Diabetes and the Environment

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 are diabetes rates increasing?

In 2006, my 23 month old toddler was diagnosed with type 1 diabetes. I remember it like it was yesterday. It's a terrifying experience. But he was not alone, far from it. Each year, an ever increasing number of children are diagnosed with type 1 diabetes. More and more children are also developing type 2 diabetes and obesity. The increasing rates are not limited to children; adults are also at risk. I myself developed diabetes as an adult in 1999, while pregnant with my older child. The doctors thought it was gestational diabetes, and then pre- type 2 diabetes, but later testing showed that I had type 1. My story illustrates how distinguishing the types of diabetes is not always easy.  

While my family probably has some genetic risk for type 1, it is clear that environmental factors also play a role in the development of the disease. 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 (Feltbower et al. 2002). Genetics alone cannot account for the recent increasing incidence worldwide.

The increasing incidence in type 2 diabetes is generally attributed to increasing weight gain, a poor diet, and lack of exercise, all of which play a role, but are they the whole story? There is tons of scientific evidence that environmental chemicals can also contribute to the development of type 2 diabetes-- most people are probably not aware of this research. Did you know there are high rates of diabetes in Bangladesh and other areas of the world where people's drinking water is contaminated with arsenic

And what about type 1 diabetes? Do environmental chemicals contribute to that as well? How about gestational diabetes? What about diabetes complications? This website examines the evidence.

About this website

This website is my attempt to summarize the scientific evidence surrounding our exposure to synthetic chemicals and the development of diabetes. I focus on type 1, since my son and I both have type 1, but also include information on type 2 and gestational diabetes as well as obesity. I've also expanded into metabolic syndrome, non-alcoholic fatty liver disease, and diabetes complications.

After my son was diagnosed, I heard about the increasing incidence of type 1 diabetes (summarized on the incidence and historical trends page). I wondered what evidence there was for that increase, found PubMed, and have spent the subsequent years searching for and reading studies. PubMed literally changed my life. 

Coincidentally, one of the ground-breaking studies on diabetes and environmental chemicals (Lee et al. 2006) was published about the time my son was diagnosed. I emailed the author, who encouraged me and helped start me on this journey. Thanks Duk-Hee Lee!

I started scouring PubMed to find studies, and found more research than I imagined literature. In 2010 I started this website to summarize it all. There are pages on individual environmental chemicals like arsenic or PFAS, air pollution, microplastics, and many more (see sidebar). There are also pages on everything from viruses to vitamin D deficiency to nutrition. There are pages that focus on mechanisms like autoimmunity or beta cell dysfunction. And a conclusions page that summarizes the findings (and a summary section on the top of each page).

References and new studies

There are thousands of studies summarized on this website. I still update it regularly, and search for new research every week.

I send out weekly summaries new studies via email; sign up for the HEEDS Research Roundup of Environmental Chemicals in Diabetes and Obesity. HEEDS stands for Healthy Environment and Endocrine Disruptor Strategies, which is a program of Environmental Health Sciences. I actually turned some of this work into a part-time job! 

I sometimes post new studies on X @sarhoward but more often post new science on endocrine disrupting chemicals from @HEEDSorg.

Photos and figures

All of the people in the photos on this site have diabetes, or are scientists studying diabetes or obesity. Some names have been changed.

Figures are used with permission as noted or are from Environmental Health Perspectives, which is in the public domain.


This webpage relies solely on published studies in peer-reviewed scientific journals, available and categorized by topic on the references page.

Infographic from The Lancet. Read the full series: The Lancet: Risk factors for type 1 diabetes, 2016.