CHUCK DODD: Eating dirt can be bad for you

New York Times journalist Jane Brody suggests that eating dirt is an instinctive behavior in humans. In her article, Eating dirt can be good for you – just ask babies, she interviewed researchers who think people should eat dirt in order to stimulate their immune system.  Brody says that immune system disorders such as asthma and allergies have risen significantly in the United States. 

Although allergies do appear to be on the rise, the awareness of allergies, the ability to diagnose allergies, and the number of people at risk (the U.S. population) have also risen significantly. 

The director of gastroenterology and hepatology at Tufts Medical Center in Boston, Dr. Joel Weinstock, said in the interview,

"There are very few diseases that people get from worms. Humans have adapted to the presence of most of them. … 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…let kids have two dogs and a cat, which will expose them to intestinal worms that can promote a healthy immune system.”

Dr. Weinstock, I’m sure glad you aren’t my doctor. 

I agree that immune systems are naturally stimulated by various exposures to the environment, and that Americans use too many antibacterial products, but I question Dr. Weinstock’s knowledge of zoonotic diseases.  Intestinal parasites from animals that infect humans, since many are not adapted to humans, often leave the intestines and migrate through the body.  There are approximately 10,000 human cases of larva migrans in the U.S. each year.  Unfortunately, most of these cases are in children, and a few of these kids die.

Eating dirt is an instinct?  Not for me.  Babies eat dirt because they don’t know better.  Some may think that bad behavior is an instinct, but calling bad behavior an instinct doesn’t excuse it.  Bad advice shouldn’t be excused either. 

Dirt may have poop in it, so don’t eat it.


CRAIG ANDREW-KABILAFKAS: This article made me barf

I’m usually immune to many of the crazy notions that appear in FSnet, but having been touched by the recent and tragic Pseudomonas aeruginosa-linked death of Brazilian model Mariana Bridi, reading  Eating dirt can be good for you – just ask babies  made me barf. Surely it’s not too hard to understand that the evolutionary advantage Jane Brody references is Darwin’s survival of the fittest.  This means that the weak do not survive, they die.  Yes, it is better for humanity in the long run, but are there really parents alive today that want to play Russian roulette with their infants? 

Not me.

I know that 99% of the food that my kids eat is not sterile.  If tested it in a food microbiology lab there will be a bacterial count, but hopefully no pathogens.  I know that my mouth has trillions of bacteria resident in it even though I brush and floss my teeth twice daily.  I know that the air is not sterile and that my nose connects to my throat.  Some of the bacteria filtered by my nostrils will make their way into my throat and stomach.  Same with my kids.  I want my kids to survive and thrive so I get them to practice good personal hygiene.  I teach them about understanding and avoiding risk.  I think that it is an instinctive behaviour for children to crawl, but I prevented my children from crawling on the road because they had no concept of the risk of being hit by a car.

I also stopped them from putting dirt into their mouth.  They are still alive, strong and healthy today.  Bacteria don’t have discretion.  Mariana Bridi was in her prime and yet could not withstand the attack of a potent and pathogenic invader.  All of our knowledge, technology, and intellectual effort could not defeat her Pseudomonas aeruginosa infection.  Is society better off for her passing? 

Bridi’s untimely death has affirmed my knowledge that survival of the fittest is still in play.  It can also serve to remind that we are not good judges of what is truly meant by "fittest".  Your child may look healthy and robust, but by exposing her to pathogens that are readily found in dirt and pet faeces you are conducting a life threatening experiment. You are playing Russian roulette with your child’s life and that is not the way to ensure survival. 

Practice good personal hygiene, good parenting and just hope that you and your family are fortunate enough to avoid the deadly, painful and destructive pathogenic bacteria that surround us.

Craig is a food microbiologist working as a food safety consultant across the Australasian region.