In 2006, Americans learned that a salad could be hazardous to your health. The media flurry and the elected official posturing that followed the September 14 outbreak of E. coli 0157:H7 associated with spinach, is still fresh on American minds and making daily headlines thanks in no small part to the brisk recalls associated with tainted beef.
So is our food supply less safe and are the growers, shippers and various groups and agencies tasked with oversight not doing all they can to protect the consumer from deadly microbes as some believe? While the media and the public at-large lays blame at the doorstop of industry and government, might the brunt of this burden be misplaced? Simply, are we so involved in finger pointing, fences and hairnets that we don’t see the forest for the trees? An evolutionary perspective on the problem suggests, maybe.
Forgetting for a moment that the latest deadly microbe on the scene originates in cows, one needs to come to grips with the fact that the microbes have us out numbered. When a handful of rich soil contains tens of millions of tiny microbes, and that a single leaf of spinach may be covered in millions more, you start to get a feel for the germ warfare we are up against. Even worse, our so-called modern diet which is dominated by highly-processed grains and added sugars and fats, is putting us at significant disadvantage in the battlefield that is us.
But evolution has equipped humans with an ingenious system for defending against this daily microbial onslaught, most of which are harmless. Our very own microbial foot soldiers, which set up shop in our guts the minute we entered this world. There are so many microbes in the human body that if you added up their total number of cells, they would out number our human cells 9 to 1. In other words, we are more microbe than mammal.
The vast majority of the trillions of bacteria that live in our gut, most of which can be found in our large bowel and represent hundreds of species, make it their evolutionary job to keep out the pathogens that seek to do us harm. In this complex bacterial ecosystem, potentially pathogenic bacteria (e.g., E. coli 0157:H7, Salmonella, Listeria) from the “outside” world are typically suppressed by a mechanism called colonization resistance. Since the human intestinal tract is a continuous system from mouth to anus, anything present within our gut is technically still outside our body. That said, a deadly strain of E. coli does very little harm as it travels through our gut, it’s when it attempts to attach to the wall of our intestinal tract that problems occur.
In order for deadly pathogens to attach, they must compete for nutrients and colonization sites under a steady fire of microbial substances being hurled at them by our resident gut bugs. No doubt about it, this is germ warfare 101 and our gut bugs want to win. If our microbial foot soldiers are successful, then the pathogen cannot gain a foothold and consequently are swept from the system. If they are not suppressed, we quickly become aware of the lost battle from the all-to-familiar gut ache, cramping,
and diarrhea, or even worse, death.
This germ warfare has been raging in the human gut for as long as humans have been around. But recently, breath taking changes in our diet has put us at a disadvantage. In order for our gut bugs to fight the good fight, they need nutrients and a critical component of that nutrient base is dietary fiber. By definition, dietary fiber is any part of a plant that cannot be digested and absorbed in the small intestine and ends up in the large bowel (colon). Once in the colon, dietary fiber is broken down and utilized by our good bugs for their own growth. This means, dietary fiber is not food for us but food for the trillions of bacteria that live in our colons. If you feed them, the bacteria will do their evolutionary job and make life a living hell for foreign pathogens.
Our modern genome and the symbiotic relationship we developed with our gut bugs was selected on a nutritional landscape very different from the one we find ourselves today. Our not-so-distant ancestors consumed between 50, 75 and up to often greater than 100 grams a day of dietary fiber. The average American today consumes between 12 to 15 grams. More importantly, our gut bugs evolved on a diet that included an extraordinary variety of fiber sources from hundreds of plants. Humans and our evolutionary hitchhikers went from a large quantity and diversity of fibers, to a small quantity and a limited diversity. We are literally starving our gut bugs to the point that we have opened the pathogen door just enough for E. coli 0157:H7 and its band of pathogenic brothers to compete successfully for nutrients and attachment sites. Not good.
The decrease in quantity and diversity of nutrient sources (dietary fiber) has created a nutritional tipping point in the germ warfare raging in the American gut. While increased oversight, inspections, sampling and stepping up good agricultural practices are important, there are simply too many contamination variables from plough to plate. So rather than look at the recent spike in outbreaks as a result of more pathogens in the food supply and sloppy farming, might the problem have more to do with our own dietary choices. That is, our breathtaking drop in the diversity and quantity of dietary fiber might be the real problem – or at least part of the problem. In other words, dare I say, there is some personal responsibility the American public has in this germ warfare.
When someone spends a lifetime smoking two packs a day, are they not aware that if they succumb to lung cancer, that it’s in affect their own fault? So where is the personal responsibility in our national discussion on food-borne illness and the produce industry we seek to blame? Rather than run from spinach, let us run to it.
As the amount of dietary fiber in the American diet continues to decrease – and probably even more so since last years outbreaks – and our ignorance of the consumers responsibility in this germ warfare continues, we may be seeing a perfect storm of our own creation – though unintended. The litigious atmosphere surrounding this perfect storm has already created the potential for a public that sees
diarrhea as a result of a nasty microbe as something akin to a winning lottery ticket. And the situation is likely to get worse.
However, the public’s current mistrust of the produce industry may be an opportunity. Though tragic in its realization, the microscope the industry is currently under may provide a platform to explore some positive steps the industry might take in educating the public about how to increase their natural resistance to food-borne pathogens by returning the quantity and diversity of dietary fiber needed to support a healthy population of gut bugs. By consuming more vegetables and fruits, the American public may be able to add another weapon in our arsenal in our battle with food-borne pathogens and importantly, own some of the responsibility in this germ warfare. Currently, the consumer is totally unaware of the important role they play in keeping themselves and their family members healthy.
The produce industry does not need to wait until tomorrow to start this process, but start today. On September 14, 2006 the produce stepped through a door and there is no going back. It’s time to reposition produce in the American conciseness. The antioxidant and other micronutrient wagons the industry has hitched itself to in the past is tired and the American public has been yawning at that message for years. The American public needs a reason to eat more produce, something new, something fresh. Significant gains may be realized if produce is positioned more as fiber – that is, produce farmers are in fact fiber farmers. This “Fiber Defense Diet” may in fact play a role in a much need rallying call for produce in America and give consumers a very important reason to increase intake.
Some may suggest that the fiber defense argument for fighting food-borne pathogens is too simple, and therefore could not possible make a difference. And they may be right. However, the human immune system and accompanying colonization resistance mechanism that is facilitated by our own natural gut bugs, makes all external attempts such as fences, increased inspections, and triple washing look like child’s play. Our best defense has always been and will always be our natural resistance. Not nurturing our gut bugs with the nutrients they need has consequences. Continuing to ignore this basic tenant of human biology will only result in an increasing number of our fellow citizens in the emergency room and decreased sales at the farm gate.
Jeff D. Leach is the Founder of the Paleobiotics Lab (www.paleobioticslab.com), New Orleans. Comments welcome