Recommendation 13 Background

Curing is a method of preserving meat and fish. It has been used for thousands of years. Foods are cured by immersion in or injection of a solution of nitrate or nitrite, salt and other condiments. The nitrates and nitrites act as preservatives and, at the same time, color the meat.

Smoking, by exposing meat and fish to the smoke of wood or coal fire, is also an old way of preservation. The wood smoke may contain carcinogenic compounds. Cured meats may also be smoked and smoked foods are often also salted.

Prior to refrigeration, cured and smoked foods formed a larger share of the intake of food. Although vegetables, baked goods, beer, and processed cereal products contribute a very small amount of nitrites to the diet, cured meats are the main single dietary source.

Carcinogenic compounds may be formed in cured meats. Since we became aware of this, the amount of nitrite has been reduced and ascorbic acid is used to inhibit nitrosamine formation. Current exposure of the public in developed countries to nitrite is lower than in the past.

Boiling, steaming and stewing expose food to a temperature of 100 degrees C or lower. Baking, roasting and microwaving expose food to up to 200 degrees C. Here, direct flame is not applied; oils or fats may be used to baste in roasting. Broiling, also known as grilling, and barbecuing may use direct flame and temperatures of up to 400 degrees C. High surface temperatures are used for frying with a pan or wok.

Broiling meat, fish or other foods with intense heat and over a direct flame can generate carcinogens. Dropping of the fat on the hot fire yields flames that contain polycyclic aromatic hydrocarbons (PAH) and heterocyclic amines (HCA). These substances adhere to the surface of the food. Many PAH and HCA derivatives are carcinogenic in laboratory animals. Lower amounts of PAH and HCA are present in oven-grilled food because the drippings usually do not make their way back to the meat.