My grandpa told me this about investing safely: Buy stock in things you use. If you get gas at a Shell station then buy Shell stock(RDSa.L). Verizon(VZ) for your cell phone/land line/internet. Buy utility stock in your electric company (DUK). If you drive a Ford then buy Ford stock (F). On and on and on.
This way, you get paid back a percentage for your purchases and those become discounted from the companies you do business with.
World conglomerate food companies like Con Agra(CAG), Nestle (NESN.VX), and Monsanto (MON) are always going to be a safe bet because people still have to eat regardless of where the tumult occurs.