Examination of Dietary Recommendations for Salt-Cured, Smoked, and Nitrite-Preserved Foods

October 27, 1997

Examination of Dietary Recommendations for Salt-Cured, Smoked, and Nitrite-Preserved Foods

CAST News Release, October 27, 1997

Dietary Restrictions Questioned

The scientific evidence does not support restrictions in the consumption of salted, smoked, or nitrite-preserved foods by the U.S. population, according to a new task force report. The report, which was authored by eleven international scholars, was released by the Council for Agricultural Science and Technology (CAST), a consortium of 34 professional scientific societies.

Salt-Cured Foods

Dr. Michael W. Pariza, Director of the Food Research Institute at the University of Wisconsin, Madison and chair of the CAST report Examination of Dietary Recommendations for Salt-Cured, Smoked, and Nitrite-Preserved Foods states that "many Americans are concerned about eating salt-cured foods. But the link between salt-cured foods and cancer is observed only in developing nations where salt curing is uncontrolled. In this country, there is no risk at all."

Pariza cites the American Cancer Society's 1986 "Cancer Facts and Figures," which states that "in areas of the world where salt cured and smoked foods are eaten frequently there is more incidence of cancer of the esophagus and stomach. The American food industry has developed new processes to avoid cancer causing by-products."

"Most research linking salt-cured foods with gastric cancers was based on epidemiological studies of populations eating heavily salted foods such as dried seafood and pickled vegetables. None of the foods studied was commonly eaten in the United States," Pariza explains.

Smoked Foods

The levels of carcinogens associated with smoking methods commonly used in this country are negligible. The amount of carcinogenic compounds in wood smoke depends greatly on conditions under which heating or burning occurs. "In the United States," states Pariza, "we use methods that essentially eliminate the problem."

Most sausages made in the United States are manufactured in removable, semipermeable casings. If natural wood smoke is used, the very low levels of cancer-causing tars do not pass through the casing and seldom come in contact with the sausage.

Liquid smoke flavorings, which research indicates are free of carcinogens, may be applied toproducts by dipping, by showering, or by aerosolizing. In rodents, studies of liquid smoke flavoring consumption have produced no evidence that these flavorings are cancer-causing. Smoke flavorings have been reviewed extensively for safety and have been authorized for use by the U.S. Food and Drug Administration.

"A critical review of the available information on smoked food sold in the United States indicates that these foods are safe," states Pariza. "The scientific evidence does not support recommendations to limit consumption of smoke flavored foods."

Nitrite-Preserved Foods

Substantial changes have taken place in the use of nitrite to process cured meats, for certain related compounds have been shown to cause cancer in laboratory animals. The food processing industry has decreased the residual levels of nitrites in modern nitrite-cured meats fivefold over the last twenty years. And perhaps more important, ascorbate or erythorbate, known inhibitors of the N-nitrosation reaction, have been added to nitrite-preserved foods to help protect consumers.

These changes have led the American Cancer Society to state in 1996 that "nitrites in food are not a significant cause of cancer in Americans."

Recently, attention to the use of nitrite in cured meats has been heightened by epidemiological reports that have associated cured meats with childhood cancers. One of the major limitations of these studies is that they have been susceptible to memory failure or bias on the part of subjects: after the child was diagnosed with cancer, parents or children were asked to recall consumption of cured meats. Another major limitation to the studies is that individuals who eat hot dogs have other differences in their diets and lifestyles that may be the real cause of their health problems. Most, if not all studies so far have failed to account for differences in dietary intakes of fat, folate, and fruits and vegetables among individuals who do eat cured meats and those who do not.