Friday, March 9, 2012

Chamois Creme Potential Reason for Elevated Estrogen in Cyclists +Triathletes Have 2x More Testosterone Than Average Men and 71% More Than Active Individuals

Image 1: Norman Stadler 2004 winner of the Ironman Hawaii probably had a hell of a testosterone boost, when this photo was taken (img. Kai Baumgartner. 2004)
Disturbances of the endocrine (=hormonal) milieu are among the hall-mark features of what sport scientists call the "female athlete triad". The unholy trinity of osteoporosis, disordered eating and, as a direct consequence of the aforementioned hormonal imbalances, menstrual disorders. Men, the purportedly "stronger sex", on the other hand are supposedly pretty resistant to exercise-, or, I should say, overtraining-induced hormonal imbalances - bullshit? Well, probably... after all, with insufficient fuel and recovery everyone, man or woman will eventually maneuver him- or herself into a situation where his endocrine system is no longer functioning optimally. A recent study from UCLA does yet show that mother nature must have been aware that a) exercise is part of what the "hunters" (=us men ;-) do and that b) men are in the lucky position not to have carry a child full term - so, as long as they are we are not sick, there is no reason for mother nature to shut our reproductive system down completely.

What's worse? Cycling, or swimming, cycling and running?

To test the hypothesis that "serious leisure time athletes", in this case cyclists (>8h of intense training per week) and triathletes (>5h of intense training per week), are at much greater risk of developing training-related hormonal disturbances than the average "recreational athlete" who performs less than 3.5h of moderate exercise per week, L.Z. Fitzgerald and his colleagues from the School of Nursing at UCLA assessed the body composition, physical activity and hormonal and inflammatory markers of 107 healthy men (age 18-60 years).
Figure 1: Demographic and physical variables of the cyclists (n=46), triathletes (n=16) and recreational athletes (n=45) of which I believe that they me independent (caffeine, age) and dependent (body fat, lean body mass) confounding factors data expressed relative to the statistical average; calculated based on Fitzgerald. 2012
In figure 1, I have compiled a few of the demographic and physiological parameters of the the three study groups of which I believe that they may be confounding factors that may - independent of the type of exercise these men were doing - contribute to differences in the endocrine parameters between the highly active cyclists and triathletes and the moderately active recreational trainees. Of these, the higher age, which is obviously associated with a decline in testosterone levels, and the significantly higher caffeine intake in the cyclists (with 317.3mg/day this is well within the regions where it boosts testosterone, though; cf. Beavan. 2011) are independent, while both the amount of body fat (more = more aromatization = more estrogen and less testosterone), as well as the total lean mass the athletes are carrying around are obviously influenced by the type and amount of exercise they perform.
Figure 2: Estradiol, testosterone, SHBG, luteinizing hormone (LH) and follicle stimulating hormone (FSH) expressed relative to data from a reference cohort I "borrowed" from Brambilla et al. (2009); calculation based on Fitzgerald. 2012
Apropos, as you can see in figure 2 we do once again have one of my favorite (roughly!) bell-shaped dose-response curves (orange line), with the highest exercise load (cyclists - more than 8h of training per week) producing the most unfavorable testosterone to estrogen ratio, a pronounced peak that is associated with the medium to high volume, high intensity approach of the triathletes (>5h) and a slightly above average testosterone to estrogen ratio in the group of recreationally active men.

If you cherish your manhood, man up and don't use chamois cream

A closer analysis of the individual hormone levels does yet reveal a pretty awkward phenomenon: In spite of having the lowest luteinizing hormone levels of all three groups (-56% below "my" reference, i.e. Brambilla. 2009) and an exorbitant amount of estrogen (+113% more than "my" reference) they also have the highest amount of testosterone in their blood. And while I am usually smart-assing scientists for following mainstream paradigms and not following up interesting / surprising results, this is one of the rare cases, where I really have to take my hat off to Mr. Fitzgerald and his colleagues, because I would never have thought of the somewhat shocking explanation the guys came up with:
Some cyclists apply chamois cream to their perineum area to help prevent chafing and bacterial infections related to bicycle saddle sores. The various commercial creams contain a variety of ingredients including lubricants, polymers, oils (jojoba, lanolin, mineral, olive, peppermint, rosewood, soybean, tea tree, St John’s wort), vitamins (A, C, D, E), and alcohols. Additionally, some of these creams contain parabens which are anti-microbial preservatives, but also weak estrogen agonists (Frederiksenet. 2011). In vitro studies demonstrate that parabens bind to estrogen receptors and initiate estrogenic cellular path-ways (Darbre. 2004).
And in fact, a follow up questionnaire confirmed the scientists' suspicion. While only 10% of the triathletes, who obviously cycle as well, used paraben-containing chamois cream roughly 50% of the cyclists applied them regularly to their best parts - with shocking side-effects:
Among the cyclists, there was a significant dose-dependent increase in estradiol levels with increasing years of chamois cream use for men using the cream for more than 4 years (p = 0.03) with notable effect size (partial n² =0.12).
If we briefly discard the high estrogen levels in the cyclists and take an objective look at what conventional wisdom tells us about the detrimental effects of high intensity endurance exercise in general and the arduous combination of swimming, cycling and running, also known as triathlon, this study does still provide enough evidence to cause another of our broscientific myths to totter...

...high intensity endurance exercise does not per se reduce testosterone levels!

Image 2: I wonder if there is a "don't use if you don't want to castrate yourself" warning anywhere on this tub of chamois crème.
At least in the study at hand, both triathlon training and cycling even at doses of >1h per day was associated with statistically significantly higher testosterone levels, statistically identical cortisol levels (cyclists: 309µg/dL; triathletes: 292µg/dL; recreational athletes: 376µg/dL) and - as if that was not beneficial enough - significantly reduced baseline interleukin 6 levels (-50% in cyclists; -74% in triathletes)... if future controlled studies are able to confirm these preliminary results, this would not only confirm the initial hypothesis that the male hormonal milieu is much more resilient than its female counterpart, it would also put a huge question mark beyond the underlying hypothalamic adaptation processes and the dose-response relationship - after all, these results to not contradict previous findings by Hackney et al., who did even coin a special term for the ultra-endurance exercise induced downregulation of the reproductive system: the "exercise hypogonadal male condition" (Hackney. 2008).