- Products that are classified as drugs/medicine are required to meet standards of quality and consistency in manufacturing and of safety. Studies are done in vitro, on animals, and finally on humans. Drug interactions are checked. Information is gathered on how the drug is metabolized. Drugs are sometimes metabolized into something deadly before being rapidly metabolized into something safe. Tylenol is an example. Not a problem unless something, like alcohol, blocks a metabolic step and traps Tylenol in its deadly form. This is why people sometimes die when they drink alcohol and then take Tylenol. This should be common knowledge, but it isn’t, yet.
- Another important thing to know about a drug or supplement is its “Effective Dose.” How much is needed to give a desired effect? How much selenium is needed for health? How much is too much? How much is “optimal”? These are unanswered questions for many nutritional supplements. What happens if you take too much? Frequently the answer to that question is unknown as well.
- Anti-Oxidants should not be assumed to be safe. Recent research has indicated that anti-oxidants, like oxidants, can harm DNA. DNA damage can lead to cancer, the very thing anti-oxidants in nutritional supplements are supposed to prevent.
- The last point to raise for this article is a manufacturing issue. Like most people, I used to assume that vitamins and supplements contained what was written on the package. But this is not always the case. An example is the recent report of human growth factors added to deer antler velvet supplements. It is hard to believe human growth factors were accidentally added to deer antler velvet supplements. You’d have to hear the manufacturer out on that one. However, problems like poor mixing and poor calculations can and do happen. Our research group found that out the hard way when we tried to use a well-known brand of vitamins for a human health study.
This site provides articles on health, nutrition and chemical exposures. There is a focus on current research and areas where there is controversy and need for further investigation.
Wednesday, December 18, 2013
Why supplements including anti-oxidants should be taken seriously.
Why supplements including anti-oxidants should be taken seriously. Originally published in WODMASTERS. Click for complete article.
Saturday, June 15, 2013
New Video on The Economic Costs of Obesity
The producers (?) of this video asked if we would post it on our blog. The organization is called Academic Earth. The video discusses obesity and brings up some interesting statistics on agricultural subsidies. Apparently, fresh fruit and vegetables don't get much in the way of subsidies. This may make them more expensive for consumers. The final result is that calories from junk food are cheaper than calories from healthy food. They also bring up some disturbing numbers about changes in caloric intake since the 1970s.
If this is true (and it probably is) why has it happened? Changes in family structure and habits? Environmental chemicals that interfere with metabolism or satiety? Lack of exercise? The development of eating as a recreational activity? Eating out more? Being too busy to cook or not knowing how to cook? Its an interesting and sometimes frightening topic. Here is the video. What do you think?
Created by AcademicEarth.org
You can support this site by purchasing a Strong Woman T-shirt at WODMasters.
If this is true (and it probably is) why has it happened? Changes in family structure and habits? Environmental chemicals that interfere with metabolism or satiety? Lack of exercise? The development of eating as a recreational activity? Eating out more? Being too busy to cook or not knowing how to cook? Its an interesting and sometimes frightening topic. Here is the video. What do you think?
Created by AcademicEarth.org
You can support this site by purchasing a Strong Woman T-shirt at WODMasters.
Friday, April 5, 2013
New Book: The Rise of the U.S. Environmental Health Movement by Dr. Kate Davies
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| Author Dr. Kate Davies |
In some ways things are vastly different today than they were just a few decades ago. Companies are much more cautious about introducing new chemicals into the environment. Testing for potential problems is much easier today. This helps companies avoid producing or using chemicals that come back to bite them in the ass. Advances in chemistry have also made it much easier for companies to develop less toxic alternatives. The history of the US environmental health movement also examines how chemical companies and other responsible parties attempted to undermine what were usually poorly funded and poorly organized grass-roots activists. The fights go on. Both sides have become more sophisticated in their political and public relations battles. A better understanding of history and science among all parties should help take us away from battles and towards rational approaches to the resolution of problems that effect us all.
Friday, October 5, 2012
Protecting Children from Celiac Disease and a Child's View the problem.
Protecting children from Celiac Disease:
I've written several articles about gluten, microbes and auto-immunity. All those interactions are interesting to think about. To me this has been like tinkering with puzzles. Celiac disease is a problem of auto-immunity and exposure to the plant protein gluten. It can be a rough road to follow, especially for children. They can't eat the same things other kids eat, and other kids and even adults may not understand that something that seems so normal to them, like a cupcake or sandwich, can cause serious pain and discomfort for a celiac child. This website, "Growing Up Gluten Free" is written and maintained by a child with celiac disease. It helped me understand what life is like for kids like her.![]() |
| Two children enjoy a Box lunch at CrossFit Seven in Fort Worth, TX. |
A Systematic Review of infant feeding practices and incidence of Celiac (Coelicac) disease has also been published very recently (Szajewska et al. 2012). The authors suggest that the best time to introduce wheat into an infant's diet is between 4 and 7 months, and that it should be done while the child is still breastfeeding. Introducing wheat before a child is under 4 months increases the likelihood that he or she will develop Celiac Disease. Likewise, delaying introduction until a child is older than seven months may also increase risk of Celiac's.
There are lots of unknowns still. The Szajewska paper does a great job of defining what they are.
Szajewska H, Chmielewska A, Pieścik-Lech M, Ivarsson A, Kolacek S, Koletzko S, Mearin ML, Shamir R, Auricchio R, Troncone R, & PREVENTCD Study Group (2012). Systematic review: early infant feeding and the prevention of coeliac disease. Alimentary pharmacology & therapeutics, 36 (7), 607-18 PMID: 22905651
Tuesday, September 25, 2012
Correlation and Causality: Alcohol and Diabetes to BPA and Estrogen Disruption
Alcohol and Diabetes:
From a purely health-oriented perspective, alcohol is one of those things where a little seems to be good and more than a little puts you at risk for a bad health outcome. One of the positive things small regular intake can do for you is protect you from diabetes. There is good epidemiological evidence that this is the case. Light drinkers are less likely to develop diabetes than those who abstain.![]() |
| Samples prepared for analysis. |
As most people know, just because two things occur together does not mean that one caused the other. Correlation and causality are two different things. It is important to keep this in mind when reading about human health studies in the news. Epidemiology is a wonderful tool however, and provides clues to problems that might have gone unnoticed. In addition to identifying potential problems correlational (and epidemiological) studies are important in evaluating how a problem identified in the lab may be harming people in the real world. Are light drinkers more likely to eat better, exercise better, be healthier than those who drink more alcohol or even none at all?
An important next step is figuring out why the correlation exists. Here is a case where epidemiology observed something (low alcohol = less diabetes, high alcohol = more diabetes) and experimental study identified a physiological reason that explains those observations. He et al. (2007) discovered that light alcohol intake activates a biochemical pathway that has a positive influence on removal of blood sugar from the blood stream. Higher alcohol intake disrupts glucose management by activating an additional protein that blocks the positive effects seen with light alcohol intake. This discovery helps explain why you can see two different outcomes with alcohol. At first light it may have seemed that scientific studies conflicted each other. The appearance of contradiction may lead some people to throw up their hands and decide to disregard health news or science in general.
Sometimes we need to keep working at the puzzle.
There may be a similar issue with environmental contaminants. Sometimes a relationship is observed and someone publishes on it, and there there are a flurry of other studies that confirm or don't confirm the relationship, expand it or limit it. Identifying the mechanism and understanding how it works under varied circumstances becomes essential. There are now many correlational studies that show that Bisphenol A (BPA) intake is associated with health problems. There are also mechanistic studies that show how BPA interacts with estrogen receptors and causes things to go arwy. One could stop here and take steps to remove BPA from use. Environmentalists and children's health advocates could claim victory. This might result in fewer birth defects, less obesity, less diabetes, fewer behavioral problems in children etc. But it might not.
Plastics are more complex than they seem. Even without BPA many of the chemicals that go into or are released from different plastics may be may activate estrogen receptors. Would people be exposed to less estrogenic chemicals if BPA is banned? We still don't know. While many studies have used data on concentrations of BPA or BPA-metabolites, to the best of my knowledge no one has looked at total exposures to estrogenic chemicals originating from plastics. (There are also estrogenic chemicals from sources other than plastics too). Does removing BPA from a plastic actually make it less estrogenic? Is BPA, rather than other chemicals coming off of plastics, the main source of dietary exposures to estrogenic compounds?
Plastics are amazing, really, and have made many positive and important contributions to our economy and quality of life. For information on how plastics benefit the environment and contribute to quality of life take a look at this pdf from the British Plastics Federation. Its taken tremendous effort and ingenuity to develop polymers. We can figure out where they might cause problems in the environment or in human health by continuing polymer research and including within, cell and molecular studies. We should not have to leave epidemiology to discover problems that could have been avoided after the fact.
He L, Marecki JC, Serrero G, Simmen FA, Ronis MJ, & Badger TM (2007). Dose-dependent effects of alcohol on insulin signaling: partial explanation for biphasic alcohol impact on human health. Molecular endocrinology (Baltimore, Md.), 21 (10), 2541-50 PMID: 17622585
Nguyen KH, Lee JH, & Nyomba BL (2012). Ethanol causes endoplasmic reticulum stress and impairment of insulin secretion in pancreatic β-cells. Alcohol (Fayetteville, N.Y.), 46 (1), 89-99 PMID: 21840159
Labels:
alcohol,
blood sugar,
BPA,
diabetes,
drinking,
heart disease,
plastic
Saturday, September 15, 2012
What are obesogens?
Living things are delicate, resilient and tenacious. Their chemistry is fascinating. We are molecular machines, in a sense, and fine tuned to interact with the external world. The chemical systems that make us who and what we are took many millions of years to develop. It is incredible that we are now able to synthesize molecules by ingenuity. Chemical engineering, pharmaceutical companies and even the much
maligned agrochemical industry have, and are, incredibly important to
where we stand now. The drugs, and even pesticides, that have been
produced have saved countless lives. It is just now that we have calmed down a little from the excitement of synthesizing new molecules, and started looking at the unintended effects these new molecules have on biochemistry. Things that alter our biochemistry can alter our health. Sometimes they can alter the developmental paths we follow in utero. It would be wonderful if inadvertent exposures to new molecules had beneficial effects. Its possible. As with most things, the good things that happen by accident usually go unnoticed. However, as in most situations, it is far easier to be destructive than constructive.
Obesogens are chemicals that change the way fats (lipids) are handled. Exposure, especially early in life, may influence patterns of fat distribution, the way the body uses fat, and/or the way fat is synthesized. It is possible that some chemicals might make us develop as lean, fat burning machines. This would be a huge problem if we ever have a famine, but that is not our current issue. Obesity, and its associated health problems, is on the rise. Some of the chemicals that may be acting as obesogens in people are:
Organotins (used in marine paints, production of plastics, pesticides. Exposure may come through seafood, produce, drinking water and plastics.
Bisphenol A (BPA): from plastics.
Phthalates: from plastics
Perfluoroalkyll compounds (PFCs): water repellant fabrics, stain preventing treatments.
Grün F, & Blumberg B (2006). Environmental obesogens: organotins and endocrine disruption via nuclear receptor signaling. Endocrinology, 147 (6 Suppl) PMID: 16690801So, back to the post title: what are obesogens?
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| Obesity can make your life harder than it needs to be |
Organotins (used in marine paints, production of plastics, pesticides. Exposure may come through seafood, produce, drinking water and plastics.
Bisphenol A (BPA): from plastics.
Phthalates: from plastics
Perfluoroalkyll compounds (PFCs): water repellant fabrics, stain preventing treatments.
How to avoid obesogens.
Avoid plastics when possible. Avoid fabrics treated with water repellants or stain blockers. Avoid carpet treatments.
Sunday, September 9, 2012
Plastics, Diabetes and Obesity
Things start to get interesting when the results human epidemiology and animal exposure studies meet. Epidemiology studies of human exposures to a xenoestrogen like BPA show relationships between exposure and diabetes, or exposure and obesity. But it is very difficult to say that exposure to a plastics component causes obesity, diabetes or heart disease. People who are exposed to a lot of xenoestrogens may eat more canned food and have more BPA (or similar) circulating in their systems, but people who eat a lot of canned and packaged food may also eat poorly, exercise less, and/or be less educated compared to someone who has very little plastics exposure.
This is why animal studies are so important. When the results of controlled animal studies are similar to trends we are observing in people the case for concern about a particular chemical jumps. Many people oppose animal studies for ethical reasons, but sometimes leaving questions unanswered is unethical as well.
There is increasing evidence that chemicals in the environment may be
contributing to diabetes and obesity. This is not to say that there is no such thing as good habits, but biochemical variables, set during early life, may make it harder to regulate things like blood sugar and weight. For current reviews and discussion
take a look at:
- Toxic environment and obesity pandemia: Is there a relationship?
- Impact of environmental endocrine disrupting chemicals on the development of obesity.
Katzenellenbogen JA (1995). The structural pervasiveness of estrogenic activity. Environmental health perspectives, 103 Suppl 7, 99-101 PMID: 8593885
Thursday, September 6, 2012
Xenoestrogens and Plastics
This post covers one of the problems posed by endocrine disruptors (ECDs) that I don't think has gotten a lot attention, or at least broad enough attention. This is the issue of estrogen-mimics. These are also known as Xenoestrogens. A lot of people seem to be aware of BPA and take steps to avoid it. However, BPA is a relatively small part of the story. Plastics labeled BPA-free may not be Estrogen Activity-Free at all (Yang et al. 2011).
Normal estrogen acts by docking at an estrogen-receptor, like a lock fitting into a key, and turns on various biochemical pathways. These pathways play important roles in maintaining normal function in various tissue, allow girls to develop normally through puberty, make reproduction possible, organize behavioral responses and neurological function among other things.
The problem with xenoestrogens is that the body can't tell the difference between these molecules and natural estrogen. Its an issue of molecular structure or shape (Katzenellenboggen 1995). That means biochemical pathways can be turned on at inappropriate times, upsetting the normal course of development, including brain development. It may also mean that more estrogen activity is happening because estrogen-regulated cell activity is ramped up. This might mean more cell division and change in estrogen-sensitive tissue, which can increase risk of breast cancer. There is also evidence that xenoestrogens can harm male development as well (Ogura et al. 2007).
The problem with xenoestrogens is that the body can't tell the difference between these molecules and natural estrogen. Its an issue of molecular structure or shape (Katzenellenboggen 1995). That means biochemical pathways can be turned on at inappropriate times, upsetting the normal course of development, including brain development. It may also mean that more estrogen activity is happening because estrogen-regulated cell activity is ramped up. This might mean more cell division and change in estrogen-sensitive tissue, which can increase risk of breast cancer. There is also evidence that xenoestrogens can harm male development as well (Ogura et al. 2007).
| A normal three-year old performs with her toy cat |
Many chemicals have estrogen-activity. Some chemicals are more estrogenic than others. Household products, dusts, plastics, cosmetics, personal care products may all contain estrogenic chemicals. Note that, dust aside, there are products that don't contain estrogenic chemicals. For example, plastics can be produced that do not have estrogenic activity.
It may just be hard to find them. For example, the only company I know of that produces a plastic water bottle that is independently certified as Estrogen Activity Free is a small company called The Water Geeks. The Headline on the Link says BPA-Free, but these are Estrogen-Activity Free as well. A small company, Certichem, run by a bunch of University of Texas professors, certifies chemicals as Estrogen-Actity Free. They also test things for androgen and anti-androgen activity as well.
BPA-Free is great, but BPA bottles and cans are not necessarily Estrogen-Activity Free. I try to use glass, which is not always practical or even permitted in some situations. We probably don't want to see fields of pee-wee soccer players running around with glass bottles, and a lot of boxes probably don't want to see exhausted athletes staggering around with glass either.
The Environmental Working Group provides a website that will help you identify products that contain fewer ECDs. They also have a lot of other well-written and informative material on the topic of chemicals in the environment. You can read more about Endocrine Disruption and the concerns of the scientific and medical communities in this pdf published by The Endocrine Society.
Katzenellenbogen JA (1995). The structural pervasiveness of estrogenic activity. Environmental health perspectives, 103 Suppl 7, 99-101 PMID: 8593885
Yang CZ, Yaniger SI, Jordan VC, Klein DJ, & Bittner GD (2011). Most plastic products release estrogenic chemicals: a potential health problem that can be solved. Environmental health perspectives, 119 (7), 989-96 PMID: 21367689
Ogura Y, Ishii K, Kanda H, Kanai M, Arima K, Wang Y, & Sugimura Y (2007). Bisphenol A induces permanent squamous change in mouse prostatic epithelium. Differentiation; research in biological diversity, 75 (8), 745-56 PMID: 17459086
What are endocrine disruptors?
The next several posts will be devoted to the subject of endocrine disruption with a focus on environmental chemicals that interfere with sex steroids, chiefly estrogens and androgens.
Most people are probably familiar with estrogen and testosterone. These are steroids produced by the human body (and the bodies of other species) that play important roles in sexual development and reproduction. They also play many other related roles, influence growth and tissue maintenance, neurological function and behavior.
An endocrine disruptor is a chemical agent that interferes with very complex, inter-regulating and intertwined endocrine systems. Interference with one steroid hormone can produce chain reactions that impact other hormones that, in turn, influence other systems and other hormones. For example, Bisphenol A, an estrogen mimic will change production of Prolactin (Steinmetz et al. 1997).
The effects of endocrine disruptors can be strongest during critical periods such as fetal development, infancy, adolescence, conception and pregnancy. These are times of important changes that will have long-term consequences for a child (fry, larvae, pup, chick etc.) and its future children. Thousands of chemicals have been found to be endocrine disruptors. Some of them are very resistant to degradation and remain in the environment and in people's bodies for decades or longer. Many of these are no longer in use even though with can still easily detect them. They were found to be a threat to health and were banned and/or replaced with something less dangerous. There are many other chemicals in use that have not been tested. There are others that are current foci of research and debate. These chemicals were not developed to cause harm to humans (at least not most of them), rather they were found to be harmful after they were already in use. An example that you may be aware of is the plastics additive Bisphenol A.
Bisphenol A is commonly called BPA. After years of debate and conflict among interested parties BPA has been banned from baby bottles in the US. Manufacturers are adapting and produced new products. Consumers can easily find BPA-Free materials and it seems likely that BPA will leave many markets. While BPA may be in decline the issue of endocrine disruptors is far from resolved. The plastic products used to make some BPA-Free plastics also appear to be endocrine disruptors (Yang et al. 2011.) Some of them appear to be more disruptive than the BPA-laced plastics they are meant to replace. It would be better to produce Endocrine-Disruptor-free products Instead of BPA-Free products
It is very difficult to pull something out of the market once it is already there. People's livelihoods have become dependent on continuing use, reputations are at stake, there may be millions of dollars spent on legal fees, on efforts to fund studies that would show that the product in question was harmless after all, and then more time and more money spent arguing why banning a product would be unfeasible and not worth the cost of replacing it, developing alternative technology, or cleaning up environmental messes. Banning chemicals after they become part of the economy is hugely wasteful, makes people on both sides of the playing field upset and erodes public confidence. We may discuss this in greater detail later, but for now, just be aware that the chemical problem of endocrine disruptors is also an economic and then a political problem as well. This should be resolved eventually, but until then, we may have a very interesting, and for some a painful, ride.
Steinmetz R, Brown NG, Allen DL, Bigsby RM, & Ben-Jonathan N (1997). The environmental estrogen bisphenol A stimulates prolactin release in vitro and in vivo. Endocrinology, 138 (5), 1780-6 PMID: 9112368
Yang CZ, Yaniger SI, Jordan VC, Klein DJ, & Bittner GD (2011). Most plastic products release estrogenic chemicals: a potential health problem that can be solved. Environmental health perspectives, 119 (7), 989-96 PMID: 21367689
Steinmetz R, Brown NG, Allen DL, Bigsby RM, & Ben-Jonathan N (1997). The environmental estrogen bisphenol A stimulates prolactin release in vitro and in vivo. Endocrinology, 138 (5), 1780-6 PMID: 9112368
Yang CZ, Yaniger SI, Jordan VC, Klein DJ, & Bittner GD (2011). Most plastic products release estrogenic chemicals: a potential health problem that can be solved. Environmental Health Perspectives, 119 (7), 989-96 PMID: 21367689
An endocrine disruptor is a chemical agent that interferes with very complex, inter-regulating and intertwined endocrine systems. Interference with one steroid hormone can produce chain reactions that impact other hormones that, in turn, influence other systems and other hormones. For example, Bisphenol A, an estrogen mimic will change production of Prolactin (Steinmetz et al. 1997).
![]() |
| A young boy ponders something. |
The effects of endocrine disruptors can be strongest during critical periods such as fetal development, infancy, adolescence, conception and pregnancy. These are times of important changes that will have long-term consequences for a child (fry, larvae, pup, chick etc.) and its future children. Thousands of chemicals have been found to be endocrine disruptors. Some of them are very resistant to degradation and remain in the environment and in people's bodies for decades or longer. Many of these are no longer in use even though with can still easily detect them. They were found to be a threat to health and were banned and/or replaced with something less dangerous. There are many other chemicals in use that have not been tested. There are others that are current foci of research and debate. These chemicals were not developed to cause harm to humans (at least not most of them), rather they were found to be harmful after they were already in use. An example that you may be aware of is the plastics additive Bisphenol A.
Bisphenol A is commonly called BPA. After years of debate and conflict among interested parties BPA has been banned from baby bottles in the US. Manufacturers are adapting and produced new products. Consumers can easily find BPA-Free materials and it seems likely that BPA will leave many markets. While BPA may be in decline the issue of endocrine disruptors is far from resolved. The plastic products used to make some BPA-Free plastics also appear to be endocrine disruptors (Yang et al. 2011.) Some of them appear to be more disruptive than the BPA-laced plastics they are meant to replace. It would be better to produce Endocrine-Disruptor-free products Instead of BPA-Free products
Steinmetz R, Brown NG, Allen DL, Bigsby RM, & Ben-Jonathan N (1997). The environmental estrogen bisphenol A stimulates prolactin release in vitro and in vivo. Endocrinology, 138 (5), 1780-6 PMID: 9112368
Yang CZ, Yaniger SI, Jordan VC, Klein DJ, & Bittner GD (2011). Most plastic products release estrogenic chemicals: a potential health problem that can be solved. Environmental Health Perspectives, 119 (7), 989-96 PMID: 21367689
Sunday, July 15, 2012
Are Silver Nanoparticles in Clothing Safe?
Silver nanoparticles are woven into high-tech athletic clothing as a means of controlling bacteria and odors. Silver has low toxicity for people, but is able to kill bacteria. How it kills bacteria is not completely understood, but it is believed to cause oxidative stress. Oxidative stress is harmful for us as well, but bacteria can be killed at lower levels than can hurt us. Still, oxidative stress is not good. That's why anti-oxidants are protective against cancer and effects 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:
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 you'll have to rely on your own judgement.
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. Benn TM, & Westerhoff P (2008). Nanoparticle silver released into water from commercially available sock fabrics. Environmental science & technology, 42 (11), 4133-9 PMID: 18589977
- Can silver nanoparticles be absorbed through people's skin? Apparently they can. Silver nanoparticles are being used a a topic anti-biotic in burn patients. Infection is a major, major factor in recovery (and mortality) for burn patients. 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
- 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? 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. Silver nanoparticles appear to have harmful effects on some human (and animal) cells. (Comparative in vitro cytotoxicity study of silver nanoparticle on two mammalian cell lines- citation)
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 you'll have to rely on your own judgement.
Sunday, May 20, 2012
High Fat Diet, Cholesterol, the Swiss and the Australian Aboringinals
Jansen, J., van Dam, N., Hoefsloot, H., & Smilde, A. (2009). Crossfit analysis: a novel method to characterize the dynamics of induced plant responses BMC Bioinformatics, 10 (1) DOI: 10.1186/1471-2105-10-425
I'm sure the intentions of whoever wrote the press release were good . . . but . . . it is quite a stretch. Still, interesting that it made it into Google News. The research the author discusses has nothing to do with Crossfit. The press release does, however, attempt to associate a high-fat diet (promoted by some Crossfitters as healthy than other diets) with lower incidence of cardiovascular disease by comparing incidence of disease between residents of Switzerland and Australian aboriginals living in modern Australia. The claim was that a high-fat dining Swiss have less cardiovascular disease than the presumed low-fat dining Australian Aboriginals and that, therefore, high-fat diets are healthier than low-fat diets.
I have not looked up the statistics for the Swiss, but Australian Aboriginals have been suffering increasing rates of cardiovascular disease over at least the last 30 years. Few modern Aboriginals are likely to be following a traditional Aboriginal diet. It is extremely unlikely that the increasing rate of heart disease observed in Australian Aboriginals has been caused by low intake of dietary fat. Aboriginals are suffering from increasing obesity and diabetes just like so much of the rest of the world. The high incidence of cardiovascular disease in Aboriginals may be due to genetic factors and a change to a Western-type diet but extremely unlikely to be caused by a low-fat diet (especially since they are not eating this way anymore anyway). There are also obviously many other differences between the Swiss and the Aboriginals (differences in poverty levels, availability of lederhosen and differences in other possibly important variables like intake of strong coffee and chocolate).
Thursday, November 17, 2011
Estrogen and Progesterone in Waterways
In the last post, I was speculating about how estrogens from effluent might end up in way water ways and end up increasing the incidence of prostate cancer. I wondered if the problem (if it there is anything more than a chance association) might be progesterone from birth control pills rather than estrogen. Progesterone is markedly non-soluble in water so it seemed unlikely at first thought. Poking around a little, progesterone might end up in sewage effluent after all. The three studies below report on fecal and/or urinary progesterone, conjugated progesterone or "progesterone metabolites" in animals. So . . . maybe progesterone contamination of water might be relevant. And, not all sewage is filtered and treated. I recently watched someone emptying a truckload of portapotties into one of our local creeks. (Yes, I called the police, who told me it was not their problem.) Don't know if anyone has looked at this or not. If you know, please have at it in comments.
deCatanzaro D, Muir C, Beaton EA, & Jetha M (2004). Non-invasive repeated measurement of urinary progesterone, 17beta-estradiol, and testosterone in developing, cycling, pregnant, and postpartum female mice. Steroids, 69 (10), 687-96 PMID: 15465115Kinoshita K, Inada S, Seki K, Sasaki A, Hama N, & Kusunoki H (2011). Long-term monitoring of fecal steroid hormones in female snow leopards (Panthera uncia) during pregnancy or pseudopregnancy. PloS one, 6 (5) PMID: 21559303Brown JL, Wasser SK, Wildt DE, & Graham LH (1994). Comparative aspects of steroid hormone metabolism and ovarian activity in felids, measured noninvasively in feces. Biology of reproduction, 51 (4), 776-86 PMID: 7819459google-site-verification: googleaa234ad89e44d776.html
deCatanzaro D, Muir C, Beaton EA, & Jetha M (2004). Non-invasive repeated measurement of urinary progesterone, 17beta-estradiol, and testosterone in developing, cycling, pregnant, and postpartum female mice. Steroids, 69 (10), 687-96 PMID: 15465115Kinoshita K, Inada S, Seki K, Sasaki A, Hama N, & Kusunoki H (2011). Long-term monitoring of fecal steroid hormones in female snow leopards (Panthera uncia) during pregnancy or pseudopregnancy. PloS one, 6 (5) PMID: 21559303Brown JL, Wasser SK, Wildt DE, & Graham LH (1994). Comparative aspects of steroid hormone metabolism and ovarian activity in felids, measured noninvasively in feces. Biology of reproduction, 51 (4), 776-86 PMID: 7819459google-site-verification: googleaa234ad89e44d776.html
Wednesday, November 16, 2011
Response to a friend on significance of Triclosan in drinking water
Sorry Friend. That was a poor response to your question about the significance of Triclosan following news of the chemical as an androgen blocker in water.
Triclosan is a thyroid disruptor and according to recent reports, an androgen blocker. As an anti-androgen, exposure could be important to male fetuses, since it could potentially interfere with development of the genito-urinary system, which could mean birth defects like hypospadias, small phallus, or non-obvious problems like changes in numbers and proportions of cells that would, later in life, produce sperm and testosterone. Thyoid inhibition has its own effects on development of the male reproductive system as well. So there might be some interesting interactive effects if both thyroid hormones and androgens are impacted. If that would occur you'd see reduced fertility. In an adult lowered testosterone would lead to other problems.
Blocking androgens, on the upside, might lead to less prostate cancer. It would be interesting to see if Dial Soap or other triclosan-containing products use this as a marketing point. "protects against body odor, gingivitis AND prostate cancer" Let's guess not.
Lastly, there was also an article out recently that associates rates of prostate cancer with presumed levels of estrogen (presumably from urine from women on birth control) in water supplies (Margel & Fleshner 2011). This was unexpected to me, until I thought about the pathway through which testosterone is produced. Testosterone can be synthesized from Progesterone, which is also present in birth control pills. So, it may be the progesterone, rather than estrogen, that is causing the problem. Progesterone is not water soluble, so its unlikely to be found in water systems unless conjugated to something else or incorporated in something else, so this is just speculation on my part.
Back to Triclosan. You can find some basic information on what kinds of products contain Triclosan at the Environmental Working Group Website. Its dated 2008, but the basic information may be useful.
For all of this, note that, for Triclosan, the picture is far from clear, as recent papers also report Triclosan enhancing androgenic activity in vitro (Christen et al. 2010) and as having estrogenic activity (Jung et al. 2011). Neither of those qualities is desirable in an environmental contaminant.
Best wishes,
Margel, D., & Fleshner, N. (2011). Oral contraceptive use is associated with prostate cancer: an ecological study BMJ Open, 1 (2) DOI: 10.1136/bmjopen-2011-000311
Christen V, Crettaz P, Oberli-Schrämmli A, & Fent K (2010). Some flame retardants and the antimicrobials triclosan and triclocarban enhance the androgenic activity in vitro. Chemosphere, 81 (10), 1245-52 PMID: 20943248
Jung EM, An BS, Choi KC, & Jeung EB (2011). Potential estrogenic activity of triclosan in the uterus of immature rats and rat pituitary GH3 cells. Toxicology letters PMID: 22062131
Rostkowski, P., Horwood, J., Shears, J., Lange, A., Oladapo, F., Besselink, H., Tyler, C., & Hill, E. (2011). Bioassay- directed identification of novel antiandrogenic compounds in bile of fish exposed to wastewater effluents. Environmental Science & Technology DOI: 10.1021/es202966c
Triclosan is a thyroid disruptor and according to recent reports, an androgen blocker. As an anti-androgen, exposure could be important to male fetuses, since it could potentially interfere with development of the genito-urinary system, which could mean birth defects like hypospadias, small phallus, or non-obvious problems like changes in numbers and proportions of cells that would, later in life, produce sperm and testosterone. Thyoid inhibition has its own effects on development of the male reproductive system as well. So there might be some interesting interactive effects if both thyroid hormones and androgens are impacted. If that would occur you'd see reduced fertility. In an adult lowered testosterone would lead to other problems.
Blocking androgens, on the upside, might lead to less prostate cancer. It would be interesting to see if Dial Soap or other triclosan-containing products use this as a marketing point. "protects against body odor, gingivitis AND prostate cancer" Let's guess not.
Lastly, there was also an article out recently that associates rates of prostate cancer with presumed levels of estrogen (presumably from urine from women on birth control) in water supplies (Margel & Fleshner 2011). This was unexpected to me, until I thought about the pathway through which testosterone is produced. Testosterone can be synthesized from Progesterone, which is also present in birth control pills. So, it may be the progesterone, rather than estrogen, that is causing the problem. Progesterone is not water soluble, so its unlikely to be found in water systems unless conjugated to something else or incorporated in something else, so this is just speculation on my part.
Back to Triclosan. You can find some basic information on what kinds of products contain Triclosan at the Environmental Working Group Website. Its dated 2008, but the basic information may be useful.
For all of this, note that, for Triclosan, the picture is far from clear, as recent papers also report Triclosan enhancing androgenic activity in vitro (Christen et al. 2010) and as having estrogenic activity (Jung et al. 2011). Neither of those qualities is desirable in an environmental contaminant.
Best wishes,
Margel, D., & Fleshner, N. (2011). Oral contraceptive use is associated with prostate cancer: an ecological study BMJ Open, 1 (2) DOI: 10.1136/bmjopen-2011-000311
Christen V, Crettaz P, Oberli-Schrämmli A, & Fent K (2010). Some flame retardants and the antimicrobials triclosan and triclocarban enhance the androgenic activity in vitro. Chemosphere, 81 (10), 1245-52 PMID: 20943248
Jung EM, An BS, Choi KC, & Jeung EB (2011). Potential estrogenic activity of triclosan in the uterus of immature rats and rat pituitary GH3 cells. Toxicology letters PMID: 22062131
Rostkowski, P., Horwood, J., Shears, J., Lange, A., Oladapo, F., Besselink, H., Tyler, C., & Hill, E. (2011). Bioassay- directed identification of novel antiandrogenic compounds in bile of fish exposed to wastewater effluents. Environmental Science & Technology DOI: 10.1021/es202966c
Sunday, May 1, 2011
Selenium, Brazil Nuts and Testosterone
There seems to be a lot out in the popular press or online material that incresing selenium intake will increase a healthy man's testosterone production (example and example II from Forbes Magazine: what were they thinking?), but little, if anything, in the scientific literature to support that idea. (I like the scientificky approach used by that website, especially the graph that shows no effect, and no indication of variability in the data points). However, elevated testosterone, long term, will increase risk of testicular and prostate cancer. There has also been recent emphasis on consumption of brazil nuts as a natural source of selenium that will boost testosterone and increase virility.
Selenium is protective against prostate cancer, and good for testicular development (fetal period . . . sorry guys) and possibly protective against other oxidative-stress-induced ailments, testicular or not. On the other hand, selenium, at high concentrations can result in DNA damage, and thus increase risk of cancer. The problem with supplementing, either through tablets, or through consumption of a natural product high in selenium, is that we do not know where the lines of good and evil cross.
As for Brazil nuts, selenium concentrations in any plant should be dependent on the concentration of selenium in the soil in which it grows, therefore, the concentration of selenium in Brazil nuts probably varies. This turns out to be the case, with nuts grown in Manaus-Belem more than ten times higher in selenium than those grown in Acre-Rondia. Someone consuming Brazil nuts may or may not be making a significant increase in selenium intake.
Chang, J. (1995). Selenium content of Brazil nuts from two geographic locations in Brazil Chemosphere, 30 (4), 801-802 DOI: 10.1016/0045-6535(94)00409-N
ATIF, F., YOUSUF, S., & AGRAWAL, S. (2008). Restraint stress-induced oxidative damage and its amelioration with selenium European Journal of Pharmacology, 600 (1-3), 59-63 DOI: 10.1016/j.ejphar.2008.09.029
Brozmanová J, Mániková D, Vlčková V, & Chovanec M (2010). Selenium: a double-edged sword for defense and offence in cancer. Archives of toxicology, 84 (12), 919-38 PMID: 20871980
Henderson, B. (2000). Hormonal carcinogenesis Carcinogenesis, 21 (3), 427-433 DOI: 10.1093/carcin/21.3.427
Selenium is protective against prostate cancer, and good for testicular development (fetal period . . . sorry guys) and possibly protective against other oxidative-stress-induced ailments, testicular or not. On the other hand, selenium, at high concentrations can result in DNA damage, and thus increase risk of cancer. The problem with supplementing, either through tablets, or through consumption of a natural product high in selenium, is that we do not know where the lines of good and evil cross.
As for Brazil nuts, selenium concentrations in any plant should be dependent on the concentration of selenium in the soil in which it grows, therefore, the concentration of selenium in Brazil nuts probably varies. This turns out to be the case, with nuts grown in Manaus-Belem more than ten times higher in selenium than those grown in Acre-Rondia. Someone consuming Brazil nuts may or may not be making a significant increase in selenium intake.
Chang, J. (1995). Selenium content of Brazil nuts from two geographic locations in Brazil Chemosphere, 30 (4), 801-802 DOI: 10.1016/0045-6535(94)00409-N
ATIF, F., YOUSUF, S., & AGRAWAL, S. (2008). Restraint stress-induced oxidative damage and its amelioration with selenium European Journal of Pharmacology, 600 (1-3), 59-63 DOI: 10.1016/j.ejphar.2008.09.029
Brozmanová J, Mániková D, Vlčková V, & Chovanec M (2010). Selenium: a double-edged sword for defense and offence in cancer. Archives of toxicology, 84 (12), 919-38 PMID: 20871980
Henderson, B. (2000). Hormonal carcinogenesis Carcinogenesis, 21 (3), 427-433 DOI: 10.1093/carcin/21.3.427
Wednesday, February 9, 2011
Schistosomiasis may be protective against Auto-Immune Disease
Following up here on the associations between parasite infection and reduced incidence of autoimmune diseases such as diabetes, thyroid disorders, arthritis and possibly asthma, this time with a specific focus on Schistosome infection. Schistosomias is a common infection in many areas of the developing world, and is thought to be the second most important human parasite after malaria. Infection may be sub-clinical with little or no indication of infection.
Osada et al. (2009) reported on lower inflammation and less arthritic response in infected mice. Arthritis can be induced in mice by injecting them with Collagen II. A recent publication by Xiao-Ping Chen's group (He et al. 2010) further report that the inhibitory effect of schistosomiasis is dependent on the life stage of the schistosomes. Schistosomes have a very complex life cycle and apparently some phases are more protective or induce different physiological responses in the host than others. Acute infection and egg-laying by the parasite are associated with less response to the collegen injections. Very interesting.
However, it is not advised that people run out and attempt to infect themselves, which can be pretty horrible and disfiguring. Malnutrition, anemia and lowered IQ have been observed in infected children, and increased incidence of bladder cancer is seen among infected adults. Still, it will be interesting to see where this work goes, and what treatments may be eventually developed. Thank you Osada et al. and He et al.
He, Y., Li, J., Zhuang, W., Yin, L., Chen, C., Li, J., Chi, F., Bai, Y., & Chen, X. (2010). The inhibitory effect against collagen-induced arthritis by Schistosoma japonicum infection is infection stage-dependent BMC Immunology, 11 (1) DOI: 10.1186/1471-2172-11-28
Araújo, M., Hoppe, B., Medeiros Jr, M., & Carvalho, E. (2004). Schistosoma mansoni infection modulates the immune response against allergic and auto-immune diseases Memórias do Instituto Oswaldo Cruz, 99 DOI: 10.1590/S0074-02762004000900005
OSADA, Y., SHIMIZU, S., KUMAGAI, T., YAMADA, S., & KANAZAWA, T. (2009). Schistosoma mansoni infection reduces severity of collagen-induced arthritis via down-regulation of pro-inflammatory mediators International Journal for Parasitology, 39 (4), 457-464 DOI: 10.1016/j.ijpara.2008.08.007
Osada et al. (2009) reported on lower inflammation and less arthritic response in infected mice. Arthritis can be induced in mice by injecting them with Collagen II. A recent publication by Xiao-Ping Chen's group (He et al. 2010) further report that the inhibitory effect of schistosomiasis is dependent on the life stage of the schistosomes. Schistosomes have a very complex life cycle and apparently some phases are more protective or induce different physiological responses in the host than others. Acute infection and egg-laying by the parasite are associated with less response to the collegen injections. Very interesting.
However, it is not advised that people run out and attempt to infect themselves, which can be pretty horrible and disfiguring. Malnutrition, anemia and lowered IQ have been observed in infected children, and increased incidence of bladder cancer is seen among infected adults. Still, it will be interesting to see where this work goes, and what treatments may be eventually developed. Thank you Osada et al. and He et al.
He, Y., Li, J., Zhuang, W., Yin, L., Chen, C., Li, J., Chi, F., Bai, Y., & Chen, X. (2010). The inhibitory effect against collagen-induced arthritis by Schistosoma japonicum infection is infection stage-dependent BMC Immunology, 11 (1) DOI: 10.1186/1471-2172-11-28
Araújo, M., Hoppe, B., Medeiros Jr, M., & Carvalho, E. (2004). Schistosoma mansoni infection modulates the immune response against allergic and auto-immune diseases Memórias do Instituto Oswaldo Cruz, 99 DOI: 10.1590/S0074-02762004000900005
OSADA, Y., SHIMIZU, S., KUMAGAI, T., YAMADA, S., & KANAZAWA, T. (2009). Schistosoma mansoni infection reduces severity of collagen-induced arthritis via down-regulation of pro-inflammatory mediators International Journal for Parasitology, 39 (4), 457-464 DOI: 10.1016/j.ijpara.2008.08.007
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