Last week I wrote about research showing that environmental chemicals are major causes of Type 2. There is also surprising evidence for toxics promoting Type 1. Let’s look at that data this week, before next week looking at what we can do about it.
As with last week’s article, I have to credit Sarah Howard, MS, National Coordinator of the Diabetes and Obesity project of the Collaborative on Health and the Environment (CHE) for much of this info. Here is Howard’s diabetes Web site.
As I wrote here in August, rates of Type 1 are growing just as fast as Type 2, although without all the publicity. With Type 2, “experts” are blaming lifestyles and bad food, but they say almost nothing about Type 1’s ongoing epidemic.
In reality, it seems that environmental pollution is a major factor in both (all) types of diabetes. There is more similarity between types than we had thought. In Type 1 diabetes, the beta cells in the pancreas do not produce insulin. But in Type 2, there also is evidence of decreased beta cell mass and function.
In both Type 1 and Type 2, beta cells die, often from apoptosis, or programmed cell death, although the mechanisms may be somewhat different.
And, says Howard, “there is growing evidence that immune system abnormalities may play a role in Type 2, not only Type 1… Fifteen to thirty-five percent of Type 2 patients diagnosed before age 45 test positive for antibodies to [glutamic acid decarboxylase or] GAD.” GAD antibodies are a major indicator of Type 1, because they indicate the immune system is attacking beta cells.
So what is causing these beta cell deaths in all diabetes types? Chemicals could play a major part:
• The first ones identified as potential threats were nitrates and nitrites, the additives you see listed on processed meats. The diabetes link was discovered in Iceland. Before nitrates and nitrites were made in factories, it was traditional in Iceland to eat a lot of smoked lamb at the holiday season. After the smoking and curing became available in bottles in the 1940’s, researchers noted that boys born in October (who were conceived during the time of the chemically-smoked lamb eating) started having very high rates of Type 1.
Since then, the link has been confirmed in a number of studies in mice and a few in children. The risk is for children of the people consuming nitrates, not the adult consumers themselves. Fathers’ consumption of nitrates/nitrites is just as much a risk as mothers’.
The main source of human exposure to these nitrogen compounds is via food. But you can also get them from cigarettes, car interiors, and cosmetics.
• Air pollutants: Air pollutants are some of the only environmental contaminants that have been directly studied in relation to Type 1 diabetes. A large study in southern California found that children exposed to high levels of ozone and sulfate in the air had nearly triple the Type 1 risk of controls.
Interestingly, while the pollutants nitrogen dioxide and particulate matters have been strongly associated with Type 2, they do not appear to affect Type 1. Only ozone and sulfates have shown that effect, but not much research has been done.
• Trichloroethylene (TCE): The CHE Web site reports, “(TCE) is an industrial solvent and environmental contaminant, commonly found in hazardous waste sites. Although most of the studies have been in mice, Dan Hurley writes in his book Diabetes Rising that consistent findings of studies and the similarities between studies in mice and humans support the idea that TCE may cause autoimmune disease. Remember that Type 1 is thought to be “autoimmune,” meaning that the body’s immune cells cause the damage by attacking healthy beta cells.
Exposure can occur via drinking water, food, or air, or in occupational settings. TCE can enter the body by ingesting contaminated water, and from showering in it, both by absorption through the skin or via inhalation. Again, more research is needed, but we don’t see drug companies, chemical companies, or governments rushing to do these studies.
• Heavy Metals include mercury, lead, or cadmium. Arsenic is a metal that is not quite so heavy, but also toxic.
One study of 76 children with Type 1 in Pakistan found that mothers and children both had higher levels of lead, arsenic, and cadmium in their blood than did controls without diabetes.
Mercury is very widespread in modern societies. Some Taiwanese studies have shown that mercury damages beta cell function and often kills them, at levels close to the legally permissible limits.
So environmental pollution possibly contributes to both Type 1 and Type 2 diabetes through stressing beta cells, causing inflammation, promoting insulin resistance, disrupting endocrine glands, interfering with gene expression, interfering with the immune system, and promoting autoimmunity, among other ways. It also seems that chemical exposure promotes weight gain and obesity.
So what can we do about this chemical threat, especially those of us who already have diabetes? We’ll look at that next week.