INSIGHTS ALONG THE PATH TO SUSTAINABILITY| November 30, 2005

Meat Consumption and Cancer: Evaluation of Methods to Assess Dietary Exposure to Heterocyclic Amines and Polycyclic Aromatic Hydrocarbons

NICOLE CARDELLO DEZIEL, M.H.S., Doctoral Candidate, Department of Environmental Health Sciences, JHSPH

SUMMARY

Consumption of meat in America has risen steadily over the past few decades. Most of the meat consumed in this country is produced by factory farms, which are not sustainable due to the great demand for and depletion of natural resources, the tremendous volume of liquid waste, the burden of air and water pollution on the surrounding environments, and the overuse of antibiotics and risk of microbial resistance (12, 13).  A diet high in meat, such as the typical Western diet, has also been implicated as risk factor for many different types of diseases, including cancer (1,6,8).  

While the weight-of-evidence shows that increased meat intake is associated with cancer, the etiology behind this association has yet to be fully elucidated (2,4,10,11).  Dietary carcinogens formed during the cooking of meat, poultry, and fish (hereafter referred to as “meat”) may play a role in the development of cancer (2,7,9).  These dietary carcinogens include heterocyclic amines (HCA) and polycyclic aromatic hydrocarbons (PAH) (7).  Numerous epidemiological studies have explored the association between specific dietary carcinogens and cancer, with overall suggestive but inconsistent results.  Some of the inconsistencies among studies may be attributable to difficulties in making precise exposure measurements (2).  Epidemiological studies rely on information about meat intake from food frequency questionnaires (FFQ) and databases of average concentrations of dietary carcinogens measured in meats prepared under various conditions, but there are several limitations of the indirect survey-based method (14,15). 

In light of these limitations, biological monitoring of HCA and PAH could offer a more accurate and precise measure of exposure and internal dose, relative to estimates derived from the FFQ, since it is an objective measure of exposure (5).  However, only short-term urinary biomarkers for HCA and PAH are currently available (2,14).  Multiple longitudinal measurements of HCA and PAH urinary excretion products could provide useful information regarding typical human exposure to HCA and PAH in the diet (3).  No comparison of the FFQ-derived exposure estimates and repeated biological monitoring samples of these dietary carcinogens has been presented in the literature to date. 

The proposed research project will draw comparisons among dietary exposure assessments of PAH and HCA derived from an array of different methods, including FFQs, diet diaries, and longitudinal biological monitoring. Participants are being recruited from an ongoing case-control study of risk factors of colon adenomas at the Johns Hopkins Bloomberg School of Public Health.  The proposed study has the potential to identify improved methods for assessing exposure to dietary carcinogens.  These new methods could be used to clarify the diet-cancer link and contribute to the growing body of literature implicating high meat consumption as deleterious to one’s health, helping to shape new policies and guidelines on behavioral changes.  The growing awareness that the majority of American’s are consuming excessive amounts of meat that have serious adverse health impacts would be a powerful motivator for dietary changes, leading the way to decreased consumption.  The decreased consumption would lead to a decrease in production, guiding us toward a more livable future.  
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PRESENTER BIOGRAPHY

Nicole Cardello Deziel received her Bachelors of Science in Public Health at the University of North Carolina at Chapel Hill. She pursued a Masters in Occupational and Environmental Hygiene at the Johns Hopkins Bloomberg School of Public Health, during which she received a National Institute of Occupational Safety and Health (NIOSH) training grant. Currently, Nicole is in her fourth year of the doctoral program in Environmental Health Engineering. Prior work experiences include research positions at the Environmental Protection Agency and the Physicians Committee for Responsible Medicine as well as being the teaching assistant for graduate and undergraduate environmental and occupational health courses. Nicole has several research interests, including assessment of dietary exposure to carcinogens and assessing children’s exposure to environmental chemicals. She served on the EPA’s Voluntary Children’s Chemical Evaluation Program Peer Consultation Panel as well as an expert panel at an EPA workshop on Characterizing and Presenting Chemical Exposure Assessment Results.