If the old saying is true—what we are is what we eat—then Milton alumnus Ian Cheney’s new documentary film released in Boston this week proves that we are corn. In King Corn, Ian and Curt Ellis, Ian’s best friend from college, move to the heartland of America to learn where our food comes from. With the help of friendly neighbors, genetically modified seeds, and powerful herbicides, Ian and Curt plant and grow a bumper crop of America’s most-productive, most-subsidized grain on one acre of Iowa soil. But when the pair try to follow their corn into the food system, what they find raises troubling questions about how we eat—and how we farm. Ian has been featured on PBS’s On Point with Tom Ashbrook, and his film has been the subject of features in the New York Times food section and the film section, as well as in theBoston Globe. Ian participates in other media features in Washington, D.C. next week, when the Senate takes up discussion of farm subsidies. He’s pictured here with his trusty truck—which accompanied him in Iowa—as he retrieved it at Milton for the trip to Washington. King Corn opens on Friday, October 19, in Coolidge Corner Theatre in Brookline.