Category Archives: diabetes

High protein diet is protective for older people, but may be unhealthy for others

We’ve written several articles on the apparent benefits of a higher protein diet for the older athlete.  Loss of muscle mass starts fairly early and loss of strength is often apparent by middle age.  We do not know how much protein intake is ideal for humans.  High protein diets for older people have been geared towards controlling sarcopenia.  Sarcopenia is the term used to describe the muscle loss that happens as people age.  Sarcopenia is a major cause of frailty.  Osteoporosis, where loss of calcium from bones leads to brittleness and fractures, is the other big problem.   Sarcopenia and osteoporosis can be worse for women who have less bone mass and less muscle mass to start with.  A number of studies have shown that older people preserve more muscle if their protein intake is increased.  If older people can preserve more muscle that should mean fewer people needing assisted-living.  Exercise, including resistance exercise also helps preserve muscle.  Exercise also strengthens bone and protects against osteoporosis.  As for the older athlete, preservation of muscle mass may provide a competitive edge.  For more easy-going people, preservation of muscle mass may mean:

  • less of the sinking feeling you get when you realize you know exactly where your body should have been when you took that flying leap for a frisbee.
  • fewer pained expressions on the faces of children when you fail a back flip
  • less aggravation opening jars
woman masters crossfit athlete high protein diet
Masters Crossfit Athlete competes in the Crossfit Games Open 14.1 in the 50-54 age category.

A new study by a team of researchers from the US and Italy examined protein intake in adults over age 50 compared with rates of Cancer, Diabetes, Mortality in general and IGF-1 (a growth hormone) levels.  Study subjects were divided into two groups: ages 50 to 65 and those over 65.  For people ages 50 to 65 a high protein diet increased risk of cancer, diabetes and death in general.  IGF-1 levels were also higher in these adults.  IGF-1is a growth hormone that may preserve muscle mass, but may also increase risk of cancer.  Middle-age users of deer antler velvet, which contains IGF-1, beware.  Researchers also found that people who ate more plant protein had lower death rates than people who ate more animal protein.  In bullet points:

High protein diet for people age 50 to 65

  • High animal protein diet increased risk of cancer by 400% in adults 50-65
  • High animal protein diet Increased risk of death by 75%
  • High animal protein diet increased risk of death from diabetes-related causes by 500%
  • High plant-based protein diet showed little to no increase in death or cancer risk

High protein diet for people over age 65

  • high protein diet reduced risk of cancer and death in people over age 65
  • Risk of death from diabetes-related causes was the same as it was for adults 50-65

Conclusions for dietary protein intake:

The researchers in this case also compared epidemiological findings with data derived from mice, which is unusual.  One of their conclusions was that a low protein intake diet during middle age followed by a high protein intake in later age may “optimize healthspan and longevity.”  I would add some considerations to that:

  1. It didn’t seem to be protein in itself thatwas the main culprit in the study, although there was some interesting data on ifg-1 levels and protein intake.  One of the problems with some forms of animal protein (meat) is that carcinogents (cancer causers) may form during high heat cooking. 
  2. Animal fat will contain more lipophilic chemicals than vegetable fats.  Some lipophilic chemicals build up in humans over time. 
  3. It seems likely that something besides protein is causing the problem. 
  4. There may be other considerations for post-menopausal women, who seem to weather aging (functionally) better when protein intake is higher.
  5. People age 50-65 are different than people 65 and older.  The 65 and older group may already have weeded out people who were vulnerable to heart disease.  (This would probably not hold for cancer).

High protein diets have been popular for a number of years now.  High protein diets, especially meat based high protein diets, have been especially popular in the Crossfit Community.  Unless you are a middle aged adult, a high animal protein diet may be bad for your long-term health.    It would be nice to know what the results would be if high-fat/high protein/poor lifestyle/obesity was separated from high protein/healthy lifestyle/healthy weight.  Hopefully the researchers will continue this line of inquiry. 

 

Levine, M., Suarez, J., Brandhorst, S., Balasubramanian, P., Cheng, C., Madia, F., Fontana, L., Mirisola, M., Guevara-Aguirre, J., Wan, J., Passarino, G., Kennedy, B., Wei, M., Cohen, P., Crimmins, E., & Longo, V. (2014). Low Protein Intake Is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population Cell Metabolism, 19 (3), 407-417 DOI: 10.1016/j.cmet.2014.02.006

Gregorio L, Brindisi J, Kleppinger A, Sullivan R, Mangano KM, Bihuniak JD, Kenny AM, Kerstetter JE, & Insogna KL (2014). Adequate Dietary Protein is Associated with Better Physical Performance among Post-Menopausal Women 60-90 Years. The journal of nutrition, health & aging, 18 (2), 155-60 PMID: 24522467

Beasley JM, Wertheim BC, LaCroix AZ, Prentice RL, Neuhouser ML, Tinker LF, Kritchevsky S, Shikany JM, Eaton C, Chen Z, & Thomson CA (2013). Biomarker-calibrated protein intake and physical function in the Women’s Health Initiative. Journal of the American Geriatrics Society, 61 (11), 1863-71 PMID: 24219187

CrossFit Training: How fitness protects from chronic disease

CrossFit Training and recent research on links between adaptation to fitness and increased levels of anti-oxidants. Anti-oxidants lower risk of cancer, diabetes and heart disease.There are many benefits in maintaining fitness.  Regular exercise reduces risk of cancer, diabetes and heart disease.  While the association of exercise and disease prevention has been strong, understanding why has been unclear.  But this is changing.

CrossFit Training, Anti-oxidants, free-radicals and fitness.

Uncontrolled free-radicals are major factors in the development of serious diseases.  Diabetes, cancer and cardiovascular disease are all conditions where free-radicals are thought to play major roles.  Free radicals are molecules or atoms that have lost an electron.  These pose problems because they are very reactive and will grab electrons from other molecules.  Free radicals can also interact with other molecules, stress cells and throw wrenches in the works.  This includes wrench throwing into your DNA.    Damaged DNA that is not repaired can result in cancer.  Or birth defects.  Free radicals also  damage tissues and organs by damaging large numbers of cells. They can damage pancreatic beta cells and increase risk of type 2 diabetes.

CrossFit Training and How fitness protects from cancer, heart disease, diabetes.

Of CrossFit Training and General Health.  Anti-oxidants protect us from free-radicals by neutralizing them.  Having enough anti-oxidants reduces risk of diabetes, cancer, or heart disease.  Exercise causes a number of changes beyond weight loss and fitness.  And these changes play into the free-radical games.   These changes are adaptions to the increased stress of exercise.  When people are first getting in shape there is an increase in free-radical production.  And a temporary increase in physical stress.   As a result, your body suffers inflammation, along with aches and pains. This is very much like what happens when you get sick with a fever.  This may be a good part of why getting in shape sucks so much.   When you are getting in shape (or trying to push yourself to a higher level) your body will produce more free-radicals, including more reactive oxygen species, until it adapts to your new level of activity.  Part of that adaptation includes increasing production of its own anti-oxidants.  Once you have adapted you will be producing enough anti-oxidants to protect against other sources of free-radicals.

CrossFit Training, Endurance or Weight Training?

What is CrossFit looking like in terms of increasing anti-oxidants?  Is Endurance Training best?  Or Resistance Training?  So far animal testing indicates that endurance exercise works best for protection against inflammation and production of anti-oxidants (Oliveira et al. 2012).  The animals in the study were subjected to endurance training, resistance training or combination training.   Hopefully more work will be done in this area and we will get a better picture of what is optimal for humans.  Weight training (resistance exercise) remains important.  And CrossFit exercises (and high intensity interval training) show very promising results on other aspects of health and fitness.  It seems likely that adaptation to these forms of exercise (i.e. CrossFit) will produce similar results to endurance training.

 

de Lemos ET, Oliveira J, Pinheiro JP, & Reis F (2012). Regular physical exercise as a strategy to improve antioxidant and anti-inflammatory status: benefits in type 2 diabetes mellitus. Oxidative medicine and cellular longevity, 2012 PMID: 22928086

de Oliveira VN, Bessa A, Jorge ML, Oliveira RJ, de Mello MT, De Agostini GG, Jorge PT, & Espindola FS (2012). The effect of different training programs on antioxidant status, oxidative stress, and metabolic control in type 2 diabetes. Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme, 37 (2), 334-44 PMID: 22458821

Crossfit High Intensity Interval Workouts

Crossfit – High Intensity Interval Training workouts.

crossfit men discuss womens resistence training
Two ugly crossfit men talk about crossfit, high intensity interval training workouts and WODMASTERS WORKOUT SHIRTS.  Why aren’t they weraing them now?  Get to the shop guys.

Endurance exercise is recommended for cardiovascular health.  Years of research have found that about 30 minutes of cardio will reduce risk of stroke and heart attack.  It will also improve insulin sensitivity, reduce risk of diabetes and improve memory and brain function.  Until very recently, there has been little research on the benefits of CrossFit type exercise on health.  These studies focus on High Intensity Interval Training.  High Intensity Interval Training workouts consist of multiple sets of intense exercise that last 1-4 minutes.  These are spaced with short rest periods.  Or periods of light exercise.

High Intensity Interval Training Workouts with gas mark.
There are so many ways to make life harder. High Intensity Interval Training Workouts can make you hurt faster

Research on this approach to exercise indicates that this approach may number of ways.  These include cardio and respiratory fitness.  And also insulin sensitivity and arterial stiffness.  Arterial stiffness is an indicator for risk of cardiovascular disease.  It is also looking like High Intensity Interval Training may be better at controlling or preventing high blood pressure than the traditional 30 minutes of sustained cardio.

CrossFit Training vs. Running?

The question of is CrossFit better than running is not known yet.  And CrossFit is different than the types of High Intensity Interval Training being tested.  In a nutshell, CrossFit is a fitness program that involves high intensity exercise.  Many different muscle groups are targeted in a CrossFit workout (also known as a CrossFit WOD.)  Workouts may last 5-20 minutes and involve springs, weight lifting, pull-ups and other bodyweight exercises.  If you are wondering “what is CrossFit” try this link. CrossFit exercises may or may not include periods of rest between sets.  However, there is a lot of shifting of focus.  Intensity may be sustained, but not sustained on the same muscle groups.  This might be better for vascular health.

CrossFit High Intensity Interval Training.

crossfit shirt rhino crossfit masters
Stiff, Inflexible, Invincible WODMasters shirt for the Masters CrossFit Athlete. And for other people who may also be stiff and inflexible.

Short periods of high intensity interval training type exercise improve capillary growth.  This allows for greater blood flow to tissues.  Including muscle.   It is possible that intense exercise impacting multiple muscle groups would be better than exercise that impacts only legs (as in running). This is an exciting area of research.  It will be interesting to see what comes up next.  Hopefully more research will be done soon that will look at whether or not CrossFit or High Intensity Interval Training does as well with brain health and control of diabetes.  For a look at recent papers take a look at:

Cocks, M., Shaw, C., Shepherd, S., Fisher, J., Ranasinghe, A., Barker, T., Tipton, K., & Wagenmakers, A. (2012). Sprint interval and endurance training are equally effective in increasing muscle microvascular density and eNOS content in sedentary males The Journal of Physiology, 591 (3), 641-656 DOI: 10.1113/jphysiol.2012.239566

Spence AL, Carter HH, Naylor LH, & Green D (2013). A prospective randomised longitudinal study involving 6-months of endurance or resistance exercise on conduit artery adaptation in humans. The Journal of physiology PMID: 23247114

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

CrossFit and Paleo: 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.

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. A good explanation of what is going on was published by He et al. (2007) and was supported by their lab studies. Light alcohol intake activates a beneficial biochemical pathway. The end result is that the body is better able to synthesize glycogen, removing glucose from the bloodstream. Higher alcohol intake disrupts glucose metabolism by activating an additional protein that blocks the positive effects seen with light alcohol intake. This is a very simplified explanation, but you can think of it as someone suddenly pulling the emergency brake while driving. Doing that long term can inflict some serious damage. Stressing the system that controls your blood sugar over long periods of time can result in diabetes and other health problems.

I’ve had some questions about alcohol consumption and the paleo diet. Some people seem to hold that hard liquor is OK because it is low-carb and is not metabolized in the same manner as beer and wine. Its true that ethanol (alcohol) follows a different path than carbohydrates, but this does not mean it is a good path to follow. Alcohol has been shown to lower production of insulin, which some also favor in the belief that keeping insulin levels low is a goal in itself. Keeping insulin levels low when blood sugar is high is not a good thing to aim for. Its the sugar that is dangerous.

Joosten MM, Chiuve SE, Mukamal KJ, Hu FB, Hendriks HF, & Rimm EB (2011). Changes in alcohol consumption and subsequent risk of type 2 diabetes in men. Diabetes, 60 (1), 74-9 PMID: 20876712

Ajani UA, Hennekens CH, Spelsberg A, & Manson JE (2000). Alcohol consumption and risk of type 2 diabetes mellitus among US male physicians. Archives of internal medicine, 160 (7), 1025-30 PMID: 10761969  

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

What are Obesogens and do I need to worry about them?

What are Obesogens.  Most of this post has appeared on my Environmental Chemicals Blog, which is now being used as an example blog for a Biology course with a Science Blogging component. However, I thought it might be an interesting read for people who, despite eating well and working out like fiends, are still struggling to lean out. It is also a good read for people who want to protect their children, future children or grandkids from metabolic disorders later in life.  Here goes.

Obesity can make your life harder than it needs to be

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, it is far easier to be destructive than constructive.

So, back to the post title: what are obesogens?

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.

How to avoid obesogens.

Avoid plastics when possible.  Avoid fabrics treated with water repellants or stain blockers.  Avoid carpet treatments.  

Grün F, & Blumberg B (2006). Environmental obesogens: organotins and endocrine disruption via nuclear receptor signaling. Endocrinology, 147 (6 Suppl) PMID: 16690801
 

Thayer KA, Heindel JJ, Bucher JR, & Gallo MA (2012). Role of environmental chemicals in diabetes and obesity: a National Toxicology Program workshop review. Environmental health perspectives, 120 (6), 779-89 PMID: 22296744

Thayer KA, Heindel JJ, Bucher JR, & Gallo MA (2012). Role of environmental chemicals in diabetes and obesity: a National Toxicology Program workshop review. Environmental health perspectives, 120 (6), 779-89 PMID: 22296744

CrossFit and Paleo: Do high fat diets increase the risk of diabetes?

I’d written a while back about a relationship between eating a high fat diet and risk of diabetes.   This is an interesting topic and one might wonder why the two should be linked together.  There has been some work on this, notably  Chiang et al. 2010) who investigated two different types of high fat diet along with a low fat diet using mice. cause by experimenting with mice.  The one of the high fat diets contained fresh soybean oil while the other used oil that had been subjected to high heat and was heavily oxidized (think deep-fried food oil).  

Map by the CDC

The mice fed high oxidized frying oil exhibited reduced insulin secretion and high blood glucose levels. Very important here: their islets of Langerhans (the tissue that produces insulin, as well as glucagon) showed evidence of oxidative damage. Glucagon and insulin work together to keep blood sugar stable. It seems likely that oxidative damage would occur throughout the body, so its probably best to avoid fried food.  Interestingly, regions in the US where frying in oil is common practice are also regions with high prevalence of diabetes.  This area (the Southeastern US) has been referred to as “the diabetes belt.”

It was also interesting that mice fed the high fat diet made with fresh soybean oil did not show such changes. This implies that a diet high in fried food may put people at risk of diabetes or metabolic disorder by interfering with production of hormones regulating blood sugar, while a high fat diet of unoxidized oil might be just fine. Vitamin E is an important anti-oxidant and is protective against the effects of High Oxidized Frying Oil. Chiang et al. found that adding Vitamin E to the diet reduced the effects of the Oxidized Fat diet.

Chiang YF, Shaw HM, Yang MF, Huang CY, Hsieh CH, & Chao PM (2011). Dietary oxidised frying oil causes oxidative damage of pancreatic islets and impairment of insulin secretion, effects associated with vitamin E deficiency. The British journal of nutrition, 105 (9), 1311-9 PMID: 21205372

CrossFit and Paleo: Plastics, Obesity and Diabetes

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 (Katzenellenbogen 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

Weight Loss Raises Testosterone

Losing weight and getting in shape can make you feel like Burt Reynolds circa 1978 too.

The Annual Endocrine Society Meeting of 2012 is over and some interesting reports have been made that will be sure to interest Masters CrossFit, men who are trying to lose weight and the women who love them . . . or at least might find them hot (Dwyer et al. 2012).  Being overweight or pre-diabetic can lower testosterone levels.  That is not surprising, since fat cells produce an enzyme called aromatase.  Aromatase converts testosterone to estrogen.  Insulin resistance seems to slow production of testosterone.  Diabetic, overweight men are probably getting hit from two different directions. 

The men who participated in the study were part of a diabetes prevention program that had them either taking a placebo, taking a diabetes drug called Metformin, or increasing their exercise levels to 150 minutes a week and reducing caloric intake.  All the men were pre-diabetic.  Neither Metformin nor placebos had an effect on testosterone levels.  Men on the workout and exercise program  had a significant increase in testosterone at the end of the study.  Effects were strongest in men who had the lowest testosterone at the start of the study.  Men in the workout program lost an average of 17 pounds over the course of a year.  Men who received the drug lost about 6 pounds, and men on the placebo did not lose weight.

Overweight also puts women (and men) at greater risk of breast cancer.  Being overweight increases aromatase in breast tissue.  Losing weight (if you are overweight) is important for women’s health as well.

Chen D, Zhao H, Coon JS 5th, Ono M, Pearson EK, & Bulun SE (2012). Weight gain increases human aromatase expression in mammary gland. Molecular and cellular endocrinology, 355 (1), 114-20 PMID: 22342815

The very basics of Insulin: what Masters Crossfit and people in general should know.

This post is in response to stuff we overhear, or see repeated on CrossFit affiliate websites, or are told by well-meaning individuals:  The message we keep encountering is that insulin is bad.  A quote that seems to have been copied and pasted to a number of different sites is “insulin makes people sedentary” and it has been attributed to Dr. Robert Lustig.  If he wrote this, it was probably taken out of context and then confused.  That sort of thing happens all the time.  Or there might have been a typo at some point.  (The statement does bring up some thoughts as to how you could test to see if insulin makes people sedentary.  Inject them and see if they decided they’d rather stay home and watch TV or go for a walk?  You might cause their blood sugar to plunge, which might pull the floor out from under them and send them into a coma, but that’s not the same thing as becoming sedentary.  At least not in the context of exercise and fitness.)
Future CrossFit Dude and EMT with his Dad.

Insulin gets sugar out of your blood stream, and keeps it from damaging your blood vessels.  This is important.  If your fat cells are full, or otherwise stressed, they may stop responding to insulin.  They are protecting themselves (Hoehn et al. 2009) possibly at the expense of other types of cells.  The result is that sugar stays in your blood stream. This is what is bad, especially since this can easily become a chronic condition.

Insulin is part of a system that keeps your blood sugar stable.  You want just enough.  Not too much sugar which will cause damage.  Not so little sugar that there will not be enough energy available to keep you walking around.  You need the entire system to function well.  Its system health that matters. Trying to stop one part from doing its job is not going to help.  What you can do to help your body regulate itself, and keep things from spiraling out of control, is to eat well, keep stress at manageable levels, and exercise.   Avoid long periods of sitting too.  You can be a high performer at the gym, but its hard to be active all day long if you have a desk job.  Get up and move around a little, especially after meals (Dunstan et al. 2012).  Even this little bit of effort will help lower blood glucose after a meal, and reduce your body’s need to put out more insulin response (at least in Masters).  You will be keeping your body from having to deal with chronic overloads, which will wear it out (Ceriello et al. 2008), and allow it to keep running the system efficiently.  Again, its the system that matters, not insulin by itself.

Ceriello, A., Esposito, K., Piconi, L., Ihnat, M., Thorpe, J., Testa, R., Boemi, M., & Giugliano, D. (2008). Oscillating Glucose Is More Deleterious to Endothelial Function and Oxidative Stress Than Mean Glucose in Normal and Type 2 Diabetic Patients Diabetes, 57 (5), 1349-1354 DOI: 10.2337/db08-0063

Dunstan, D., Kingwell, B., Larsen, R., Healy, G., Cerin, E., Hamilton, M., Shaw, J., Bertovic, D., Zimmet, P., Salmon, J., & Owen, N. (2012). Breaking Up Prolonged Sitting Reduces Postprandial Glucose and Insulin Responses Diabetes Care, 35 (5), 976-983 DOI: 10.2337/dc11-1931  

Hoehn KL, Salmon AB, Hohnen-Behrens C, Turner N, Hoy AJ, Maghzal GJ, Stocker R, Van Remmen H, Kraegen EW, Cooney GJ, Richardson AR, & James DE (2009). Insulin resistance is a cellular antioxidant defense mechanism. Proceedings of the National Academy of Sciences of the United States of America, 106 (42), 17787-92 PMID: 19805130 ResearchBlogging.org