The environmental pollutants we consume are probably the reason why some people develop type 1 diabetes. A new study from the University of Oslo (UIO) suggests that lower concentrations of such pollutants may cause cells to produce less insulin.
About 400 children and adolescents are diagnosed with type 1 diabetes each year in Norway, and the number of new cases among children and adolescents has doubled since the 1970s. The disease is also diagnosed in adults.
Type 1 diabetes is an autoimmune disease characterized by the destruction of the beta cells of the pancreas that produce insulin. The body’s own defense system makes the mistake of assuming that these insulin-producing cells are harmful foreign cells that need to be destroyed.
What causes the onset of type 1 diabetes is not clear to scientists. Can it be hereditary? Environmental factors related to diet, polluted drinking water or could it be due to viral infection?
Researchers find more environmental pollutants in the blood of children with type 1 diabetes
In collaboration with the University of Troms and several research teams in the United States, UIO scientists have studied environmental pollutants in blood samples from American children and adolescents who have been diagnosed with type 1 diabetes. These were compared with blood samples from a control group that did not suffer from type 1 diabetes.
We found that a large proportion of people with type 1 diabetes had such pollutants in their blood. Sophie E., PhD student in the Department of Molecular Medicine at the Institute of Basic Medical Sciences at the University of Oslo. On average, they also had higher concentrations of several types of environmental pollutants, says Bresson.
To examine these findings in more depth, the researchers used beta cells from mice. To find out what happened next, toxic substances were applied to these cells.
– We found that beta cells produced very little insulin even after just two days and with very low concentrations of environmental pollutants. When beta cells are exposed to pollutants for long periods of time, they die. We therefore believe that environmental pollutants play a role in triggering the onset of type 1 diabetes, concludes Bresson.
Bresson, Professor Jerome Ruzin and the research team recently published their findings in an article in the International Journal of the Environment.
Environmental pollutants are a global threat to mankind
Many environmental pollutants studied by the research team, such as PCBs and pesticides, were banned 20 years ago by the Stockholm Convention. But these substances are found in food, plastics, paints, building materials, soil and water and are broken down naturally to some extent. They may be trapped in the ice, and when the ice melts due to global warming, the pollutants are released.
In addition, many countries that have not signed the convention are still using these substances to deter insects from attacking crops.
We consume most of the environmental pollutants through the food we eat. Once these pollutants enter the body, unfortunately there is nothing we can do to eliminate them, Bresson says.
As part of the study, researchers obtained blood samples from the US. Could the level of environmental pollutants there be different from Norway?
– We have no reason to believe that there are significant differences. But we need to find out for sure, Bresson says.
Eat less meat and more lean fish
Professor Jason Mathews in the Department of Nutrition at the University of Oslo explains that 90% of the environmental pollutants we consume through food come from fish, meat and dairy products.
Scientists show that fatty fish such as herring, mackerel, halibut, salmon and trout contain more dioxins and DL-PCBs than lean fish filaments. Examples of lean fish are coalfish, cod and haddock.
So what can we do to reduce the level of environmental pollutants in our food?
Eating less meat and choosing leaner fish can be a good place to start. Ecologically farmed foods will have fewer trace elements of pesticides because they are not sprayed, but they will still absorb pollutants through water and soil, Mathews revealed.
Source:
University of Oslo, Faculty of Medicine
Journal Reference:
Bresson, SE, and others. (2022) Association between persistent organic pollutants and type 1 diabetes in youth. Environment International, doi.org/10.1016/j.envint.2022.107175.
