Sun protection – the next generation

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Over 1000 Australians are treated for skin cancer every day, and a staggering 67 per cent of Australians will be diagnosed with skin cancer by the age of 70.

Intrinsic, or chronological ageing, is based on the constantly ticking biological clock of skin cells. This is a gradual and continuous process. Extrinsic ageing, however, results from external influences such as UV damage, pollution, smoking and poor nutrition.

The sun can be both friend and foe. It is a source of life for organic matter, providing essential vitamin D for bones and calcium absorption and to stimulate the production of natural endorphins, the ‘feel-good’ hormones. On the other hand, solar damage leads to solar elastosis (premature ageing), pigmentation disorders, skin cancers and malignant melanoma. In fact, solar exposure is responsible for 90 per cent of premature extrinsic ageing.

UV and SPF explained

There are two types of UV light that penetrate our skin: UVA and UVB.

The alarming rise in skin cancer may be the result of common sunscreens primarily protecting against UVB (burning rays) thus allowing people to stay in the sun longer without burning. Sunburn is the body’s warning that irreversible damage is occurring. Lulled into a false sense of security, people who would normally stay out of the sun are exposing themselves to excessive amounts of UV radiation.

Most of us believe that these ‘burning’ rays (UVB) are the most damaging rays. This is incorrect! It is the longer wavelength UVA rays which penetrate deeper into the dermis of the skin to do two things: First, they break down collagen which results in photo ageing and wrinkles. Second, and more importantly, they disable the immune surveillance cells (Langerhans cells) which recognise skin abnormalities such as melanoma and other forms of skin cancer. UVA rays are, therefore, far more insidious than their UVB counterpart.

Did you know that SPF (Sun Protection Factor) only measures protection against the burning UVB rays? It is surprising how many people do not realise that the term ‘SPF’ only measures the ability for the product to protect against UVB rays and not the UVA ‒ ageing and cancer-producing rays.

SPF15 indicates 93 per cent absorption of these UVB burning rays, while SPF30 equals 97 per cent UVB absorption. There is currently no Australian standard to measure protection from UVA. This is a major concern and measures are being taken to come up with a new UVA/B protection rating.

Chemical sunscreens

There are two broad groups of sun protection products available: chemical (organic) sunscreens and physical (inorganic) sunscreens. Chemical sunscreens act by absorbing into the skin and once inside the skin, they absorb UV light (often only UVB rays).

Over 90 per cent of sunscreens are ‘chemical’ (organic sunscreens due to the presence of carbon atoms) which act by absorbing UV light. They absorb into the dermis and even if these products claim broad-spectrum protection, there is often insufficient UVA protection. A few hours after application, the chemicals will break down and are found in the bloodstream. Staying power is also a big issue. Many women don’t realise that their chemical SPF30 moisturiser applied at 7am has been broken down and is ineffective by lunchtime.

There are currently clinical studies suggesting the link between many common chemical sunscreen ingredients and problems such as hormone imbalances, skin irritation and allergy. Common examples of chemical sunscreen ingredients are:

  • Octyl methoxycinnamate
  • Oxybenzone
  • Butyl methoxydibenzoyl methane

Oxybenzone, recently tested by the National Toxicology Program, has proven to produce enlarged livers, kidney lesions, lower sperm density and oestrus cycle irregularities. Octyl methoxycinnamate has been shown to damage human skin cells when exposed to UV light. New chemicals are now being added to some chemical sunscreens to help screen UVA rays. Ironically, these can be broken down by sunlight and may also react with other UVB-absorbing ingredients.

Physical sunscreens

In more recent times, there has been a growing trend towards using physical sunscreens due to their ability to physically reflect both UVA and B rays off the skin surface without being absorbed inside the body. This breakthrough has come with the ability of scientists to break down the particles of the mineral zinc oxide to be small enough (microfine) to appear clear on the skin surface, instead of the traditional ‘white nose’ look of the old thick zinc cream.

For full broad-spectrum protection, look for formulations containing a minimum of 15 percent zinc oxide.  I also recommend the use of high-quality mineral make up containing zinc oxide. Because zinc is naturally calming and does not absorb into the skin or bloodstream, it is non-allergenic and highly recommended for acne, irritated or sensitive skin. Physical sunscreen adheres gently to the skin surface and is considered highly water resistant. It must, however, be reapplied following rubbing or excessive physical activity.

The next generation of solar protection
Solar radiation does not only include UV rays. Infrared radiation is now a new player in the solar ageing arena. Infrared (IR) damage produces effects on the skin known as “infra-’ageing”. IR rays are not only produced by the sun but also by electric ovens, hair dryers, laptops and even certain light bulbs. UVB and UVA rays encompass solar radiation between 290 and 400nm in wavelength. IR rays are much longer in wavelength with IRA starting at 760nm and IRB extending to 300nm. IRA (near infrared) penetrates into the deep dermal layers while IRB and IRC are absorbed only by the epidermis. Infrared also damages skin cells with the conversion of IR energy to heat energy in the cells.

IRA does not generate heat and is the most ageing of the IR rays. These rays can lead to hyperpigmentation, inflammation and loss of firmness and elasticity. According to US dermatologist Professor Leslie Baumann, infrared A rays can damage the powerhouse of the cell (the mitochondria) by generating free radicals and inducing damaging MMP (matrix metalloproteinase) expression which breaks down the structural integrity of the skin. Recent clinical studies have found that IR results in activation of cellular enzymes (MMP-1 and MMP-3) which lead to degradation of collagen and elastin. IR also causes the formation of reactive oxygen species (ROS) and free radical damage leading to solar elastosis and premature ageing.

Interestingly, infrared rays may also be the cause of the condition known as ‘laptop rash’, where the skin may present with red or brown blotches on areas of heat contact with home computers.

Scientific research has given rise to the first active ingredient to directly reduce the impact of infra’ageing, a botanical extract sourced from Polygonum Aviculare. The plant has in fact been used for centuries in Chinese medicine. This novel new cosmeceutical ingredient can reduce the activation of MMP following infrared radiation, thus reducing dermal damage to mature elastic fibres and increasing the elasticity and firmness of skin.

Savvy skin care companies are now creating products to protect against IR rays by using a combination of physical blockers: zinc, iron oxide and titanium dioxide. In fact, the ideal UV/IR blocker is mineral makeup containing high levels of zinc oxide and at least four per cent iron oxide as pigments rather than artificial colour. Antioxidants such as L-ascorbic acid, lycopene and green tea are also able to neutralise the free radicals generated by IR damage. With the added benefit of zinc oxides anti-inflammatory properties, many women are now opting for using high-quality mineral makeup as their sunscreen.

Solar protection is paramount to any clients’ skin care regimen. It is no longer limited to just the impact of ultraviolet light. So, what should you recommend to your clients? It is imperative to read labels, analyse your ingredients and collect reliable information to supply the best advice possible.

The next generation of solar defence must include active ingredients, physical blockers (zinc oxide, titanium dioxide and iron oxides), and also botanical polygonum aviculare extract and antioxidants to combat extrinsic ageing and the damaging effects of not just UV, but also infrared radiation. It is important to strike a balance between sensible sun exposure and solar protection. Just ten minutes of gentle early morning sunlight is sufficient to prevent vitamin D deficiency.

It is now more important than ever to adopt a conscious attitude in educating ourselves and our clients on complete solar protection. As industry professionals, we are all aware of the responsibility we hold for giving our clients accurate information to empower them to make an informed choice about the most essential skin care and makeup product they purchase – sun protection.

 

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