It is likely that if you ate enough to be of concern for cancer, you would already be a major candidate for heart disease. There are carcinogens everywhere, why commit yourself to food austerity just to avoid a few out of thousands of chemicals that will also harm you?
That said, the only substance I have heard of that is directly linked to cancer are nitrosamines.
These are usually produced during high cooking temperatures such as when cooking bacon or searing a steak.
From a 1983 NIH paper on nitrosamines in food.
Nitrosamines are formed by reaction of secondary or tertiary amines with a nitrosating agent. In foods, the nitrosating agent is usually nitrous anhydride, formed from nitrite in acidic, aqueous solution. Food constituents and the physical make-up of the food can effect nitrosamine formation. Ascorbic acid and sulfur dioxide are used to inhibit nitrosamine formation in foods. Nitrosodimethylamine has been shown to be formed in certain foods as a result of the direct-fire drying process. In this case, oxides of nitrogen in the drying air nitrosate amines in the food being dried. The volatile nitrosamine which occurs most commonly in food is nitrosodimethylamine, and nitrosopyrrolidine occurs to a lesser extent. Due to limitations in analytical methodology, very little information is available on the levels of nonvolatile nitrosamines and other N-nitroso compounds in foods. Foods which have been shown to contain volatile nitrosamines include cured meats, primarily cooked bacon; beer; some cheeses; nonfat dry milk; and sometimes fish. It should be emphasized that not all samples analyzed contain detectable amounts of nitrosamines. When present, the volatile nitrosamines usually occur in the lower microgram/kg range. Estimates by several investigators suggest that the average daily intake of volatile nitrosamines from foods is approximately 1 microgram/person.
One thing is for sure, we all are going to die of something sometime. I am glad I had the opportunity to have perfect racks of ribs for my trouble.
JC
