DESIGN: Prospective cohort study.

SETTING: PURE study in 21 countries.

PARTICIPANTS: 148 858 participants with median follow-up of 9.5 years.

EXPOSURES: Country specific validated food frequency questionnaires were used to assess intakes of refined grains, whole grains, and white rice.

MAIN OUTCOME MEASURE: Composite of mortality or major cardiovascular events (defined as death from cardiovascular causes, non-fatal myocardial infarction, stroke, or heart failure). Hazard ratios were estimated for associations of grain intakes with mortality, major cardiovascular events, and their composite by using multivariable Cox frailty models with random intercepts to account for clustering by centre.

RESULTS: Analyses were based on 137 130 participants after exclusion of those with baseline cardiovascular disease. During follow-up, 9.2% (n=12 668) of these participants had a composite outcome event. The highest category of intake of refined grains (≥350 g/day or about 7 servings/day) was associated with higher risk of total mortality (hazard ratio 1.27, 95% confidence interval 1.11 to 1.46; P for trend=0.004), major cardiovascular disease events (1.33, 1.16 to 1.52; P for trend<0.001), and their composite (1.28, 1.15 to 1.42; P for trend<0.001) compared with the lowest category of intake (<50 g/day). Higher intakes of refined grains were associated with higher systolic blood pressure. No significant associations were found between intakes of whole grains or white rice and health outcomes.

RESEARCH DESIGN AND METHODS: Data on 132,373 individuals aged 35-70 years from 21 countries were analyzed. White rice consumption (cooked) was categorized as <150, ≥150 to <300, ≥300 to <450, and ≥450 g/day, based on one cup of cooked rice = 150 g. The primary outcome was incident diabetes. Hazard ratios (HRs) were calculated using a multivariable Cox frailty model.

RESULTS: During a mean follow-up period of 9.5 years, 6,129 individuals without baseline diabetes developed incident diabetes. In the overall cohort, higher intake of white rice (≥450 g/day compared with <150 g/day) was associated with increased risk of diabetes (HR 1.20; 95% CI 1.02-1.40; P for trend = 0.003). However, the highest risk was seen in South Asia (HR 1.61; 95% CI 1.13-2.30; P for trend = 0.02), followed by other regions of the world (which included South East Asia, Middle East, South America, North America, Europe, and Africa) (HR 1.41; 95% CI 1.08-1.86; P for trend = 0.01), while in China there was no significant association (HR 1.04; 95% CI 0.77-1.40; P for trend = 0.38).

METHODS: Male rat offspring from female Sprague-Dawley rats fed with a high-fat diet (HFD) alone, HFD + GBR, or HFD + GABA extract throughout pregnancy and lactation were weaned 4 weeks after delivery and followed up for 8 weeks. A biochemical analysis and an assessment of the hepatic expression of insulin signaling genes were performed.

RESULTS: The results showed that intrauterine exposure to HFD caused metabolic perturbations in rat offspring which gravitated towards insulin resistance even though the rat offspring did not consume an HFD. GBR and GABA attenuated the HFD-induced changes by underlying regulation of the insulin signaling genes.

METHODS: GBR were extracted separately by employing different solvents with ultrasound-assisted. Pancreatic lipase activity was determined spectrophotometrically by measuring the hydrolysis of p-nitrophenyl butyrate (p-NPB) to p-nitrophenol at 405 nm. Adipogenesis and lipolysis were assayed in fully differentiated 3T3-L1 adipocytes by using Oil Red O staining and glycerol release measurement.