J. Burema

Calcium does not protect against colorectal neoplasia

&NA; Calcium could decrease risk of colorectal neoplasia by binding bowel‐irritating compounds and diminishing mucosal proliferation. This study quantitatively summarizes epidemiologic studies addressing this hypothesis and aims to explain heterogeneity between studies. Twenty‐four articles reported 43 measures of relative risks (RRs). The weighted mean, according to a random effects model, did not indicate substantial protection by calcium [RR = 0.89; 95% confidence interval (CI) = 0.79‐1.01]. Results from different studies showed substantial heterogeneity, with the “true” underlying RRs ranging from about 0.50 to 1.60. Summary RRs for cohort and case‐control studies were 0.90 and 0.88, respectively. For adenomas and carcinomas, RRs were 1.13 (95% CI = 0.91‐1.39) and 0.86 (95% CI = 0.74‐0.98), respectively, both falling within the range of betweenstudy heterogeneity. With respect to subsites, lower RRs were observed for estimates that included proximal colon as one of the subsites (RR = 0.67), whereas the RR was close to 1.0 for distal (RR = 0.97) and rectal subsites (RR = 0.99). Stratification on study characteristics and weighted regression analysis yielded RRs slightly below 1.0, with considerable heterogeneity. These results do not support the hypothesis that calcium prevents colorectal neoplasia. (Epidemiology 1996;7:590‐597)

Body fatness, relative weight and frame size in young adults

1. Body-weight, body height, knee width, wrist width and skinfold measurements were made on males (n 139) and females (n 167) in three age-groups (20-22, 25-27 and 30-32 years). Percentage of body fat was calculated from skinfold thicknesses using regression equations according to Durnin & Womersley (1974). Three indices of relative weight were calculated: W/H2, W/Hp and W/W, where W is body-weight, H is body height, p is the exponent that made the index of relative weight independent of height and W is the weight estimated from body height and frame size. 2. The standard error of the estimate of body-weight was only reduced by 5% in males and by 13% in females when, in addition to body height, knee width was taken into account. The addition of wrist width did not improve the accuracy of estimation of body-weight in either sex. Therefore in further analyses W was estimated from body height and knee width. In the present population the exponent p was 1.7 in males and 1.6 in females. 3. The correlations between the percentage of body fat and the indices, W/H2, W/Hp, and W/W, were all very similar, being approximately 0.8 in both sexes. 4. A positive relationship was observed between percentage of body fat and knee width in females, which may be explained by an artifact of measurement. 5. In conclusion it can be stated that the accuracy of estimation of percentage of body fat was not improved when the index of relative weight was adjusted for knee width or wrist width in the present population. The W/H2 was the most preferable of the three indices which were calculated.

Reproducibility of a semiquantitative food frequency questionnaire to assess the intake of fats and cholesterol in The Netherlands.

The reproducibility of a 104 item semiquantitative food frequency questionnaire to estimate the intake of energy, fat, fatty acids and cholesterol was assessed in a group of 93 men and women in the Netherlands. The questionnaire was administered by trained interviewers. Subjects were asked to recall the consumption of 104 items during the past month. A second interview was conducted 8 weeks later. The mean difference in nutrient intake between the two assessments was very small, with a maximum of 5% for cholesterol intake, but the variance of individual differences was considerable. Pearson correlation coefficients between two assessments 8 weeks apart ranged from 0.71 for polyunsaturated fatty acids intake (when expressed as percentage of energy intake) up to 0.91 for energy intake. The reproducibility was found to be similar in males and females. Reproducibility was assessed for separate food items as well as for 20 food groups. Items consumed were often highly reproducible and rarely had a poor reproducibility. This food frequency questionnaire is considered to be a suitable tool to estimate and monitor the intake of fat, fatty acids and cholesterol in the Netherlands.

Efficacy of iron fortification compared to iron supplementation among Vietnamese schoolchildren.

The effect of iron fortification is generally assumed to be less than iron supplementation; however, the magnitude of difference in effects is not known. The present study aims to compare the efficacy of these two strategies on anaemia and iron status. After screening on low Hb, 425 anaemic children in six primary schools in Tam Nong district of Phu Tho province were included in a randomized, placebo-controlled trial comparing two groups receiving iron fortified instant noodles or iron supplementation for 6 months and a control group, with children in all groups having been dewormed. Blood samples were collected before and after intervention for haemoglobin, serum ferritin (SF), serum transferrin receptor (TfR), C-reactive protein (CRP), and haemoglobinopathies analysis. Regression analysis was used to assess the effect of iron fortification and iron supplementation on haemoglobin concentration, SF, TfR, body iron, and anaemic status as outcome variables. The improvement of haemoglobin, SF, and body iron level in the group receiving iron fortification was 42% (2.6 g/L versus 6.2 g/L), 20% (23.5 μg/L versus 117.3 μg/L), and 31.3% (1.4 mg/kg versus 4.4 mg/kg) of that in the iron supplementation group. The prevalence of anaemia dropped to 15.1% in the control group, with an additional reduction of anaemia of 8.5% in the iron supplementation group. The additional reduction due to iron fortification was 5.4%, which amounts to well over 50% of the impact of supplementation. In conclusion, the efficacy of iron fortification based on reduction of prevalence of anaemia, and on the change in haemoglobin level, is about half of the maximum impact of supplementation in case of optimal compliance. Thus, in a population of anaemic children with mild iron deficiency, iron fortification should be the preferred strategy to combat anaemia.

The effect of iron fortification and de-worming on anaemia and iron status of Vietnamese schoolchildren

Previous data from Vietnam show that anaemia is highly prevalent among schoolchildren, who are considered not to be iron deficient. Trichuris infection doubled the risk of anaemia. The present study aimed to evaluate the hypothesis that de-worming is more effective than iron fortification in an anaemic, infection-prone population. In a trial with a 2 x 2 factorial design, 425 anaemic children aged 6-8 years were randomly assigned to receive either iron-fortified noodles or placebo, and mebendazole or placebo. Outcomes considered were change in haematological indicators of iron status (Hb, serum ferritin (SF), serum transferrin receptor (TfR) and haemoglobinopathies analysis); inflammations (C-reactive protein (CRP)); parasite infection status (hookworm, Trichuris and Ascaris infection); and IgE. ANOVA and logistic regression were used to assess the effects of iron fortification and de-worming on Hb, SF, TfR, body iron and anaemia. Hb improved in all groups after 6 months of intervention. Iron fortification significantly improved Hb, SF and body iron (2.6 g/l, 16.3 microg/l and 1 mg/kg, respectively). Prevalence of elevated IgE was very high at baseline (99%) and significantly reduced to about 75% in all groups after intervention. De-worming unexpectedly showed no effect on Hb, iron status and IgE level. It is concluded that iron fortification slightly improved anaemia and iron status in anaemic schoolchildren in rural Vietnam that were not considered iron deficient. Chronic infection or other unidentified factors may play an important role in the seasonal reduction of anaemia seen in all treatment groups.

Family Resemblance in Beliefs, Attitudes and Intentions Towards Consumption of 20 Foods; a Study Among Three Generations of Women☆☆☆

Family resemblance in beliefs, attitudes and intentions towards the consumption of 20 foods that contribute to the fat intake was investigated in 97 adult women, their mothers and their grandmothers. Mean correlation for elements from the Fishbein and Ajzen theory of reasoned action between younger and middle generations ranged from 0.09 to 0.17 and between middle and older generations from 0.12 to 0.17. All significant correlations were positive. More statistically significant correlations were found for liking attitudes between the younger and middle generations (p < 0.05 for ten out of 20 correlations) than for other pairs. Between the older and younger generation the number of significant correlations could be due to chance alone. From the relative importance of liking and good/bad attitude on intention it appeared that liking contributed the most to the variance in intention scores. Health related beliefs and attitudes became of increasing importance in the older generations. From this study it can be concluded that mothers and their adult daughters resemble each other in beliefs, food preferences, attitudes and intentions, although resemblance is poor.

Energy balance and health in SENECA participants

In 1988 a European Community project, SENECA (Survey in Europe on Nutrition and the Elderly, a Concerted Action), started with nineteen research groups in twelve countries to work on the major nutritional issues affecting the growing number of elderly people. About 2600 subjects aged 70-75 years old were studied, according to a strictly standardized methodology. The study has a mixed longitudinal design with an intermediate contact carried out in 1991 and a follow-up study conducted in 1993 in nine centres. An important indicator of the nutritional status is a change in the energy balance leading to either overweight or underweight. Overweight is associated with increased abdominal fat deposition (Shimokata, 1989; Den Tonkelaar et al. 1990) and has been implicated in the development of cardiovascular risk factors, including diabetes mellitus, hypertension, hypercholesterolaemia, and left ventricular hypertrophy in the young as well as older persons (Harris et al. 1993). Underweight is associated with decreased immune response and the development of decubitus ulcers, in addition to increased hip fractures and mortality (Morley & Kraenzle, 1994). Results of the SENECA baseline study showed that obesity, defined as BMI 230 kg/m2, was prevalent in at least 20% of men in eight centres and women in twelve centres. Underweight, defined as a BMI lower than 20 kg/m2, occurred less frequently, but in four centres the prevalence amongst men was higher than 10% (De Groot et al. 1991). In order to get a better insight into predictors of changes in the energy balance, the present paper describes the relationship between BMI (kg/m2) and, more specifically, underweight on the one hand and health, nutrition and life-style factors on the other hand.

Household fuel use and food consumption: Relationship and seasonal effects in central Malawi

The present study analysed the relationship between household fuel use on one hand and food preparation and consumption on the other. Data were collected in the rainy season, a period of relatively low food availability, and in the post‐harvest season, a period of sufficient food availability. In both seasons, a high fuel use was associated with a high energy intake. In the rainy season, this association was determined chiefly by food availability whereas in the post‐harvest season fuelwood availability was a determinant of food intake as the correlations became stronger with decreasing fuelwood availability. In both seasons, households with a high fuel use showed a high energy intake from cooked foods made of cereals. Only in the post‐harvest season was a high fuel use also related to a high energy intake from other food groups, especially beans. In the rainy season, vegetable intake was increased with an increase in fuel use, but this did not affect energy intake due to the low calorie content of vegeta...

Dietary methodology: implications of errors in the measurement

The assessment of food consumption of individuals and groups is extremely important for the science of nutrition. In the past decades several methods have been developed with various characteristics (Table 1) and adapted to serve widely different purposes of nutritional research. Although it is generally accepted that all methods have limitations and advantages, there are doubts about, for instance, the reliability of interview methods. To examine the validity of data obtained by such methods it is important to consider questions such as those phrased by Beaton, 1990 (presented at IUNS Conference Seoul, 1989): What does the estimated intake really represent? What is the nature and magnitude of the error in that estimate? What is the implication of the error for interpretation of analyses? To answer these and similar questions, methods should be validated. The criteria for the validation procedure partly depend on the purpose of the study in which the method will be used.

Affective and cognitive determinants of intention to consume twenty foods that contribute to fat intake

Fishbein and Ajzens theory of reasoned action was used as a framework to study beliefs and attitudes towards twenty foods that contribute to fat intake in a Netherlands sample population. Subjects between 18 and 75 years of age (n = 419, response rate 23%) filled out a self‐administered questionnaire. Subjects were Dutch, city‐dwellers and from low‐income areas. Due to the low response rate this sample must be considered as a convenience sample. The percentage of variance explained ranged from 35% for cheese to 69% for smoked beef. Attitudes were more important predictors of intention to consume foods than subjective norms were. Additional path analyses on behavioral beliefs and attitudes showed that the liking attitude was a more important predictor of intention than the good/bad attitude. Behavioral beliefs about tastiness of the food had a strong effect on intention to consume, that is, the sum of path‐coefficients ranged from 0.32 for margarine to 0.71 for semiskimmed milk; the effect of the belief good/bad for figure was considerably lower (0.00–0.32); and the belief about prevention of heart disease had little effect (‐0.00–0.12) on intention to consume the foods. This suggests that short‐term rewards (taste) are more important than medium‐term rewards (figure) and long term (heart disease).