miércoles, 17 de junio de 2009

Dioxins in food chain linked to breastfeeding problems

Dioxin accumulation explains why some women have trouble breastfeeding or produce too little milk.

A study from the University of Rochester Medical Center (URMC), in the United States, has found that contact with the toxic chemical harms the cells in rapidly changing breast tissue that occurs during pregnancy.
While the results have only been demonstrated in mice so far, researchers believe their investigations may help to address an issue that affects between three and six million women worldwide.
Role of environmental contaminants
The group said that most people are exposed to dioxins through diet. The majority of dioxins are generated by the incineration of municipal and medical waste – especially certain plastics – and these enter the food chain when air emissions settle on food crops and pastures where livestock graze.
Humans are said to ingest dioxins mostly through eating meat, dairy products and shellfish. The chemical settles in the fatty tissues where “natural elimination occurs very slowly”, said the URMC researchers. The typical daily exposure is thought to be low but this has already been linked to health problems such as possible impairment of the immune system and developing organs, added a statement from the group.
New findings
The findings reported in Toxicological Sciences this week demonstrated that dioxin “has a profound effect on breast tissue by causing mammary cells to stop their natural cycle of proliferation as early as six days into pregnancy, and lasting through mid-pregnancy”, said Lawrence. Tissue samples taken from mice showed a 50 percent decrease in new epithelial cells that help to protect or enclose organs, she added.
Timing irrelevant for humans
The timing of dioxin exposure also seemed to be significant, the study noted. Results showed early exposure may give time for the cells to recover. But Lawrence stressed that while understanding of the timing of exposure was important for research purposes it was “irrelevant for humans, who cannot really control their exposure to dioxins".
Source: Toxicological Sciences

1 comentario:

Pamela Ubilla Thennet dijo...

Profesor: este articulo ya fue publicado en español el 11 de junio....