Nagako Okuda

Nutrient intakes of middle-aged men and women in China, Japan, United Kingdom, and United States in the late 1990s: the INTERMAP study

The purpose of the study was to compare nutrient intakes among Chinese, Japanese, UK, and US INTERMAP samples, and assess possible relationships of dietary patterns to differential patterns of cardiovascular diseases between East Asian and Western countries. Based on a common Protocol and Manuals of Operations, high-quality dietary data were collected by four standardized 24-h dietary recalls and two 24-h urine collections from 17 population samples in China (three samples), Japan (four samples), UK (two samples), and USA (eight samples). There were about 260 men and women aged 40–59 years per sample—total N=4680. Quality of dietary interview and data entry were monitored and enhanced by extensive systematic ongoing quality control procedures at local, country, and international level. Four databases on nutrient composition of foods from the four countries were updated and enhanced (76 nutrients for all four countries) by the Nutrition Coordinating Center, University of Minnesota, in cooperation with Country Nutritionists. The mean body mass index was much higher for Western than East Asian samples. Macronutrient intakes differed markedly across these samples, with Western diet higher in total fat, saturated and trans fatty acids, and Keys dietary lipid score, lower in total carbohydrate and starch, higher in sugars. Based on extensive published data, it is a reasonable inference that this pattern relates to higher average levels of serum total cholesterol and higher mortality from coronary heart disease in Western than East Asian populations. The rural Chinese diet was lower in protein, especially animal protein, in calcium, phosphorus, selenium, and vitamin A. Dietary sodium was higher, potassium lower, hence Na/K ratio was higher in the Asian diet, especially for Chinese samples. This pattern is known to relate to risks of adverse blood pressure level and stroke. At the end of the 20th century, East Asian and Western diets remain significantly different in macro- and micronutrient composition. Both dietary patterns have aspects that can be regarded, respectively, as adverse and protective in relation to the major adult cardiovascular diseases. In both Asian and Western countries, public efforts should be targeted at overcoming adverse aspects and maintaining protective patterns for prevention and control of cardiovascular diseases.

INTERMAP: the dietary data--process and quality control.

The aim of this report is to describe INTERMAP standardized procedures for assessing dietary intake of 4680 individuals from 17 population samples in China, Japan, UK and USA: Based on a common Protocol and Manuals of Operations, standardized collection by centrally trained certified staff of four 24 h dietary recalls, two timed 24-h urines, two 7-day histories of daily alcohol intake per participant; tape recording of all dietary interviews, and use of multiple methods for ongoing quality control of dietary data collection and processing (local, national, and international); one central laboratory for urine analyses; review, update, expansion of available databases for four countries to produce comparable data on 76 nutrients for all reported foods; use of these databases at international coordinating centres to compute nutrient composition. Chinese participants reported 2257 foods; Japanese, 2931; and UK, 3963. In US, use was made of 17 000 food items in the online automated Nutrition Data System. Average time/recall ranged from 22 min for China to 31 min for UK. Among indicators of dietary data quality, coding error rates (from recoding 10% random samples of recalls) were 2.3% for China, 1.4% for Japan, and UK; an analogous US procedure (re-entry of recalls into computer from tape recordings) also yielded low discrepancy rates. Average scores on assessment of taped dietary interviews were high, 40.4 (Japan) to 45.3 (China) (highest possible score: 48); correlations between urinary and dietary nutrient values—similar for men and women—were, for all 4680 participants, 0.51 for total protein, range across countries 0.40–0.52; 0.55 for potassium, range 0.30–0.58; 0.42 for sodium, range 0.33–0.46. The updated dietary databases are valuable international resources. Dietary quality control procedures yielded data generally indicative of high quality performance in the four countries. These procedures were time consuming. Ongoing recoding of random samples of recalls is deemed essential. Use of tape recorded dietary interviews contributed to quality control, despite feasibility problems, deemed remediable by protocol modification. For quality assessment, use of correlation data on dietary and urinary nutrient values yielded meaningful findings, including evidence of special difficulties in assessing sodium intake by dietary methods.

Association of raw fruit and fruit juice consumption with blood pressure: the INTERMAP Study

BACKGROUND Epidemiologic evidence suggests that fruit consumption may lower the risk of cardiovascular diseases through blood pressure (BP)-lowering effects; little is known on the independent effect of raw fruit and fruit juice on BP. OBJECTIVE The objective was to quantify associations of raw fruit and fruit juice consumption with BP by using cross-sectional data from the INTERnational study on MAcro/micronutrients and blood Pressure (INTERMAP) of 4680 men and women aged 40-59 y from Japan, China, the United Kingdom, and the United States. DESIGN During 4 visits, 8 BP, four 24-h dietary recalls, and two 24-h urine samples were collected. Country-specific multivariate-controlled linear regression coefficients, including adjustment for urinary sodium excretion, were estimated and pooled, weighted by inverse of their variance. RESULTS The average total raw fruit consumption varied from a mean ± SD of 52 ± 65 g/1000 kcal in the United States to 68 ± 70 g/1000 kcal in China. Individual raw fruit intake was not associated with BP in pooled analyses for all countries or in participants from Western countries, although a positive association with diastolic BP was observed in East Asian participants (per 50 g/1000 kcal; 0.37 mm Hg; 95% CI: 0.02, 0.71). Positive relationships with diastolic BP were found for citrus fruit intake in Western consumers (per 25 g/1000 kcal; 0.47 mm Hg; 95% CI: 0.12, 0.81) and for apple intake in East Asian consumers (0.40 mm Hg; 95% CI: 0.03, 0.78). Among East Asian banana consumers, banana intake was inversely associated with diastolic BP (-1.01 mm Hg; 95% CI: -1.88, -0.02). Fruit juice intake, which was negligible in Asia, was not related to BP in Western countries. CONCLUSION Consistent associations were not found between raw fruit and fruit juice consumption of individuals and BP. This observational study was registered at www.clinicaltrials.gov as NCT00005271.