Mice develop diabetes after exposure to mothers.
A new UC Riverside study shows that flame retardants in almost every American home cause mice to give birth to offspring that become diabetic.
These flame retardants, called PBDEs, are associated with diabetes in adults. This study shows that PBDEs cause diabetes in mice that are only exposed to the chemical by their mothers.
“The mice received PBDEs from their mothers while in the womb and as young babies through breast milk,” said Elena Kozlova, lead study author and UC Riverside neuroscience doctoral student. “Remarkably, the female offspring had diabetes in adulthood, long after exposure to the chemicals.”
The results of the study were published in the journal Scientific reports.
PBDEs are common household chemicals that are added to furniture, upholstery and electronics to prevent fires. They are released into the air that people breathe at home, in their cars and in airplanes because their chemical bonding to surfaces is weak.
‘PBDEs are everywhere in the house. It is impossible to avoid completely, ”said UCR neuroscientist and corresponding author of the study, dr. Margarita Curras-Collazo, said.
‘Although the most harmful PBDEs are produced and imported in the USA, the insufficient recycling of products containing them still leached PBDEs into water, soil and air. As a result, researchers are still finding them in human blood, fat, fetal tissues, as well as breast milk in countries worldwide. ”
Given their previous association with diabetes in adult men and women, and in pregnant women, Curras-Collazo and her team wanted to understand whether these chemicals could have harmful effects on children of PBDE-exposed mothers. But such experiments can only be done on mice.
Diabetes leads to elevated levels of blood sugar, or blood sugar. After a meal, the pancreas releases insulin, a hormone that helps cells use glucose in food. When cells are resistant to insulin, it does not work as intended, and glucose levels remain high in the blood even when no food is eaten.
Chronically high levels of glucose can cause damage to the eyes, kidneys, heart and nerves. It can also lead to life-threatening conditions.
“This study is unique because we tested both the mothers and their offspring on all the characteristics of diabetes that are displayed in humans,” Curras-Collazo said. “These kinds of tests have not been done before, especially not in female offspring.”
The researchers gave PBDEs to the mouse mothers at low levels comparable to the average human exposure during pregnancy and lactation.
All the infants developed glucose intolerance, high fixed glucose levels, insulin insensitivity and low blood insulin levels, all of which are the hallmarks of diabetes. In addition, researchers also found that babies have high levels of endocannabinoids in the liver, which are molecules associated with appetite, metabolism and obesity.
Although the mothers developed some glucose intolerance, they were not as affected as their offspring.
“Our findings indicate that chemicals in the environment, such as PBDEs, can be passed from mother to offspring, and exposure to them during the early developmental period is harmful to health,” Curras-Collazo said.
The research team believes that future longitudinal studies in humans are necessary to determine the long-term consequences of exposure to PBDE in early life.
“We need to know whether infants exposed to PBDEs before and after birth become diabetic children and adults,” Kozlova said.
Meanwhile, Curras-Collazo advises people to limit exposure to PBDEs by taking steps such as washing hands before eating, vacuuming regularly and buying furniture and other products that do not contain it. She also hopes that expectant mothers are well informed about stealth environmental chemicals that can affect their unborn and developing children, as well as their breast milk.
“We believe that the benefits that babies have from breast milk outweigh the risks of transmitting PBDEs to children. We do not recommend limiting breastfeeding, ”she said. “But let’s advocate for the protection of breast milk and our bodies against chemicals in the couch.”
Reference: “Maternal transfer of environmentally relevant polybrominated diphenyl ethers (PBDEs) produces a diabetic phenotype and disrupts glucoregulatory hormones and hepatic endocannabinoids in female offspring of mouse females” by Elena V. Kozlova, Bhuvaneswari Pedio A. Chinthir. , Donovan A. Argueta, Allison L. Phillips, Heather M. Stapleton, Gwendolyn M. González, Julia M. Krum, Valeria Carrillo, Anthony E. Bishay, Karthik R. Basappa en Margarita C. Currás-Collazo, 22 October 2020, Scientific reports.
DOI: 10.1038 / s41598-020-74853-9