Study design and methods for a randomized crossover trial substituting brown rice for white rice on diabetes risk factors in India.

India has the second largest number of people with diabetes in the world following China. Evidence indicates that consumption of whole grains can reduce the risk of type 2 diabetes. This article describes the study design and methods of a trial in progress evaluating the effects of substituting whole grain brown rice for polished (refined) white rice on biomarkers of diabetes risk (glucose metabolism, dyslipidemia, inflammation). This is a randomized controlled clinical trial with a crossover design conducted in Chennai, India among overweight but otherwise healthy volunteers aged 25-65 y with a body mass index ≥23 kg/m(2) and habitual rice consumption ≥200 g/day. The feasibility and cultural appropriateness of this type of intervention in the local environment will also be examined. If the intervention is efficacious, the findings can be incorporated into national-level policies which could include the provision of brown rice as an option or replacement for white rice in government institutions and food programs. This relatively simple dietary intervention has the potential to substantially diminish the burden of diabetes in Asia and elsewhere.

Glycemic Index and Microstructure Evaluation of Four Cereal Grain Foods.

To determine the glycemic index (GI) of selected cereals and association with their microstructure. The GI of whole grain pilaf (WGP), instant brown rice (IBR), whole maize ugali (MWU), and refined maize ugali (RMU) was assessed in a randomized trial. Fourteen healthy participants with mean age of 25 years were administered 50 g portions of available carbohydrates from glucose and various test foods after an overnight fast on separate occasions. Capillary blood samples of participants were used to measure blood glucose over 2 hr. The GI was calculated as per standard protocol. The microstructure of test foods, determined by scanning electron microscopy was evaluated to understand the measured GI values. The GI (mean ± standard error) of IBR was the highest (87.8 ± 6.8) followed by RMU (74.7 ± 6.5) and WMU (71.4 ± 5.1). WGP had medium GI (58.9 ± 5.1; P < 0.01 vs. IBR). Microstructure examination of IBR revealed disruption of bran layer and presence of fissures indicating loss of intactness of bran. Stereozoom images for WGP revealed intact bran and germ. For RMU and WMU, the grain was milled leading to loss of integrity. IBR, RMU, and WMU have high GI values, which is likely due to disruption of bran layer, endosperm modification (IBR), and loss of grain matrix (WMU, RMU). WGP has medium GI probably due to fairly intact bran and germ. PRACTICAL APPLICATION: Wholegrain or whole meal flour may not necessarily be low in glycemic index (GI; low GI < 55; medium 55 to 69 and high GI ≥70). "Ugali" a commonly consumed cereal staple food in Tanzania made from either refined or whole meal maize flour was found to be a high GI food. Intact whole grain foods, such as whole grain pilaf (mixed intact whole grains) is a healthier alternative to milled whole grains such as whole meal maize flour. Instant quick cooking brown rice exhibited a high GI, due to the processing method, suggesting that regular brown rice may be a healthier option.

Dietary fat intake and its association with risk of selected components of the metabolic syndrome among rural South Indians.

CONTEXT: There is limited literature on the dietary fat intake of rural Indian populations, particularly in relation to the risk of metabolic syndrome (MS). AIM: This study aims to assess the dietary fat intake and analyze its association with the risk of selected components of the MS among rural population in the state of Tamil Nadu. SETTINGS AND DESIGN: Adults (n = 27012) ≥20 years of age were recruited from the rural component of the Chennai Urban Rural Epidemiological Study, a cross-sectional study conducted in 42 villages in Kanchipuram District of Tamil Nadu. SUBJECTS AND METHODS: Using a validated food frequency questionnaire, data were obtained on the fat intake among 6907 adults. Anthropometric and clinical measures were collected using standard methods. The components of the MS assessed were abdominal obesity, hypertension, and impaired fasting glucose. All analyses were performed using SPSS software (version 20). RESULTS: Prevalence of abdominal obesity, hypertension, and impaired fasting glucose were significantly higher in the highest quintile of fat intake (33%, P < 0.001; 39%, P = 0.04, and 23.3%, P = 0.003, respectively). Highest intake of fat was also significantly associated with risk of abdominal obesity (P < 0.001), hypertension (P = 0.04), and impaired fasting glucose (P = 0.01). Sunflower oil as the main cooking oil was significantly associated with a higher risk of these components of the MS (P for trend <0.001) compared to traditional oils and palmolein. CONCLUSIONS: Higher dietary fat was significantly associated with risk of components of the MS and use of sunflower oil as main cooking oil increased metabolic risk in rural South Indians.