Category Archives: Health

CrossFit Clothing: Lulu, Reebok and Anti-Microbial Fabrics

Silver nanoparticles are woven into high-tech athletic clothing as a means of controlling bacteria and odors.  How it kills bacteria is not completely understood, but it is believed to kill through oxidative stress.  Oxidative stress is harmful for us as well, but bacteria can be killed at lower levels.  Still, oxidative stress is not good.  That’s why anti-oxidants are protective against cancer and other forms of cell damage.  Silver nanoparticles are used in topical antibiotics to treat life threatening infections in burn patients.  Better to risk a little oxidative stress from silver nanoparticles than to die from an infection.So, is it a good idea to put silver nanoparticles in clothes? No one knows the answer to this question.  But there are a few answers to a few related questions.  For example, do the silver nanoparticles embedded in fabrics some off the cloth and end up in wastewater?  Do the particles come off the cloth and enter peoples bodies? Are there any known health effects from exposure to silver nanoparticles?  If the particles stay in the fabric there is probably little to worry about.  Let’s take a look:

  • Do Silver nanoparticles come off the fabrics in which they are embedded?  Apparently they do, but different fabrics lose nanoparticles at different rates, at least during the wash cycle.
  •  Can silver nanoparticles be absorbed into or through skin?  Apparently they can and have been shown to cause ill effects in laboratory tests of skin cells
  • How long do silver nanoparticles stay in a person once they get there?  This is an important question.  If they stay around a long time, they can do damage for a long time.  If they leave quickly they would be less dangerous.  Same thing goes for a lot of other substances.  The answer to this question appears to be unknown 
  • Are there any known health effects if silver nanoparticles are absorbed?  Silver nanoparticles appear to have harmful effects on some human (and animal) cells including nerve cells and interfere with synthesis of seleno-proteins.  Seleno-proteins are important anti-oxidants and detoxifying enzymes.  This means someone might show the effects of selenium deficiency even though dietary intake was adequate.

South Central CrossFit Regional Athlete Mackey Hermosillo finds an alternative means of protection against odor.

While its been demonstrated that the particles can harm cells, tissues or organs we don’t know how much would be needed to harm health.  The amount of silver nano-particles absorbed from clothing may not be high enough to matter.  Its an unanswered question.   We’ll probably hear more about this in coming years.  For now we recommend against using, eating or wearing things if we aren’t sure if they are going to bite us in the ass later.

Back to Lulu and Reebok and CrossFit Clothing.

Lulu Lemon uses silver nanoparticles for their anti-microbial fabrics.  We could not find any information on Reebok and silvernanoparticals, so we are assuming they are not using them.  On a positive note for Lulu, their silver nanopartical shirts really work for stink prevention.  We tested one by wearing it for two weeks straight on a challenging backpacking trip and it smelled fine.

Benn TM, & Westerhoff P (2008). Nanoparticle silver released into water from commercially available sock fabrics. Environmental science & technology, 42 (11), 4133-9 PMID: 18589977

Brandt O, Mildner M, Egger AE, Groessl M, Rix U, Posch M, Keppler BK, Strupp C, Mueller B, & Stingl G (2012). Nanoscalic silver possesses broad-spectrum antimicrobial activities and exhibits fewer toxicological side effects than silver sulfadiazine. Nanomedicine : nanotechnology, biology, and medicine, 8 (4), 478-88 PMID: 21839058

Lim DH, Jang J, Kim S, Kang T, Lee K, & Choi IH (2012). The effects of sub-lethal concentrations of silver nanoparticles on inflammatory and stress genes in human macrophages using cDNA microarray analysis. Biomaterials, 33 (18), 4690-9 PMID: 22459196.

CrossFit and Paleo: Why cutting gluten out of your diet may set you up for trouble later: the microbial explaination

CrossFit, Paleo and Gluten

Many CrossFit enthusiasts follow the “paleo diet”.  This diet claims, among other things, that gluten is bad for you.  Is gluten “bad” or are some people not able to tolerate it?  Is toleration genetic or aquired?  So far it looks like exposure to gluten during infancy plays a key role in determining whether or not someone will become gluten intolerant.

The human gut maintains large bacterial populations. In fact they outnumber you by about 10 to 1 on a cell to cell level (as in for each of your cells, there are ten bacteria). Each of us is a walking bus. We are designed to be this way. Our bacterial passengers have always been here. Our good health requires passengers who are not hijakers, jerks or even dead weight. The good ones help us digest food, keep us from getting horrible gas and other forms of intestinal distress, may protect us from obesity, defend against pathogens and degrade harmful substances.

Gut Bacteria and health

The dominant bacterial family present in infants, if they are breast fed, are Bifidobacteriaceae. Bottlefed infants also harbor Bifida sp., but not as much. If a breastfed infant is supplemented with formula he or she will experience a rapid loss of bifida sp. Bifida sp. provide many benefits to their human hosts including protection against pathogens, prevention of diarrhea, maturation of the immune system and reduced risk of developing allergies. Breastfed infants may be better able to handle exposures to environmental chemicals too (Shellor et al. 2012).

The bacteria in your gut will also be dependent on what you eat. A change in diet, for example elimination of gluten by a person who does not have celiac disease, may cause a decline in bacterial populations that help digest gluten (Nistal et al. 2012).

A person eating gluten after a period of abstinence may not be able to digest gluten as well if they eat it again, at least not until bacterial populations re-balance. This may lead some people to get gas, cramps etc. and conclude that they have celiac disease, or that gluten is harmful in itself. It has been brought up by some that the intestinal distress suffered by people following a Paleo-type diet who start eating wheat again is all in their heads (some chat board or other). It probably isn’t. But it’s probably not because gluten is inherently bad either.

Shelor, C., Kirk, A., Dasgupta, P., Kroll, M., Campbell, C., & Choudhary, P. (2012). Breastfed Infants Metabolize Perchlorate Environmental Science & Technology, 46 (9), 5151-5159 DOI: 10.1021/es2042806

Nistal, E., Caminero, A., Herrán, A., Arias, L., Vivas, S., de Morales, J., Calleja, S., de Miera, L., Arroyo, P., & Casqueiro, J. (2012). Differences of small intestinal bacteria populations in adults and children with/without celiac disease: Effect of age, gluten diet, and disease Inflammatory Bowel Diseases, 18 (4), 649-656 DOI: 10.1002/ibd.21830

WOD Master Cooking

We’ve noticed that a lot of these health and fitness sites put a lot into the importance of nutrition and a lot into the Paleolithic, primal lifestyle.  So, we will be adding a few posts and “how to” videos on The Primal Master Lifestyle.  Here is episode 1, where we demo how to cook refried black beans using a solar-heated cast-iron frying pan.  These are good for you despite what some people say.  A single cup of black beans (once they’ve been cooked . . . uncooked they may pass completely in their original, undigested state and provide neither calories nor protein) will give you 15 g of protein, along with iron, magnesium phosphorus and manganese (all natural and derived from the dirt in which they grew) and the B vitamins thiamin and folate, or folic acid. 

Anti-bacterial soap, male fertility and endocrine disruption

Triclosan is used in many personal care products as an anti-bacterial agent. You can find it in soaps, toothpaste etc. Triclosan has estrogenic properties  or estrogen boosting properties.  This means it can behave like natural estrogen in the body.  Or, it may increase the power of natural estrogen.  Estrogen, like other hormones, is a chemical messenger.  It passes through cell membranes, attaches to estrogen receptors and “tells” genes it is time to make some product or activate some process.  Adding estrogen-like chemicals can result in increased activity.   Too much estrogenic activity can increase risk of cancer in estrogen-sensitive tissues: Breasts, for example.  In men, too much estrogen can reduce fertility.  The role estrogen plays in men is still under investigation.  Here is a recent article from the NY Times on estrogen and aging in men that will help explain things.  In rats, triclosan has been found to cause abnormal testicular development and abnormal “other” male tissue.

WODMaster - Experienced as Hell T-Shirt
Join us.! Wear the shirt!

Other interesting findings about triclosan are:

  • People with high triclosan levels also have higher BMI on average
  • Are more likely to suffer from allergies, including food allergies

Paul et al. (Dec 2010) have demonstrated that triclosan alters thyroid hormone levels early in lactation. Thyroid hormones are especially important during fetal and infant development because they play crucial roles in brain development. Early thyroid hormone deficiency alters neurological function in animals, and in human, reduces IQ and increases ADHD-like behavior. There are many environmental contaminants that interfere with thyroid hormones including PCBs, PBDEs, perchlorate, and nitrate. It is difficult to study the impact of exposures to these chemicals in humans because its hard to know how much people are exposed to over time, and people are probably never exposed to just one agent at a time. Its important to consider additive (or synergistic or antagonistic) effects and not consider them individually. For now, its probably best for pregnant and lactating women to limit their exposure to triclosan.  Guys, you too.

Paul KB, Hedge JM, Devito MJ, & Crofton KM (2010). Developmental triclosan exposure decreases maternal and neonatal thyroxine in rats. Environmental toxicology and chemistry / SETAC, 29 (12), 2840-4 PMID: 20954233
Lankester J, Patel C, Cullen MR, Ley C, & Parsonnet J (2013). Urinary triclosan is associated with elevated body mass index in NHANES. PloS one, 8 (11) PMID: 24278238
Stoker TE, Gibson EK, & Zorrilla LM (2010). Triclosan exposure modulates estrogen-dependent responses in the female wistar rat. Toxicological sciences : an official journal of the Society of Toxicology, 117 (1), 45-53 PMID: 20562219

Savage JH, Matsui EC, Wood RA, & Keet CA (2012). Urinary levels of triclosan and parabens are associated with aeroallergen and food sensitization. The Journal of allergy and clinical immunology, 130 (2), 453-600000000 PMID: 22704536

Kumar V, Chakraborty A, Kural MR, & Roy P (2009). Alteration of testicular steroidogenesis and histopathology of reproductive system in male rats treated with triclosan. Reproductive toxicology (Elmsford, N.Y.), 27 (2), 177-85 PMID: 19118620

Telomeres and aging and exercise

Telomeres and Aging

Teleomeres are little caps on the ends of DNA that protect DNA from damage during cell division.  They get a little shorter with each cell division.  Telomeres are shorter in older people than in younger people. Telomere length has been reported to be longer in older endurance athletes than in older couch potatoes  Telomeres are thought to be important in aging.  You can find the abstract and access the full text through:   This is hopefully good news for older endurance athletes and an encouragement to others to get moving.   (It is also possible that people with more resistant telomeres are the ones able to continue intense exercise into middle age and that the exercise did not change the nature of the telomeres.)  But interesting . . . Take a look at table 1.  There are a number of other variables aside from telomere length that you’d think would have been statistically significant but weren’t.  More research?

Congratulations to authors Larocca, Seals and Pierce.  And thank you for publishing this, Mechanisms of Ageing and Development (journal).