Current evidence does not indicate that sunscreen ingredients increase cancer risk; shows that unprotected sun exposure


SAY

“Sunscreens cause cancer, not the sun”; Sunscreens and sunless tanning products contain carcinogenic ingredients.

DETAILS

not supported: No evidence indicates that sunscreen ingredients increase the risk of any type of cancer. On the contrary, much evidence shows that the use of sunscreen reduces the risk of skin cancer.
Incorrect: Overexposure to the sun is the main cause of skin cancer, contrary to what social networks claim.
lack of context: Benzene is not an ingredient in sunscreen. The presence of minute levels of benzene in the sunscreen was likely due to contamination from certain batches of the product.

KEY TO TAKE

Skin cancer is the most common type of cancer in the United States and its main cause is overexposure to ultraviolet radiation from the sun. Medical associations and public health authorities recommend that people minimize the risk of skin cancer by avoiding overexposure to the sun and wearing sunscreen when outdoors.

COMPLETE CLAIM: “Sunscreens cause cancer, not the sun”; “spray tans and sunless tanning lotions/serums change your DNA”; The sunscreen products were “recalled for containing benzene, a known carcinogen that experts say may increase the risk of cancer.”

REVISION

Skin cancer it is the most common type of cancer in the U.S. Estimates indicate that up to one in five Americans will develop skin cancer in their lifetime[1]primarily associated with overexposure to ultraviolet (UV) radiation from the sun. Therefore, the best way to prevent skin cancer is to protect the skin from UV rays.

The American Academy of Dermatology recommends seeking shade in peak sun hours, wearing protective clothing and sunglasses, and always using sunscreen when outdoors. Nevertheless, myths Y misconceptions Concerns about skin cancer, sun exposure and prevention remain widespread and contribute to hesitancy in following these simple protective measures.

As of early April 2022, publications claiming that sunscreens cause cancer (see examples here, hereY here) circulated on social media platforms. Such posts received a total of more than 13,000 interactions on Facebook and Instagram.

As we will explain below, the claim that sun protection increases cancer risk or has harmful effects in humans is not supported by currently available scientific evidence. In contrast, data from multiple studies indicates that regular sunscreen use is safe and prevents sunburn, long-term skin damage, and skin cancer.

This review explains where this claim might have originated and what the state of current scientific evidence is regarding sun exposure, skin cancer, and sunscreen safety.

Ultraviolet radiation from the sun is a known carcinogen.

Publications claiming that the sun does not cause cancer are inaccurate, as Health Feedback explained earlier in this review. The sun not only emits visible light, but also invisible ultraviolet radiation. Thus our skin also receives UV radiation. Overexposure to the sun can damage the skin through two different types of UV. UVA rays are primarily associated with long-term damage and premature aging (wrinkles and age spots). UVB rays have a higher amount of energy than UVA rays and are the main cause of sunburn and skin cancer, but both UVA and UVB rays increase the risk of skin cancer.[2].

Epidemiological studies show a causal association between exposure to sunlight and artificial ultraviolet radiationsuch as tanning beds and sunlamps, and all major types of skin cancer[3,4]. UV radiation is a proven cause of basal cell carcinoma Y squamous cell carcinoma (SCC), and is also associated with an increased risk of developing melanoma[5]. This is because UV radiation can penetrate skin cells and damage its genetic material. Cells can only partially repair this damage, which accumulates over time and can end up disrupting cell function and leading to skin cancer.

In 2009, the International Agency for Research on Cancer (IARC) classified sun and artificial UV radiation under Group 1 carcinogens, that is, agents that have been shown to cause cancer in humans[6].

Concerns about ingredients in sunscreens

Sunscreen products are regulated as over-the-counter drugs by the US Food and Drug Administration (FDA). This means that the active ingredients they contain must be shown to be safe and effective before these products enter the market.

Multiple studies, including randomized controlled clinical trials evaluating sunscreen use for more than ten years, indicate that regular sunscreen use is safe and reduces the risk of skin cancer[7-9]. Based on this evidence, the American Academy of Dermatology and the American Cancer Society recommends that everyone wear sunscreen when outdoors. The most suitable sunscreen would be one that offers broad-spectrum protection, that is, a sunscreen that protects from both UVA and UVB rays. sun protection factor (SPF) of at least 30, and is waterproof.

Initially, the active ingredients in sunscreens were supposed to remain on the surface of the skin. In 2019 and 2020, the FDA published two clinical trials showing that this was not the case, and several common active ingredients, including oxybenzone, octinoxateY octocrylene were absorbed into the bloodstream[10,11]. These results led the FDA to to update marketing requirements for sunscreens and request additional safety data to fill data gaps resulting from this new evidence.

While the FDA findings did not mean that sunscreen ingredients are unsafe, some social network users incorrectly interpreted the findings to mean that the ingredients were harmful. Some of them cited previous studies showing that high concentrations of some of these active ingredients caused cancer and hormonal disorders in experimental animals and cell cultures.[12,13].

However, animals and cells are very different from humans, and the results of these studies cannot be directly extrapolated to humans. Furthermore, these studies generally used much higher concentrations of the active ingredients than those found in sunscreens.[12-14]. Some of these studies also used a different route of administration, for example, feeding the animals food containing chemical UV filters rather than applying the chemicals to the skin.

In other words, while these preliminary findings warrant further investigation, they do not provide evidence that sunscreens harm people’s health. In fact, the US National Academies of Sciences, Engineering and Medicine. state that “sunscreen use is not associated with higher rates of any type of cancer.” This means that the known risk of developing skin cancer from unprotected sun exposure far outweighs any potential risk in sunscreen ingredients.

Concerns about the presence of benzene in sunscreen products

Some publications like East specifically linked cancer risk to the presence of benzenea chemical that the IARC recognize causes cancer in humans after long-term exposure. In 2021, an analysis by the independent laboratory Valisure reported trace amounts of benzene in 78 unique batches of sunscreen products out of 294 analyzed (27%). One of the affected companies, Johnson & Johnson, issued a voluntary recall of affected products and batches as a precautionary measure.

However, it’s important to note that benzene is not an actual sunscreen ingredient. Therefore, the authors of the report assumed that their presence was due to the contamination of certain batches during the manufacturing process. The report also stated that the minute amounts detected do not indicate a safety issue with sunscreens in general, as most of the lots tested did not contain detectable levels of benzene.

The US Centers for Disease Control and Prevention (CDC). Explain that people are exposed daily to low levels of benzene from tobacco smoke, gas stations, motor vehicle exhaust, and industrial emissions. Based on guidance from the Environmental Protection Agency (EPA), Johnson & Johnson fixed that “everyday exposure to benzene in these aerosol sunscreen products at the levels detected in our tests is not expected to cause adverse health consequences.”

david leffellchief of dermatologic surgery and cutaneous oncology at Yale School of Medicine explained in an email to Health Feedback:

“Benzene has been found in some sunscreens, perhaps as a result of the manufacturing process. But any cancer risk, which has not been specifically documented, is outweighed by the known risk of developing skin cancer from the sun.”

Concerns about the presence of dihydroxyacetone in sunless tanning lotions

Sunless tanning lotions and sprays have also been the subject of claims of supposedly harmful effects on humans. For example, this facebook post claimed that these products “change your DNA.”

The publication cited a 2004 study showing that dihydroxyacetone (DHA), the active ingredient in suntan lotions, damaged the DNA of cells grown in the lab. But as with sunscreen ingredients, the findings of this study do not imply that DHA is harmful to humans for external use at the concentrations present in tanning products.

US FDA considers DHA levels in suntan lotions and sprays safe for external use. There is no data on its safety when applied to the eyes, lips, or any other mucosa, or when ingested or inhaled, and the agency recommends avoiding this type of exposure.

conclusion

There is no conclusive evidence that ingredients in sunscreens and tanning lotions and sprays are unsafe, contrary to claims on social media. In contrast, multiple studies show that sunscreen use reduces the risk of skin damage from UV radiation, which is a well-known carcinogen. For this reason, the US CDC and the American Academy of Dermatology recommend using sunscreen when outdoors along with other protective measures, such as wearing protective clothing and sunglasses, and limiting exposure during dry periods. maximum sunlight.

COMMENTS FROM SCIENTISTS

David J LeffellProfessor of Dermatology and Professor of Surgery, Yale School of Medicine, Yale University:
DHA, which is commonly used in sunless tanners, has not been shown to cause cancer in humans.
Benzene has been found in some sunscreens, perhaps as a result of the manufacturing process. But any cancer risk, which has not been specifically documented, is outweighed by the known risk of developing skin cancer from the sun.

REFERENCES



Reference-healthfeedback.org

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