It seems like more and more people nowadays understand the importance of protecting their skin from the sun and daily use of SPF (Sun Protection Factor) becomes a non-negotiable staple in beauty routines. However, scientists know that there are no absolutes in this world and everything comes with the nuances.

Scientific studies have shed light on the potential disadvantages and health hazards associated with the everyday use of SPF. While protecting our skin from harmful UV radiation is crucial, it's important to understand the effects that prolonged and excessive SPF usage may have on our bodies. Let's explore the latest research-backed insights and learn how to use SPF-containing skincare products effectively for optimal skin health.

CHEMICAL ABSORPTION

Certain filters have the ability to permeate the body and accumulate within it. Based on a comprehensive study conducted in the United States, the benzophenone-3 filter (a common ingredient in most sunscreens) was detected in over 2,000 urine samples collected from individuals of various genders, ages, and ethnic backgrounds. Notably, the levels of oxybenzone, a component of the filter, were found to be, on average, three times higher in women than in men. The reason is straightforward: women frequently use SPF products. It is worth mentioning that numerous studies have highlighted the toxic effects of this specific ingredient found in sunscreens, both in terms of dermatological impact and its ecological implications.

ENDOCRINE DISRUPTION

Extensive research has verified that some of the filters commonly used in sunscreens act as endocrine disruptors. This is especially evident in the case of widely used UV filters such as benzophenones, camphor, and cinnamic acid derivatives (cinnamates). Scientific evidence has conclusively demonstrated the highly detrimental impact of these filters on the hypothalamic-pituitary-gonadal system, further emphasizing their negative effects on hormonal balance.

VITAMIN D DEFICIENCY 

The use of SPF products has been associated with a deficiency in vitamin D, which possesses cancer-protective properties. Redness and sunburn after sun exposure are often linked to a deficiency of this essential vitamin. Additionally, skin reddening serves as the initial stage of tanning and a signal to seek shelter from the sun. However, with the application of SPF, it becomes easier to overlook this natural response, potentially allowing UV rays to penetrate deeper into the skin.

SKIN IRRITATION

SPF products can contain various ingredients that may trigger skin sensitivity or allergies in certain individuals. Common culprits include chemical filters like oxybenzone, avobenzone, and octinoxate, as well as fragrances and preservatives. While reactions vary from person to person, some may experience redness, itching, stinging, or even a rash after applying SPF. It's crucial to select products suitable for your skin type and consider patch testing before incorporating them into your routine.

WHICH SPF IS THE SAFEST?

Solar filters can be classified into two types: physical and chemical. Physical filters, such as zinc oxide and titanium dioxide, create a protective barrier on the skin's surface and reflect sun rays. On the other hand, chemical filters, including benzophenone and avobenzone, selectively absorb UV rays. Sometimes, certain combinations of physical and chemical filters can be incompatible, leading to product instability. Additionally, SPF products may contain retinoids. It is important to note that titanium dioxide, when exposed to chlorine in swimming pools, can undergo a reaction that diminishes its sunscreen properties. Furthermore, the presence of certain stone oils like apricot kernel and macadamia can alter the refractive index of titanium particles, consequently reducing the declared level of sun protection.

The most secure sunscreens are those that utilize physical filters, specifically zinc oxide, without the presence of nanoparticles. The only drawback associated with these products is that they have the potential to cause dryness to the skin. Some concerns may arise regarding preservatives and oils; however, overall, these sunscreens are effective and provide a high level of safety.

Remember, that informed decision-making is key when it comes to SPF usage. While protection against harmful UV rays is essential, it's equally important to maintain a healthy balance and be mindful of products that you apply o your skin in large quantities over a prolonged period of time.

TIPS ON SPF CONTAINING SKINCARE

• Assess Your Sun Exposure: Evaluate the level of sun exposure you anticipate during the day. If you'll be indoors or have limited sun exposure, it may be beneficial to skip SPF and allow your skin to naturally synthesize vitamin D.
• Choose the Right SPF: Opt for broad-spectrum sunscreens that protect against both UVA and UVB rays. Look for mineral-based sunscreens containing zinc oxide or titanium dioxide, which sit on the skin's surface instead of being absorbed.
• Time Your Application: Apply SPF 15-30 minutes before sun exposure, allowing it to form a protective barrier. Reapply every two hours if you're exposed to direct sunlight for extended periods or after swimming or sweating.
• Embrace Sun-Safe Practices: Alongside SPF, embrace additional sun-safe practices like seeking shade during peak hours, wearing protective clothing, and donning wide-brimmed hats and sunglasses.
• Supplement Vitamin D Intake: If you're concerned about vitamin D deficiency due to limited sun exposure, consult with a healthcare professional who can guide you on appropriate supplementation.

REFERENCES:

1. Diffey B. Sunscreens as a preventative measure in melanoma: an evidence-based approach or the precautionary principle? J Clin Pharm Ther. 2009;34(6):587-594.
2. Diffey BL. Sunscreens and melanoma: the future looks bright. Br J Dermatol. 2011;165(1):3-5.
3. Garcia-Carrasco M, Mendoza-Pinto C, Etchegaray-Morales I, et al. Cutaneous manifestations in systemic lupus erythematosus: a comprehensive review. Clin Rev Allergy Immunol. 2017;53(3):469-480.
4. Godar DE, Landry RJ, Lucas AD. Increased UVA exposures and decreased cutaneous Vitamin D(3) levels may be responsible for the increasing incidence of melanoma. Med Hypotheses. 2009;72(4):434-443.
5. Hill L, Ferrin P, Ball G, Zhang R, Ding W, Doll M. Evaluating the safety of chemical UV-filters: developmental toxicity and endocrine activity of 11 commonly used UV-filters. Toxicol In Vitro. 2018;50:295-303.
6. Krause M, Klit A, Blomberg Jensen M, et al. Sunscreens: are they beneficial for health? An overview of endocrine disrupting properties of UV-filters. Int J Androl. 2012;35(3):424-436.
7. Mancebo SE, Wang SQ. Recognizing the impact of ambient UVA. J Invest Dermatol. 2015;135(2):277-280.
8. Matta MK, Florian J, Zusterzeel R, et al. Effect of sunscreen application on plasma concentration of sunscreen active ingredients: a randomized clinical trial. JAMA. 2019;321(21):2082-2091.