By Kim Robson:
We’ve written before about how dirt can make you happier, but for a number of reasons, dirt also makes you healthier. There’s nothing to be afraid of when it comes to good, clean dirt. I love that phrase and use it often. It comes from Thomas Hardy’s Far from the Madding Crowd, in which a guest is offered some food at a country tavern: “And here’s a mouthful of bread and bacon that mis’ess have sent, shepherd. The cider will go down better with a bit of victuals. Don’t ye chaw quite close, shepherd, for I let the bacon fall in the road outside as I was bringing it along, and may be ‘tis rather gritty. There, ‘tis good clane dirt; and we all know what that is, as you say, and you bain’t a particular man we see, shepherd.”
Good, clean dirt from a garden or forest (as opposed to city dirt full of oil, grease, soot and chemicals, or lawns and parks sprayed with pesticides and herbicides) helps strengthen our immune systems. Remember making mud pies? Why don’t kids get to play in the dirt anymore? In this age of hand sanitizing gel everywhere and anti-microbial everything, we seem to be more sick than ever. Want healthier kids with robust immune systems? Let them play in the dirt!
Dr. Richard L. Gallo, MD, PhD, professor of medicine and pediatrics, chief of UCSD’s Division of Dermatology and the dermatology section of the Veterans Affairs San Diego Healthcare System, explains:
“The so-called ‘hygiene hypothesis,’ first introduced in the late 1980s, suggests that a lack of early childhood exposure to infectious agents and microorganisms increases an individual’s susceptibility to disease by changing how the immune system reacts to such ‘bacterial invaders.’
“We used to think that children who grew up on farms were healthier than children in urban environments because they were exposed to more microbes. But studies have found that the number of bacteria in urban environments and on farms is similar. The difference is the diversity of the bacteria. Microbial diversity seems to have a very powerful impact. Children’s immune systems are very social: They like to meet and greet a lot of things. It seems the more they meet and greet, the more likely they are to be in balance, and the less likely they are to let any one microorganism grow out of control, as occurs with infection.”
Dr. Maya Shetreat-Klein, a pediatric neurologist in New York, advocates a “Dirt Cure.” She believes children should spend more time outside, and that schools should have more nature-based outdoor curriculum. Check out her book, The Dirt Cure: Growing Healthy Kids with Food Straight from Soil. Dr. Klein explained to the New York Times:
“Dirt means three things to me. It’s eating nutrient-dense food from healthy soil. It’s being exposed to certain microbes. And it’s spending time outdoors in nature. In one teaspoon of soil there are more organisms than there are humans on our planet. Soil houses about 25 percent of the world’s biodiversity.
“What we also know from studies is that when children spend time in green environments — in natural playgrounds, for example, or in parks and forests — they perform better on standardized tests, they’re more creative, they’re happier and their cortisol levels are lower, so they’re calmer and less stressed. And I think that might be somewhat related to the kind of organisms they’re exposed to when they’re playing outdoors.”
The plants we eat also benefit from healthy soil. When we strip the soil of micro-organisms through agri-chemicals, we are robbing our own bodies of the full benefit of the food we eat.
The organisms in soil impact the health of our food. Part of what makes fruits and vegetables good for us is phytonutrients — the stuff that makes cranberries red or coffee bitter. Phytonutrients are part of the plant’s immune system. Organisms in the soil stimulate plants to make more phytonutrients. Being exposed to different organisms improves the health of the plant, which improves our health.
This may be because of how plants respond to stressful environments, with attacks from insects, weeds and plant pathogens. Studies (Asami et al, Institute of Food Technologies, Rutgers University, 2003) have shown that organic production methods — which are limited in the use of insecticides, herbicides, and fungicides to control plant pests — may put greater stresses on plants, requiring plants to devote greater resources toward the synthesis of their own chemical defense mechanisms.
Another reason may have to do with the impact of different fertilizers on plant metabolism. In conventional agriculture, synthetic fertilizers make nitrogen more readily available to plants than organic fertilizers, accelerating plant growth. As a result, plant resources are allocated primarily for growth, resulting in a decrease in the production of plant secondary metabolites (compounds not essential to the life of the plant) such as organic acids, polyphenolics, chlorophyll, and amino acids.
Whatever the reason, organic fruits and veggies clearly have more nutritional value than their conventional counterparts, and that has everything to do with good, clean dirt. So let’s get filthy! One great thing about kids: they’re fully washable.