Yet another article to reinforce what I have been saying about the connection of aging and UV light.
SKIN CARE THE EFFECTS OF UV LIGHT
The effects of ultra-violet on the skin are a mixed blessing!
Some is beneficial, necessary for the formation of vitamin D, some is harmful. Much of what happens to the skin as a result of ultra-violet light is the result of the skin trying to protect itself and the body inside from the harmful effects of an excess of the rays; the skin is quite effective at preventing the rays penetrating deeply into the body.
The Stratum Corneum is a major factor in this prevention (see diagram below)
Reflection of rays by layers of the Stratum Corneum
The Stratum Corneum is maintained at such a thickness that with the ‘usual’ intensity of ultra-violet falling on it, very little passes through and no damage is caused to the live cells beneath. The Stratum Corneum of exposed parts of skin such as the face, neck and hands will be thicker than those parts normally covered by clothing.
However, exposure to higher than normal intensities of ultra-violet will allow sufficient rays to pass through the epidermis possibly to cause damage to the living cells underneath.
Penetration of Ultra-Violet Rays into the Skin
In a skin, which has active melanocytes producing melanin pigment granules, this extra ultra-violet will develop the colour of this melanin, resulting in a Tan.
But not everyone’s skin is in such a state of readiness; their melanocytes may be inactive, as a result damage will be caused to the live cells. The result reddening, discomfort, may be even blisters and peeling i.e. Sunburn.
Regardless, more UVB rays will penetrate to the Stratum Germinativum to stimulate its dividing cells into greater activity, this will produce new epidermal cells at a more rapid rate and this will eventually thicken the Stratum Corneum, thus helping to reflect UV rays.
The general increase in the skin’s metabolism reflects throughout the body in creating ‘a feeling of well-being’.
The physical, physiological and psychological effects of Ultra-Violet
Beneficial effects:
• Vitamin D production
• Stimulation of Metabolism
• Tonic Effect
• Has slight Germicidal effect on the skin
• Causes hyperkeratinisation (thickening described as above), which is thought to help with some skin conditions such as Acne Vulgaris and Psoriasis.
Screening responses against excess:
• Suntanning
• The irritant effect of sunburn
• The thickening effect of the Stratum Corneum
Damaging effects:
• Short term – Sunburn
• ***Long term – Premature aging, thickens the epidermis giving a ‘leathery’ appearance, irreversibly damages Collagen and Elastin fibres, causes dehydration, can cause allergic reactions, can produce dark pigmentation patches; Skin Cancer.
Vitamin D Production
A normal varied diet including dairy produce will supply all the vitamin D required; however through sunshine the vitamin may be made in the body with the help of ultra-violet.
In the body there are two substances, which can be converted into vitamin D, these precursor substances are 7-dehydrocholesterol and ergosterol. When vitamin D is required these substances are moved to exposed skin where using ultra-violet energy these substances are converted to Vitamin D.
The potential for making vitamin d in the skin is so enormous that merely exposing the face for less than an hour on an overcast December day will make all that is required for the day, the body is able to regulate this however so a days long sunbathing will not cause over production.
Article below from the DAILY MAIL
Blame the sun for your visible wrinkles: UV rays account for 80 per cent of skin ageing
- Exposure to sunlight is to blame for a majority of skin aging
- Research show that the effect of UV rays on skin increases with age
UV rays accounted for 80 per cent of skin ageing, including wrinkles, in a study of almost 300 women – half sun-worshippers and half shy of the sun.
The study also found that a two per cent increase in skin damage ages a face by three years.
Blame it on the sunshine: UV rays are responsible for 80 per cent of your skin's visible ageing
Long-term UV exposure can also lead to pigmentation, reduced skin elasticity and a degradation of skin texture, including yellowing.
Various other factors can also change the skin’s appearance and structure, including gravity, the natural ageing process, pollution, diet, tobacco, illness and stress.
But in the study, reported in the medical journal Clinical, Cosmetic And Investigational Dermatology, researchers wanted to calculate for the first time the effect of sunlight alone.
Dermatologists examined the faces of 298 women, aged 30 to 78, with 12 experts studying photographs of individual faces on a screen.
Cover up: The sun's damage on the skin increases with age
Another panel of volunteers also viewed the women’s faces and estimated their age.
The results show that the effect of UV exposure increases with age. Significant differences were seen in wrinkles and skin-texture quality after the age of 50, with the sun-seekers looking older than their real age.
The researchers worked out what they call a ‘sun damage percentage’ and calculated that the sun is responsible for 80.3 per cent of skin ageing.
They also found that women with 80 per cent damage look their age, while those who have 82 per cent damage look about three years older, and those with 78 per cent damage appear three years younger.
The researchers, from L’Oreal Research and Innovation Center, Paris, said: ‘Our study confirms the accountability of sun exposure in premature ageing of the face.
‘Our comparison between two groups of women, whose sun behaviour was different, has allowed us to clearly demonstrate the effect of UV exposure.’
However, the researchers added that sagging in older faces is likely to be linked to the long-term effects of gravity.
Dr Richard Warren, senior clinical lecturer and consultant dermatologist at the University of Manchester and Salford Royal NHS Foundation Trust, said: ‘It is very hard to distinguish accurately between intrinsic [natural] ageing and extrinsic [environmental] ageing, and this study goes some way to addressing the specific impact of the sun on skin.
‘Effective use of sunscreens will not only limit extrinsic skin ageing but will also reduce skin cancer risk.’
