5. Pickled and Smoked Foods

When you buy smoked and/or pickled foods prepackaged, you are also bringing home a whole load of harmful substances. Smoked meats and nuts are known to contain large amounts of tar, a known carcinogen. And pickled foods are cured using nitrates or nitrites as preservatives, which have been found to cause or increase the risk of cancers in the colon, rectum, or stomach.