Every year around this time lettuce gets bad press. Since 1995 there have been 35 outbreaks of E coli infections related to leafy greens. Last year it was cos lettuce. This year it’s romaine. The problem isn’t with the humble leaf, after all, it is nearly all water, It’s the water that’s the problem.
The human body is really one large water storage tank with entry and exit valves. Water makes up about 60% of our bodies and nearly one third of our daily water supply comes from what we eat. In the EU the average water content of food is 30%. In the USA it is less (19%) and in China it is more (40%).
For most water contaminants, there is no recommended safe level.
This water, called virtual water, is incorporated into our cells through the food chain, and is largely unregulated. In Finland, for example, only half of the water consumed is drinking water, the rest is virtual water. Even our most protected organic produce contains a large amount of unregulated water, for example, organic carrots and lettuces comprise more than 90% water. Our food chain from meat products through dairy, vegetables and nuts can carry one of at least a dozen different parasites and/or bacteria.
For most water contaminants, there is no recommended safe level, and levels can vary from population to population. Much of the measurement has centered around metals, which are relatively inert, and therefore easy to detect. For example, arsenic has been around in the drinking water in some parts of China for centuries with little effect and low levels of nickel have been reported in drinking water in New South Wales, Australia.
Water related outbreaks of infectious diseases and the discovery of harmful substances in drinking water during recent years have driven us to drink bottled water. However, bottled or filtered water may not be the answer. The materials in which this water is stored may also contaminate.
At least our drinking water is regulated to some extent. The unregulated water we consume in our food products is a looming problem for global and individual health.
Countries need work together in a global way to build and maintain adequate laboratories to respond to and manage food safety risks along the entire food chain; not just when an emergency arises. Public health departments should mandate more user friendly labelling about water content and provide access to evidence-based information.
As consumers, we need to be more vigilant about the food we eat and not assume that terms such as “organic” or “locally grown” mean the water within is contaminant-free.