Effect of a Novel High Fiber Rice Diet on 24-Hour Glycemic Responses in Asian Indians Using Continuous Glucose Monitoring: A Randomized Clinical Trial

BACKGROUND

We have recently demonstrated a medium glycemic index for novel high fiber white rice (HFWR) variety compared to regular white rice (RWR). However, substituting HFWR for RWR during the whole day's diet may provide extended benefits. The current study aims to assess the 24 h glycemic responses of a HFWR diet compared to a RWR diet.

METHODS

Continuous glucose monitoring (CGM) was used to assess the glycemic profile in 18 overweight, non-diabetic Asian Indians aged 25 to 50 in a randomized cross-over design. The volunteers were provided with iso-caloric (≈2100 kcal/day) HFWR or RWR based diets for four continuous days and switched diets after appropriate washout. Fasting blood samples for insulin assessments were collected at baseline and at the end of 4 day feeding. The glucose response in terms of incremental area under the curve (IAUC) was recorded. General linear model was used to assess the adjusted mean change of fasting insulin level of HFWR compared to RWR. Age and sex were adjusted as confounders in the model.

RESULTS

The average 24 h glucose response for HFWR was significantly lower (IAUC 66.3 ± 3.1 mg-5 min/dL) than RWR (IAUC 79.8 ± 5.7 mg-5 min/dL). The adjusted mean change in fasting insulin levels from baseline was also lower for HFWR compared to RWR. HFWR elicited a 34% and 30% lower 24 h glycemic and insulin response respectively, compared to RWR.

CONCLUSION

Replacing RWR with HFWR may be a healthier alternative for Asian Indians who are at a higher risk of developing type 2 diabetes.

One reason why waist-to-height ratio is usually better related to chronic disease risk and outcome than body mass index

The waist-to-height ratio (wtHR) has been proposed as an alternative to body mass index (BMI) as a simple anthropometric measure of body fatness. Both measures retain residual correlations with height, which causes them to over- or under-adjust for height (and thus misestimate nutritional state) when relating these measures to chronic disease risk, morbidity or mortality. The possibility that BMI has greater misadjustment than wtHR relative to waist/height (p) and weight/height (p) (where p is the optimal exponent for each population and sex group) is examined here. Analysis of anthropometric data for groups in Thailand, Papua New Guinea and Australia shows that this is the case, especially over-adjustment. This may contribute to the weaker relationships of chronic disease markers and outcomes with BMI than with wtHR.

Milk, milk products, and disease free health: an updated overview

The cow and its milk have been held sacred in the world since the dawn of human civilization. Indian ancient Vedic texts describe the virtues of milk and dairy products, as is authenticated by modern scientific principles and proofs. Therefore, milk has been considered as one of the most natural and highly nutritive part of a daily balanced diet. Currently, the integration of advanced scientific knowledge with traditional information is gaining incredible momentum toward developing the concept of potential therapeutic foods. Furthermore, new advances toward understanding the therapeutic roles of milk and milk products have also given a new impetus for unraveling the age old secrets of milk. At present, the best-known examples of therapeutic foods are fermented milk products containing health promoting probiotic bacteria. In the present article, we have tried to review the various aspects of the therapeutic nature of milk and fermented dairy products in a highly up-dated manner, and offer an in-depth insight into the development of targeted therapeutic future foods as per the requirements of consumers.

Glycaemic index of three Indian rice varieties

Three commonly consumed Indian rice varieties (Sona Masuri, Ponni and Surti Kolam) were tested for their glycaemic index (GI). Healthy volunteers were recruited and after an overnight fast were given a 50 g available carbohydrate portion of glucose (reference food) or different varieties of cooked rice (test foods) on separate occasions. The fasting as well as postprandial capillary blood glucose response was determined over 2 h, and the incremental area under the curve (IAUC) was calculated. The GI was calculated as the IAUC of the test food/IAUC of the reference food (glucose) × 100. The differences between the GI values for Sona Masuri (72.0 ± 4.5), Ponni (70.2 ± 3.6) and Surti Kolam (77.0 ± 4.0) rice varieties were non-significant (p = 0.606) and are all classified as high GI varieties of rice. There is an urgent need to study the GI of other commonly consumed rice varieties and to develop rice of a lower GI value.

Cancer-preventing attributes of probiotics: an update

Cancer is a serious global public health problem. Cancer incidence and mortality have been steadily rising throughout the past century in most places of the world. There are several epidemiological evidences that support a protective role of probiotics against cancer. Lactic acid bacteria and their probioactive cellular substances exert many beneficial effects in the gastrointestinal tract, and also release various enzymes into the intestinal lumen and exert potential synergistic (LAB) effects on digestion and alleviate symptoms of intestinal malabsorption. Consumption of fermented dairy products with LAB may elicit anti-tumor effects. These effects are attributed to the inhibition of mutagenic activity, the decrease in several enzymes implicated in the generation of carcinogens, mutagens, or tumor-promoting agents, suppression of tumors, and epidemiology correlating dietary regimes and cancer. Specific cellular components in lactic acid bacteria seem to induce strong adjuvant effects including modulation of cell-mediated immune responses, activation of the reticulo-endothelial system, augmentation of cytokine pathways, and regulation of interleukins and tumor necrosis factors. Studies on the effect of probiotic consumption on cancer appear promising, since recent in vitro and in vivo studies have indicated that probiotic bacteria might reduce the risk, incidence and number of tumors of the colon, liver and bladder. The protective effect against cancer development may be ascribed to binding of mutagens by intestinal bacteria, may suppress the growth of bacteria that convert procarcinogens into carcinogens, thereby reducing the amount of carcinogens in the intestine, reduction of the enzymes beta-glucuronidase and beta-glucosidase and deconjugation of bile acids, or merely by enhancing the immune system of the host. There are isolated reports citing that administration of LAB results in increased activity of anti-oxidative enzymes or by modulating circulatory oxidative stress that protects cells against carcinogen-induced damage. These include glutathione-S-transferase, glutathione, glutathione reductase, glutathione peroxidase, superoxide dismutase and catalase. However, there is no direct experimental evidence for cancer suppression in human subjects as a result of the consumption of probiotic cultures in fermented or unfermented dairy products, but there is a wealth of indirect evidence based largely on laboratory studies.

Glycaemic index of some commercially available rice and rice products in Great Britain

The glycaemic response to nine types of rice (white basmati, brown basmati, white and brown basmati, easy-cook basmati, basmati and wild rice, long-grain rice, easy-cook long-grain rice, Thai red rice, Thai glutinous rice) and two types of rice vermicelli (Guilin rice vermicelli, Jiangxi rice vermicelli) commercially available in the United Kingdom were compared against a glucose standard in a non-blind, randomized, repeated-measure, crossover design trial. Fourteen healthy subjects (six males, eight females), mean age 38 (standard deviation 16) years and mean body mass index 21.3 (standard deviation 2.3) kg/m(2), were recruited for the study. Subjects were served portions of the test foods and a standard food (glucose), on separate occasions, each containing 50 g available carbohydrates. Capillary blood glucose was measured from finger-prick samples in fasted subjects (-5 and 0 min) and at 15, 30, 45, 60, 90 and 120 min after the consumption of each test food. For each type of food, its glycaemic index (GI) was calculated geometrically by expressing the incremental area under the blood glucose curve as a percentage of each subject's average incremental area under the blood glucose curve for the standard food. The 10 foods exhibited a range of GI values from 37 to 92. The study indicated that rice noodles, long-grain rice, easy-cook long-grain rice and white basmati rice were low-GI foods, whilst all of the other foods were medium-GI and high-GI foods. The information presented in this paper may be useful in helping people select low-GI foods from the customary foods consumed by the British and Asian populations.

Use of low-glycaemic index bread to reduce 24-h blood glucose: implications for dietary advice to non-diabetic and diabetic subjects

The present study investigated the effect of a simple dietary change on 24-h blood glucose. In a randomized cross-over design, 10 healthy subjects were prescribed a low-glycaemic-index (LGI) diet and a high-glycaemic-index (HGI) diet. The diets were identical with the exception of the type of bread consumed (LGI or HGI). Glucose concentrations over 24 h were measured using a continuous glucose monitoring system. The LGI diet resulted in a lower mean glucose response compared with the HGI diet over 24 h (P=0.135), during the day (P=0.171) and at night (P=0.100). Similarly, the 24-h, daytime and overnight incremental area under the curve for glucose following the LGI diet was consistently lower than following the HGI diet (P=0.093, P=0.132 and P=0.061, respectively). The results demonstrate how a very simple dietary change can favourably alter overall blood glucose concentrations. Such small modifications to the diet, if adopted in the long term, could improve glucose control and consequently reduce the risk of chronic disease in both diabetic and non-diabetic individuals.

Glycaemic index of common foods tested in the UK and India

The aim of this study was to ascertain whether international glycaemic index (GI) values, predominantly developed using peoples living in Europe, North America or Australia, are applicable to Asian Indians resident in their own country. Thirty-four Caucasian subjects were recruited in Oxford, UK and thirteen Asian Indian subjects in Chennai, India. Two types of sweet biscuits and three breakfast cereals were tested for glycaemic response in each group. Subjects were served equivalent available carbohydrate amounts (50 g) of test foods and a reference food (glucose), on separate occasions. Capillary blood glucose was measured from finger-prick samples in fasted subjects ( - 5 and 0 min) and at 15, 30, 45, 60, 90 and 120 min after starting to eat. For each test food, the incremental area under the curve (IAUC) and GI values were determined. Although the glycaemic response to the reference food was higher in Asian Indian subjects compared with UK Caucasian subjects (IAUC 219 mmol/min per litre v. 157 mmol/min per litre, respectively; P < 0.01), there was no significant difference in GI values of the five test foods between the two groups. This is the first study known to the authors to examine the role of ethnicity on GI when the subjects are resident in their own countries. The findings from this study have important implications for the use of the GI concept worldwide and support the application of international values to different ethnic groups. The higher glycaemic response to all foods in Asian Indians may represent another mechanism for increased diabetes susceptibility among Asian Indians.

Dietary variety and its effect on food intake of elderly adults

BACKGROUND

Older people frequently have poor food intake. This present study investigated the effect of dietary variety on food intake in younger and older people.

METHODS

Eighteen young adults (mean age = 26 years) and 18 older adults (mean age = 70 years) consumed four consecutive courses of sandwiches on two occasions. In the plain treatment, each course of sandwiches was of the same type, while in the variety treatment four courses, each of a different type of sandwich, were served. Each time the participants were presented with a serving of sandwiches and asked to eat as much as they liked.

RESULTS

In the plain condition, the older adult group consumed more than their young counterparts. This situation was reversed for the variety condition when the young group ate more than the older adults. Interestingly, the older adult group ate more when a variety of sandwiches was presented. This may be contrary to what is predicted by the sensory-specific satiety model of eating behaviour.

CONCLUSIONS

This study suggests that presenting the older people with a varied meal may be a valid strategy to improve food intake in this group.

The Oxford Brookes basal metabolic rate database – a reanalysis

Objective

To produce prediction equations for basal metabolic rate (BMR) derived from weight and height covering the age range from birth to old age.

Design

Cross-sectional data on BMR, sex, age, weight, height, ethnicity and measurement technique from the Oxford Brookes BMR database.

Setting

Worldwide.

Subjects

Data for 13 910 men, women and children from 174 papers published between 1914 and 2001.

Results

Absolute and proportional regression models were developed for each sex, showing a steep rise in predicted BMR with age until 15 years, more pronounced in males than females, then a gradual fall through adulthood. Predicted BMR increased by 6% and 1.4%, respectively, per standard deviation increase in weight and height. Predicted BMR in Caucasians was 4% higher than in non-Caucasians, though the effect size was sensitive to the inclusion or exclusion of data from certain influential publications. The effect of measurement technique on BMR, closed-circuit versus open-circuit, was small, near 1%.

Conclusions

It is possible to develop prediction equations that avoid splitting the data into arbitrary age groups. Heterogeneity between publications is greater than might be expected by chance, probably due to undocumented differences in technique.

Basal metabolic rate studies in humans: measurement and development of new equations

OBJECTIVE

To facilitate the Food and Agriculture Organization/World Health Organization/United Nations University Joint (FAO/WHO/UNU) Expert Consultation on Energy and Protein Requirements which met in Rome in 1981, Schofield et al. reviewed the literature and produced predictive equations for both sexes for the following ages: 0-3, 3-10, 10-18, 18-30, 30-60 and >60 years. These formed the basis for the equations used in 1985 FAO/WHO/UNU document, Energy and Protein Requirements. While Schofield's analysis has served a significant role in re-establishing the importance of using basal metabolic rate (BMR) to predict human energy requirements, recent workers have subsequently queried the universal validity and application of these equations. A survey of the most recent studies (1980-2000) in BMR suggests that in most cases the current FAO/WHO/UNU predictive equations overestimate BMR in many communities. The FAO/WHO/UNU equations to predict BMR were developed using a database that contained a disproportionate number--3388 out of 7173 (47%)--of Italian subjects. The Schofield database contained relatively few subjects from the tropical region. The objective here is to review the historical development in the measurement and application of BMR and to critically review the Schofield et al. BMR database presenting a series of new equations to predict BMR.

DESIGN

This division, while arbitrary, will enable readers who wish to omit the historical review of BMR to concentrate on the evolution of the new BMR equations.

SETTING

BMR data collected from published and measured values.

SUBJECTS

A series of new equations (Oxford equations) have been developed using a data set of 10,552 BMR values that (1) excluded all the Italian subjects and (2) included a much larger number (4018) of people from the tropics.

RESULTS

In general, the Oxford equations tend to produce lower BMR values than the current FAO/WHO/UNU equations in 18-30 and 30-60 year old males and in all females over 18 years of age.

CONCLUSIONS

This is an opportune moment to re-examine the role and place of BMR measurements in estimating total energy requirements today. The Oxford equations' future use and application will surely depend on their ability to predict more accurately the BMR in contemporary populations.

The impact of the addition of toppings/fillings on the glycaemic response to commonly consumed carbohydrate foods

OBJECTIVE

To investigate the influence of the addition of various toppings/fillings on the glycaemic response to baked potato, pasta and toast.

DESIGN

Randomised, repeated measures design.

SETTING

Oxford, UK.

SUBJECTS

Forty normal, healthy subjects (11 males and 29 females) were recruited to the study. Subjects were staff and students from Oxford Brookes University.

INTERVENTION

Cheddar cheese, chilli con carne, baked beans and tuna were added to baked potatoes, cooked pasta and toast to determine the effect on glycaemic response.

RESULTS

No significant difference was found among the various toppings and baked potato (P=0.06), pasta (P=0.06) and toast (P=0.39). However, the addition of toppings to a carbohydrate-rich food had a consistent lowering effect on glycaemic index (GI). In particular, the addition of cheddar cheese to potato, pasta and toast reduced the GI of the test meal to a value that is considered to be low-GI (39, 27 and 35, respectively). This is particularly notable for potatoes, which, when eaten alone, had the highest GI value of all the staples.

CONCLUSIONS

This study has shown that the addition of foodstuffs to the staples baked potato, pasta and toast had a consistent lowering effect on the GI value of that meal. These findings emphasise the importance of investigating the GI of composite meals.

Does eating environment have an effect on food intake in the elderly?

Identical meals were prepared and served to 49 elderly subjects (mean age 74.3 +/- SD 7.7 years) in two different eating environments. The improved environment was a state of the art training restaurant and the standard environment was a staff canteen. Each subject was served an identical meal in both environments. The energy intake of each meal consumed was determined using the weighed intake method. There was a significant difference (p < 0.001) in the energy intake in the elderly between the improved (4894 +/- 613 kJ) and standard (4536 +/- 620 kJ) eating environments. Eating environment has a positive effect on the energy intake of elderly subjects. Changes to eating environment may be a useful way to improve energy intake in the elderly.

The potential impact of soil ingestion on human mineral nutrition

Geophagia, the intentional and repeated ingestion of soil material, is a complex eating behaviour with incomprehensible aetiology. It is generally assumed that geophagia may help supplement mineral nutrients and thus should not be dissuaded, particularly in subsistence communities. This is largely based on the assumption that a large proportion of mineral nutrients in geophagic materials is potentially available for absorption in the body. We tested this hypothesis on five soils collected from geophagia-prevalent communities by using an in vitro soil ingestion simulation test that is broadly similar to the gastrointestinal (GI) tract. The results show that, despite the soils being rich in mineral nutrients, soil ingestion, inadvertent or through geophagia can potentially reduce the absorption of already bioavailable nutrients, particularly micronutrients such as Fe, Cu and Zn. These in vitro findings, while disagreeing with the commonly held view of geophagia as a source of nutrient supplementation, are consistent with micronutrient deficiency problems observed in clinical nutrition studies conducted amongst geophagic populations. The work also showed that, in some cases, the ingested soils may become a source of Ca, Mg and Mn, although it is not clear why other similar soils should not release any of these mineral nutrients.

Effect of age and disease on taste perception

Abnormalities in taste function may contribute to poor dietary intake in the elderly, and in patients with renal failure or cancer. This study examined the effect of age on taste thresholds, and taste thresholds adjusted for age, in patients with renal failure with and without dialysis, and patients with cancer receiving chemotherapy and/or radiotherapy. Three groups of healthy volunteers aged 21-34 (n=26), 36-61 (n=13), and 69-94 (n=24), were recruited for the study on the effect of age. Nineteen patients with chronic renal failure on chronic ambulatory peritoneal dialysis (CAPD) and 11 age-matched chronic renal failure patients not yet requiring dialysis were recruited to examine the effect of chronic renal failure on taste function. Twenty-four inpatients with various types of cancer were recruited from a clinical oncology ward. Taste threshold was measured using commercial flavors supplied by Firmenich (pork, beef) and the ascending forced-choice method. Results showed that taste threshold increased with age. No abnormality in taste threshold was observed in patients with chronic renal failure with and without dialysis, and in patients with cancer. However, altered taste occurred in a large number of these patients. Abnormal taste function is present in healthy elderly people, and in patients with chronic renal failure and cancer. The nature of the abnormality differs among these groups, consisting of elevation of taste threshold in the elderly, and dysgeusia in those with disease.

Sexual dimorphism in fat patterning in a sample of 5 to 7-year-old children in Oxford

It is now well recognised that, in addition to total body fat, fat distribution is a major risk factor for cardiovascular disease and insulin resistance/diabetes in both adults and children. Traditionally, sexual dimorphism in fat patterning has been regarded as occurring at puberty. The aim of this study was to investigate gender differences in fat patterning in a group of children in Oxford. Anthropometric data was collected for 95 girls and 93 boys aged 5-7 years. Body mass index, percentage body fat and fat patterning indices were calculated using skinfold thickness measurements. While girls at this age had significantly larger percentage body fat and skinfolds, the fat patterning indices showed no differences between genders and no indication of greater truncal adiposity. The boys had a larger mean waist-hip ratio (0.96+/-0.04) compared with the girls (0.93+/-0.04) (P<0.001). The larger ratio in boys was the outcome of the smaller hip circumference in the boys reflecting less gluteal adiposity. This suggests that even at this young age there is clear evidence of sexual dimorphism in fat patterning, with girls showing greater subcutaneous adiposity mainly contributed by gluteal fat. The present study confirms the findings of American and European workers that sexual dimorphism of fat patterning in children is present at 5-7 years of age. Second, that these differences in fat patterning can be detected using simple anthropometric measurements such as hip circumference and skinfold thicknesses. The significance and importance of hip circumference measurements in predicting health outcome is an area that merits further investigation.

Evaluation of a pilot school programme aimed at the prevention of obesity in children

This paper describes the development, implementation and evaluation of a school- and family-based intervention to prevent obesity in children aged 5-7 years. In addition, the efficacy of three different intervention programmes was compared. Children aged 5-7 years (n=213) were recruited from three primary schools in Oxford and randomly allocated to a control group or one of three intervention groups: nutrition group, physical activity group, and combined nutrition and physical activity group. The setting for the interventions was lunchtime clubs, where an interactive and age-appropriate nutrition and/or physical activity curriculum was delivered. The intervention lasted for 20 weeks over four school terms (approximately 14 months). Children's growth, nutrition knowledge, diet and physical activity were assessed at baseline and at the end of the intervention. Significant improvements in nutrition knowledge were seen in all children (p<0.01) between baseline and post-intervention, and results were highly significant in the nutrition and combined group (p<0.001). Overall, fruit and vegetable intake increased significantly (p<0.01 and <0.05, respectively), with changes seen in fruit consumption in the nutrition group (p<0.05) and the control group (p<0.05) in particular. No significant changes in the rates of overweight and obesity were seen as a result of the intervention. Gender differences were not detected in the majority of assessments and there was no clear effect of programme type per se. This pilot study has demonstrated that school may be a suitable setting for the promotion of healthy lifestyles in children, but requires replication in other social settings. Future initiatives should be long-lasting, multi-faceted and sustainable, involving all children in a school, and should target the whole environment and be behaviourally focused. The ultimate goal of any such programme is to lead to positive behaviour change which will have a beneficial effect on long-term health. Successful targeting of the family remains a challenge to such interventions.

New predictive equations for estimation of basal metabolic rates of adolescents: tropics versus temperate

The energy and nutritional requirements of adolescents are influenced primarily by the growth spurt that occurs at puberty, and also by the need to maintain adequate levels of physical activity. Predictions of BMR have gained attention since the publication of the FAO/WHO/UNU (1985) expert consultation report, which adopted the principle of relying on energy expenditure rather than energy intake to derive requirement of individuals. While the report predicts BMR accurately in many individuals from temperate climate, they are said to be less accurate in predicting BMR in populations living in the tropics. The collation of worldwide data on basal metabolism indicated that, relative to adults, there was a paucity of data in other age groups including the adolescents. Although several BMR studies among children had been reported in the 90's, the data in normal weight children are almost exclusively from small control groups in obesity studies. Furthermore, we know little as to whether BMR of children differs in differing climatic conditions. This paper presents predictive equations for estimating BMR from a two-centre study, Bangi (Malaysia) and Oxford (UK) and to compare the results with the currently used predictive equations.

Nutritional losses and gains during processing: future problems and issues

Developments in food technology and nutrition today are shaping our food supply in an unprecedented way. They have not only helped produce a variety of foods with varying taste and texture but also optimally retain the nutritional quality of food. Increased use of novel ingredients in the future manufacture of foods is likely to reduce the amount of micronutrients available in our diet. To combat this, food fortification may be more widely used. Collaboration between food technologists and nutritionists is imperative if we are to see the continued manufacture of wholesome food.

Intraindividual variation in the basal metabolic rate of women: Effect of the menstrual cycle

The validity of using the basal metabolic rate (BMR) to calculate an individual's energy requirements is based upon the assumption that the intraindividual variation in BMR is small. Early studies (pre-1940) on BMR in women had shown that the menstrual cycle may have a profound effect, contributing to high levels of intraindividual variation. To investigate this issue further, and to explore whether BMR is indeed a biological constant in women, sequential measurements of BMR were made in women over one menstrual cycle. Two independent studies were undertaken in which the BMR of 12 weight-stable women (not taking the contraceptive pill) was measured every day (excluding weekends) for a period of 5 weeks. The six women participating in the first study were measured using a Douglas bag, while the six subjects in the second study were measured with a Deltatrac (Datex, Helsinki). Nine of the 12 subjects demonstrated a peak in BMR during the late luteal phase of the menstrual cycle, while 8 of the 12 subjects exhibited a fall in BMR after the onset of menstruation. Group analysis of the results indicated that the BMR during the early follicular phase was significantly lower than the BMR during the late luteal phase (Wilcoxon's signed rank test: P < 0.01). The level of intraindividual variation was assessed by calculating the coefficient of variation (CV) for the measurement period. The CV in six of the women exhibited a level of variation comparable to men (2-4%). However, intraindividual variation in the BMR of the other six women was considerably higher (up to 12%). In these six women, therefore, BMR may not be considered a biological constant. All available data on sequential measurements of BMR in fertile women were collated from the literature for the first time, and statistically analyzed. BMR during the early follicular phase was found to be significantly lower (P < 0.05) than during the late luteal phase. Further work on the biological constancy of BMR in women and the impact of the menstrual cycle on BMR is required. This area is of particular importance given the fact that the energy requirements of both individuals and populations are now calculated using the BMR. © 1996 Wiley-Liss, Inc.