Triclosan induces hypothyroidism and is transfered to infants during lactation.

Triclosan is used in many personal care products as an anti-bacterial agent. You can find it in soaps, toothpaste etc. It is also an endocrine disruptor that effects at least two different (albeit interrelated) systems. Triclosan has some estrogenic effects. 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. Thank you, Paul et al., for your hard work, and for fitting yet another piece into the puzzle. Here is the U.S. FDA's position on Triclosan safety.
as of today.

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

Fried food may cause diabetes in thin people too.

A Taiwanese research group published on the effects of high oxidized frying oil on insulin secretion (reduces insulin secretion)in 2007. In this study they (Chiang et al. 2010) attempt to determine the cause by experimenting with mice. They used three treatment groups:

Low Fat Diet
High Fat Diet
High Oxidized Frying Oil Diet.

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 even if diabetes or metabolic syndrome is not one of your concerns.

The High Fat diet mice 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. Thanks to all for their hard work.

Ya-Fan Chiang, Huey-Mei Shaw, Mei-Fang Yang, Chih-Yang Huang, Cheng-Hsien Hsieh and Pei-Min Chao (2011). Dietary oxidised frying oil causes oxidative damage of pancreatic islets and impairment of insulin secretion, effects associated with vitamin E deficiency British Journal of Nutrition : 10.1017/S0007114510005039

Chao, P., Huang, H., Liao, C., Huang, S., & Huang, C. (2007). A high oxidised frying oil content diet is less adipogenic, but induces glucose intolerance in rodents British Journal of Nutrition, 98 (01) DOI: 10.1017/S000711450769000X

Autoimmune disease and inhalation of particulates

Airborne particulate matter appears to increase risk of diabetes, as discussed a few posts down and diabetics appear to have altered immune function according to a number of parameters. Diabetics have now been observed to have stronger indicators of immune response when air pollution levels (particulate matter in this case) are high. Schneider and Alexis (2010 . . . two first authors, congratulations all) observed increased blood levels of endogenous promotors of Activated Protein C Resistance. Diabetics who were also obese, or who did not express GSTm1, (not having this, by the way, increases risk of a wide array of cancers) or who already had elevated HbA1C (this is an indicator of longer-term blood glucose levels) had the strongest response to particulate matter. So, are diabetics more vulnerable to challenges to the immune system? Do these challenges contribute to development of diabetes? Or is there an interplay in each (diabetes and immune response)alters the pattern of the other. Lets hope they don't progressively spiral over time and continued exposure. The cohort was small with only 20 subjects, but it would be interesting to look at response to particulate matter by age, or time since diagnosis of type II diabetes.


Schneider A, Alexis NE, Diaz-Sanchez D, Neas LM, Harder S, Herbst MC, Cascio WE, Buse JB, Peters A, & Devlin RB (2010). Ambient PM2.5-Exposure Up-regulates the Expression of Co-Stimulatory Receptors on Circulating Monocytes in Diabetic Individuals. Environmental health perspectives PMID: 21169129

Inflammation, autoimmune disease, diabetes and gum disease

The other day I wrote about environmental agents increasing risk of obesity, diabetes and insulin resistance and mentioned an article associating exposure to particulate matter with increased incidence of diabetes and wondered about it. If, as the authors suggest, exposure to particulates results in low-level chronic inflammation, then other causes of chronic inflammation (like gum disease) should also be associated with increased risk of diabetes, insulin resistance or similar. A little poking around, and yes, looks like a hit: Increased Prevalence of Cardiovascular and Autoimmune Diseases in Periodontitis Patients: A Cross-Sectional Study. Just out last month by Nesse et al. at the University of Groningen in The Netherlands. Very cool guys. Congrats on the publication.

Nesse W, Dijkstra PU, Abbas F, Spijkervet FK, Stijger A, Tromp JA, van Dijk JL, & Vissink A (2010). Increased prevalence of cardiovascular and autoimmune diseases in periodontitis patients: a cross-sectional study. Journal of periodontology, 81 (11), 1622-8 PMID: 20583916

A Little More on Lipophilic Chemicals, Diabetes and Obesity

This is just a little continuation of the post made yesterday in which I wondered if associations between intake of animal protein (vs. vegetable protein) and waist circumference had anything to do with increased exposure of consumers of animal products to environmental contaminants. This is not my area of research . . . but it is an area of research for a lot of other people. Diabetes and/or Insulin Resistance is associated with exposure to Brominated Flame Retardants, Persistent Organic Pollutants, polychlorinated diphenyl ethers, and, interestingly (perhaps because I don't understand the mechanism by which this would occur . . . will have to look into it) airborn particulates. A brief and very readable review of environmental (chemical) causes of diabetes was made in 2008 by Oliver et al.

Jones, O., Maguire, M., & Griffin, J. (2008). Environmental pollution and diabetes: a neglected association The Lancet, 371 (9609), 287-288 DOI: 10.1016/S0140-6736(08)60147-6
Lee, D., Lee, I., Jin, S., Steffes, M., & Jacobs, D. (2007). Association Between Serum Concentrations of Persistent Organic Pollutants and Insulin Resistance Among Nondiabetic Adults: Results from the National Health and Nutrition Examination Survey 1999-2002 Diabetes Care, 30 (3), 622-628 DOI: 10.2337/dc06-2190
Lim, J., Lee, D., & Jacobs, D. (2008). Association of Brominated Flame Retardants With Diabetes and Metabolic Syndrome in the U.S. Population, 2003-2004 Diabetes Care, 31 (9), 1802-1807 DOI: 10.2337/dc08-0850
Pearson JF, Bachireddy C, Shyamprasad S, Goldfine AB, & Brownstein JS (2010). Association between fine particulate matter and diabetes prevalence in the U.S. Diabetes care, 33 (10), 2196-201 PMID: 20628090

Animal vs. Plant Protein, Adiposity, Persistent Organic Pollutants and Endocrine Disruption

Intake of vegetable protein is negatively correlated with waist circumference and BMI. In contrast, intake of animal protein is positively correlated with waist circumference and BMI, at least in Belgians. There are a lot of questions to raise with this including the possibility that people who eat less animal protein consume less animal fat which can be a rich source of bioactive, lipophilic contaminants which may also be endocrine disruptors that increase adiposity or alter blood lipids. Note Ruzzin et. al.'s April 2010 paper "Persistent Organic Pollutant Exposure Leads to Insulin Resistance Syndrome." (Very nice work! Congratulations to all authors.) Also possible that people who eat a lot of vegetable protein also eat fewer calories, are less sedentary etc. There is also the argument that lean, grass-fed animals (happy cattle, miserable chickens) would eliminate this vulnerability in meat eaters. That would be an interesting study. BMI and blood lipid profiles in matched cohorts of grass-fed/organic animal protein eaters vs. regular grocery store consumers. Anyone . . . ?


Ruzzin J, Petersen R, Meugnier E, Madsen L, Lock EJ, Lillefosse H, Ma T, Pesenti S, Sonne SB, Marstrand TT, Malde MK, Du ZY, Chavey C, Fajas L, Lundebye AK, Brand CL, Vidal H, Kristiansen K, & Frøyland L (2010). Persistent organic pollutant exposure leads to insulin resistance syndrome. Environmental health perspectives, 118 (4), 465-71 PMID: 20064776

Lin, Y., Bolca, S., Vandevijvere, S., De Vriese, S., Mouratidou, T., De Neve, M., Polet, A., Van Oyen, H., Van Camp, J., De Backer, G., De Henauw, S., & Huybrechts, I. (2010). Plant and animal protein intake and its association with overweight and obesity among the Belgian population British Journal of Nutrition, 1-11 DOI: 10.1017/S0007114510004642

Nutritional Stuff, Protein and Vegetarianism

This is not my field but, late at night, when I can't sleep, I sometimes look at articles dealing with nutrition and here are two that piqued my curiosity.
One is that high protein maternal diets may predispose infants (at least rats anyway) to greater risk of obesity later in life.  Maternal consumption of high-prebiotic fibre or -protein diets during pregnancy and lactation differentially influences satiety hormones and expression of genes involved in glucose and lipid metabolism in offspring in rats, British Journal of Nutrition.  Of course there are lots of questions.  The young rats were switched to a "normal" diet after weaning.  What if they had stayed on the same diet their mothers had been on?  For review of fetal programming see Godfrey et al. 2007.  Is the problem when diet changes after an infant as been "programmed" to a particular nutritional condition?  i.e. is it mismatch between fetal expectation and the reality of later life, or is it a problem created by a high protein diet? 

The other is that creatine supplements appear to increase cognitive function in vegetarians:  The influence of creatine supplementation on the cognitive functioning of vegetarians and omnivores also just out in the British Journal of Nutrition.  I'm a vegetarian with ADHD-like traits.  Time to try a supplement?  Opposed on principle, but what the hey, I can use all the cognitive function I can get.

Godfrey KM, Lillycrop KA, Burdge GC, Gluckman PD, & Hanson MA (2007). Epigenetic mechanisms and the mismatch concept of the developmental origins of health and disease. Pediatric research, 61 (5 Pt 2) PMID: 17413851

Ototoxicity

You don't hear much about ototoxicity (pun completely intended), but I think it is fascinating (what???).  Hearing is relatively easy to evaluate and can serve as marker of neurological effect for chemicals targetting the developing nervous system (i.e. harm nerve development in general and you may see poor functioning in general, including poor hearing).  Like other cells in the body, cells involved in hearing are vulnerable to oxidative stress.  Oxidative attack can result in damage to a cell's DNA, which can lead to development of a cancerous cell or, if you are a fetus, in the development of a birth defect.  Your body is not completely defenseless against a cancerous cell.  Abnormal cells normally self-destruct in a process called "apoptosis".  Its when a cell loses the ability to undergo apoptosis that you may have a serious problem. 

When you combine something like Arsenic, which is a great creator of oxidative stress, with exposure to loud noise you get more hearing loss than you would if you were not also exposed to Arsenic.  Heavy metals, mercury and lead, are classic ototoxicants as are some antibiotics and drugs for erectile dysfunction. 

Hearing loss is also seen when environmental chemicals interfere with neurodevelopment.  There is some very interesting work being done in this area by Tomas Trnovec (Slovakia) et al. that focuses on hearing deficits in children exposed to PCBs.  PCBs were bannned in the US decades ago, but continued to be produced by the Soviet Block.  Poor environmental regulation in Eastern Europe has left those countries with some major environmental health problems.  Best wishes to all working in this area.

High Fructose Corn Syrup

I have been detecting a bit of concern about high fructose corn syrup in my local atmosphere (gas chromatography, of course), and there is a simple solution: avoid regular indulgence, as you would for popcorn balls, frosting and jolly ranchers.  However, small amounts are extremely unlikely to cause any harm (Please note that as a scientist I have been trained not to make absolute statements.  There is always the possibility that new information will come along, even for very well-established theories like "gravity").  Be rational.  Read widely.  You should neither let those who enjoy fanning flames keep you from enjoying your life, nor let those intent on obscuring truth keep you from making good decisions. 

For a recent review of the current state of the debate about high fructose corn syrup take a look at this publication: Fructose and Cardiometabolic Disorders: the controversy will, and must, continue by Wiernsperger, Geoloen and Rapin from October 2010. Nice work gentlemen, and very much appreciated.  Another review has been published this month by Dekker et al., but I don't yet have access.  Thanks to all for their work in this area.

For a well-crafted response from the Corn Syrup interests click this link.  Wiernsperger et al., Dekker et al. . . . it will be hard to compete.

In the Darkness before Science

We lost power last night, coming home to a darkening house, cold and quiet, fumbled for belongings to pack in bags for the drive to a friend's house.  It reminded me very much of the times we were homeless when my daughter was small and it was just the two of us.  The home in which we sought sanctuary was dark and quiet too, but only because I couldn't figure out the lights.  We sat together my blonde girl, who towers over me now, and I.  I asked her what she remembered of those days.  "I don't remember much from back then, Mom.  But I remember the cold and the darkness, and being alone together, and talking.  And it was nice.  I feel good now too".

Politics, Money, Chemicals, Health and the Environment

Oh Canada
has declared BPA . . . (fit that into the music for the national anthem) to be a toxicant.  That does make sense, given the growing body of evidence that it is an endocrine disruptor that produces wide-ranging effects in test animals and is positively correlated with adverse effects in humans.  It is also usual for industries involved in production, use and distribution of chemicals found to have strong potential for causing health problems in humans to argue with scientists and regulatory personnel and to try to convince the population at large that there is nothing wrong with their products.  I wonder if this is simply characteristic of democracies.  I'm sure graft and favoritism plays a role in other systems of government (and in ours as well).  Part of me is just morbidly fascinated with how truth, logic and fairness are knotted up into some very twisted wads. 

A spokesman for the BPA people is claiming that BPA is safe and that Canada's decision will only alarm and confuse the public.   (I do agree that no one should have to go grocery shopping in an alarmed and confused state of mind . . . that's how products like "Lunchables" are purchased).  You can read the American Chemistry Council statement here where it claims that the European Food Safety Authority (EFSA) confirms the safety of BPA and that Canada's decision flies in the face of "World Wide Scientific Evidence".   Funny Funny. In fact the EFSA is stating that there is no compelling evidence that the Tolerable Daily Intake should be changed from its current level.  This is a far cry from stating that BPA is safe. 

Some legitimate arguments in BPAs favor is that it makes food packaging and transport safer and more economical.  This does have economic and social value.  But please, let's honor good work done and the validity of concerns for human and environmental health.

Diabetes and Bisphenol A (BPA)

There is increasing evidence that chemicals in the environment may be contributing to diabetes and obesity. 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.

Here is specific evidence on the relationship between exposure to bisphenol A and risk of diabetes: Bisphenol A Exposure during Pregnancy Disrupts Glucose Homeostasis 
in Mothers and Adult Male Offspring. As discussed in previous posts, nearly everyone is exposed to Bisphenol A (BPA) through consumption of food and beverages packaged in plastic.

Atrazine

Congratulations to Walid D. Fakhouri, Joseph L. Nuñez, and Frances Trail for their recently published work on reduction of growth hormone production by the herbicide Atrazine.  Growth hormone is important, as will sound obvious, because it plays a key role in growth (cell proliferation) but also because it influences production of many other hormones including those important in sexual development and reproduction. Changes in growth hormone produce a range of effects that extend far beyond body size. 

The battles over Atrazine have been politically intense and, at times, highly entertaining to those on the sidelines.  It was banned in Europe in 2004, but remained in use in the US after studies were provided to the EPA through Syngenta, the company that manufactures Atrazine, that contradicted studies by independent scientist Tyrone Hayes at the University of California at Berkeley. 

Understanding Atrazine's mechanism of action will be invaluable in making informed well-reasoned decisions for protection of human health and the environment. 

Fakhouri, W., Nuñez, J., & Trail, F. (2010). Atrazine Binds to the Growth Hormone–Releasing Hormone Receptor and Affects Growth Hormone Gene Expression Environmental Health Perspectives, 118 (10), 1400-1405 DOI: 10.1289/ehp.0900738

Mercury

Just out, news that rice is a major pathway for methylmercury exposure in a mining community in Inland China.  This is big news because fish consumption has been the focus of exposure assesments for mercury exposure.  Mercury, when methylated (hence methylmercury) can be devastating to developing fetuses, causing severe brain damage.  For a detailed history of a methylmercury incident look up "Minimata, Japan".  Keep in mind this was an unusual tragedy and human exposures are normally much lower than those that occurred there. 

Would have to search to see if anyone has done similar work to test produce or other agricultural projects near US coal plants, but it would be interesting to know (hopefully soon).  Mercury uptake by plants apparently varies by species, with most of it remaining in roots, and most mercury detected in/on plant leaves may be from simple settling of dust.  To the right is a USGS map of wet mercury deposition in the (on the) US.  Above is the link for further information.  Health effects are minimal for unmethylated mercury, with methylation being performed by anaerobic bacteria in oxygen poor environments . . . which you would see in swamp bottoms, ocean floor etc. . .  and would probably not (to the best of my knowledge) be occurring in common agricultural conditions.  Rice fields, being flooded and marsh-like, may provide good conditions for methylated microorganisms. 

Further note, China does not export much rice and mercury in rice may be only a local problem. 

Zhang H, Feng X, Larssen T, Qiu G, Vogt RD, 2010 In Inland China, Rice, rather than Fish is the Major Pathway for Methylmercury Exposure. Environ Health Perspect doi:10.1289/ehp.1001915

Environmental Chemicals, Obesity and Diabetes

Exposure to chemicals may change the way people (and other creatures) deposit fat within  their bodies which may play a role in obesity.  Since Obesity is also associated with diabetes, cancer and heart disease it is also possible that the same chemicals play a role in development of these diseases as well.

A study published in this month's (April) issue of Environmental Health Perspectives by Ruzzin et al.describes the effects of exposure to Persistent Organic Pollutants (POPs) on insulin and lipid profiles in rats.  POPS is a term usually used to describe a set of chemicals that are very slow to degrade, accumulate in body fat, and concentrate as you move up the food chain.  The POPs in this study were isolated from farmed Salmon, and it is thus not much of a stretch to expect that people consuming farmed salmon would be exposed to a similar mixture of this particular soup.
It is important to keep in mind that anything with animal fat will contain POPs, so avoiding salmon consumption may not be particularly protective. An earlier and equally intriguing paper  by Somme et al. 2009 showed altered fat deposition when newborn rats were exposed to Bisphenol A.  So what's going on with the current obesity epidemic?  Are chemical exposures playing a role?  Hopefully further research will elucidate this mystery. 
For those interested in protecting their health: eat low on the food chain (bugs, shrimp, vegetables).  And, avoiding drinking or eating things that have been packaged in BPA-containing plastics would be a simple way to reduce BPA exposure.

The original "dirty dozen" POPs have been banned in the US.  Exposure, however, is universal because POPs accumulate in fat, and we pass them on to our children during pregnancy and lactation. Anyone interested in a multi-generational fat biopsy study?   Bisphenol A is not banned and is believed to be rapidly excreted in urine (Yeah!).

Plastic water bottles

Yes, it is true.  There is very little point in using these unless you live in an area where drinking water is contaminated with sewage/agricultural run-off (West Bank, Palestine), high arsenic (areas of India and Bangladesh) or nitrate concentrations (any of the above places, and possibly agricltural areas in the US.).  Bisphenol A, a major ingredient in many plastics is an endocrine disruptor.  The health effects of Bisphenol A are still under investigation.  How much is safe is not known.  Biological systems effected are not well understood.  How much is coming off the water bottle and into the water it contains is unknown.

On environmental impact level, plastic water bottles just use petroleum and create mountains of waste.  Yes, they can be recycled, but recycling is not cost free.  Someone pays for it (whether through taxes, higher costs, or energy consumption and more pollution). 

Carry a glass bottle, carry a cup, use a drinking fountain.

Dipping into Psychology, but keeping focus on Oxytocin and Cortisol

Briefly here, on today's NY Times article on touch , and that warm touches (and who knows, maybe the playful punch in the arm or slap to the back of the head) results in release of oxytocin and reduction of cortisol.  Oxytocin is released within the brain and triggers feelings of relaxation, well-being and warmth towards others. For more info look that hormone up on Wikipedia.  Cortisol is elevated in people who are under prolonged stress and is associated with a range of undesirable health effects like cancer, elevated blood pressure, cardiovascular disease and if I remember correctly possibly diabetes. Oxytocin is probably signalling "its OK.  You are not alone"  "The threat is gone", or "we will fight this battle together".

So, reach out and support your friends, colleagues, team-mates and loved ones.  It is likely to do a statistically significant world of good

This week's topic is Androgen/Estrogen Disruption

Could write a book here, but will be brief for now.  First listen to (and watch if you want) this clip:  Tone setting music.  Endocrine disruptors are chemicals that mimic or interfere with "signals" from the endocrine system (glands).  Examples of hormones are androgens (such as testosterone), estrogens, thyroid hormones, epinephrine (aka adrenaline) etc.  Examples of endocrine disrupting chemicals in the environment (and/or food and drinking water) are phthalates, bisphenol A (BPA) and perchlorate.  You can read numerous articles on endocrine disruption in Environmental Health Perspectives, including that of Reproductive Toxicology Rock Star Shanna Swan.  This is a great source of information because its peer-reviewed and you can get the entire article for free. 

Phthalates and BPA are part of many plastics and they interfere with sex hormones (in this case estrogen mimics).  This is hugely important during fetal development as organsystems (including brain) are being formed.  Had a student ask if increased exposures to estrogenic compounds would results in higher rates of homosexuality.   Not sure that this is appropriate to discuss here, but estrogen is the hormone that  masculinizes the brain, so you might see a tendency towards masculinization and associated behavioral traits.  Yes, sex hormones are important for brain development. A lot of other chemicals may have similar effects. Will link to an interesting article reporting on prenatal exposure to phthalates and aggressive, disruptive behavior during childhood.
Click "manufacturer's point of view" for information on industry response.  Businesses often put their own interests first.  There is nothing wrong with that as long as it doesn't hurt anyone else.  My opinion.

Reading about Health and Science

Sometimes a health or science story comes up in the news that catches people's interest.  Here is some simple advice:

go find the original publication or read the abstract on PubMed( http://www.pubmed.gov/). 

Often a journalist will pick up on one aspect of a study and not mention other aspects, or limitations, or may misinterpret the conclusions of the study authors.  So take a look at the original yourself.  Peer-reviewed articles published in highly-ranked journals put out quality work.  Getting through peer-review is a rigorous process as exemplified in this video Scientific Peer Review ca. 1945.

Telomeres, aging and exercise

An interesting bit of research has been picked up by the press.  Telomere length has been reported to be longer in older endurance athletes than in older couch potatos  Telomeres are thought to be important in aging.  You can find the abstract and access the full text through: http://www.pubmed.gov/.   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). 

Light

Light controls our circadian rhythms.  These determine our daily pattern of waking and sleeping, and probably how our energy levels vary throughout the day as well.  In the modern environment, most of us spend most of our time indoors with artificial light.   The signals our brains get from light are no longer triggered exclusively by the rising and setting of the sun.  A number of health effects from altered light exposure have been noted including

• Increased incidence of cancer (esp. breast and colorectal cancer in shift workers)
• Insomnia
• Obesity
• Diabetes
• Depression
• Timing of onset of puberty

For more detailed discussion, references to specific papers and the above image see: http://ehp03.niehs.nih.gov/article/info:doi/10.1289/ehp.117-a20

AND

http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.118-a22 for a more detailed discussion with emphasis on blue light and photoreceptors.

Human Health and Environmental Factors

There are a lot of things that influence health beyond diet and exercise, and many ways in which our health may be influenced by the world we create.   

• Exposure to light: 
• Temperature control
• Psychological stress (traffic, kids, job etc.)
• Quality of friendships and community
• Exposure to environmental agents
• Drugs
• Air Quality
• Water Quality

and etc.  It is important to keep in mind that all of these things can impact your physical health, and that they can all influence each other.