Yes - but only if they used the exact same address. Some emails have random generated adresses made up of numers and letters that seem to be used only once. It will not stop email from those senders who use a \'different\' address each time.
Another-view is correct. Spammers send out millions of email addresses at once to both genuine emails and computer generated addresses. By unsubscribing, you have shown the spammer that yours is a genuine address and so will be spammed even more.