A population-based dietary intervention trial in a high-risk area for stomach cancer and stroke: changes in intakes and related biomarkers.
BACKGROUND
Dietary intervention is one of the important fields in cancer and cardiovascular disease prevention. The Hiraka Dietary Intervention Study is a community-based randomized cross-over trial designed to develop an effective dietary modification tool and system in an area with high mortality of stomach cancer and stroke.


METHODS
The subjects were 550 healthy volunteers and were randomized into two groups with tailored dietary education to decrease sodium intake and to increase vitamin C and carotene intakes either in the first year (intervention group) or in the second year (control group). Dietary changes were assessed using a validated self-administered diet history questionnaire, fasting blood samples, and 48-hour urine samples, which were obtained before and after the one year period.


RESULTS
During the first year, changes differed significantly between the intervention and control group for both dietary sodium intake (-384 and +255 mg/day, intervention and control respectively, p < 0.001) and urinary sodium excretion (-1003 and -84 mg/day, p < 0.001). Although favorable net changes were also observed in dietary carotene (+418 and +220 mug/day, p < 0.05) and vitamin C (+13 and +2 mg/day, p < 0.05), the serum level differences were modest (+13 and -25 mg/L, p = 0.09 for carotene, +0.1 and -0.5 mg/L, p = 0.07 for ascorbic acid).


CONCLUSIONS
The present dietary intervention strategy effectively decreased sodium and increased carotene and vitamin C intakes, although the former was more distinct.
Takashashi
Yoshiko
Y
Epidemiology and Biostatistics Division, National Cancer Center Research Institute East, Japan.
Sasaki
Satoshi
S
Takahashi
Masako
M
Okubo
Shunji
S
Hayashi
Masato
M
Tsugane
Shoichiro
S
D000368:Aged; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000097:blood; D002338:Carotenoids / Q000008:administration & dosage / Q000097:blood / Q000172:deficiency; D018672:Community Health Planning / Q000379:methods*; D018592:Cross-Over Studies; D004034:Diet Surveys; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D005500:Follow-Up Studies; D006266:Health Education / Q000458:organization & administration*; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015596:Nutrition Assessment; D052756:Nutritional Sciences / Q000193:education*; D012307:Risk Factors; D012423:Rural Health / Q000706:statistics & numerical data; D012964:Sodium / Q000097:blood / Q000652:urine; D017673:Sodium Chloride, Dietary / Q000009:adverse effects; D012982:Sodium, Dietary / Q000009:adverse effects; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D011795:Surveys and Questionnaires
D017673:Sodium Chloride, Dietary; D012982:Sodium, Dietary; D002338:Carotenoids; D012964:Sodium; D001205:Ascorbic Acid