Cos lettuce (also known as romaine lettuce in the US) is a bit of worry. There have been a spate of health scares relating to E. coli connected to the leafy salad green - both in Australia and abroad. Here's what you need to know.
What is it about romaine/cos lettuce?
Vegetables, including lettuce, are a major source of foodborne illness. A few of the factors working against cos lettuce here:
Lettuce isn’t (usually) cooked before eating. Cooking kills bacteria, so raw veggies are riskier.
Cos lettuce and other greens are hard to effectively wash. You’re as likely to spread the bacteria as to remove it.
Lettuce requires a lot of water as it grows (each bite of lettuce contains very few nutrients and a lot of water). Pathogens can come in on contaminated water.
Cos lettuce is really popular. Kale probably has its outbreaks too, but more people are eating cos lettuce. That just means outbreaks are bigger and more noticeable.
Packaged salad greens have an additional problem: they get washed, often mixed together with other farms’ greens. Personally, I give bagged salad greens serious side-eye, even if I do get lazy and use them sometimes.
Is the answer to buy local?
Small, local farms are great in many ways, but they’re no insurance against foodborne illnesses. The reason you never hear about huge outbreaks coming from small farms is simply that they’re small.
If a few people get sick, that might not be enough data for anyone to track down which food made them sick. (Remember, most food poisoning reports come from people who were so sick they needed to seek medical care. For every reported case, there are likely many more that flew under the radar.)
As a general rule of thumb, only buy reputable brands and make sure it's thoroughly washed.