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Skin cancer is currently an epidemic.
50% of cancers diagnosed are skin cancers. The incidence of skin cancer has doubled every decade since 1930. 80% of skin cancers are diagnosed as basal cell carcinoma, 20% as squamous cell carcinoma, and less than 1% as melanoma.
Risk factors for developing skin cancer include increased sun exposure, aging, decreasing distance from the equator, increasing altitude, family history, and having fair skin that burns easily. If one parent has had skin cancer, your risk of getting skin cancer increases about four-fold. If one parent has had skin cancer, your risk increases 18-fold.
Basal cell carcinoma is the most common type of skin cancer. Most basal cell carcinomas occur in areas that are most exposed to the sun. 70% occur on the face and 20% occur on the nose. Typical signs of basal cell carcinoma include open or non-healing sores, inflamed reddish spots, shiny bumps, pink growths, or scar-like areas.
Squamous cell carcinoma is the second most common type of skin cancer. It usually occurs in areas exposed to the sun and usually appears as an ulcer that does not heal.
Melanoma is the most serious type of skin cancer and has a tendency to spread and metastasize. When it occurs in young adults, it is usually aggressive and occurs on the back or legs. In older people, it tends to be less aggressive and usually occurs on the face or scalp.
The ABCs of skin cancer include asymmetrical lesions where one area doesn’t look like the other, irregular and unclear borders, lesions that change color or tone, diameters larger than a pencil eraser or larger, and lesions that evolve or change in size, shape, or color.
When UV rays hit the surface of the skin, they can have a variety of effects. They can break the chemical bonds between atoms and molecules, potentially damaging DNA. They can also damage the collagen fibers in skin cells, causing wrinkles.
SPF or Sun Protection Factor is a measure of how well sunscreen chemicals protect your skin from UVB rays. SPF 15 means 1/15th of the UV rays will penetrate your skin. SPF 30 means 1/30th and SPF 40 means 1/50th of the UV rays will reach your skin.
If you want to be in the sun for 10 minutes, applying an SPF 15 sunscreen will extend the time it takes you to be exposed to the same amount of UV rays to 150 minutes. In other words, SPF 15 blocks about 93% of UV rays, SPF 30 blocks about 97% of UV rays, and SPF 50 blocks 98% of UV rays.
There are currently 16 approved sunscreen chemicals in use in Canada, including 14 organic carbon-based filters and two non-organic sunscreens, which contain titanium dioxide and zinc oxide. Organic sunscreens, usually derived from petrochemicals, absorb UV rays. Non-organic sunscreens reflect and scatter UV rays.
A review of currently available evidence suggests that regular use of sunscreen may prevent the development of squamous cell carcinoma and possibly melanoma. Sunscreen does not prevent the development of basal cell carcinoma. Most reputable dermatology societies recommend regular use of a sunscreen with an SPF of 30 or higher during periods of strong sun exposure. Sunscreen is not recommended for children under 6 months of age.
The appropriate amount of sunscreen to use is about 30ml (or 2 tablespoons) for each part of the body that is exposed to the sun. Sunscreen should be reapplied every 2 hours, after sweating or swimming.
Vitamin A or retinyl palmitate is involved in skin cell metabolism at various levels. It is easily absorbed and has powerful antioxidant properties. At a concentration of 1% to 2%, it provides an SPF of about 20 on the skin.
Vitamin C is a powerful water-soluble antioxidant as well as a proven skin protective factor. Vitamin C is involved in collagen synthesis and maintains a strong, healthy skin barrier within the dermis. Vitamin C is easily absorbed and stimulates collagen production. It is a powerful antioxidant at concentrations of 5-20%.
Vitamin E is a major fat-soluble antioxidant that prevents oxidative damage to cell membranes. Vitamin E can reduce some of the damaging effects of UV rays on skin cells.
Vitamin B3 or niacinamide has been shown to prevent photoaging and non-melanoma skin cancer. It prevents DNA damage, promotes cell repair, prevents immune suppression, improves cell function, and prevents water loss. A review of 29 trials involving 3,039 patients who received niacinamide showed a reduction in the incidence of basal cell and squamous cell carcinomas by up to 50%.
Polyphenols, found in a wide variety of foods and herbs, have been shown to provide more or less broad-spectrum sun protection. Other foods rich in antioxidants, such as green tea, grape seeds, blueberries, milk thistle, and pomegranate, have also been shown to provide more or less broad-spectrum sun protection.
Dietary antioxidants such as vitamins A, C, E, and niacinamide taken orally or applied topically in sunscreens can help prevent the development of skin cancer.
The information provided in this article does not constitute, nor is it intended to constitute, medical advice. All information and content is for general informational purposes only.
This article was written by or on behalf of an external columnist and does not necessarily reflect the views of Castanet.
