Spam is another food that's been the subject of many an urban legend -- there's just something about a gelatinous brick of pink meat that makes people recoil in horror. The Spam ingredient list actually isn't all that long or scary -- pork shoulder, ham, salt, sugar, sodium nitrite and water -- but that salt really packs a punch. You'll get 33 percent of your daily sodium allowance in one helping [source: Grabianowski]. There's just a small amount of sodium nitrite (a common preservative that kills bacteria and keeps the meat pink), but it's on the top of most experts' lists of food ingredients to stay far, far away from. So it's probably best if Spam sits on your shelf for a very long time -- that means you haven't eaten it yet.