It's brought down governments from the Czar, to Chang Kai Shek, to Somalia. When food runs out, the leader has got to go.
Now, the turn of Syria.
Trade sources said a reluctance among foreign banks, shipowners and grain traders to sell to import-dependent Syria - even though food is not itself subject to sanctions - has forced Damascus into an array of unusually small deals, many arranged by shadowy middlemen around the Middle East and Asia.
On Friday, in what might prove to be a turning point on a path toward a politically corrosive food crisis, government data showed the domestic grain harvest falling well short of target and the state grains agency failing to find a single acceptable offer to fulfill a major import tender it issued last month to buy animal feed for its livestock farmers.
"Syrian purchase interest has fallen off in the last 10 days or so," one trade source familiar with exports to Syria of wheat and other grains for human consumption and animal feed told Reuters. "Banks are becoming tougher in checking compliance with sanctions. It is becoming more difficult to get finance from any banks."
State currency reserves have been depleted and the Syrian pound has lost nearly half its value, adding to import problems.
Data for stocks in Syrian granaries is kept secret but there has so far been little widespread disruption evident in subsidized supplies of bread - a staple of a diet in which every Syrian consumes on average half a kilo (a pound) of wheat a day.
But international aid agencies, which are already helping up to a million Syrians stave off hunger, report patchy but spreading food shortages and sharply rising prices. Grain traders cite anecdotal evidence that stocks, concentrated in the restive countryside, are being run down or looted. That may mean the government needs to import more for the big cities it controls.
Syria's elites are not going to starve, and President Assad is going to make sure the army is fed before anyone else - except he and his gang of Alawite thugs. But hungry people in the streets is the last thing Assad needs.
Demonstrations for food coupled with demonstrations for political change is a winning combination.