In last week’s post, I talked about the toxicity of commercial sunscreens, and why they are bad for your health. I also mentioned that the sun is not the primary cause of skin aging and skin cancer, and promised to share my conclusions with you this week.
Despite the enormously bad press the sun has received in the past few decades, all skin damage is not the fault of the sun. The root cause of skin aging (including wrinkling, hyperpigmentation, and loss of collagen) as well as skin cancer is oxidative damage caused by reactive oxygen species (ROS). While the sun is one of the factors that create ROS, there are many other culprits, including external factors (air pollution and chemical exposure) and internal factors (poor diet, emotional stress, lack of sleep, and the natural aging process). ROS are believed to trigger skin cancer and photosensitivity diseases by activating proliferative and cell survival signaling that can alter apoptotic pathways (the self-destruction of abnormal cells).
ROS also cause inflammatory changes and inhibit collagen production. The process of glycation (the cross-linking of protein and sugar molecules) is another significant cause of oxidative stress to the skin; the result is hyperpigmentation, the brown spots that are commonly referred to as “age spots” or “liver spots.” Although age spots are often regarded as a normal part of aging, glycation is directly related to the excessive consumption of refined sugars. Recent studies also show that a decline in the body’s natural protective antioxidant systems is a key factor in how skin ages, as well as in the development of skin cancer.
I believe that it is the worsening ratio of omega-3 fats to omega-6 fats in our diets, not sunscreens, which is causing the increase in skin cancers. In 2001, the National Academy of Sciences published a comprehensive review showing that the ratio of omega-3 to omega-6 fats is the key to preventing skin cancer. More than a decade ago, an Australian study showed a 40-percent reduction in melanoma for people who included fish (an excellent source of omega-3s) in their diets. This benefit occurred without any attention to reducing intake of omega-6 fats.
Omega-3 and omega-6 fats are both essential for human health, but the typical American consumes far too many omega-6 fats while consuming very few foods that are good sources of omega-3s. While the ideal ratio of omega-6 to omega-3 fats is 1:1, our ratio of omega-6 to omega-3 averages from 20:1 to 50:1!
The primary sources of omega-6 fats are commercial, refined, GMO, and oxidized canola, corn, safflower, soy, and sunflower oils; these oils are overabundant in the typical diet, which explains our excess omega-6 levels. Avoid or limit these oils. Extra virgin olive oil (abundant in beneficial monounsaturated omega-9’s) is our mainstay in the kitchen—I recommend it for salad dressings and low to medium temperature cooking. For cooking at higher temperatures, I recommend coconut oil. People often avoid coconut oil because it is high in saturated fats. However, it is the refined oxidative polyunsaturated trans fats that cause health problems, not saturated fats. Natural coconut fat is unusually rich in short and medium chain fatty acids, and can actually help to normalize body lipids, as well as improve the immune system’s anti-inflammatory response. A diet that includes healthful fats such as olive oil and coconut oil provides the fatty acids that keep skin smooth and supple.
To change the balance of omega-6 and omega-3 fats to a more favorable ratio, you must not only avoid omega-6 oils, but also increase omega-3 fats in your diet. Omega-3 fats occur in significantly fewer foods; they’re primarily found in flaxseed oil, walnut oil, and fish. By far, the most beneficial omega-3 fats are those that occur in fish. That’s because the omega-3 oils in fish are high in two fatty acids crucial to human health, DHA and EPA. These two fatty acids are pivotal for preventing heart disease, cancer, and many other degenerative diseases. They’re also essential for maintaining healthy skin and for helping to prevent the development of skin cancer.
Skin cancer is a complex process that develops in three stages: initiation, promotion, and progression. These three stages are mediated by various cellular, biochemical, and molecular changes. ROS have been shown to be involved in all three stages. Initiation is the first stage of carcinogenesis and involves the induction of structural alterations in DNA that create mutations. Genetic alterations in proto-oncogenes and tumor suppressor genes may render epidermal cells resistant to signals for terminal differentiation. At this stage, ROS may induce extensive DNA damage, which includes DNA base damage, DNA single-strand and double-strand breaks, crosslinking between DNA and proteins, or DNA and chromosomal aberrations that are mutagenic.
Obviously, the depletion of antioxidants in the skin and the increase in oxidative stress results in skin damage, including cellular mutations that can result in cancer. It has been postulated that patients with actinic keratoses (pre-malignant lesions) and basal cell carcinoma (BCCs), the most common type of non-melanoma skin cancer, have diminished levels of antioxidant enzymes in plasma/serum.
I find it disturbing that chemical sunscreens continue to be widely promoted as valid protection against sun damage and skin cancer. In 2007, the Food and Drug Administration acknowledged, “(the) FDA is not aware of data demonstrating that sunscreen use alone helps prevent skin cancer.”
In some studies, people who use sunscreen have been shown to suffer from malignant melanoma more frequently than those who don’t use sunscreen (Westerdahl J, et al. 2000). This may be because people who use sunscreen spend more time in the sun (believing they are protected) and thus are exposed to more UV rays. Or it could be that sunscreens screen out UVB rays, which in excess cause sunburn but in moderation are essential for health. However, many sunscreens don’t block UVA rays, which are the primary culprits in skin damage.
Adding to the problem are the ROS generated from the chemicals in sunscreens, and the additional ROS created when sunscreens are exposed to sunlight. Even vitamin A (in the form of retinyl palmitate), which sounds like a healthy ingredient, has been shown in an FDA study to be photocarcinogenic when applied topically. According to the Environmental Working Group (EWG), manufacturers add vitamin A as an anti-aging ingredient to approximately one-third of all sunscreens. Unfortunately, the FDA has not banned sunscreens containing vitamin A; nor does it ban chemicals that are proven hormone disrupters or consider the stability of sunscreen ingredients when exposed to sunlight.
If you are going to use sunscreen, I recommend only mineral sunscreens, made from zinc or titanium dioxide. Mineral sunscreens have the benefit of being stable in sunlight, and offer both UVA and UVB protection. But avoid any products made with nano-particles—extremely small particles that can penetrate the skin, where they can trigger ROS and cellular damage.
The best approach, as I mentioned last week, is to wear protective clothing, a broad brimmed hat, and sunglasses if you are going to be in the sun for an extended period of time. Plan your recreational activities for early morning or late afternoon, and avoid unprotected peak sun exposure (generally between the hours of 10 a.m. and 4 p.m.).
An excellent way of augmenting tissue antioxidant levels is through the topical application of antioxidants. As I noted in last week’s post, our skin (our largest organ), is remarkably adept at absorbing whatever is applied to it. Applying various plant and nutrient antioxidants augments tissue antioxidant levels, protects against the damaging effects of ROS-generating agents, and helps to restore homeostasis and the skin’s natural ability to repair damage and regenerate healthy cells.
I believe that a skin care product should:
- Promote healthy, moist and vibrant skin
- Slow aging of the skin
- Protect against oxidative and inflammatory damage
- Protect against skin cancer
In my clinical practice, I have observed that therapeutic levels of unique and highly advanced antioxidants applied to the skin interact with ROS or their by-products to neutralize them or to minimize their deleterious effects. These topical antioxidants activate and enhance the skin’s natural healing responses, improving the skin’s ability to repair oxidative damage, calm inflammation, and combat environmentally induced stresses.
Specific botanical extracts contain a variety of polyphenols that act as antioxidants to modulate carcinogen metabolism, trap reactive electrophilic metabolites, scavenge free radicals, inhibit cell proliferation, arrest the cell cycle, and induce apoptosis. These protective compounds also repair oxidative and pro-inflammatory damage, normalize and enhance healthy gene expression, regulate signal transduction pathways, and vitalize and hydrate, improving the appearance of skin and encouraging collagen synthesis.
The following are some of my favorite topical botanical phytoceuticals:
- Turmeric: contains curcumin; anti-inflammatory and antioxidant; research indicates that curcumin inhibits mutations that lead to cancer.
- Green tea: contains EGCG and other catechins and phenols; antioxidant.
- Gotu kola: contains triterpenoids including Asiatic acid; antioxidant and cell reparative.
- Squalene: from olive oil; contains phenols and n-9 fatty acids; skin moisturizer, reparative and antioxidant.
- Rosemary: contains rosmarinic acid and carnosic acid; antioxidant.
- Sage: contains ursolic acid; antioxidant.
- Milk thistle: contains silymarin; antioxidant.
- Royal jelly: moisturizing and restorative.
- Sea buckthorn oil: rich in antioxidants (vitamins A, C, and E) and EFAs, which nourish the skin and help to maintain cellular membranes.
Along with nourishing your skin with topical antioxidants, it’s important to consume a diet rich in antioxidants and phytonutrients. Include an abundance of fresh vegetables (particularly dark leafy greens and deep yellow/orange vegetables), fruits (especially berries), cold-water fish, extra virgin olive oil, and green tea. These foods will increase antioxidant levels, providing natural protection against sun-induced UV damage.
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Ichihashi M, Ueda M, Budiyanto A, Bito T, Oka M, Fukunaga M, Tsuru K, Horikawa T. UV-induced skin damage.Toxicology. 2003 Jul 15;189(1-2):21-39.
Linos E, Keiser E, Fu T, Colditz G, Chen S, Tang JY. Hat, shade, long sleeves, or sunscreen? Rethinking US sun protection messages based on their relative effectiveness, Cancer Causes Control. 2011 Jun 3.
Planta MB. Sunscreen and melanoma: is our prevention message correct? J Am Board Fam Med. 2011 Nov-Dec;24(6):735-9.
Westerdahl J, Ingvar C, Mâsbäck A, Olsson H (July 2000). “Sunscreen use and malignant melanoma”. Int. J. Cancer 87 (1): 145–50.