New Study Shows the Health Implications of UV Filters on Human Sperm
Our company founder and my father Dr. Denis Dudley has been voicing his concerns about the role of some UV filters and other potential endocrine disrupting chemicals since we first started making sunscreens back in 2008. Anyone who has ever met him (in the hallways of our sister dermatology clinic, in airports, drug store aisles or when sitting by the beach) can vouch for how passionate he is about the role of sunscreens and their impact on our health and environment. I think this passion partially stems from a little bit of frustration and a whole lot of being perplexed. The argument against using certain filters seems so practical, reasonable, and intuitive and yet it’s not very well received by many medical professionals, regulatory agencies and academics. These critics point to a dearth in rigorous science but as my father has pointed out- a rigorous experiment would involve applying these products every day across generations to see their full potential effect and how ethical is that?
In case you are new to our blog and/or our company, the argument for avoiding certain chemicals in your sunscreen is this:
Certain UV filters gain entry into your body with topical application
Oxybenzone was found in 96% of a study population of 2000 Americans. At least one UV filter was found in 85% of breast milk sampled in another study in the EU.
Many of these UV filters have the potential to mimic our own natural hormones, i.e. are Endocrine Disrupting Chemicals (EDC’s). Even at low doses (in fact in endocrinology, low doses can sometimes have more severe effects than high doses), these EDC’s can have significant effects on our health and on our children’s health. Fetuses, infants and adolescents are especially vulnerable.
Many of these UV filters also provide patchy protection against UV, which is why you see them in combination with others. Most of them, with the exception of Avobenzone, Zinc Oxide and Tinosorb M and S, mainly protect against UVB, the burning rays.
A recent study out of Germany and Denmark found that 45% of filters interfered with human sperm. It was found that at low levels commonly measured in body fluids, these filters increased calcium levels in sperm and affected their motility. They also potentially hampered penetration into the protective egg coat. Oxybenzone was implicated in the study- but what is more worrisome is that Avobenzone was also included in the list of UV filters. Avobenzone does not have the body of evidence pointing to it as an endocrine disruptor however the theory of isoform function in endocrinology (whereby a similarly shaped key (i.e. endocrine disruptor) fits in the same lock (hormone receptor)) has always made it a possibility. It’s arguably the most popular ingredient in sunscreens so any health implications are huge.
The German/Danish study is definitely alarming but it’s not the first warning we’ve had. If you remember last year, the National Institute of Health found that Oxybenzone could reduce fertility in men by 30%. That is an astonishing figure. Thirty percent could make a material difference in a couple who has had what is termed ‘unexplained infertility’. The NIH went so far as to tell men to wash off their sunscreen when they get home but that advice misses the fact that not all sunscreens are created equal.
European Union data has recently tried to calculate the potential cost to their health care system specifically in relation of EDC’s to female reproductive issues. They looked at the outcome-exposure relationship between two EDC’s (not specific to sunscreen) and found that they could contribute up to 20-39% of cases for fibroids and endometriosis. This translated into a cost of well over 1 billion euro to treat both forms of the female reproductive disorder. They also warned that is but the ‘tip of the iceberg’ since it was restricted to two specific disorders.
Finally, the US Endocrine Society warned again in the fall of 2015 against what has become even more damning evidence of EDC’s in general in contributing to obesity and type II diabetes in addition to reproductive health, hormone related cancer, and a host of other disorders. They highlighted their role against obesity and type II diabetes specifically because the “evidence for effects on these diseases is much stronger than it was 5 years ago”. Their end take-away was to urge physicians of all kinds including GP’s, paediatricians, OB/GYN’s and fertility doctors to speak to their patients about the role of EDC’s in their life and look to limit their exposure.
Certainly, limiting our use of materials containing BPA, avoiding microwaving plastics, and paying attention to exposure to pesticides are all important steps. However, limiting our use of sunscreen containing filters that do get absorbed into our bodies is also a crucial step. It’s one of the few personal care products that we are meant to apply daily and often apply from head to toe depending on the season or climate. Topical application also means that it enters blood and tissue directly while toxins that are ingested at least get filtered by the liver on its first pass.
In the end, every family has to decide for themselves since it might be a while before it’s common practice for physicians to include it in their counsel. It certainly still is possible to find ‘safe’ sunscreens and I would hope that the emerging controversy does not make consumers shy away from them altogether. They still are essential but in the end, every family has to decide what’s best for them and what their level of risk tolerance is with respect to specific ingredients.