Free shipping on all domestic orders over $39

No evidence that sunscreen prevents cancer says scientist

Is a Solution for:
Sun Protection for Body
September 24, 2009 Reviewed by Marta 3 Comments
An article in the British Journal of Dermatology claims that there is a lack of evidence demonstrating the ability of modern sun protection products to prevent melanoma.

The author, Professor Brian Diffey from the department of Dermatology at Newcastle University, says that recent meta-analyses of observational case control studies have demonstrated no association between sunscreen use and either the prevention of the development of malignant melanoma.

There are some scientists who even believe that sunscreen might actually cause melanoma. For example, Octocrylene can penetrate into the skin and act as a photosensitizer, resulting in an increased production of free radicals. Free radicals can induce indirect DNA damage and potentially contribute to the increased incidence of malignant melanoma in sunscreen-users compared to non-users. Although this might theoretically apply to other sunscreens, the study that made this conclusion refers only to octocrylene.

Nonetheless, Prof Diffey says this lack of conclusive evidence to prove sunscreen efficacy should not stop it from being recommended as a preventative measure.
  • May 18, 2010

    by Brian in MO

    A new study published in the peer-reviewed journal “Dermato-Endocrinology” shows that there is no statistically significant connection between sunbeds and melanoma in those who can develop suntans (skin type II-VI), with increased risk centered only on those whose skin is so fair it cannot tan (skin type I).

    William B. Grant, PhD, a former NASA atmospheric research scientist and founder of SUNARC, Sunlight, Nutrition and Health Research Center (SUNARC), re-examined the same epidemiological data used by the International Agency for Research on Cancer (IARC) group from their findings in 2007 titled, “The association of use of sunbeds with cutaneous malignant melanoma and other skin cancers: a systematic review.” Grant’s study strongly challenges this review and argues it is both flawed and cannot be used as the basis for U.S. health policy.

    The IARC review originally claimed a 15% increased risk of melanoma for ever use of sunbeds and a 75% increased risk in melanoma for respondents who had ever used or first used a tanning bed prior to age 35. Grant’s findings show that with the removal of those with skin type I who possess the greatest genetic risk of cutaneous malignant melanoma (CMM), there fails to be any statistically significant link between ever use of indoor tanning facilities and CMM.

    ACCORDING TO GRANT’S ANALYSIS:

    •The reported 75% increased risk of melanoma for those ever having used a sunbed prior to age 35 drops to a 25% reduced risk of melanoma in the United States based on a scientifically-centered reanalysis of the data in the IARC report.
    •When skin type I is omitted from the IARC analysis, the reported 15% increased risk in melanoma fails to remain statistically significant. This is based on a meta-analysis of the 14 studies not from the UK, where skin type I is most prevalent.
    •The IARC study inappropriately combined four studies from northern Europe, one from the UK, one from Canada, and one from the U.S. in the analysis of first use of sunbeds before the age of 35 years. There are vast differences between American and European sunbed regulations and use. US regulations do not allow Skin Type I patrons to tan, European tanning beds are often used at home or are unsupervised and do not follow the regulations in the U.S. The study fails to state that its findings are not, and should not be considered “universal findings.”
    “The reason this ‘Skin Type I’ distinction is so important is that we now know that UV avoidance among people who can develop a tan has contributed to epidemic-level vitamin D deficiency in North America, with 3 out of 4 Americans being vitamin D deficient today,” said Grant. “Our public health messages about the benefits of UV radiation from any source need to recognize this.”

    The IARC report was a meta-analysis of epidemiologic surveys — questionnaire surveys designed to retrospectively identify correlations, but which do not by nature identify causation. As stated in the IARC report, “Epidemiologic studies to date give no consistent evidence that use of indoor tanning facilities in general is associated with the development of melanoma or skin cancer.”

    Melanoma’s connection with UV exposure is controversial, as research clearly shows it is more common in indoor workers than in outdoor workers and is more common on parts of the body that aren’t regularly exposed to sunlight, implicating sun burning rather than regular tanning.

    THE IARC REVIEW ALSO NEGLECTED TO:

    •Find a dose-response relation between the amount of sunbed use and risk of melanoma — which would be key to establishing a causal relationship.
    •Recognize a growing body of literature that shows that non-burning UVB exposure reduces the risk of CMM, and that recreational exposure and sun burning increases risk.
    •Cite other potential reasons for increases in melanoma, including: geography, differing sunbed regulations in various locations, gender, increased travel to sunny places, greater levels of sunscreen use, or the nature of solar UV exposure.
    IMPORTANCE OF SUNLIGHT AND VITAMIN D TO OUR SURVIVAL

    Another recent study from Grant, “In Defense of the Sun,” published in Dermato-Endrocrinology, suggests that raising vitamin D blood levels to 45 ng/ml could reduce mortality rates in the United States by 15% and prevent up to 400,000 premature deaths from vitamin D deficiency-related diseases annually. Such diseases include many types of cancers, cardiovascular disease, heart failure, respiratory infections, diabetes, and falls and fractures.

    Vitamin D researchers today recommend vitamin D blood levels should be maintained above 40-60 ng/ml. At least 2,000 IU of vitamin D daily in addition to dietary sources and casual solar UV irradiance are required to maintain those levels. According to peer-reviewed, published research, indoor tanners have those levels, but non-tanners do not.

    Indoor tanners: 42-49 ng/ml

    American average: 23-25 ng/ml

    In addition, two 2009 Swedish studies of indoor tanners showed a reduced risk of endometrial cancer and thrombotic events. A recent study at Boston University School of Medicine also found that blood levels of D3 were almost twice as high in sunbed users as in non-users. Sunbed users’ bone densities at the hip were also significantly higher.

    “There is conclusive evidence that indoor tanning in a non-burning fashion offers a tremendous source of vitamin D,” Grant says. “The benefit of regular UV exposure as the body’s only true natural source of sufficient vitamin D production easily outweighs the manageable risks associated with overexposure to sunlight,” Grant says. “We know now through more than 2,000 papers published in 2009 that smart UV exposure and increased vitamin D levels will not only save lives, but also extend and increase our quality of life.”

    About Dr. William Grant:

    Dr. William Grant is a former NASA PhD and founder and current Director of SUNARC (Sunlight, Nutrition and Health Research Center). SUNARC, www.sunarc.org, is devoted to research, education, and advocacy relating to the prevention of chronic disease through changes in diet and lifestyle.

    Grant was formerly a senior research scientist in the fields of optical and laser remote sensing of the atmosphere and atmospheric sciences at SRI international, the Jet Propulsion Laboratory and the NASA Langley Research Center. Grant is author and coauthor of over 70 articles on ultraviolet irradiance and vitamin D and 100 articles on other topics in peer-reviewed journals and has contributed half a dozen chapters to additional books. He was elected fellow of the Optical Society of America in 1992. Dr. Grant is known for publishing the first paper linking diet to Alzheimer’s disease, presenting strong evidence that sweeteners are an important risk factor for coronary heart disease for women, and identifying the risk of vitamin D deficiency for ten internal cancers among other ground-breaking research.

    Grant graduated with a Ph.D. in Physics from U.C. Berkeley.

    I hope this helps you out.

  • September 28, 2009

    by admin

    Laura, sorry for the tardy response. I thought I should do some research on the correlation between sunburn and melanoma. It doesn't seem to be a simple cause and effect. Summing up some of what I have read:

    Based on the evidence, there are researchers who have concluded that sunburn, in and of itself, probably does not cause melanoma, but that sunburn is an important sign of excessive sun exposure that can cause melanoma in people who are genetically susceptible because of their skin type.

  • September 25, 2009

    by Laura

    Sunscreen does prevent sunburns. I can personally attest to that. And don't sunburns also lead to melanoma?

Join the discussion! Leave a comment below.

My Comment

Add a comment...

-or- Cancel Comment
* Required Fields
truth in aging's five best

Truth In Aging's Five Best

The very best to choose from for your skin concerns.

Read More

truth in aging videos

Truth In Aging Videos

Helpful how-tos and reviews from Marta and friends.

Watch Now

meet our contributors

Meet Our Contributors

The TIA community consists of our trusted reviewers.

Meet Them

be inspired

Be Inspired

Inspiring thoughts and women who are aging gracefully.

Read More

  Loading...