Going through isles of sun care products, you probably
noticed that many offer “Complete UVA/UVB protection”.
Why do you need to be protected from both, and what is
the difference between the two?
UVA and UVB are two types of ultraviolet rays that change
physical and chemical condition of the skin. They produce
different effects, but at the same time enhance each
UVB rays are the burning rays that cause immediate skin
reaction – redness and swelling that you see within hours
of sun exposure. As you look at yourself in the mirror, you
are not likely to think of your sun kissed skin in these terms.
It definitely looks better now that there is a glow to it and
wrinkles seem to be less visible. But the look is deceiving.
The glow is caused by increased blood flow to the skin as
a rescue response to repair the damage, and wrinkles are
less visible because your skin has just suffered an injury
and is puffed.
UVB rays are responsible for skin cancer and cataract.
UVA rays stimulate production of melanin, the skin pigment.
Melanin is formed in deeper skin layers and reaches the
surface in two-three days. This is when you see that you
got tan. Unfortunately, there is little to be proud about,
as tanning is what your body does to protect itself from the
sun. It is a reaction to potentially dangerous conditions
that you expose yourself to.
If your are trying to avoid freckles, age spots, pregnancy
mask or any other type of skin discoloration, UVA rays are
your first enemy. It is important to remember that while glass
windows block UVB rays, they do nothing to shield you
form UVA rays.
UVA rays were thought to be less damaging, and common
belief was that safe tanning was possible: you block UVB
and enjoy the bronzing effect of UVA rays. Wrong! Recent
research proves that UVA rays may be even more dangerous
than UVB. They reach deeper into the skin layers and contribute
to photoaging and development of melanoma, a very dangerous
type of skin cancer.
Photoaging is aging of the skin caused by sunlight. Collagen,
a large protein, is the main skin building block. 90% of the
skin mass is collagen which contributes to skin’s firmness,
strength and elasticity. Skin has the ability to renew collagen
fibers: grow new ones and dissolve those that are damaged. UV
rays interfere with these chemical reactions and suppress
collagen production while stimulating collagen destruction. In
our 20’s, collagen production slows down, and eventually all
that the skin is left with is damaged collagen, which is not as
flexible and cannot perform its original functions. The skin
loses its elasticity and forms wrinkles.
Sooner or later, wrinkles happen to everyone due to natural skin
aging and gravity. However, without proper sun protection, skin
ages a lot faster, and unfortunately, the damage is irreversible.
There are two types of protection used in skin care products:
physical and chemical, where physical block reflects sun rays,
and chemical absorbs them, similar to melanin, before they can
do any harm.
Physical sun screens include zinc oxide and titanium oxide, with
zinc oxide (aka Z-Cote) being more powerful. Now creams with
Z-Cote are available in wearable form, when they do not look
like white paste, but spread into an invisible barrier that
reflects both UVB and UVA sun rays.
Most powerful UVB screen is PABA, but it is not perfect for
everyone as it often can cause an allergic reaction. Other
chemical screens are:
· Cinnamates absorb UVB.
· Benzophenones absorb UVA.
· Anthranilates absorb UVA and UVB.
Usually, your sunscreen product will contain several
protective ingredients, as combining them provides better
shield, according to research.
FDA requires each batch of sunscreen products to go
through SPF testing to ensure the effectiveness of the
product. At this time, sun protection factor applies to UVB
rays only as more research is necessary to determine the
standards for UVA protection.
As a rule, SPF number translates into the amount of time
one can safely be in the sun without burning. If you are an
individual with fair skin and burn in 10 minutes if unprotected,
SPF 15 will allow you to stay in the sun 15 times longer
(150 minutes). If your skin is dark and you burn in 30 minutes,
the same product will protect you for 450 minutes.
This formula is very approximate and does not provide for real
life conditions: wind, humidity, season, your location, etc.
Humidity and wind, for example, maximize the power of sun
rays, and your SPF 15 lotion may offer much less protection
when used on a breezy day or near water. Proximity to the
equator and elevation should not be forgotten: the closer you
are to the sun, the stronger its effect.
Reapplying your SPF often provides better protection than
purchasing a product with a higher SPF number. SPF protection
does not actually increase proportionately with an SPF number.
Under lab conditions, SPF 2 equals 50% absorption of burning
UVB rays, SPF of 15 indicates 93%, and SPF 30 and higher –
As you see, some sunrays will still reach your skin, even if you
use lotion with a high SPF number. To shield these remaining
rays, use other means of sun protection: clothes, hats,
umbrellas and shades. Please remember that many surfaces –
snow, sand, water, concrete – reflect sun rays, so don’t be
surprized if you got tan or burn even though you spent most of
your beach day under umbrella.