The high-fat Greek diet: a recipe for all?

OBJECTIVE: To examine critically the published results of dietary surveys on the fat content of the Greek diet, and to assess its evolution and its relationship to the health of the Greeks. To consider the implications of these findings for current views on the nature and health implications of the traditional Mediterranean diet and how best to define it for use in modern policy making. DESIGN: A systematic review of the literature on food consumption in Greece. SETTING: Greece. RESULTS: The first fully published data on the fat content of the Greek diet-the Seven Countries Survey-relates only to a small number of adult males in Crete and Corfu; the legitimacy of extrapolating these results to the rest of Greece is questioned. Earlier studies and chemical validation of intakes point to a lower fat content of the traditional diet than that inferred for Crete. Nearly all later surveys relate only to urban groups in Athens (mostly case-control hospital-based samples) and a variety of non-representative Cretan groups. Only two studies are larger and more representative, but one uses FAO food balance-sheets to reflect the national diet, and the other surveyed school-age children in three out of the 52 Greek counties. Unfortunately recent dietary studies have proved unreliable, given the continuing lack of national food composition tables with survey methods which proved inaccurate for dietary fat content. A progressive upward trend in total and saturated fat intake appears to have occurred with all health indicators in relation to fat indicating remarkable increases in adult and childhood obesity with attendant progressive deterioration in cardiovascular mortality and its risk factors, ie hypertension and diabetes. These data emphasise the need to alter current nutritional advice in Greece, particularly when it focuses on the promotion of olive oil and a high-fat diet. CONCLUSIONS: The findings reaffirm low-moderate fat policies for optimum health, within which olive oil can be an important component of the diet.

Seasonal aspects of weight-for-age in young children in Zimbabwe.

OBJECTIVE: To identify the season with the highest prevalence of underweight among young children and to examine geographical variation in seasonality of underweight. DESIGN: This analysis is based on monthly data from a clinic-based growth monitoring programme that forms part of the National Health Information System. A regression-based technique is used to identify seasonal patterns in both underweight prevalence and attendance nationally and in 60 different districts. SETTING: The analysis covers the period 1988-1995 and is based in Zimbabwe. SUBJECTS: The analysis is based on weight-for-age measurements of Zimbabwean children less than 5 years old, who attended health centres as part of a growth monitoring programme. RESULTS: Nationally, a small but significant increase in levels of underweight takes place during January-March. Participation in growth monitoring also varies seasonally and could account for the increase observed. No evidence of seasonal variation in underweight prevalence is found in the majority of districts studied, although 11 of the districts showed a similar pattern to the national data set. This peak in the incidence of poor nutritional status also coincides with the period of food scarcity before harvest, which is also associated with higher prevalence of diarrhoea and malaria. No differences in seasonality of under-nutrition were found between districts with predominantly subsistence agriculture and those with more commercial forms of agriculture. CONCLUSIONS: Seasonal variation in child weight-for-age exists in some parts of Zimbabwe, but its effects on cross-sectional prevalence studies are likely to be small. There are no readily discernible differences between areas that show evidence of seasonality in levels of underweight and those that do not.

High-performance liquid chromatography with coulometric electrode array detector for the determination of quercetin levels in cells of the immune system.

There is mounting evidence emphasizing the importance of intracellular antioxidant levels for maintenance of the immune function. The flavonoid quercetin, a natural antioxidant, has been shown to modulate enzymes involved in the regulation of the inflammatory response. However, up to now, there have been no studies describing quercetin levels in cells of the immune system. A gradient reversed-phase HPLC technique to identify and quantify intracellular levels of quercetin and its application in mice splenocytes are described. Mobile phases were a 0.01 M sodium phosphate monobasic solution adjusted to pH 2.8 with 85% orthophosphoric acid (buffer, Solvent A) and methanol (Solvent B) with a flow rate of 1 ml/min. An eight-channel coulometric electrode array detector was used. In vitro supplementation with increasing concentration of quercetin (25, 50, and 100 microM) raises intracellular quercetin levels in a dose-dependent manner. The method has the required features of specificity and sensitivity for monitoring quercetin uptake in cells of the immune system.

Basal metabolic rate in anorexia nervosa: relation to body composition and leptin concentrations.

BACKGROUND: Leptin is thought to represent a peripheral signal involved in the regulation of energy balance. Its action has been studied in animals and obese subjects. Little is known about leptin's role during negative energy balance. OBJECTIVE: The objective was to evaluate the relation between energy turnover, body composition, and plasma leptin concentrations in anorexia nervosa (AN). DESIGN: Sixteen weight-stable women with AN were compared with 22 control subjects and 14 rehabilitated AN patients (R-AN). Basal metabolic rate (BMR) was measured by indirect calorimetry; fat-free mass (FFM) and fat mass (FM) were calculated according to a 4-compartment model. Plasma leptin was determined by radioimmunoassay. RESULTS: The BMR of AN patients (2.73 +/- 0.37 kJ/min) was significantly lower than that of control subjects (3.45 +/- 0.34 kJ/min) (P < 0.001), even after adjustment for FFM (2.92 +/- 0.33 kJ/min in AN patients and 3.30 +/- 0.26 kJ/min in control subjects; P < 0.004). Plasma leptin concentrations in AN patients were 76% lower than in control subjects, even after body fat was controlled for. In R-AN patients, BMR was not significantly different from that of control subjects and leptin concentrations were generally close to normal. Plasma leptin concentrations correlated significantly with FM (r(2) = 0.53, P < 0.0000) and BMR, even after adjustment for FFM (r(2) = 0.21, P < 0.0003). CONCLUSIONS: BMR and plasma leptin concentrations are depressed in patients with AN; this is not explained by body-composition changes. The relation between leptin and BMR suggests that leptin plays a role in the energy sparing response to exposure to chronic energy deficiency. The return of BMR to normal and the significant increase in leptin concentrations in R-AN patients suggests a full reversibility of this adaptation mechanism.

The potential use of maternal size in priority setting when combating childhood malnutrition.

OBJECTIVE: To devise a strategy for assessing the nutritional status of a household and specifying the major needs in combating childhood wasting, distinguishing between inadequate food availability, poor parental care and/or the need for improved public health measures. DESIGN: An evaluation of the relationship between children's wasting, stunting, or underweight and mothers' or adult women's body mass indexes (BMIs) in the same household. A household was designated as 'malnourished' on the basis of a single child's weight/height of < -2.0 s.d. or at risk of being malnourished if the Z-score was below--1.5. Adult women's BMI was taken to signify adequate household food availability. Sibling concordance of anthropometric measures was investigated. RESULTS: A wide variety of prevalence of severe (BMI < 16.0), moderate (BMI 16.0-16.9) and marginal (17.0-18.4) malnutrition existed in the various study areas. The worst condition was recorded in India, while 18% of the women in Zimbabwe were classified as obese. Similarly wide variation in the prevalence of child wasting and stunting was observed, with the Indian children again faring worst and those in Zimbabwe the best. The within-household analysis of concordance gave higher concordance for height than for weight between siblings. Mothers' BMI was highly correlated with the BMI of all other adult women in the same household and the BMI of all the women was found to be as useful as that of the mother for relating to children's anthropometry. Households with mothers of normal body weight but wasted children were designated as in need of public health measures and improved parental care rather than of enhanced food security. The distribution of households on this combined basis of maternal BMI and child nutritional status highlighted very diverse situations in the various study areas, with higher proportions of combined maternal and child malnutrition in India and in some areas of Ethiopia, while in Zimbabwe only 1-2% presented this condition. On this basis, the principal problem in India was food security; in Zimbabwe household security was rarely apparent, so public health measures and maternal care were designated as problems. In three Ethiopian communities there was a mixture of needs. CONCLUSIONS: A relatively simple household-based approach is proposed to discriminate the most pressing needs in combating childhood malnutrition, and a policy-making tool is suggested for setting priorities in community action.

Body composition changes in anorexia nervosa.

OBJECTIVE: To assess the body composition changes in anorexia nervosa and after medium term recovery. DESIGN: A descriptive study. SETTING: Rome, Italy. SUBJECTS: Twenty women affected by anorexia nervosa (AN) with a BMI [weight (kg)/height (m2)] below 17 kg/m2 and weight-stable for at least three months, were compared with 10 well nourished control women (CO) and nine rehabilitated subjects (R-AN), who had a BMI above 18.5 kg/m2 stable for at least the last six months. INTERVENTIONS: Body fat was assessed by underwater weighing, muscle mass by urinary creatinine, total body water (TBW) by impedance parameters (50 kHz and 800 microA), skeletal mass by anthropometry and radius bone mineral density by dual photon absorptiometry in ultra-distal (UD-BMD) and medio-distal (MD-BMD) sites. RESULTS: The AN group, as compared to the control group, had a significantly lower weight, body mass index (BMI kg/m2) and percent body fat (P < 0.0000). Creatinine urinary excretion was lowest in absolute term and when expressed as creatinine height index or per kg fat free mass (FFM) (P < 0.0000); muscle mass per kg body weight was 13% lower (P < 0.01). Ultra distal bone mineral density (UD-BMD) was 6% lower (not significant). TBW as percent of body weight was significant higher (P < 0.001): however TBW/FFM % was not statistically different with large inter-individual variability. An altered distribution of extra and intra-cellular water was suggested by the phase angle (AN: 4.4+/-0.8 degrees; CO: 6.1+/-0.4 degrees; (P < 0.0000). In rehabilitated anorexic patients (R-AN) the fat mass represented 53% of the weight gain. Their creatinine excretion remained still below the mean value of the controls (P < 0.001). The impedance parameters were not significantly different between the R-AN and the CO groups, however, the phase angle of the R-AN (5.0+/-0.7 degrees) remained lower than in the CO group, indicating that the water distribution was still altered. CONCLUSIONS: This study shows that AN is a condition of reduced body fat as well as of muscle mass, with a slightly reduced bone mass. In the course of rehabilitation, most of the weight regained is represented by fat, while the muscle mass appears to lag behind, at least in the medium term.

The basal metabolic rate and energy cost of standardised walking of short and tall men.

OBJECTIVES: To assess the influence of stature on the basal metabolic rate (BMR) and on the energy cost of standardised walking. A second objective was assess the accuracy of the FAO/UNU/WHO (1985) equations to predict BMR. DESIGN/SUBJECTS: Forty-six young men were selected on the basis of their stature and assigned to the group of short, S (n = 25, mean stature = 1.65 +/- 0.03 m) or of tall, T (n = 21, mean stature = 1.87 +/- 0.04 m). SETTING: Rome, Italy. INTERVENTIONS: Body composition was assessed by underwater weighing. BMR and energy cost walking at 5 km/h was measured by the Douglas bag. RESULTS: Body fat % was similar in the two groups (15.2 +/- 4.3 for S; 17.4 +/- 5.3 for T; ns). The BMR of T was 20% higher than that of S, but 12% and 10% lower when standardised respectively for body weight (BW) and fat free mass (FFM). However these differences were removed when BMR was covaried for BW or FFM, or normalised by BW0.62 or FFM0.64. Measured BMR was 7% for T and 6% for S lower than that predicted by the FAO/WHO/UNU (1985) equation; the inclusion of stature did not reduce the overestimation. The energy cost of walking was 27% higher in T than in S, but 9% and 5% lower when standardised respectively for BW and FFM. The differences disappeared when expressing the energy cost of walking as net cost per kg FFM. CONCLUSIONS: Tall people have lower BMR per unit of BW or FFM than short people, and it is necessary to control for the diverse body mass by the appropriate method. However, qualitative differences in the composition of FFM are plausible, due to the diverse proportion of metabolically active internal organs in people of different height, which might be reflected in the higher BMR/kg FFM of the shorter subjects. The sex- and age-specific FAO/WHO/UNU (1985) equation significantly overestimates the BMR of both short and tall people, but there is no simple explanation of this observation. The energy cost of walking is not affected by stature when expressed as net cost per kg FFM.

Alcohol-free red wine enhances plasma antioxidant capacity in humans.

Moderate wine consumption is reputed to exert a protective effect against coronary heart disease (CHD). The nature of the protective compounds is unclear and the mechanisms are incompletely understood. We studied whether the nonalcoholic component of wine increases plasma antioxidant capacity measured as total radical-trapping antioxidant parameter (TRAP), and whether such an effect is associated with the presence of phenolic compounds in plasma. The TRAP and plasma levels of phenolic compounds were measured in 10 healthy subjects after the ingestion of 113 mL of tap water (control) and alcohol-free red and white wine at 1-wk intervals. Both alcohol-free wines possessed an in vitro dose-dependent peroxyl-radical activity, but red wine, with a polyphenol concentration of 363 +/- 48.0 mg/L quercetin equivalent (QE), was 20 times more active (40.0 +/- 0.1 mmol/L) than white wine (1.9 +/- 0.1 mmol/L), which has a polyphenol concentration of 31 +/- 1 mg QE/L. The ingestion of alcohol-free red wine caused significant increases in plasma TRAP values and polyphenol concentrations 50 min after ingestion. Alcohol-free white wine and water had no effects on either of the plasma values. The parallel and prompt increase of antioxidant status and of circulating levels of polyphenols in fasting subjects after bolus ingestion of a moderate amount of alcohol-free red wine suggests that polyphenols are absorbed in the upper gastrointestinal tract and might be directly involved in the in vivo antioxidant defenses.

Validation of expedient methods for measuring body composition in Indian adults.

The body composition of 99 men and 89 women from south India was estimated using hydrodensitometry, bioelectrical impedance and skinfold thickness. Comparisons of the hydrodensitometry (reference method) and skinfold methods showed that there were no significant differences between the methods, for estimates of fat free mass (FFM) and per cent fat. The mean difference between the estimates FFM (bias), from skinfold measurement and hydrodensitometry was small for both groups (+0.16 +/- 1.09 kg in men and +0.67 +/- 0.9 kg in women). The same trend was observed in per cent fat estimates (-0.37 +/- 2.04 in men and -1.49 +/- 2.28 in women), showing that the skinfold method can be used as an accurate and expedient method to determine body composition. The bioelectrical impedance method obtained a significantly lower FFM and higher body fat than the reference (hydrodensitometry) method. This could have been due to the use of an inappropriate equation derived from Western population studies. Hence, a new predictive equation, for the measurement of FFM by the bioelectrical impedance method was derived for this population, using the variables of height2/impedance and FFM measured by underwater weighing. The new equation for the bioelectrical impedance method then gave values of body composition which compared well (0.26 +/- 2.32 kg) in men and (0.36 +/- 2.49 kg) in women with the hydrodensitometry method.

Plasma (carotenoids, retinol, alpha-tocopherol) and tissue (carotenoids) levels after supplementation with beta-carotene in subjects with precancerous and cancerous lesions of sigmoid colon.

OBJECTIVES: (1) To compare tissue and plasma carotenoids status of healthy subjects and subjects with pre-cancer and cancer lesions; (2) to evaluate the effect of beta-carotene supplementation on the concentrations of other carotenoids in tissue (luteine + zeaxanthin, cryptoxanthin, lycopene, alpha-carotene) and in plasma and also retinol and alpha-tocopherol levels. DESIGN: Eighteen subjects were divided into three groups on the basis of colonoscopy and histological analytical findings: four healthy subjects (control group A); seven subjects affected by adenomatous polyps (group B with pre-cancer lesions); seven subjects suffering from colonic cancer (group C). Blood and colonic biopsy samples were taken (of colon and rectal mucosa) before and after beta-carotene supplementation in all subjects. Groups A and B received a daily dose of beta-carotene (30 mg/die) for 43 d. Group C's supplementation was terminated at the time which was performed, usually within 15 d. The tissue and plasma concentration of carotenoids, retinol and alpha-tocopherol were determined by high-performance liquid chromatography. RESULTS: The tissue concentrations of each carotenoid were similar in all the intestinal sites examined as regards groups A and B, although there was a high degree of intra individual variability within each group. Only beta-carotene made significant increases (P < 0.001) after supplementation. The subjects with cancer show tissue levels for each carotenoid lower than those of healthy subjects or subjects with polypous. The plasma levels of alpha-tocopherol did not change after supplementation while significant increases were noted of retinol, alpha-carotene (P < 0.01) and of beta-carotene (P < 0.001). CONCLUSIONS: The patients with colonic cancer seemed to undergo a significant reduction in their antioxidant reserves with respect to the normal subjects and or polyps. We can confirm that oral B-carotene supplementation induces also an increase in plasma alpha-carotene in all groups.

Basal metabolism of weight-stable chronically undernourished men and women: lack of metabolic adaptation and ethnic differences.

The purpose of this study was to investigate whether weight-stable chronically energy-deficient subjects exhibit evidence of metabolic adaptation and to establish whether international predictive equations overestimate the basal metabolic rate (BMR) of tropical populations. BMR, body weight, height, and fat-free mass (FFM) by underwater weighing were measured in healthy, physically active urban dwellers of low socioeconomic status (178 men and women aged 22-38 y) in Bangalore, Southern India. Subjects were selected on the basis of body mass index (BMI; in kg/m2) and classified in three groups: severely undernourished (BMI < 17.0; n = 30 men, n = 25 women), marginally undernourished (BMI = 17.0-18.5; n = 31 men, n = 30 women), and well nourished (BMI > 18.5; n = 27 men, n = 35 women). The BMR of the well-nourished group, expressed in absolute terms (6.20 and 5.18 MJ/d for men and women, respectively), was significantly higher (P < 0.000) than that of the severely undernourished group (5.72 and 4.64 MJ/d for men and women, respectively). Normalizing BMR for either body weight or FFM by analysis of covariance abolished all differences. The mean BMR of the low-BMI study group was substantially higher (11-14%) than reported previously for undernourished Indian adults. The BMR of both men and women, regardless of their nutritional status, was accurately estimated by age- and sex-specific FAO/WHO/UNU equations. These findings suggest the absence of an enhanced metabolic response in weight-stable chronically undernourished adults. This is in contrast with earlier reports, and supports more recent views. The study also provides evidence of the absence of ethnic-specific energy turnover in Indians.

Prediction of total body water in Indian men from anthropometry and bioelectrical impedance using deuterium dilution as reference.

Total body water (TBW) obtained by deuterium dilution (TBWD) in 45 adult Indian males of low body mass index was compared with values obtained from bioelectrical impedance (TBWImp) and two anthropometry-based prediction equations. Bioelectrical impedance significantly underestimated TBW when compared with deuterium dilution, by 2.75 SD 2.86 kg. Comparisons of the anthropometry-based prediction equations demonstrated that TBW was overestimated by 0.87 SD 2.49 kg, and 2.47 SD 2.57 kg, respectively. Since all parameters in the bioelectrical impedance method were standardized, the difference in the values could have been because of the equation used. Therefore, a fresh equation for the measurement of TBW by the bioelectrical impedance method was derived using the variables of height2/impedance and weight. New prediction equations for TBW were also derived based on anthropometric variables of weight and height. Body weight has the greatest influence in the prediction equations for TBW, and the equation derived was TBW (kg) = 0.533 x body weight (kg) + 3.77, SEE = 2.4 kg. Using height2/impedance gave the relationship: TBW (kg) = 0.568 body weight-0.04 height2/impedance + 4.35, SEE = 1.9 kg.

A new look at dietary carbohydrate: chemistry, physiology and health. Paris Carbohydrate Group.

The current view of dietary carbohydrates as simply providing us with energy is outdated. Because of their varied chemistry and physical form the rate and extent to which the different types are digested in and absorbed from the small intestine varies. This in turn leads to affects on satiety, blood glucose and insulin, protein glycosylation, lipids and bile acids. Some carbohydrates reach the colon where they are fermented and affect many aspects of large bowel function, colonocyte and hepatic metabolism. A new framework for classifying and measuring food carbohydrates is needed to allow a greater understanding of the role of individual species in health and to inform the public of their importance. A classification based primarily on molecular size (degree of polymerisation) into sugars, oligosaccharides and polysaccharides, is suggested, with sub-groups identified by the nature of the monosaccharides. Greater knowledge of the chemical and physical properties of carbohydrates allow a more precise relation with physiology and health to be drawn. The Carbohydrate Group met in Paris in December 1995 at the invitation of Gerard Pascal, Director of CNERNA. Financial support for the meeting was provided by CNERNA.

Body composition by a three compartment model in adult Indian male and female subjects.

The body composition of 10 adult Indian male and female subjects was investigated by a three compartment model, using measurements of Total Body Water (TBW) by deuterium dilution, and of body density by hydrodensitometry. The three compartment model yielded significantly different (P < 0.005) estimates of percent body fat of 15.9+/-3.8 and 19.7+/-4.2% and of the Fat Free Mass (FFM) of 41+/-3.3 kg and 33.9+/-4.1 kg in the male and female subjects respectively. The hydration of the FFM was 0.704+/-0.032 in the males and 0.719+/-0.024 in the females; this difference was not signifcant between groups. The density of the FFM, measured from estimates of percent body fat by the 3 compartment approach and of body density by hydrodensitometry, was 1.107+/-0.014 in the males and 1.101+/-0.001 in the females with no significant differences between the groups. This study demonstrates differences in body composition between BMI matched healthy adult male and female subjects. Although there are significant differences for % Fat and FFM between the sexes, there are no significant differences in the hydration fraction and the density of the FFM.

Application of a new high-performance liquid chromatographic method for measuring selected polyphenols in human plasma.

We developed a method to measure plasma levels of selected polyphenols before and after ingestion of green tea. Blood samples were obtained from four healthy women before and 30 and 50 min after the ingestion of 300 ml of green tea infusion. A 1-ml volume of plasma was hydrolysed with 0.5 M HCl-methanol (1:1, v/v) for 30 min at room temperature, extracted with ethyl acetate and separated by reversed-phase chromatography. Polyphenols were identified on the basis of their retention times and by spectrum analysis. Green tea caffeine has the same retention times as caffeic acid. Consumption of green tea produces a notable increase in the plasma levels of caffeine plus caffeic acid and the appearance of measurable levels of epigallocatechingallate. In conclusion, the method was found to have the requisite features of specificity and sensitivity for monitoring plasma levels of selected tea polyphenols.

Total body water measurements by deuterium dilution in adult Indian males and females.

Total Body Water (TBW) was measured in a group of 20 healthy adult Indian men and 10 women by the deuterated water dilution technique and their body composition was determined by applying a hydration factor of 0.7194 for fat free mass (FFM). The TBW in the male subjects whose mean body weight was 49.8 +/- 6.7 kg, was 60.6 +/- 3.2% of body weight (range 55.8%-65.4%), from which a FFM of 41.9 +/- 6.1 kg (range 31.8 kg-51.3 kg) was obtained. Total body water in the group of 10 female subjects whose mean body weight was 42.7 +/- 4.9 kg, was 57.0 +/- 4.5% of body weight (range 52.5%-64.2%) from which a FFM of 34.0 +/- 5.1 kg (range 28.4 kg-39.4 kg) was obtained.