdoors. Use sunscreen on all skin surfaces that will be exposed to the sun. If you don't have much hair on your head, apply sunscreen to the top of your head or wear a hat. Reapply sunscreen every two hours — and immediately after swimming or heavy sweating.
>> Sand, water, snow and concrete reflect sunlight and make it even more important to use sunscreen.

>> Don't choose a product that may affect hormones and may be potentially carcinogenic, such as oxybenzone.
>> Don't waste money on sunscreens claiming an SPF higher than 50+. There's no evidence that such products provide better protection.
>> Don't forget to reapply after 2-3 hours as towels and clothes can easily rub off sunscreens.
>> Don't use a spray sunscreen as although convenient, these sprays make it easy to miss spots or apply too little. Furthermore, sprays can be easily inhaled and can contain toxic ingredients.

Sunscreen for men
>> The sun causes the same damage to the male skin as it would to a female skin, namely sunburns, age changes and skin cancers. It is vital for men to apply sunscreens just as women or children do.
>> Regular sunscreens work well for men. A few important points would be use of spray/gel forms of sunscreens for hairy areas of the body like the chest, scalp, thick beard areas and lotion/emulsion for other areas.

Try out these sunscreens

Kiehl’s Ultra Light Daily UV Defence Rs 2,800 for 30ml & Rs 4,000  for 60ml

Lancome UV Expert XL Shield  Rs 2,600

Ideal Soleil Hydramist SPF 50 from Vichy Laboratories can be applied evenly, is non-greasy and non-sticky. Rs 1,890

Himalaya’s Protective Sunscreen Lotion with Cinnabloc. Rs 110 for 50 ml and Rs 200 for 100 ml on www.himalaya

Lakme Sun Expert Fairness + UV Lotion contains SPF 24 & PA++ that shields the skin from UVA/UVB rays. Rs 374 on

Inputs from Dr Mohan Thomas, Cosmetic Surgeon, Cosmetic Surgery Institute & Breach Candy Hospital and Dr Pravin Banodkar, Consultant Dermatologist at Cumballa Hill Hospital and Heart Institute

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