Dr. Michael T Murray answered:
Preservatives, such as sodium benzoate, nitrates, nitrites, and sulfites, work to prevent spoilage by checking the growth of microorganisms. All of these preservatives have come under attack recently. Nitrates and nitrites are known carcinogens. Sulfites and benzoates, on the other hand, are capable of producing allergic reactions Benzoic acid and benzoates are the most commonly used food preservatives. Although for the general population, the rate of allergic response is thought to be less than one percent, the frequency of positive challenges in patients with chronic hives or asthma varies from four to 44 percent. Sulfites pose even more of a problem. Sulfites were once widely used on produce at restaurant salad bars. Since most people were not aware that sulfites were being added, and because most people were unaware they had sensitivity to sulfites, many unsuspecting people experienced severe allergic or asthmatic reactions.
For years, the FDA refused to consider a ban on sulfites, even while admitting that these agents provoked attacks in an unknown number of people and in five to 10 percent of asthma victims. It was not until 1985, when sulfite sensitivity was linked to fifteen deaths between 1983 and 1985 that the FDA agreed to review the matter. In 1986, the FDA finally banned the use of sulfites on produce and required labeling of other foods, such as wine, beer, and dried fruit, which have had sulfites added. The average person consumes an average of two to three milligrams sulfites per day, while wine and beer drinkers typically consume up to 10 milligrams per day.
From research, it is clear that all preservatives should be avoided, especially by people prone to allergies. The best way of doing this is by consuming fresh, whole foods.Preservatives, such as sodium benzoate, nitrates, nitrites, and sulfites, work to prevent spoilage by checking the growth of microorganisms. All of these preservatives have come under attack recently. Nitrates and nitrites are known carcinogens.... More