Sarah Howard, MS
My hypothesis is that environmental synthetic chemical exposures are contributing to the development of type 1 diabetes, and also to the rising incidence rates of type 1 diabetes in children. I’ve been looking for and summarizing evidence of this on my website at www.diabetesandenvironment.org, which I started exactly 10 years ago, in April 2010.
In brief, type 1 incidence in children has been increasing in developed countries since the time of World War 2, which was when synthetic chemicals began to be produced and used in these countries. The rates have risen in tandem since then.
While we all know that correlation isn’t causation, in the past decade there’s been a lot of scientific research showing biological plausibility as well. Environmental chemical exposures can have a whole bunch of effects (shown in lab studies) linked to type 1 diabetes development. For example, various chemicals can:
- trigger or exacerbate autoimmunity;
- affect beta cells (killing them, stressing them, or affecting their function);
- increase insulin resistance;
- cause inflammation/oxidative stress/epigenetic changes
- affect the gut microbiota, gut inflammation, and gut permeability;
- affect vitamin D levels;
- increase susceptibility to and reaction to viruses…. and more.
In human studies, numerous chemical exposures are linked to an increased risk of type 2 diabetes, and some of these processes may be relevant for type 1 as well, such as beta cell stress or insulin resistance. Exposure to these chemicals is widespread and may be most harmful during development (especially in the womb), affecting the risk of disease later in life.
I’ve been trying for years to get researchers to look at type 1 and environmental chemicals in human studies (or even animal studies!) and while there is a growing body of evidence, this area is still a major knowledge gap. I’ve written a bunch of papers on the topic, but until there is more research, there’s not a lot more I can say.
Anyhow I’m curious as to what other people think. You can see links to all the evidence on my website. (I also summarize evidence on a variety of other environmental factors linked to type 1, including vitamin D deficiency, diet, viruses, and more.