A. Joel B. Mason, MD, professor at the Friedman School and Tufts’ medical school and director of the HNRCA Vitamins and Carcinogenesis Laboratory, answers: “Nowadays, many processed meats advertise themselves as being ‘uncured’ and ‘containing no nitrites or nitrates other than what naturally occurs in celery juice.’ The implication is that this is healthier, since nitrites and nitrates have been implicated as possibly increasing the risks of certain cancers. In reality, there is little reason to believe that the nitrates or nitrites in celery juice are any safer, although to my knowledge the form that is added to processed meats has not been compared to that which appears in celery juice in regards to the potential for promoting cancer risk. It is also worth pointing out that federal law strictly limits the amount of commercially produced nitrate or nitrite that can be added to meat, whereas the amount added in the form of celery juice is not regulated.”