Dietary Risk Factors for Sporadic Creutzfeldt-Jakob Disease: A Confirmatory Case-Control Study
Zoreh Davanipour *
Department of Neurology, Loma Linda University School of Medicine, Loma Linda, CA, USA and Current affiliation: Friends Research Institute, Los Angeles, CA, USA.
Eugene Sobel
Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA and Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA and Current affiliation: Friends Research Institute, Los Angeles, CA, USA.
Argyrios Ziogas
Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA and Current affiliation: University of California-Irvine, Irvine, CA, USA.
Carey Smoak
Department of Neurology, Loma Linda University School of Medicine, Loma Linda, CA, USA and Current affiliation: Roche Molecular System, Pleasanton, CA, USA.
Thomas Bohr
Department of Neurology, Loma Linda University School of Medicine, Loma Linda, CA, USA and Current affiliation: Jerry L Pettis VA Medical Center, Loma Linda, CA, USA.
Keith Doram
Department of Internal Medicine, Loma Linda University School of Medicine, Loma Linda, CA, USA and Current affiliation: Adventist Health, Roseville, CA, USA.
Boleslaw Liwnicz
Department of Pathology, Loma Linda University School of Medicine, Loma Linda, CA, USA.
*Author to whom correspondence should be addressed.
Abstract
Aims: This study’s primary purpose was to determine whether earlier findings suggesting an association between sporadic Creutzfeldt-Jakob disease (sCJD), a transmissible spongiform encephalopathy of humans and specific dietary components could be replicated. The a priori hypotheses were that consumption of (i) foods likely to contain organ tissue and (ii) raw/rare meat are associated with increased sCJD risk.
Study Design: Population-basedcase-control study.
Place and Duration of Study: Department of Neurology, School of Medicine, Loma Linda University, Loma Linda, CA, USA; 4 years.
Methodology: An 11-state case-control study of pathologically confirmed, definite sCJD cases, matched controls, and a sample of control-surrogates was conducted. Ninety-six percent (106/110) of the case data was obtained in 1991-1993, prior to variant CJD publicity.
Results: Using control self-responses, consumption of hot dogs, sausage, pepperoni, kielbasa, "other" canned meat, poultry liver, any stomach/intestine, beef stomach/intestine, any organ tissue, and beef organ tissue was individually associated with increased sCJD risk; odds ratios (OR) ranged from 2.4 to 7.2 (0.003 <p<0.025). Rare/raw meat consumption was associated with sCJD (OR=2.0; p<0.05). Greater consumption of hot dogs, bologna, salami, sausage, pepperoni and kielbasa was associated with significantly higher risk. The OR for gizzard consumption was 7.6, p<0.04. Bologna, salami, any liver, beef liver and pork stomach/intestine were marginally associated with sCJD: ORs ranged from 1.7 to 3.7; 0.05 <p< 0.10. Brain consumption was not associated with an elevated risk. Analyses using control-surrogate data indicate that use of the control self-responses did not bias the results away from the null hypothesis.
Conclusions: The a priori hypotheses were supported. Consumption of various meat products may be one method of transmission of the infectious agent for sCJD.
Keywords: Sporadic Creutzfeldt-Jakob disease, dietary risk factors, confirmatory case-control study, prion diseases, neuroepidemiology