Study Suggests Leafy Greens Could Account For Nearly 10% Of Foodborne Illnesses

Eating a salad full of fresh leafy greens is not only delicious, but we've been told it's good for our health in many ways. However, there's a reason to be a cautious consumer, too. A recent study from The Ohio State University highlights the frequency of foodborne illness caused by lettuces and other fresh greens. The researchers found that about 9% of all food related sickness caused by germs can be linked to leafy greens. If you're surprised to hear this news and only think about raw meats and spoiled mayonnaise as things that can make you sick, you might have missed hearing about some large romaine lettuce recalls in the news in recent years.

The contamination often happens because lettuces and other fresh leafy greens are grown close to the soil, which could contain microbes from animal compost or contaminated water sources. One large E. coli outbreak was caused by feedlot runoff reaching an irrigation canal used to water romaine lettuce in 2018, for example. Cross contamination can occur when the greens are being packaged too. In January of 2024, BrightFarms packaged spinach and salad kits were voluntarily recalled due to possible listeria contamination in the processing plant.

Don't let this new study keep you from eating all the healthy salad greens and other leafy vegetables you love. Although the researchers highlight one source of foodborne illness, the purpose of the study was to learn more about new ways to estimate the impact of these outbreaks, not to scare consumers. The US Dietary Guidelines, due to be updated next year, still recommend that you fill half your plate with fresh fruits and vegetables, and we expect that will keep trending. The key is to be an informed consumer, keeping an ear out for news of outbreaks in your area and knowing how to properly clean produce you buy.

One trick to a safer salad at home is knowing the right way to wash your head of lettuce. Rinse the exterior of the lettuce under running water before cutting it up to remove any contaminants. Then, wash the cut or torn pieces to remove any particles or bugs that could be hiding inside. Other steps to keep your greens safe include properly refrigerating them to prevent any microbes that might be present from growing out of control, and always cleaning your knife and cutting board between tasks to prevent cross contamination. Growers are constantly improving their safety protocols, so don't avoid your greens — they're a great source of nutrients when you handle them safely.