I recently read a fascinating article in a newsletter I received. This article talks about the truth about Vitamin D and sun exposure. I found it quite useful and wanted to pass it along..
Keep On The Sunny Side
by Daniel I Newman, M.D., N.D., M.S.O.M.
"Sunshine has been praised in so much literature, poetry, songs, aphorisms, and even religions, that you would think our society would encourage people to have as much fun in the sun as possible. While that was true in the past, nowadays sunshine is demonized as the envoy of premature skin aging and, most menacingly, skin cancer.
But sun exposure provides functions essential for our health. It sparks Vitamin D production in the skin. There is burgeoning evidence that most people are Vitamin D deficient, which increases the risk of everything from cardiovascular disease to cancer to diabetes. And, since it is virtually impossible to get enough Vitamin D in your diet to achieve optimal blood levels without eating inordinate amounts of foods that most people find objectionable (like sardines, mackerel, and herring), sunshine is the only option save supplementation.
Sunshine also enters the eyes and stimulates melatonin production in the pineal gland, which aids sleep and has anti-cancer properties. These pathways also enhance serotonin levels in the brain, which staves off depression (particularly seasonal affective disorder).
So what is the solution to this dilemma? Like most things in life, it is moderation. Just as too little food leaves you undernourished, and too much leads to obesity, too much sun can cause skin damage, and too little leads to other health problems.
How much sun exposure is too much? That depends upon where you live, the color of your skin, and your personal history with skin cancer. If you are a dark skinned individual with (likely) no history of skin cancer, living in Alaska, you would be well served by spending as much time outside with as little clothing on as you can stand whenever the sun rears its head. On the other end of the spectrum, if you are very fair skinned and living on the equator, you better not be out in midday without shielding every patch of skin from direct sunlight.
On a more practical level for most people, use nature's sun overexposure indicator: the sunburn. Unless you have already had skin cancer, or evidence for pre-cancerous lesions, you should get as much sun exposure as you can without turning pink. As this threshold of sun tolerance, called the 'Minimal Erythema Dose' varies not only by geographic location, but also time of year, you will have to get to know yourself enough to figure this out. Obviously, it is better to err on the side of caution, especially with children who tend to be oblivious to their limitations.
But let's back up and examine the original premise that has led so many experts to damn sun exposure: Does sun exposure cause skin cancer? Skin cancers, like all cancers, arise when there has been enough DNA damage to the cells that the cells begin to proliferate without regard to the community in which they live. (I will resist the temptation to use Wall Street metaphors here).
Sunshine contains ultraviolet radiation of two types: UVA and UVB. UVA is far more prevalent, but UVB is stronger. Both have been implicated in causing sun damage leading to skin cancer. Since UVB is most intense April through October (in the northern hemisphere) and from 10AM - 4PM, either cover up or avoid the sun during these times, if you are particularly prone to sunburn.
But what about sun exposure short of sunburn, does that lead to skin damage and skin cancer? The answer, as is often the case with other health issues, seems to come down to diet. Greece has one of the lowest incidences of melanoma (that most dreaded and lethal of skin cancers) in the world. However, when Greeks move to Australia, and forsake their whole foods diet for the refined, processed Western diet, their melanoma incidence and mortality skyrockets.
Aside from eating a healthful whole foods diet, (as I harp on incessantly for many reasons), several nutrients have been shown, especially in combination, in both human and animal studies, to offer protection against sun damage from UV radiation. These include: Vitamin A, methylfolate (an active form of the B vitamin folate), Vitamin C, Vitamin E, β-carotene, fish oil, olive oil, lutein (from tomatoes, watermelon, etc.), EGCG (in green tea), theaflavins and thearubins (in black tea), citrus bioflavinoids, proanthocyanodins (such as in blueberries), caffeine (coffee drinkers rejoice), and polyphenols (in grape seeds, wine, and cocoa). And, a 2006 Italian study found that patients with melanoma had double the risk of metastasis if their CoQ10 levels were low.
Some of these nutrients you can get in your diet, but others, such as Vitamin C, Vitamin E, and Fish Oil, you will need to supplement to get adequate UV protection levels. Make note here that I am talking about taking these nutrients orally, not rubbing them on your skin!
What about topical skin protection, i.e., sunscreens: should you use them and do they protect against skin cancers? While most experts suggest using sunscreen for UV skin protection, there is no consensus that sunscreen prevents skin cancer. You see, while there are studies which indicate that sunscreen users have a lower incidence of squamous cell skin cancers, other studies suggest they actually have a higher risk of deadly melanomas. Even the FDA says that it is "not aware of data demonstrating that sunscreen use alone helps prevent skin cancer." Further, while blocking UV rays, sunscreen can reduce the conversion of Vitamin D in the skin.
Therefore, don't depend upon sunscreen as your hedge against sunburn and its consequences. Primarily use physical barriers, like shade and cover-up clothing when you have had enough sun. Restrict the use of sunscreen to areas you cannot easily cover, like your face and hands. And, if you are going to use sunscreen, there are some things you should know, because not all sunscreens are created equal.
First and foremost, most sunscreens contain ingredients that are potentially harmful: some are carcinogens; others endocrine disrupters which impair the body's hormonal functions; and some may even increase the risk of skin cancer! Even natural ingredients, such as Vitamin A, when applied to the skin, may increase the risk of sun damage. Also beware of 'nano' forms of sunscreens such as Zinc Oxide or Titanium dioxide. While these substances may be preferred sunscreen active ingredients, when they are made into nano-particles, they penetrate too deeply into the skin, and have raised safety concerns in some studies.
A recent study by the independent, non-profit Environmental Working Group (EWG) found that 84% of 785 sunscreen products had potentially toxic ingredients! You can go to the EWG database @ http://www.ewg.org/2010sunscreen/ for details about specific brands, and also find information about specific ingredient toxicity issues on their website. (We carry one of the EWG's top rated brands here at Rising Health).
Second, many sunscreens have exaggerated claims about their efficacy, or SPF (Sun Protection Factor). According to another study by the Environmental Working Group, sunscreens claiming SPF 50 protection only offered 1.3% more protection from the powerful UVB rays than SPF 30 sunscreen. Once you get to SPF 15 - SPF 30 and above, how heavily and how often you smear on the sunscreen (especially after sweating or aquatic activities) is much more important than the claimed SPF protection rating. For example, most people rub on one-half to one-fifth the thickness used in the SPF studies. Applying an SPF 30 sunscreen at one quarter thickness (about 0.5gm/cm2, a normal amount), exponentially decreases the protection down to a little over SPF 2!
In summary, the traditional notion that sunshine is good for you is correct: we need it to be healthy and happy. (Just ask my wife during the dreary days of January if the latter is true)! Unless contraindicated for medical reasons, sunshine should not be avoided, but rather sought out in places where it is limited, like here in the northwest. The trick is to modulate your sun exposure so you avoid getting burned. This is accomplished by appropriately limiting your duration of exposure, and by consuming protective foods and supplements. Skin protection should be primarily accomplished by using shade and protective clothing, and only secondarily by using sunscreen. If you are planning to use sunscreen, get one with non-toxic ingredients, and apply it liberally. Then go out there and enjoy my favorite time of year - summer! "