UNDERNEWS

Undernews is the online report of the Progressive Review, edited by Sam Smith, who has covered Washington during all or part of one quarter of America's presidencies and edited alternative journals since 1964. The Review has been on the web since 1995. See main page for full contents

January 27, 2009

DIRT IS GOOD FOR YOU

JANE E. BRODY, NY Times - In studies of what is called the hygiene hypothesis, researchers are concluding that organisms like the millions of bacteria, viruses and especially worms that enter the body along with "dirt" spur the development of a healthy immune system. Several continuing studies suggest that worms may help to redirect an immune system that has gone awry and resulted in autoimmune disorders, allergies and asthma.

These studies, along with epidemiological observations, seem to explain why immune system disorders like multiple sclerosis, Type 1 diabetes, inflammatory bowel disease, asthma and allergies have risen significantly in the United States and other developed countries.

"What a child is doing when he puts things in his mouth is allowing his immune response to explore his environment," Mary Ruebush, a microbiology and immunology instructor, wrote in her new book, "Why Dirt Is Good". "Not only does this allow for 'practice' of immune responses, which will be necessary for protection, but it also plays a critical role in teaching the immature immune response what is best ignored."

One leading researcher, Dr. Joel V. Weinstock, the director of gastroenterology and hepatology at Tufts Medical Center in Boston, said in an interview that the immune system at birth "is like an unprogrammed computer. It needs instruction."

He said that public health measures like cleaning up contaminated water and food have saved the lives of countless children, but they "also eliminated exposure to many organisms that are probably good for us."

"Children raised in an ultraclean environment," he added, "are not being exposed to organisms that help them develop appropriate immune regulatory circuits."

Studies he has conducted with Dr. David Elliott, a gastroenterologist and immunologist at the University of Iowa, indicate that intestinal worms, which have been all but eliminated in developed countries, are "likely to be the biggest player" in regulating the immune system to respond appropriately, Dr. Elliott said in an interview. He added that bacterial and viral infections seem to influence the immune system in the same way, but not as forcefully. Most worms are harmless, especially in well-nourished people, Dr. Weinstock said. . .

Dr. Ruebush deplores the current fetish for the hundreds of antibacterial products that convey a false sense of security and may actually foster the development of antibiotic-resistant, disease-causing bacteria. Plain soap and water are all that are needed to become clean, she noted.

"I certainly recommend washing your hands after using the bathroom, before eating, after changing a diaper, before and after handling food," and whenever they're visibly soiled, she wrote. When no running water is available and cleaning hands is essential, she suggests an alcohol-based hand sanitizer.

Dr. Weinstock goes even further. "Children should be allowed to go barefoot in the dirt, play in the dirt, and not have to wash their hands when they come in to eat," he said. He and Dr. Elliott pointed out that children who grow up on farms and are frequently exposed to worms and other organisms from farm animals are much less likely to develop allergies and autoimmune diseases.

Also helpful, he said, is to "let kids have two dogs and a cat," which will expose them to intestinal worms that can promote a healthy immune system.

1 Comments:

Anonymous Anonymous said...

I couldn't stop thinking of Haiti as I read this - where the people are so long-deprived they're making and eating mud cookies to staunch their hunger pangs.

January 28, 2009 5:43 AM  

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