 Alex has had type 1 diabetes since age 1. Alarmingly, the incidence of type 1 diabetes is increasing fastest in children under 5 years of age. Why? Each year, an ever increasing number of children are diagnosed with type 1 diabetes. Among children under age 15, the risk of developing type 1 diabetes has been increasing since the 1950s around the world, and there are no signs that this trend is abating. The increase has been very rapid, particularly in the youngest children, under age 5 (Diamond Project Group 2006). I know what it's like to take care of a child under 5 with type 1 diabetes: it's scary. No child should have to go through the constant parade of needles, or have to deal with high and low blood sugars that might appear at any time. Meanwhile I could use a full night's sleep, without wondering if my child was going to wake up in the morning. Between 2005 and 2020, the number of European children under 5 who have type 1 diabetes is expected to double (Patterson et al. 2009).
Like type 1 diabetes in children, the incidence of type 2 diabetes in adults is also increasing rapidly (Geiss 2006). Not only that, but type 2 diabetes incidence is increasing in children as well as adolescents. And, more and more children are showing signs of both type 1 and 2 diabetes (Pozzilli et al. 2007). The appearance of these diseases early in life is likely to have serious ramifications on health later in life.
And then there are the economic costs. It is estimated that type 1 diabetes costs the U.S. $14.4 billion in medical costs and lost income, each year (Tao et al. 2010). In 2002, U.S. spending on diabetes (type 1 and type 2) was estimated to be $132 billion. Rising health care expenditures are a serious problem, and a significant portion of health care spending is incurred by people with diabetes (Hogan et al. 2003).
But why the rising rates?
The increasing incidence in type 2 diabetes is generally attributed to increasing weight gain, a poor diet, and lack of exercise, but is that really the whole story? There is growing scientific evidence that environmental contaminants can also contribute to the development of type 2 diabetes. Do contaminants contribute to the development of the autoimmune disease type 1 diabetes as well? This website is my attempt to examine the scientific evidence surrounding our exposure to contaminants and the development of diabetes. I focus on type 1, since my young son and I both have type 1, but also include information on type 2, gestational diabetes, and other related conditions.
It is clear that some environmental, not solely genetic, factors play a role in the development of type 1 diabetes. For instance, in sets of identical twins in which one twin has type 1 diabetes, the other twin does not necessarily develop the disease (Hyttinen et al. 2003). Also, people who move from a country where type 1 is rare to a country where it is more common have an increased incidence of the disease, implying that genetics alone does not tell the whole story (Feltbower et al. 2002). See the incidence pages for more information on type 1 diabetes incidence trends and patterns around the world.
Scientists have proposed a number of hypotheses to explain the rising rates of type 1, summarized on the hypotheses page. A number of environmental factors may contribute to the development of type 1 diabetes. Many of these factors (including vitamin D deficiency, a leaky gut, etc.) are discussed on the other environmental factors pages. Environmental contaminants are seldom mentioned in conjunction with type 1 diabetes, but there is increasing scientific evidence that they may also contribute to the development of this disease. This evidence is presented on the pages focusing on environmental contaminants (e.g., air pollutants, persistent organic pollutants, etc.). Clicking on the arrows on the list on the sidebar will show all the pages and subpages in these sections.
While type 1 diabetes is a relatively well studied disease, and there are also many studies on the health effects of contaminants, there are very few studies directly linking the two fields. This website aims to connect and juxtapose these two fields of literature, suggesting how environmental contaminants might plausibly influence the development, progression, and incidence of type 1 diabetes, either alone or in conjunction with other factors. It also aims to put research into the hands of parents, patients, and others dealing with the everyday management of type 1 diabetes.
We may be able to prevent children from getting diabetes. Let's say that again. Type 1 diabetes may be a preventable disease. If the incidence is rising in children, then something is causing it, and we as a society can make it go down again.
Even if we do not know what is causing incidence to rise, and even though there have been no successful intervention trials to prevent type 1 diabetes, we can still use current information to try to prevent this disease in our children, for example by avoiding vitamin D deficiency, or cow's milk infant formula. Ludvigsson (2006) writes, "While searching for new knowledge... we could already now use existing knowledge to prevent diabetes... We must not wait for prevention of all cases! Every single case that can be prevented is wonderful for that child or adult!"
National Toxicology ProgramThe National Toxicology Program held a workshop in 2011 to evaluate the scientific evidence linking diabetes to environmental chemicals. For the free full text of the report, see the Role of Environmental Chemicals in Diabetes and Obesity: A National Toxicology Program Workshop Report (Thayer et al. 2012). From the report:
“Overall, the existing literature was judged to provide plausibility, varying from suggestive to strong, that exposure to environmental chemicals may contribute to the epidemic of diabetes and/or obesity.”“Research on environmental chemical exposures and type 1 diabetes was very limited. This lack of research was considered a critical data gap.”Where's the beef?Strapped for time because your toddler has type 1 diabetes? Most pages are summarized at their end, so just skip to the bottom if you want an overview. If you prefer reading the ending first, go directly to the recommendations and conclusions page.
A note on referencesAll information used here (except for the articles in the popular press page) is cited from peer-reviewed, published sources, unless otherwise noted. The author and date are included in the text, with a link to the title, journal, and abstract (summary) on the PubMed database. Some of the basic biology information is taken from cell biology or immunology textbooks. Textbooks and other book citations are linked to the references page, where there is also a full list of journal articles cited. Some of the full articles are available for free online, but to obtain the full text of these articles for free, you may have to visit your local university library, ask your local public library, or write directly to the author. Terms that may be unfamiliar are linked to Wikipedia, generally the first time they are used on each page. It is also important to note that "correlation does not imply causation." Many of the studies cited on the webpage note that "associations" have been found between two factors, but that does not mean that one necessarily causes the other. For example, within Europe, type 1 diabetes incidence is correlated to gross national product (GNP) (Patterson et al. 2001). Of course, a higher GNP does not cause type 1 diabetes, any more than high type 1 diabetes incidence causes a higher GNP (darn). There may, however, be some other factors, still unidentified, that could explain this particular correlation (discussed further on the type 1 diabetes incidence page). Correlation, then, might provide a hint of causation, but other factors may ultimately be responsible for the correlation itself.
PhotosAll of the people in the photos on this site have diabetes. Some names have been changed.
What do you think?I began this research in order to find out if there was anything I could do as a parent to prevent type 1 diabetes in my child. I wondered whether type 1 diabetes was really getting more common, and if so, why? Could environmental contaminants have anything to do with this rise? Read on to find out what I discovered, and let me know what you think (see about the author and the get involved pages).
Note this website's new URL: www.diabetesandenvironment.org
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