Tuesday, 24 March 2015

How to choose the best sunscreen

Wearing sunscreen should now be part of our daily routine before we go out. UV rays not only cause skin cancer, they are also responsible for most of the skin damage associated with premature aging.

Couple wearing sunscreen to protect against UVA & UVB raysHaving become such an important factor in our lives it is imperative that we know how to choose the best sunscreen for us. There was a time when choosing a sunscreen was all about the SPF (Sun Protection Factor). New research and studies have made it far more complex.

UVB and UVA Rays

There are two types of UV rays: UVB and UVA. Both types of UV rays cause cellular damage and can cause skin cancer.

UVB rays are responsible for you getting a sunburn. SPF refers to this type of UV rays. When choosing a sunscreen make sure it is at least SPF 15. Active ingredients that protect against UVB rays are:
      • Para-aminobenzoic Acid (PABA)
      • Cinoxate
      • Ensulizole
      • Homosalate
      • Octocrylene
      • Octinoxate
      • Octisalete
      • Padimate O
      • Trolamine Salicylate

UVA rays penetrate deep into the skin and cause premature aging such as wrinkles, lax skin and pigmentation. Sunscreens that protect against UVA rays say “Broad Spectrum”. Ingredients that protect against UVA rays are:
      • Avobenzone
      • Ecamsule (Mexoryl SX)
      • Meradimate

Ingredients that offer both UVB and UVA protection are:
      • Dioxybenzone
      • Oxybenzone
      • Sulisobenzone
      • Titanium Dioxide
      • Zinc Oxide

What SPF should I choose?

The SPF tells us how effective a sunscreen is in preventing sunburn. If you burn in 10 minutes an SPF 15 will protect you for 150 minutes (10x15) or 2 hours and a half, SPF 30 for 300 minutes or 5hours. This doesn't mean that you can be that long without reapplying, remember that rubbing, sweating, swimming, etc. will decrease its effectiveness.

SPF 15 filters out 93% of UVB rays, SPF 30 filters 97% and SPF 50 filters 98%, so the added protection after SPF 15 is not much.

Chemical vs Physical Sunscreens

Sunscreens can be further classified into Chemical or Physical depending on the ingredients they contain. Chemical sunscreens absorb the UV rays converting them into heat energy, while physical ones deflect and scatter the UV rays before they penetrate the skin.

Titanium Dioxide and Zinc Oxide are physical sunscreens. These are the sunscreens that used to leave a white film over our skins. New manufacturing methods now break the molecules into micro-particles that penetrate the skin without leaving a white residue, beware the cheaper sunscreens may still leave you looking ghostly.

Physical sunscreens are better because they are gentler and less likely to cause an allergic reaction. They are better suited for babies and people with skin conditions such as eczema, and Rosacea.

Chemical sunscreens have also the disadvantage that when they absorb the UV rays they break down and produce free radicals. Free radicals can also damage our cells accelerating ageing. So, if you can, choose a sunscreen that contains Titanium Dioxide or Zinc Oxide.

Other factors to consider

When choosing the best sunscreen for you it is important to consider your skin type. Oily skins will benefit for a light formula, water based, rather than cream. Spray on sunscreens may be better for this type of skin. Ensulizole has a lighter consistency that other UVB filters. If you suffer from Acne and you are using Retinol or Roaccutane you should consider that these products make your skin more sensitive to the sun and take extra precautions, such as using a higher SPF, keeping in the shade and wearing a wide brimmed hat and long sleeves.

If your skin is dry, some sunscreens come with added moisturisers which will help maintain your skin balance.

If you have sensitive skin or suffer from eczema or Rosacea avoid sunscreens containing PABA or Oxybenzone as well as fragrances, alcohol and preservatives. The best sunscreens for sensitive skins are those containing Titanium Dioxide, Zinc Oxide, Trolamine Salicylate or Ecamsule

For babies and children it is also best to use a physical sunscreen because they are less likely to cause any skin reactions. Also, a spray on sunscreen may be easier to apply, just make sure you don’t spray directly onto their face, but rather on your hands and then rub it on the face.

How to use sunscreen correctly

Most of us don't know how to use sunscreen correctly. Here are some tips to make sure you are well protected at all times:

  • Apply liberally. Most people don't apply enough or leave patches uncovered and thus don't get the level of protection stated in the package. It is recommended that you wait 10 minutes and reapply to make sure you have achieved the best coverage.
  • Make sure you also apply sunscreen to the back of your neck, nose, tip of your ears, back of your legs, and feet.
  • Reapply frequently. Sweating, water, rubbing off with clothing and towels, removes some of the sunscreen, so it is important to reapply every two hours.
  • Wait at least 20 minutes before going under the sun. Sunscreen takes that long to be absorbed by the skin.
  • If you are swimming or exercising you should buy a water resistant sunscreen. Water resistant sunscreens are good for 40-80 minutes in the water, so you need to reapply often.
  • Apply sunscreen even if the day is cloudy or overcast. Remember, UV rays are not visible to the naked eye, and on a cloudy day up to 80% of the UV rays can get through.
  • Just because the day is cold it doesn't mean you won't get damage from the sun. You may need less sunscreen during the winter months, but if you are having a day out in the sun, you still need to put on sunscreen.
  • Sunscreen is not enough:
    • Try to avoid being under the sun between 10am and 4pm.
    • Keep to the shade
    • Wear a wide brimmed hat
    • Wear sunglasses
    • Wear long sleeves, and preferably dark clothes with tight woven fabric.

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