Whats the meaning of genetically modified to pull double-duty as pesticides?

Does it mean that GM foods are two times dangerous to health than pesticides?

From Dr. Mercola's Diet and Cancer Risk:

Are you eating foods that are loaded with antibiotics and hormones?

Are you eating foods that contain ingredients that are genetically modified to pull double-duty as pesticides?

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    Just so you know, the source you're citing is wildly disreputable. He's gotten in trouble with federal regulators repeatedly for false medical claims. I am resisting arguing with the specific claims made here, but I did want to make his complete and utter fraudulent nature apparent in case the language barrier was an issue. That said, to "pull double-duty" means to do two jobs at the same time. Presumably the first job is being food and the second is being a pesticide. Jan 30, 2015 at 12:57

3 Answers 3


"double duty" is an idiom that refers to doing two jobs, or having two uses. The idiom is often used with "to pull", as "to pull double duty". For example:

‘Star Trek 3’: Simon Pegg to pull double duty as co-writer, costar


meaning that Simon Pegg will do both jobs: being a co-writer and being a co-star.


When Restaurant Kitchens Do Double Duty: Two Side-by-Side Restaurants, With Two Different Menus But One Kitchen, Attract a Trendy Clientèle


meaning that one kitchen can serve two restaurants at once.

In any case, the phrase has nothing specifically to do with danger, although the author may be trying to make you think that there is something dangerous.


In this case duty means purpose or responsibility, and double takes its usual meaning two of.

The ingredients have been genetically modified for two purposes: To help them grow bigger and healthier (the usual and assumed reason people genetically modify food), and also to kill insects when they try to eat them.


The much more common idiom is 'do double-duty', that is, to perform two functions or serve two purposes, as this ngram attests.

To 'pull duty' as in to pull KP duty or to pull latrine duty means to be assigned a task, often an unpleasant, boring, disgusting, or onerous task.

The document quoted is conflating these two idioms, IMO.

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