The phrase "you are what you eat" is suddenly more literal for some than it has ever been. According to a Clear Labs genetic and nutritional analysis study, recently shared by Gizmodo, some burgers contain traces of ingredients that are not on the menu, including pathogens as well as rat and human DNA.

For the study, the researchers analyzed 258 burger samples collected from 79 brands and 22 retailers in northern California. They used next-generation sequencing and other tests to determine authenticity, search for contaminants and allergens, and to determine if advertised ingredients were present in ground meat, veggie patties, frozen patties, and fast food products.

In addition to finding one black bean burger with no black beans, Clear Labs found meat in veggie burgers; beef DNA in lamb, chicken, and bison burgers; and pork, turkey, and chicken DNA in beef samples. It also detected rat DNA in a fast food burger, beef sample, and veggie burger, and human DNA in a frozen veggie burger.

"While unpleasant, the presence of human DNA or rat DNA is not likely to be harmful for human health," the authors write. They're likely the result of poor food handling practices.

Moreover, as the report notes, "What many consumers don't know is that some amounts of human and rat DNA may fall within an acceptable regulatory range. The amounts we detected in our research most likely fell within the acceptable regulatory range as we understand them." 

Of the samples tested, about 4 percent (11 of the 258) were found to include pathogenic DNA that could lead to food poisoning. However, the researchers cautioned that they could not determine whether the pathogens were dead or alive, issuing a warning to consumers that the best way to protect against illness is to handle and prepare food properly.

The lab also states that the purpose of the study is not to make consumers swear off all burgers, but to "help the food industry future-proof their supply chains, reduce the risk of costly recalls, and generally improve qualities of safety and quality by calling out all observable trends and insights at the molecular level, regardless of whether or not they are acceptable according to FDA guidelines."

[h/t Gizmodo]