News — zinc oxide

We would like to discuss a bit about the safety of “Zinc Oxide” and “Titanium Dioxide” in sunscreen.

“Tips for sun safety – to wear light clothing, hats, make or use of shade and to plan your day around the sun.”

We feel it is really important to mention the importance of increasing vitamin D levels through safe (gradual) sun expose. Sunshine is good for you!  More and more research is being presented on the benefits of vitamin D and in fact, it is estimated that you can prevent as many as 16 types of cancers by having sufficient vitamin D in your body (i.e. pancreatic, breast, lung, prostate and colon cancers). Interesting to note that receptors that respond to vitamin D have been found in almost every cell in the body.

I am concerned when I see mothers apply sunscreen/sunblock if they see that their child is going to be out in the sun for any length of time, I truly believe this practice is doing much more harm than good. At the beginning of the season limit sun exposure to 5-10minutes a day and gradually increase the time so that in a few weeks an individual can experience normal sun exposure without concern of burning or doing damage to the skin.

If you have to use a sunscreen, “non-nano” or “non-micronized” zinc oxide seems to be the next best option available although not without some risk.

Most of the zinc oxide in sunscreens have been micronized or developed into nanoparticles with a width of 7-15 nano which poses a serious problem to your health and the environment.  At this size especially the zinc oxide can cross to the blood-brain barrier leaving plaques in the brain/body that will never metabolize. Even worse are the zinc oxide nanoparticles can enter any part of the body, including the lungs and nervous system, which can cause not only irritation and rashes but worse consequences such as DNA damage to the cells.

My other concerns with zinc oxide is that does not allow the skin to breathe (blocks pores) or eliminate toxins etc (especially non-nano/micronized).  It is sticky and cakes on like a geisha’s makeup albeit protecting you from the sun but is ultimately unhealthy to have this substance on your skin all the time, all day.

Even though it is wise to avoid the chemical sunscreens (methoxycinnamate, padimate o, oxybenzone, avobenzone, etc.), mineral physical sunscreens have been found to generate free radicals when exposed to sunlight, which then can attack the nuclei of your skin cells and cause mutations (skin cancer) just like the chemical sunscreens.

There is a book available called “Sunscreen Photobiology: Molecular, Cellular and Physiological Aspects” which describes;

“Illumination of titanium dioxide suspensions with sunlight can degrade organic materials and purify drinking water, while illumination with short wave UV kills human cells. This work shows that the distinction between ‘chemical’ sunscreens and ‘physical’ sunscreens, attractive though it may be to those who market them, is not based on any significant difference. Both varieties have the potential to produce reactive species that can attack biological materials (human skin cells) when they are exposed to normal sunlight… What is established is that particles of titanium dioxide as large as 220 nm can enter human cells in culture, and so it seems entirely plausible that if titanium dioxide does pass through the skin it could enter cells under the skin (carrying with it the absorbed UVA and UVB radiation and hydroxyl radicals).”

Another source from “Cosmetics Trade Journal” states,

“Titanium dioxide and zinc oxide are commonly used in drug and cosmetic products. Contrary to belief, Sayre and co-workers (Cosmetics & Toiletries Oct. 2000, 75) have shown that these physical sunscreens are not photochemically inactive. Although adequate coating can reduce the risk, an increase in the destruction of photolabile skin lipids is not desirable. The photo-peroxidation of unsaturated skin lipids may result in perturbation of the lipid environment of viable cell layers and degrade skin surface lipids. “

Zinc Oxide is also widely used in mineral makeup and baby diaper creams, really everyone needs to investigate this further.

What makes this even more concerning is that there is no law requiring companies to disclose the use of nanoparticles in personal care making it use at your own risk proposition.  Canada is still looking to catch up on the technology while the EU has already implemented strict rules for its use in personal care (coming 2013) – As usual, the US FDA is the wild West of regulatory safely catering to corporate requests. In the US Nanoparticles are prohibited in Soil Association certified products, but are yet to be prohibited by the USDA National Organic Program.

Currently, non-nano/micronized zinc oxide with the plant-based base formulation is the safest option in sunscreens. However, I would strongly recommend using only a moderate amount if really needed especially considering some of the risk factors.

Another interesting option is the oral supplement astaxanthin which is a potent antioxidant that when taken can allow you to stay in the sun longer without burning.

Nanoparticles in sunscreens.
The topic of nanoparticles in personal care continues to heat up. Firstly nanoparticles or nanomaterials are particles of extremely small size with the purpose to improve their intended applications. One nanometer (nm) is one-thousandth of a micrometer (m), one-millionth of a millimeter (mm) and one billionth of a meter (m). To put that size in perspective, 1 nanometer is roughly 100,000 times smaller than the width of a human hair.

One of the obvious concerns with regards to nanomaterials in personal care products is that their size allows them to penetrate the skin and enter into the bloodstream accessing organs and tissues. To compound this concern, there are virtually no studies that indicate the safety of these materials once they enter the body.

In the case of sunscreens, using physical reflective block UV filters like titanium dioxide and zinc oxide creates a white caking or heavy feel on the skin. With these ingredients now available as nanoparticles, the lotion can be a more smooth and silky feeling. Zinc Oxide is often referred to as a natural mineral present in the earth’s crust however, most zinc oxide used commercially is produced synthetically. The other misleading claim for nanoparticle zinc oxide and titanium dioxide was that they were more effective in their ability to block UV rays than their counterparts, a claim that has been proven not be true.  

With relation to nanoparticles in sunscreens, it would appear the risks far outweighing the benefits. I believe that environmental and public interest groups are wise to demand government and industry complete testing and approval of nano-containing products before commercialization, not just for human health but also for their environmental impact.