Geographic distribution of liver and stomach cancers in Thailand in relation to estimated dietary intake of nitrate, nitrite, and nitrosodimethylamine.
It is our working hypothesis that the high rate of the liver and gastric cancers in North and Northeast Thailand is associated with increased daily dietary intake of nitrate, nitrite, and nitrosodimethylamine (NDMA). Samples of fresh and preserved Thai foods were systematically collected and analyzed from 1988 to 1996 and from 1998 to 2005. Consumption frequencies of various food items were determined on the basis of a dietary questionnaire given to 467 adults (212 males and 255 females) from 1998 to 2005. Food consumption data for the preceding and current year were collected and intakes (day, week, and month) of nitrate, nitrite, and NDMA were calculated. The trends in liver and stomach cancer age-standardized incidence rates (ASR) in four regions of Thailand were compared with the dietary intake of nitrate, nitrite, and NDMA in those same geographic regions. Mean daily intakes of nitrate of 155.7 mg/kg, of nitrite of 7.1 mg/kg, and of NDMA of 1.08 microg/kg per day were found. Significant differences in dietary nitrate, nitrite, and NDMA intakes were seen between various Thai regions (P < 0.0001), and these corresponded to the variations in liver and stomach cancer ASR values between the regions. Dietary factors are likely to play key roles in different stages of liver and stomach carcinogenesis in Thailand.
Mitacek
Eugene J
EJ
Department of Life Sciences, New York College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, New York 11568, USA. emitacek@nyit.edu
Brunnemann
Klaus D
KD
Suttajit
Maitree
M
Caplan
Lee S
LS
Gagna
Claude E
CE
Bhothisuwan
Kris
K
Siriamornpun
Sirithon
S
Hummel
Charles F
CF
Ohshima
Hiroshi
H
Roy
Ranja
R
Martin
Nimit
N
D000328:Adult; D002273:Carcinogens / Q000008:administration & dosage*; D003710:Demography; D004032:Diet; D004034:Diet Surveys; D004128:Dimethylnitrosamine / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D005504:Food Analysis; D005511:Food Handling / Q000379:methods; D006801:Humans; D015994:Incidence; D008113:Liver Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D008297:Male; D008460:Meat; D008875:Middle Aged; D009566:Nitrates / Q000008:administration & dosage / Q000009:adverse effects; D009573:Nitrites / Q000008:administration & dosage / Q000009:adverse effects; D013274:Stomach Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D013785:Thailand / Q000453:epidemiology
D002273:Carcinogens; D009566:Nitrates; D009573:Nitrites; D004128:Dimethylnitrosamine