By Craig Weatherby
Skin cancer is the most common kind of cancer in the United States.
Annually, more than two million people are diagnosed with it … more than breast, prostate, lung and colon cancers, combined.
Most people get the kinds of skin cancer considered relatively easy to detect and treat: basal and squamous cell carcinomas.
About 90 percent of these two kinds of non-melanoma skin cancer are associated with exposure to ultraviolet (UV) sunrays, and an estimated 3,170 Americans will die from them in 2013.
Melanomas constitute just five percent of skin cancers, but they cause the vast majority of skin cancer deaths, with melanoma fatalities projected to total 9,480 in 2013.
Tactics to reduce the risk of sun-induced skin cancers include limiting exposure to burning, midday rays – especially children and fair-skinned folks – and favor foods that discourage skin cancer.
(The evidence suggests it’s also unwise to overdo sun avoidance, which can lead to the vitamin D deficiencies linked to greater risk of common cancers … see “Vitamin D May Curb Killer Skin Cancer”, “Vitamin D May Lower Risk of Ovarian, Breast, Kidney, and Colon Cancers”, “Cancer Society's Anti-Sun Ads Decried as Deceptive”, and “Sunscreen Advice Called Overkill”.)
Vitamin D and plant foods rich in polyphenol antioxidants appear to help prevent pre-cancerous changes in skin, including inflammation.
For example, see “Dark Chocolate Deters Sun-Driven Skin Damage”, “Vitamin D May Curb Killer Skin Cancer” and “Lower Skin Cancer Rates Linked to Seafood Mineral”.
Omega-3s inhibit cancer-promoting skin inflammation
Prior studies have linked the omega-3s in fish oil to a reduction in skin cancer risk factors.
See “Omega-3s Fight Skin Cancer in Mice”, and “Fish Fats Called Credible Foes of Skin Aging and Skin Cancer”.
(And, studies indicate that the excessive intake of omega-6 vegetable oil fats typical of the average American’s diet produces damaging effects in skin.)
Back in 1994, a University of Manchester team began publishing human research designed to examine the effects of dietary fish oil on skin inflammation induced by solar radiation (see “Dietary Fish Oil Found to Deflect Sun Damage”).
Inflammation is a well-documented promoter of cancer in just about every human organ, including the skin.
Their investigations included two small clinical trials testing omega-3s against placebo capsules containing oleic acid (OA, the monounsaturated fat abundant in olive oil).
The results showed that people taking fish oil became increasingly resistant to sunburn.
And as the Manchester team reported, “The subjects taking [omega-3] EPA, but not OA, showed a significant rise in their minimal erythemal [skin-reddening] dose... longer-term supplementation might reduce skin cancer in humans.”
The trial groups taking omega-3 EPA – which, along with DHA is one of the two major omega-3s in fish oil – enjoyed reductions in several early markers of cancer risk in skin.
(Previous studies by the Manchester team and other groups found that omega-3 DHA exerted similar anti-inflammatory effects in skin cells exposed to UV radiation.)
Now, another clinical study from The University of Manchester adds stronger clinical evidence that omega-3 fish oil may help curb the risk of skin cancer.
Novel UK trial confirms fish oil's skin-cancer-curbing effects
The University of Manchester team conducted the first-ever clinical trial to examine the impact of the fish oils on the skin immunity of volunteers (Nicolaou A, Rhodes LE 2013).
Like the prior University of Manchester studies, this one was led by dermatology professor and inflammation expert Lesley Rhodes, M.D.
Her team’s controlled clinical trial – funded by the Association for International Cancer Research – analyzed the effect of omega-3 supplements in 79 healthy volunteers.
The results showed that taking fish oils daily boosted the immunity of volunteers’ skin to the damaging effects of sunlight.
Specifically, the fish oil regimen reduced sunlight-induced suppression of the immune system (immune-suppression), which hurts the body’s ability to fight skin cancer and infection.
Dr. Rhodes said it was the first time that such research had been carried out on humans. As she said, “… the findings are very exciting. This study adds to the evidence that omega-3 is a potential nutrient to protect against skin cancer.” (UM 2013)
She added an important point: “Although the changes we found when someone took the [fish] oil were small, “… they suggest that … taking omega-3s could reduce the risk of skin cancer over an individual’s lifetime.” (UM 2013)
The trial participants took four grams of omega-3s daily, which is the amount in 12 ounces of skinless sockeye salmon or six ounces of canned sardines.
They were then exposed to the equivalent of either eight, 15 or 30 minutes of summer midday sun in Manchester, using a special light machine.
The control group took a placebo before being exposed to the light machine.
Compared with the placebo group, immune-suppression was 50 percent lower in the fish oil groups exposed to eight or 15 minutes of simulated sunlight.
For whatever reason, the daily fish oil regimen had little effect on immune-suppression among those in the group exposed to 30 minutes of simulated sunlight.
The findings are important because previous research has shown that sunscreens are often applied inadequately and only worn during holiday periods.
However, Dr. Rhodes stressed that the omega-3 fish oil is not a substitute for sunscreen and physical protection (hats and clothing).
Instead, she says that omega-3s should be seen as an additional measure to help protect against cancer-promoting changes in skin.
Her team said it will conduct more clinical studies to confirm their findings and further detail the skin-protective effects of omega-3 fish oil.
- Black HS, Rhodes LE. The potential of omega-3 fatty acids in the prevention of non-melanoma skin cancer. Cancer Detect Prev. 2006;30(3):224-32. Epub 2006 Jul 26. Review.
- Pilkington SM, Massey KA, Bennett SP, Al-Aasswad NM, Roshdy K, Gibbs NK, Friedmann PS, Nicolaou A, Rhodes LE. Randomized controlled trial of oral omega-3 PUFA in solar-simulated radiation-induced suppression of human cutaneous immune responses. Am J Clin Nutr. 2013 Mar;97(3):646-52. doi: 10.3945/ajcn.112.049494. Epub 2013 Jan 30.
- Rhodes LE, Shahbakhti H, Azurdia RM, Moison RM, Steenwinkel MJ, Homburg MI, Dean MP, McArdle F, Beijersbergen van Henegouwen GM, Epe B, Vink AA. Effect of eicosapentaenoic acid, an omega-3 polyunsaturated fatty acid, on UVR-related cancer risk in humans. An assessment of early genotoxic markers. Carcinogenesis. 2003 May;24(5):919-25.
- The University of Manchester (UM). Taking omega-3 supplements may help prevent skin cancer, new study finds. February 26, 2013. Accessed at http://www.manchester.ac.uk/aboutus/news/display/?id=9593