The organic lettuce at your local grocery store may make you sick, according to a preliminary study released this month by a Spanish university.
Researchers at the Universitat Politècnica de València in Spain led by Dr. Yolanda Moreno released data Saturday showing that amoebas on organic lettuce may potentially harbor a number of bacteria, most notably salmonella. The scientists collected 17 samples from supermarkets.
“The presence of bacteria of public health concern contained inside the free-living amoebae suggests that they are vehicles that can easily transmit pathogens capable of reaching humans and causing health problems through contaminated organic vegetables,” Moreno said.
Researchers found 52 types of bacteria that can cause disease, with two-thirds of the samples containing Acanthamoeba castellanii, a bacteria that can cause encephalitis and blindness. A fifth of the samples carried another bacteria, Vermamoeba vermiformis, which is known to cause severe infections.
“Contamination can arise as a consequence of treating soil with organic fertilizers such as manure and sewage sludge and from irrigation water,” Moreno said.
Salmonella is responsible for the deaths of 420 Americans a year, and 26,500 hospitalizations out of more than 1.3 million infections, according to the Centers for Disease Control and Prevention (CDC). Symptoms can last from four to seven days and could begin as soon as six hours after being infected.
The CDC recommends rinsing leafy greens under running water and discarding any torn or bruised leaves. In an outbreak traced to lettuce in October 2021, 31 people across four states became ill, the CDC reported.
A University of Minnesota study published in May 2004 by the Journal of Food Protection found that generic E. coli was six times as likely to be present on organic produce than conventional produce prior to being harvested. Fecal contamination was also noted as being “significantly higher,” according to the University of Minnesota researchers.