Cancer & natural vs manmade chemicals - EFR 6-19

People "fear" chemicals in their food, proving that science is not something that people are learning! The following should at least make people want to better understand that all foods are chemicals and the danger associated with any given chemical is independent of its origin.

Excerpted from Food Chemical News, February 19, 1996, pp. 32-33

In a report from the National Research Council's Committee on Comparative Toxicity of Naturally Occurring Carcinogens, it was concluded that, while it is difficult to assess cancer risk, "...based upon existing exposure data, the great majority of individual naturally occurring and synthetic chemicals in the diet appear to be present at levels below which any significant adverse biologic effect is likely, and so low that they are unlikely to pose an appreciable cancer risk."

The committee also concluded, "Current knowledge indicates that calories in excess of dietary needs, and perhaps fat or certain components of fat, as well as inadequate dietary fruits and vegetables, have the greatest impact" on cancer risk in Americans.

The report looked at the current research on a number of known and suspected carcinogens and anticarcinogens, including synthetic chemicals (food additives, pesticide residues, drug residues and indirect additives), naturally occurring compounds, compounds arising from cooking, and macronutrients.

A main reason for the establishment of the committee was to compare the relative toxicity of naturally occurring carcinogens versus synthetic chemicals, But the committee reported that the data were not complete enough to make these comparisons because of the thousands of untested naturally occurring substances and the problems of making risk assessments.

"Data are insufficient to determine whether the dietary cancer risk from naturally occurring substances exceeds that for synthetic substances (e.g., data bases do not include concentration data on many of the potential carcinogenic constituents found in foods)," the group said. "Indeed, at the present time quantitative statements cannot be made about cancer risks for humans from specific dietary chemicals, either naturally occurring or synthetic." The complexity of the American diet, the lack of understanding of interactions between carcinogens and anticarcinogens in foods, and the uncertainties of conclusions about low doses of chemicals based on research using high doses, makes any assessment of risk very difficult, according to the committee.

When looking at mechanisms of action, the committee concluded that there was no difference between the potencies of man-made and naturally occurring substances present in the diet. The committee reported that, ".... Both categories of chemicals-- naturally occurring and synthetic--are large and diverse. Predictions based on chemical or physical properties are problematic, due to the likely overlap of values between categories."

The committee noted large gaps in knowledge existed on assessing the relative risks of synthetic and naturally occurring chemicals in the diet. "These gaps are so large--and resources are so limited--that careful prioritization of further research efforts is essential."

Among the committee's recommendations were the following:

- Additional data on the concentration and human exposures to naturally occurring and synthetic chemicals in foods are needed.

- Better methods are needed to test for carcinogens and anticarcinogens in the diet.

- Further testing of naturally occurring chemicals present in the food supply for carcinogenic and anticarcinogenic potential should be conducted on a prioritized basis.

- The risk of cancer from excess calories and fat should be explained further as it relates to naturally occurring and synthetic dietary chemicals.

- Specific chemicals in fruits and vegetables that may provide protective effects should be identified and their protective mechanisms explained.

Copies of the report are available from the National Academy Press, Box 285, Washington, DC 20055.