Riboflavin deficiency and esophageal cancer: a case-control-household study in the Caspian Littoral of Iran
aDepartment of Nutrition and Biochemistry, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences and Health Services, Tehran, Iran, bEpidemiology Research Unit, Department of Nutrition, Research Center, CHUM Hôtel-Dieu, Quebec, Canada
AIM: It has been suggested that riboflavin deficiency may play important role in the etiology of esophageal cancer. A case-control-household study was designed in two very high and low-risk regions of esophageal cancer in North of Iran to assess the role of dietary riboflavin in the etiology of this disease. METHOD: In a case-household-control-household study in two very high and low esophageal cancer (EC) risk regions of the Caspian Littoral of Iran, a total of 21 cases (12 subjects from the high risk and 9 subjects from the low risk region) and 91 household members (57 subjects from the high risk and 34 subjects from the low risk region) were investigated. Cases were matched for sex and age (±5 years) with non-blood relative controls. A standard 24-hour dietary recall questionnaire was used to estimate riboflavin intake. RESULTS: The erythrocyte glutathione reductase activity coefficient (EGR-AC) was measured to assess riboflavin status. In both regions, the mean daily intake of riboflavin for cases was less than that of the controls (0.66±0.43 vs. 0.82±0.37 mg/d) whereas for their households, it was virtually the same. Both cases and control households showed riboflavin deficiency in two regions, with higher deficiency in the high risk area. Statistical analysis revealed significant differences between the two regions for EGR-AC (P<0.001). Odd ratios indicated that the risk of developing EC for persons living in riboflavin-deficient households was more than twice that of non-deficient households. CONCLUSION: This study suggests that riboflavin deficiency may play an important role in the etiology of esophageal cancer in the Caspian Littoral of Iran.
Paper presented at the International Symposium on Predictive Oncology and Intervention Strategies; Nice, France; February 7 - 10, 2004; in poster session 793 (Dietary Influences).