Risk assessment of nutrients: There must be a threshold for their effects

Nutrients serve physiological functions in a dose-dependent manner and that needs to be recognized in risk assessment. An example of the consequences of not properly considering this can be seen in a recent assessment by the European Food Safety Authority (EFSA). EFSA concluded in 2022 that the intake of added and free sugars should be "as low as possible in the context of a nutritionally adequate diet". That conclusion of EFSA is based on the effects on two surrogate endpoints for an adverse effect found in randomized controlled trials with high sugars intake levels: fasting glucose and fasting triglycerides. The lowest intake levels in these trials were around 10 energy% and at this intake level there were no adverse effects on the two outcomes. This indicates that the adverse effects of sugars have an observable threshold value for these two endpoints. The most appropriate interpretation from the vast amount of data is that currently no definitive conclusion can be drawn on the tolerable upper intake level for dietary sugars. Therefore, EFSA's own guidance would lead to the conclusion that the available data do not allow the setting of an upper limit for added sugars and hence, that more robust data are required to identify the threshold value for intake of sugars.

Analytical approaches to food-based dietary guidelines in the European setting

OBJECTIVE

To show the effects of statistical approaches of data analysis to be used in the development of Food-Based Dietary Guidelines (FBDG).

SETTING

Databases from dietary surveys in 6 European countries.

RESULTS

Quantile analysis based on iron intake among adult women resulted in differences among European countries regarding (macro) nutrient intake and consumption of food groups. However, in all countries women in the highest quartile had a higher intake of energy and dietary fibre and a higher intake of most food groups. In developing FBDG adjustment of energy intake is recommended. Discriminant analyses showed that among Dutch women potatoes, red meat, sausages, offal, savoury snacks, eggs and total vegetables were found to be the most predictive for differences in iron intake. Relatively high correlations were observed for iron and dietary fibre and iron and (some) B-vitamins. Examples from cluster and factor analysis showed that this type of analysis considers the complexity of the dietary pattern and could also be a helpful instrument in the development of FBDG.

CONCLUSIONS

The use of a nutrient distribution can be used as a minimum approach in developing FBDG. More advanced methods can also be used in addition to set priorities for FBDG and to analyse complete dietary patterns.

Nutrition and health among migrants in The Netherlands

OBJECTIVE

this paper aims to give a broad overview of published data on nutrition and health among migrants in the Netherlands, as well as data on determinants of health.

RESULTS AND CONCLUSIONS

Depending on the definition, 9 to 17% of the population belongs to the group 'migrants' and this proportion is expected to grow in the coming years. Roughly 2/3 of migrants are of the first generation and on average, they are younger than the Dutch population. Relatively few data concerning the health status of migrants are available. The diet of migrants showed both positive (macronutrients) and negative (micronutrients) differences with the general Dutch diet. The risk of overweight was high among both children and adult women, and the data suggest a higher risk for Turkish and Moroccan groups than for Dutch groups. The importance of health determinants, such as smoking, alcohol use and physical and social environment, was different for migrants than for the Dutch population; however, there were also differences between ethnic groups. The limited data on morbidity for migrants suggest higher risks than for the indigenous population. The same holds for mortality data, especially for the younger age groups. In general, the data that are available suggest that the health status of migrants was less favourable than that of the indigenous population. However, there were also differences between the various groups of migrants. The lower socio-economic position of migrant groups partly explained the differences in health status. Nevertheless, a study among Turkish people indicated that their health status was lower than that of Dutch people of comparable socioeconomic status.

Dependence of dietary intake estimates on the time frame of assessment

Food chemical risk management needs, among other things, assessment of exposure. For dietary intake food consumption surveys are the data source to be used. One complicating factor in the usage of these data is the dependence of dietary intake estimates on the time frame of assessment. Central to this time dependence is the within-subject variation regarding the usage of food products and, as a consequence, the intake of chemicals. Within-subject variation is mostly as large as or larger than between-subject variation. Expressed per kilogram body weight, average (total) variation in intake variables depends on the age group, with variation usually being greater at younger age, most likely as a result of the higher intake levels at that age. Combination of age groups results in an increase in between-subject variation, and correction based on the figures for the total population will be too small. Ideally, exposure data for all days of one's life should be available to assess lifetime exposure. Since information on all these days is not an attainable and practical option, and not an option to strive for either, the most recent available data should be used that can be extended with simulation studies to anticipate future developments. The present food consumption surveys available in European countries are based on data that vary from 1 day (24-h recall and dietary record) to habitual intake (dietary history and food frequency). The data of a survey based on 1 day refer to 0.004% of an average lifetime of 70 years. Based on the demographic picture of the population, a reasonable approximation of lifetime intake can be obtained. The proportion of users and the consumption level among users depend on the time frame of assessment, especially for irregularly consumed products. Usage of the concept of "users only" overestimates lifetime exposure of the population, the extent of overestimation depending on the duration of the survey. The likelihood that all consumers have been exposed to a chemical once during a lifetime period is realistic in the sense of the best approximation of reality. As a result of this assumption all exposure assessments will have a similar point of departure and the dependence of the results on the food consumption method will be reduced.

Food-based dietary guidelines: some assumptions tested for The Netherlands

Recently, the concept of food-based dietary guidelines has been introduced by WHO and FAO. For this concept, several assumptions were necessary. The validity and potential consequences of some of these assumptions are discussed in this paper on the basis of the Dutch National Food Consumption Surveys. The topics were interrelationships among dietary characteristics, nutrient density, diets in accordance with the guidelines, and food variety. To obtain insight into overall diet quality, a dietary quality index based on nutrients and a food-based quality index based on food groups were created and tested. As expected the results showed that a higher dietary quality index was associated with an improved intake of the nutrients included in the index, in particular a lower intake of total fat and cholesterol. This was related to a lower consumption of cheese, fats and oils, meat and meat products, and a higher consumption of fruit and vegetables. The information obtained with a dietary quality index can be used to assess the feasibility of a particular goal in combination with other relevant goals and to obtain clues or confirmation for recommendations regarding food consumption. The food-based quality index created showed that a combination of several food-based goals (formulated in quantitative terms) was associated with an increase in food consumption, without a clear relevance for the dietary quality. Therefore, the formulation of food-based guidelines should be based on explicitly stated dietary goals. The findings regarding nutrient density were in the direction of what was assumed, namely a positive association between density and absolute intake, although the expected effects were not completely found. The results regarding the association between variety and dietary intake were characterized mainly by differences in quantity rather than dietary quality. The data indicate that energy intake may be an important pitfall in implementing food-based dietary guidelines, that 'eat a variety of food' can be an empty slogan and that nutrient density is positively related to the absolute intake of specific micronutrients. Further, the 'absence' of interrelationships among risk nutrients indicates that a selection process has to be applied.

Patterns of food and nutrient intakes of Dutch adults according to intakes of total fat, saturated fatty acids, dietary fibre, and of fruit and vegetables

Dietary intake characteristics were studied among 3833 adults of the second Dutch National Food Consumption Survey held in 1992. The subjects were classified into three groups based on their intake of total fat (% energy), saturated fatty acids (% energy), dietary fibre (g/MJ), and fruit and vegetables (g/d). All the classifications resulted in differences in energy intake. Except for dietary fibre, the mean energy intake was higher in the higher-intake tertiles. For the classification based on total fat, saturated fatty acids and dietary fibre the more prudent diets were accompanied with a lower energy-intake. As to the consumption of food groups, differences existed in both the proportion of consumers and in the mean consumption among users. It is concluded that the trends observed are probably more important than the actual figures.

Fat Watch: a nationwide campaign in The Netherlands to reduce fat intake--process evaluations

Fat Watch was a four-year campaign carried out in cooperation with retailers and industry, aiming at a reduction of fat consumption by 10% among the Dutch population. Mass media and supermarkets were the main conveyers of the message. Supermarkets participated well in the first (53%) and in the third year (51%), but to a lesser extent in the second year (36%). Campaign awareness in the target group (household shoppers for food) was relatively high in the first year (60%), but dropped in the next two years (40% and 32%, respectively). Combined with prominent mass media messages and with promotional activities of food products by suppliers, supermarkets seem a good channel for dissemination of nutrition information. Fat Watch has proved that cooperation of governmental, industrial and retail organizations for several years with respect to nutrition education activities is possible in the Netherlands.

Fat Watch: a nationwide campaign in The Netherlands to reduce fat intake--effect evaluation

In the Netherlands, the nationwide Fat Watch campaign aiming at a reduction in fat consumption was organized from 1991 onwards. This study describes the effects of the first three consecutive campaign years on attention to fat, diet and health, attitudes, self-efficacy expectations and intentions related to dietary fat reduction, and self-rated fat intake. Data were collected each year according to the Solomon design, by telephone interviews among about 1200 consumers responsible for household purchases. Campaign awareness was high in each campaign year, but a decrease in campaign awareness was found after the first campaign in 1991. The 1991 campaign was primarily aimed at getting the attention of the Dutch public for the fat-reduction message and indeed resulted in increased attention. The second campaign year resulted in small but statistically significant positive changes in attitudes, which was the specific target of the 1992 campaign. Intention to buy low-fat food products was also significantly increased. The 1993 campaign failed to realize the targeted increases in self-efficacy among the study population, but a significant campaign effect on intentions was found. The evaluation of all three campaigns indicated that the Dutch underestimate their personal fat intake and this has been identified as an important barrier to a further reduction in fat consumption. Making subjects aware of their personal fat consumption will be given priority in future campaigns.

Dietary and other determinants of vitamin B6 parameters

OBJECTIVE

To assess the dietary, physical, biochemical and lifestyle determinants of vitamin B6 status parameters among healthy adults.

DESIGN AND SUBJECTS

Dietary intake and status variables as well as other relevant characteristics were determined among 444 adults, aged 20-79 y and stratified for sex and 10-years age classes with a randomly selected control group (n = 300) and an over representation of persons with a low habitual vitamin B6 intake (n = 144).

RESULTS AND CONCLUSIONS

The direct status parameters (plasma pyridoxal-5'-phosphate (PLP), plasma pyridoxal + PLP (PL + PLP), and 4-pyridoxic acid (4-PA) excretion) were clearly related to dietary variables and plasma concentrations of vitamin C (women only), vitamin B12 and folate. The total percentage of variance in p-PLP explained in multivariate regression analysis was 41 and 30% in men and women, respectively. The most important explaining variables besides vitamin B6 intakes were variables closely related to PLP-metabolism: albumin and alkaline phosphatase. Biochemical function related status parameters showed less statistically significant correlations with dietary variables. Four to 24% of the variance in the stimulation coefficients of erythrocyte aspartate aminotransferase (alpha-EAST) and erythrocyte alanine aminotransferase (alpha-EALT) and change in homocysteine excretion after a methionin load was explained by a combination of dietary, physiological and lifestyle related variables. The low percentages explained for some variables, notably alpha-EAST (women) and the change in homocysteine excretion after a methionin load (men), suggests that these parameters are not sensitive to the level of vitamin B6 intake as found in the present study. Alcohol contributed in many of the explaining models for vitamin B6 status parameters. Therefore, when assessing the vitamin B6 status of a population, it is important to estimate the level of alcohol intake as well. Furthermore, the results illustrate the importance of sex related differences in the metabolism of some parameters, especially homocysteine excretion. The variance in the clinical function related status parameter measured in the present study, handgripstrength, was explained for 50% by a combination of age, body weight and Quetelet Index (QI) with no important contribution of dietary variables.

The study population: general characteristics and potential confounding factors

OBJECTIVE

To test the representativity of the study population and to identify potential selection bias.

DESIGN

Non-response analysis and comparison with other representative samples from the Dutch population. Description of physical and clinical biochemical variables as well as health and lifestyle characteristics among low vitamin B6 groups and reference groups.

RESULTS AND CONCLUSIONS

The non-response rate for the food frequency questionnaire was 54%; subsequently, non-response for the detail study was 42%. A greater proportion of respondents to the FFQ and of participants in the reference group of the study followed a special dietary regimen or a therapeutic diet or used dietary supplements compared with non-respondents, indicating that we may have selected a somewhat more health conscious reference group. There were no differences in vitamin B6 intake (absolute or per g protein) between participants and the total group of non-respondents for the detail study. Selection of a low B6 group did not result in important bias regarding physical, biochemical or general health and lifestyle characteristics. Exceptions were a difference in the proportion of dieters (younger women) and supplement users (older women) and a difference in creatinine clearance and supplement use between reference and low B6 groups. The differences found, however, were small. Nonetheless, these factors have to be taken into account when analysing and interpreting the results.

Dietary intake among adults with special reference to vitamin B6

OBJECTIVE

To assess the adequacy of the dietary intake in general, and that of vitamin B6 intake especially.

DESIGN AND SUBJECTS

Dietary intake based on 3 d diet-records was assessed among a random sample of the adult Dutch population (the reference group, n = 300) aged 20-79 y, stratified for age and gender and among a group with a low vitamin B6 intake, selected by means of a food frequency questionnaire.

RESULTS

Among the reference group, absolute vitamin B6 intake on average amply met the RDA in all age-gender categories, whereas the adequate level of 20 microg vitamin B6 per gram protein, was on average met by men only. The prevalences of a vitamin B6 intake below the minimum requirement (absolute) of 1 mg/d was 1-11% and below the average minimum requirement of 15 microg/g protein was 5-12% for the various age-sex reference groups. Average intake of folate among women of childbearing age did not meet the recommendation of 400 microg/d for those who want to become pregnant. Average intake of iron and iodine was also below recommended levels among women aged 20-49 y. Both absolute vitamin B6 intake and the vitamin B6/protein ratio calculated with the diet records was lower among the low vitamin B6 groups than among the reference groups, indicating that the preselection of groups with low vitamin B6 intakes on the basis of a food frequency questionnaire was successful. Intake of energy and macro- and micronutrients, as well as a nutrient density of the diet were lower among low vitamin B6 groups than among reference groups.

CONCLUSIONS

It is concluded that a low vitamin B6 intake is the result of both the quantity (energy) and quality (nutrient density) of the food consumed. The effects of this are not restricted to vitamin B6 and therefore, the low vitamin B6 groups have a combination of relatively low intakes.

Iron intake and iron status among adults in the Netherlands

OBJECTIVE

To assess the adequacy of iron intake and status, the prevalence of marginal iron status, the physiological and lifestyle factors influencing iron status and the role of dietary factors affecting the bioavailability of iron among Dutch adults.

DESIGN

Food consumption was measured with 3 d diet records. Iron status and prevalence of iron deficiency and iron accumulation were evaluated using different criteria. Physical, biochemical and lifestyle characteristics were determined and relationships with iron status were evaluated by bi- and multivariate regression analysis.

SUBJECTS

A sample of 444 adults, aged 20-79 y stratified for sex and 10 y age classes, with an overrepresentation of people with a low habitual intake of vitamin B6.

RESULTS

Average iron intake was higher than the recommended daily allowance for the Netherlands in all sex-age groups except women aged 20-49, in which group average iron intake was 23% below the recommendation. Early iron deficiency, as reflected in low ferritin levels, was not found among men aged 20-49, but was observed in 5% of women aged 50-79, 11% of men aged 50-79, and 16% of women aged 20-49. Iron deficiency anaemia as reflected in low haemoglobin levels was found in 0-5% of the age-sex groups. Among men and women, 16% and 13% of variance in haemoglobin level, respectively, could be explained by physiological and dietary factors. For ferritin, the proportions were 36% and 34%, respectively. Iron status was correlated negatively with the vegetable fraction of the diet, and positively with factors from the animal fraction (haem iron, animal protein, meat). Further, haemoglobin was positively correlated with body weight among men, and with both age and use of oral contraceptives among women. Both among men and women, blood donorship in the six months prior to the study was negatively associated with serum ferritin levels.

CONCLUSIONS

Women aged 20-49 are the adult sex-age group with the greatest risk of developing (an early stage of) iron depletion. The most important dietary factors influencing the iron status are the type of iron (haem/non-haem) and factors affecting the bioavailability of iron.

Food consumption methods. Development, reproducibility and validation of a food frequency questionnaire for vitamin B6

OBJECTIVE

The correct classification of adults with a habitual low vitamin B6 intake by means of a food frequency questionnaire (FFQ). Assessment of reproducibility of the food frequency questionnaire and of the relative validity as compared to 3 d diet records (DR).

DESIGN

A self-administered food frequency questionnaire (FFQ) to measure habitual vitamin B6 intake was developed using the data base of the first Dutch National Food Consumption Survey 1987/88 (DNFCS). The frequency and quantity of consumption of 92 (combinations of) food products, contributing to about 95% of vitamin B6 intake, were asked for. Recent food consumption was measured with 3 d diet records. Reproducibility of the FFQ was assessed after 10 months (n = 330).

SUBJECTS

Randomly selected men and women aged 20-79 y, stratified for 10 y age classes and sex.

RESULTS

A total number of 2867 FFQs was adequately completed (response rate 46%). A low vitamin B6 group was selected from the lowest tertile of age-gender specific vitamin B6 intake (36 men and 36 women, aged 20-49 and 36 men and 36 women, aged 50-79) and a so-called reference group (n = 300) was selected at random. The ratio of vitamin B6 intake according to FFQ and DR (FFQ/DR) varied between 0.77 and 0.99 for the various age-gender-study groups; for vitamin B6/g protein the FFQ/DR ratio varied between 1.00 and 1.10. After correction for intraindividual variance Pearson correlation coefficients between vitamin B6 intake according to FFQ and DR varied between 0.27 and 0.95 for the various age-gender-study groups, for vitamin B6/g protein the corrected Pearson correlation coefficients varied between 0.27 and 0.65. Of the subjects selected in the low B6 groups, 61-81% fell in the lowest tertile of vitamin B6 intake according to diet records and 3-6% fell in the extreme opposite tertile. The percentage subjects selected in the same/opposite quartile of vitamin B6 intake according to FFQ and DR was 50/11 for men, and 45/18 for women. Pearson correlation coefficients for vitamin B6 intake according to the first and the second FFQ were 0.64 and 0.72 for men and women, respectively; for vitamin B6/g protein these values were 0.70 and 0.51 for men and women, respectively. The proportion of subjects classified in the same/extreme opposite tertile of vitamin B6 intake was 56/6 and 62/5 for men and women, respectively.

CONCLUSIONS

It is concluded that the FFQ was adequate for the selection of subjects with a habitually low vitamin B6 intake.

Iodine intake and urinary excretion among adults in the Netherlands

OBJECTIVE

To assess the prevalence of low and marginal iodine intake and urinary iodine excretion among adults in the Netherlands and to investigate determinants of urinary iodine excretion.

DESIGN AND SUBJECTS

The study population consisted of 444 people aged 20-79 y, balanced for sex and 10 y age classes with an over-representation of people with a low habitual intake of vitamin B6. Food consumption was measured by three day food records and 24 h urine was sampled twice.

RESULTS AND CONCLUSIONS

On average, iodine intake (mean of three days) in men was in the recommended range of 150-300 microg/d, but average intake in women was not. Mean 24 h urinary excretion values confirmed this observation. Estimation of the prevalence of low iodine excretion depended on the parameter chosen (absolute per 24 h, per kg body weight per 24 h, as concentration or per creatinin). The prevalence of low iodine supply, based on intake <100 microg/d (mean of three days) and intake or excretion parameters per creatinin excretion or per kg body weight, varied from 4-14% among adult women and from 5-17% among adult men. The prevalence of marginal iodine intake (<50 microg/d) and excretion was less than 5% in all adult age-sex groups. Urinary iodine excretion was most strongly associated with intake of iodine as such or as bread in combination with urinary excretion of sodium or potassium, confirming the importance of iodized salt (in bread) for iodine status. Age and total energy intake had a relatively minor impact on urinary iodine excretion.

Rationale, design and methods of a study on micronutrient status among adults

OBJECTIVE

To describe the rationale, design and methods for a nutrition surveillance study with special reference to vitamin B6 and other micronutrients.

RATIONALE AND DESIGN

Several studies in the Netherlands have shown that differences in dietary intake and in nutritional status indicators are relatively small among various socio-demographic groups, so that the relevance of this traditional risk group identification in terms of public health and nutrition policy is limited. Therefore, it was decided to use the diet itself as primary selection criterion for a study on the adequacy of the vitamin B6 supply. The first Dutch national food consumption survey in 1987/88 showed, among other things, that mean vitamin B6 intake (per gram of protein) was substantially below the adequate level for all age-gender groups studied. Since the potential impact on public health of this observation may be relatively large, intake of vitamin B6 was chosen as first selection criterion. A study design that creates the largest possible distinction in vitamin B6 intake would be most efficient to study the health risks as a consequence of a low vitamin B6 intake. Several arguments, such as the need to estimate the prevalence of an inadequate status of vitamin B6 and other micronutrients, led to the decision to use a random population sample as a reference group for comparison with the group with low habitual vitamin B6 intake. Other major arguments underlying the study design and the selection of the nutritional status indicators, as well as the framework of the Dutch Nutrition Surveillance System, are discussed. Finally, the design and methods of the study are described in detail (except food consumption methods).

An effective way to identify dietary risks among adults--general discussion and conclusions

OBJECTIVE

To identify dietary risks among adults in the Netherlands, with special reference to micronutrient intake, more specifically vitamin B6, folate, iron and iodine.

DESIGN AND SUBJECTS

Dietary intake, nutritional status and other physiological and lifestyle characteristics were measured among 444 adults, aged 20-79 y, stratified for 10 y age-classes and sex, with an overrepresentation of subjects with a habitual low intake of vitamin B6.

DISCUSSION AND CONCLUSION

A general discussion of the study design and possible selection bias. Identification of groups at risk and the possible impact of low intake of several micronutrients. A discussion of dietary and other determinants of micronutrient status parameters. The results of the present survey suggest that even at vitamin B6 intakes in the lower tertile of the intake range there is no great effect on biochemical functioning. However, blood vitamin levels may not be optimal with regard to cardiovascular risk among a non-negligible part of the population and a recommendation for an adequate vitamin intake seems warranted, despite the many uncertainties concerning the relationship between vitamin intake and cardiovascular risk. Furthermore, the results of the present survey stress the importance of adequate dietary advice for women of childbearing age.

Folate intake and status among adults in the Netherlands

OBJECTIVE

To assess the adequacy of folate intake and status among adults in the Netherlands.

DESIGN AND SUBJECTS

Dietary intake was measured by 3 d diet records among 444 adults, aged 20-79 y, stratified for sex and 10 y age classes, with an overrepresentation of people with a low habitual intake of vitamin B6. Serum folate and other physical, biochemical and lifestyle characteristics were determined, and interrelationships were evaluated by bi- and multivariate regression analysis.

RESULTS

Mean folate intake was 325 and 308 microg/d in men aged 20-49 and 50-79 y, respectively. In both younger and older women mean folate intake was 270 microg/d. The prevalence of intakes below the lower limit of the recommended range (200-300 microg/d) was 10-20% among different age-gender groups. No intakes below the average minimum requirement of 100 microg/d were observed. The recommendation of 400 microg folate/d for women who wish to become pregnant was not met by 95% of the women aged 20-49 y. Potatoes, vegetables and fruit provided 36% of folate in the diet; other important sources were bread (18%) and dairy products (16%). Mean serum folate levels were 11.3 and 12.1 nmol/l in younger and older men, respectively. In younger and older women these levels were 12.2 and 14.2 nmol/l, respectively. Serum folate levels below 5 nmol/l (the 2.5 percentile of healthy blood donors) were present in 4% of the older men, but not in the other age-gender-groups. Serum folate levels were clearly influenced by recent folate intake. Furthermore, physiological and lifestyle variables, notably alcohol and tobacco use, were important determinants of serum folate.

CONCLUSION

The folate intake among adult men and women was adequate in view of recommended daily intakes. However, the folate intake among women did not meet the recommendation for those who want to become pregnant. According to criteria derived from homocysteine metabolism as related to cardiovascular disease, folate status may not be adequate in 60-79% of adult age-sex groups.

Micronutrient status, with special reference to vitamin B6

OBJECTIVE

To assess the adequacy of micronutrient status among the adult population, with special reference to vitamin B6 status.

DESIGN AND SUBJECTS

Micronutrient status was assessed among a random sample of the adult Dutch population (reference group, n = 300), aged 20-79 y, stratified for age and gender, and among a group with a low vitamin B6 intake (n = 144).

RESULTS

Low vitamin B6 groups had lower mean levels of erythrocyte and plasma pyridoxal (PL) and pyridoxal-5'-phosphate (PLP), urinary excretion of 4-pyridoxic acid, basal and stimulated erythrocyte aspartate aminotransferase (EAST) and erythrocyte alanine aminotransferase (EALT) activities and EAST stimulation coefficients but not of EALT stimulation coefficients, handgripstrength and 24 h homocysteine excretion before and after a methionin load test. Besides, plasma levels of vitamin C, B12 and folate were lower among low B6 than among reference groups indicating a combined low vitamin status. Direct biomarkers of vitamin B6 intake (plasma PLP and 4-pyridoxic acid excretion) were significantly related to more functional parameters (EAST, EALT and alpha-EAST). Among random reference groups the prevalence of plasma PLP values below 19 nmol/l was 3-7% for different age-gender groups, with the highest value of 16% among men aged 50-79 years. The prevalence of high values of erythrocyte glutathion reductase stimulation coefficient (alpha-EGR) and low levels of serum vitamin B12 and C was not more than 5% among different age-gender reference groups.

CONCLUSIONS

Direct biomarkers of vitamin B6 intake confirmed the preselection of a group with a low vitamin B6 intake. The results suggest that the sensitivity of vitamin B6 status parameters for low vitamin B6 intake was highest for the direct vitamin B6 status parameters and lowest for handgripstrength and homocysteine excretion after a methionin load; results for enzyme stimulation coefficients were intermediate. The prevalence of below adequate status parameters for vitamin B2, B6, B12 and C was not more than 7% among the different age-gender groups, with the exception of a value of 16% for plasma PLP levels below 19 nmol/l among men aged 50-79.

Adequacy of the iodine supply in The Netherlands

OBJECTIVE

To assess the adequacy of the iodine supply in the Netherlands and to study possible ways of increasing the iodine intake. DESIGN, SETTINGS AND SUBJECTS: Goitre and nutrition surveillance studies (intake and urinary excretion of iodine) among population groups (age: 12-85 y, n=57-1704) in the Netherlands in the period 1981-1993. Simulation studies, based on the Dutch Nutrition Food Consumption Surveys (n=6000), calculating iodine intake among population groups after fictively iodizing different food groups.

RESULTS

Mean intake of iodine, measured with different food consumption methods in the period 1984-1993, met the recommended amount of 150-300 microg per day in males, but not in females. Median urinary iodine excretion levels were in the range for mild Iodine Deficiency Disorders in both sexes. According to dietary methods reflecting habitual intake and urinary iodine excretion per kg body weight or per mmol creatinin the prevalence of low iodine supply among adults is between 4 and 20% for women and between 5 and 15% for men. Iodization of different products would increase mean iodine intakes by up to 45% and would give a reduction of roughly 65% in the prevalence of low iodine intakes.

CONCLUSION

The present goitre prophylaxis in the Netherlands is not optimally effective. The iodine supply is below cut-off points in 4-20% of the adult population. It is possible to decrease the prevalence of low iodine intakes without a clear risk of exceeding the maximum acceptable daily iodine intake by increasing the iodine content of baker's salt and/or by adding iodine to other foods.

Results of a community-based campaign to reduce fat intake

In 1992, a community-based 'Fat Watch' campaign was held in the city of Alkmaar in the Netherlands. The campaign was implemented within the framework of the nationwide mass-mediated 'Fat Watch' campaign (1991-1994), which aimed at a 10% reduction in fat intake among the general Dutch population. The intervention was carried out as a pilot project to study the effectiveness of strategies and activities, and to apply them subsequently in more cities. The campaign aimed primarily at the active involvement of intermediaries. Effects of the campaign were studied by telephone questionnaires among about 500 respondents, before and after the campaign in both the experimental and a control community. The questionnaire was based on the 'attitude, social influence, self-efficacy' (ASE) model. The results showed that 56% of the respondents were aware of a campaign in their community and that the campaign was positively evaluated by those familiar with it. After the campaign, self-rated fat consumption was significantly higher. No differences between the experimental and control community were found regarding attitude, social influence or self-efficacy expectations towards a reduction in fat consumption or intention to buy low-fat food products. However, as opposed to the control community, there was a significant decrease in actual fat consumption between pre- and post-test in Alkmaar. Furthermore, after the campaign, significantly more respondents in the experimental community intended to eat lower-fat food products and reported a behavioral change in the last six months. It was concluded that the campaign was quite successful as far as campaign awareness was concerned, but that it did not result in substantial change of behavior. The limited decrease in fat consumption observed should be interpreted with care.

Vitamin B-6 malnutrition among elderly Europeans: the SENECA study

Inadequate vitamin B-6 status is common among elderly people. It is still unclear to what extent factors other than reduced vitamin B-6 intake are responsible for this. We studied the vitamin B-6 intake and status [measured as plasma pyridoxal 5'-phosphate (PLP)] in 546 elderly Europeans, aged 74-76 years, with no known vitamin B-6 supplement use. In addition, we examined interrelations and associations with other dietary and lifestyle factors, including indicators of physical health. Overall, 27% of the males and 42% of the females had dietary vitamin B-6 intakes below the mean minimum requirements (.015 mg/g protein and/or < 1.0 mg/day), and 22% of both males and females had low plasma PLP levels (< 20 nmol/L). Plasma PLP was positively associated with vitamin B-6 intake, alcohol intake, and serum albumin, and was weakly negatively associated with body mass index. Although the serum albumin levels fell within the normal range, these findings suggest that this transport protein is related with vitamin B-6 status of elderly people, either directly or as a result of underlying health problems. It is concluded that, based on the references for younger adults, the vitamin B-6 status of elderly people is marginal. Trials are needed to quantify functional and health consequences of improving the vitamin B-6 status of elderly people.

Dietary intake of food contaminants in The Netherlands (Dutch Nutrition Surveillance System)

To assess the level of exposure to food contaminants (cadmium, lead, PCBs, DDT, hexachlorobenzene, nitrate and malathion) a total-diet study was carried out. A total of 226 food products were analysed individually; the concentration of contaminants in products not selected for analysis was estimated with the help of published data. The results of the analyses and estimations were used as input for the first Dutch National Food Consumption Survey (1987-1988) (n = 5898, age 1-85). Mean intakes of all contaminants analysed did not exceed the acceptable daily intake (ADI) or comparable values in any of the age-sex groups. Comparison of the results with those of previous total diet studies suggests that the intake of all contaminants analysed had declined between 1976-1978 and 1988-1989. In younger age groups an intake of lead and cadmium exceeding the tolerable daily intake (derived from the WHO/FAO provisional tolerable weekly intake) was found in 1.5% of individuals at most. For the older population groups and for the other contaminants in all population groups mean and maximum intakes were substantially below the ADL. However, individual intakes above the ADI for nitrate were found in 3-23% of individuals. For chronic exposure these percentages are likely to be overestimated because of the short time frame for food consumption measurement. In general, the difference between mean intake and tolerable daily intake was smallest for children aged 1-4. Therefore, it is recommended that future research is concentrated on the intake of contaminants in younger age groups.

Possible use of food consumption surveys to estimate exposure to additives

Several methods can be and are being used to assess individual food consumption. Four types, namely 24-h recall, dietary records, food frequency and dietary history are discussed. For assessing the exposure to additives it is concluded that the dietary history method is probably the best choice since this method is oriented towards a quantification of habitual food consumption. Dietary records and 24-h recall can be used as long as their short-term nature is accounted for. High intake levels obtained by those methods are in a way a worst-case analysis, especially when the calculations are based on users only. Since children have, on average, a higher consumption per kg of body weight and acceptable daily intakes (ADIs) are based on body weight, this group must be of special importance in risk assessment regarding additives. However, a relatively high intake among (young) children is an age effect and ADIs refer to lifetime exposure. Both food consumption and additive use in food products are changing over time, so that existing databases are prone to becoming outdated relatively fast. At the end of this paper an overview is given of existing databanks in the EU in relation to the estimation of exposure to additives.

Serum vitamin D concentrations among elderly people in Europe

Vitamin D status decreases with age, mainly as a result of restricted sunlight exposure, reduced capacity of the skin to produce vitamin D, and reduced dietary vitamin D intake. We measured wintertime serum 25-hydroxyvitamin D [25(OH)D] concentrations in 824 elderly people from 11 European countries. 36% of men and 47% of women had 25(OH)D concentrations below 30 nmol/L. Users of vitamin D supplements and/or sunlamps had higher 25(OH)D (median 54 nmol/L) than non users (median 31 nmol/L). Surprisingly, lowest mean 25(OH)D concentrations were seen in southern European countries. Low 25(OH)D concentrations could largely be explained by attitudes towards sunlight exposure and factors of physical health status, after exclusion of users of vitamin D supplements or sunlamps. Problems with daily living activities and wearing clothes with long sleeves during periods of sunshine were strong predictors of low wintertime serum 25(OH)D concentrations. These findings show that free-living elderly Europeans, regardless of geographical location, are at substantial risk of inadequate vitamin D status during winter and that dietary enrichment or supplementation with vitamin D should be seriously considered during this season.

[Nutrition and nutritional status of female somatic nursing home patients]

OBJECTIVE

To determine if the intake of energy and particular nutrients is adequate among elderly non-demented nursing home patients, and to identify possible causes of a marginal status.

SETTING

A nursing home, neighbouring service flat and a group of independently living elderly in Zeist, the Netherlands.

DESIGN

Descriptive cross-sectional study.

METHOD

Data were collected about habitual food consumption, anthropometry and indicators of nutritional status from 51 female nursing home patients (response 65%), 29 elderly women living in service flats (response 56%) and 52 independently living elderly women. Comparisons were made among the groups, with the recommended dietary allowance and with cut off values.

RESULTS

The mean daily energy intake of 5.9 MJ (SD: 1.4) by the group of nursing home patients was lower than the recommended allowance (7.8 MJ). Mean values for the anthropometric measurements hardly varied among the groups. This suggested that the low energy intake was in accordance with the actual energy requirement. Especially among the nursing home women low blood levels were frequently seen of folic acid, pyridoxine, 25-hydroxy-vitamin D, vitamin C and selenium. A lower food consumption and unfavourable food choices were considered to be mainly responsible. Low mobility and pathological processes may also play a part.

CONCLUSION

Low blood levels among non-demented nursing home patients were caused by low food consumption, unfavourable food choices and probably by health status. Prevention may include: more physical activity (whenever possible), giving information to patient and nurse, supplying food with higher nutrient density, presenting more menu choices, reporting to physician or dietician when food offered is not eaten.

Calculated iodine intake before and after simulated iodization (Dutch Nutrition Surveillance System)

To estimate the effect of possible goitre prophylactic measures on the intake of iodine among population groups, simulation studies, based on the first Dutch National Food Consumption Survey, were carried out. Iodine intake figures and prevalence of low intakes were calculated after fictively iodizing either bread, a combination of industrial products, milk and dairy products (without cheese) or margarine and shortenings. In addition, the effect of iodizing both bread and cheese or bread + biscuits + rusks was calculated. The simulated iodization of different products increased mean calculated iodine intakes by up to 45% and gave a reduction of 60-90% in the prevalence of iodine intakes below 100 micrograms/day. The maximum acceptable intake of 1 mg iodine per day was never reached by any subject (average of 2 days). It is concluded that it is possible to increase substantially the mean iodine intake of the Dutch population and to decrease the prevalence of low iodine intakes without a clear risk of exceeding the maximum acceptable daily oral iodine intake.

Combinations of low thiamin, riboflavin, vitamin B6 and vitamin C intake among Dutch adults. (Dutch Nutrition Surveillance System)

OBJECTIVE

Clustering of low vitamin intake may entail a greater functional and/or health risk than the summation of separate low intakes may suggest. Therefore, the prevalence of combined low thiamin, riboflavin, vitamin B6 and vitamin C intake in various adult sex-age groups in The Netherlands was estimated.

METHODS

Nutritional risks were evaluated by comparing the calculated intakes with the recommendations for each vitamin. For this purpose the data of a subsample of 3353 adults of a nationwide food consumption survey were used, which had been collected in 1987-88 within the framework of the Dutch Nutrition Surveillance System. Food consumption data were obtained through 2-day dietary records. Respondents were segmented into tertiles based on their vitamin intake per 1000 kcal (4.2 MJ) to adjust for energy intake.

RESULTS

As compared with the RDAs, mean overall intake was lowest for vitamin B6. Based on tertile analyses, the risk for inadequate intake was relatively high for vitamin C, small for riboflavin and intermediate for thiamin and vitamin B6. Low vitamin densities clustered somewhat since the prevalence of combined low intakes for all four vitamins was higher than expected from probability calculations. This interdependence was mainly the result of a higher consumption of alcoholic beverages and of other food products with a low vitamin density.

CONCLUSION

In affluent societies nutritional risk assessment should not be based solely on single vitamins but should also be oriented at combined low intake levels.

Body composition, health status and urinary magnesium excretion among elderly people (Dutch Nutrition Surveillance System)

Magnesium (Mg) requirements depend on body weight. Recommended dietary allowances (RDA) are mostly given in absolute amounts and are mostly similar for adults, despite differences in body composition in the adult age range. We therefore studied the interrelations of 24 h urinary Mg excretion with body build and body composition indicators, as well as with factors potentially affecting the metabolism of Mg, among 520 elderly men and women seen in a nationwide survey. Mg intake data were also obtained in the Dutch Food Composition Survey amount 5898 subjects. The results showed lower mean Mg intake among elderly people (especially men) and positive associations of body weight and body height with urinary Mg excretion, but not when expressed per mmol of creatinine excreted. Mg excretion per mmol of creatinine was not associated with body weight, body height, body mass index or body fatness (women), suggesting that the amount of fat mass did not affect Mg excretion. Mg excretion was positively correlated with Mg intake, creatinine clearance, excretion of sodium, potassium and calcium, and coffee consumption, indicating interactions at the kidney level that may increase Mg losses. Elderly people using diuretics and/or anticholinergics and male diabetics had a higher mean Mg excretion per mmol of creatinine. The results show that, besides the Mg intake, several factors affect the urinary Mg excretion among elderly people. These factors were body build and body composition, dietary intake, drug use, kidney function, and diabetes. A quantification of the effects cannot be made yet, and controlled studies on those factors potentially affecting the requirement of Mg are needed.

Comparison of dietary intake data with guidelines: some potential pitfalls (Dutch nutrition surveillance System)

In evaluating dietary data with reference to guidelines for a healthy diet, some potential pitfalls (i.e., method of food consumption assessment and calculation to include or exclude energy derived from alcohol) were investigated. The percentage of energy intake (en%) derived from total fat, saturated fatty acids (SFA), mono- and disaccharides (MD) and intake of cholesterol and dietary fiber per megajoule were calculated using 2-day records obtained in the Dutch National Food Consumption Survey of 1987-1988. Subjects (aged 4-85, n = 5595) were classified into age-sex groups. Mean values and intake distributions were calculated with and without adjustment for within-person variation. Except for the intake of cholesterol and MD, mean intake levels were not in accord with guidelines. About 20% of the women and 23% of the men met the goal for fat intake, 20% of the men and 27% of the women for dietary fiber, and about 60 and 70% for MD and cholesterol. Only 3% of subjects had SFA intake < or = 10 en%, whereas < 1% had a diet in accord with all criteria studied. After adjustment for within-person variation, percentages meeting the guidelines were generally lower for fat, SFA and dietary fiber and slightly higher for cholesterol and MD. Among elderly, unadjusted results were more in agreement with the prevalence estimates based on habitual dietary intake data than with adjusted ones. Fat intake (en%) was inversely related with intake of added MD and alcohol. Our data indicate that guidelines should state explicitly whether energy-related recommendations include energy derived from alcohol, and that the prevalence of a high-fat intake is more affected by the calculation method than by food consumption assessment.

Vitamin C status in elderly women: a comparison between women living in a nursing home and women living independently

The vitamin C status in blood fractions in 135 elderly women aged 65 years and older was studied within the framework of the Dutch Nutrition Surveillance System. Mean (+/- standard deviation) vitamin C intake (mg/day) was lower among women living in a nursing home (54 +/- 27 mg/day) than among women living in service flats (97 +/- 55 mg/day) and women living independently (132 +/- 44 mg/day). (Service flats are apartments in which the rent includes housekeeping and, when ordered, meal service.) Marginal vitamin C values (< 23 mumol/L) in blood fractions and even levels as low as those found in clinical scurvy (< 11 mumol/L) were frequently observed. In the nursing home, 35% of the women had plasma vitamin C values below 11 mumol/L, and 23% had values between 11 and 23 mumol/L. Blood levels were not significantly affected by age, smoking status, or use of particular drugs but were strongly (r = .47 or, after logarithmic transformation, r = .64) associated with daily intake of vitamin C. Low intake of vitamin C resulted from an overall low food consumption and selective restriction of food products rich in vitamin C. Vitamin C losses caused by food preparation practices and distribution in the nursing home's catering system reduced actual vitamin C intake levels but these losses were not substantially greater than those that are assumed to occur as a result of preparation practices by women living independently.

Marginal nutritional status among institutionalized elderly women as compared to those living more independently (Dutch Nutrition Surveillance System)

The nutritional status (assessed by anthropometric indices, and biochemical and hematological variables in blood) of three groups of elderly women (aged > or = 65 years) was evaluated within the framework of the Dutch Nutrition Surveillance System. The groups were composed of women living in a nursing home (n = 51), women living in service flats and receiving their dinners from the nursing home kitchen (n = 29), and women living independently (n = 52). Mean blood levels of folate, pyridoxal 5'-phosphate, 25-hydroxyvitamin D, alpha-tocopherol, vitamin C, albumin, selenium and total cholesterol were significantly (p < 0.05) lower among nursing home women. Among these women a biochemical deficiency was frequently found for 25-hydroxyvitamin D (73%), pyridoxal 5'-phosphate (57%), vitamin C (38%), selenium (30%) and folate (28%). These nutritional risks were largely independent of each other. Since folate and pyridoxal 5'-phosphate were associated with several clinicochemical indicators, health status may be an important determining factor for this unfavorable situation. Low 25-hydroxyvitamin D concentrations were associated with limited exposure to ultraviolet radiation and nonusage of vitamin D supplements. We conclude that dietary intake variables are not the only determinants of a marginal nutritional status among nursing home women. Use of foods with a high nutrient density should be encouraged, whereas other preventive measures are needed to improve vitamin D status.

Iodide excretion before and after revision of goiter prophylaxis (Dutch Nutrition Surveillance System)

To assess the iodine supply in The Netherlands after the revision of the goiter prophylaxis measures (Bread Act of 1982, with an increase of iodine content of bread salt) the data of a nationwide survey among Dutch elderly people conducted in 1984/1985 were analysed. Iodide excretion in 24 h urine samples was used as the main iodine status indicator. The data were compared with data on iodine nutriture obtained among an elderly population in The Netherlands before the revision of goiter prophylaxis. High prevalences (greater than or equal to 37%) of low iodine excretion (less than 0.78 mumol/24 h; 100 micrograms/24 h) were found for Dutch elderly people. Mean urinary iodide excretion was 0.95 mumol/24 h (121 micrograms/24 h) for men and 0.79 mumol/24 h (100 micrograms/24 h) for women which is low, especially among women, in comparison with the United States recommended dietary allowance (118 mumol/day = 150 micrograms/day). Consistent positive associations of iodide excretion were found with urinary potassium and sodium excretion, bread consumption and total iodine intake. Bread, as the iodine carrier chosen for goiter prophylaxis in The Netherlands, was found to be the main dietary iodine source. No improvement in iodine nutrition was found among the elderly studied in 1984/1985 in comparison with an elderly population seen in 1981. Therefore, it is concluded that the present measures regarding goiter prophylaxis in The Netherlands might be of limited effectiveness.

Institutionalized elderly women have lower food intake than do those living more independently (Dutch Nutrition Surveillance System)

The habitual intake of energy and nutrients (assessed through dietary history) among elderly women (aged 65 and over) living in a nursing home (n = 54), elderly women living in service flats and receiving their dinners from the nursing home kitchen (n = 29), and elderly women living independently (n = 52) was evaluated within the framework of the Dutch Nutrition Surveillance System. Intake of energy and nutrients was lowest among women in the nursing home and highest among those living independently. Almost all differences in absolute intake found were significant, both unadjusted and adjusted for age. In the nursing home the intake of energy and nutrients was lower at higher age. In qualitative terms the differences among the groups of women were less striking. Mean daily intakes of iron, vitamin A, thiamin, vitamin B6 and vitamin C were below the Dutch recommended dietary allowances (RDAs) among the nursing home women. Several interrelationships among nutrient intakes were found, low intake levels clustering somewhat among elderly subjects. Our data indicate that these nutritional risks are due to a lower food intake resulting in a lower intake of energy and nutrients, and owing to differences in food choice resulting in a lower nutrient density. We conclude that it is difficult to design a diet containing all essential nutrients at the RDA level in a nursing home with residents who have a relatively low intake of energy, especially among those at higher age.

Clustering of dietary variables and other lifestyle factors (Dutch Nutritional Surveillance System)

STUDY OBJECTIVE

The aim was to investigate whether dietary factors cluster in a favourable or unfavourable way and to characterise the groups identified by lifestyle and sociodemographic variables.

DESIGN AND SETTING

This cross sectional study was based on data of the 1987-1988 Dutch national food consumption survey (DNFCS), obtained from a panel by a stratified probability sample of the non-institutionalised Dutch population.

PARTICIPANTS

3781 adults (1802 males and 1979 females) of the DNFCS, aged 19 to 85 years, were studied.

MEASUREMENTS AND MAIN RESULTS

To estimate dietary intake two day food records were used. Lifestyle factors were collected by structured questionnaire and sociodemographic variables were available from panel information. Cluster analysis was used to classify subjects into groups based on similarities in dietary variables. Subsequently, these groups were characterised by sociodemographic and lifestyle factors as well as by the consumption of food groups. Eight clusters were found. In comparison with the guidelines, the dietary quality in four clusters was poor. The cluster with the poorest dietary intake (high intake of fat, cholesterol, and alcohol; low intake of dietary fibre) showed on average a high consumption of animal products (except milk), fats and oils, snacks, and alcoholic beverages, and a low consumption of fruit, potatoes, vegetables, and sugar rich products. Smoking, body mass index, dietary regimen on own initiative, hours of sleep, gender, age, socioeconomic status, and day of the week were found to discriminate among the clusters.

CONCLUSIONS

Cluster analysis resulted in substantial differences in mean nutrient intake and seems useful for dietary risk group identification. Undesirable lifestyle habits were interrelated in some clusters, but an exclusive lifestyle for health risk has not been found.

Hematocrit and cardiovascular risk factors among elderly men and women (Dutch Nutrition Surveillance System)

Changes in whole blood viscosity associated with hematocrit could be one of the pathways along which the cardiovascular disease (CVD) risk factors affect these diseases. Therefore, we studied in a nationwide survey comprising 514 apparently healthy Dutch elderly men and women aged 65-79 the possibility of any association between hematocrit and CVD risk factors (tobacco smoking, serum cholesterol, body mass index and blood pressure). Among men, diastolic blood pressure and total serum cholesterol were positively associated with hematocrit in both bivariate and multivariate regression analysis, whereas positive associations of hematocrit with body mass index and smoking were only significant (p < 0.05) in bivariate analysis. Among women, hematocrit was positively associated with body mass index and smoking. Except for smoking, which was associated with the mean corpuscular volume of the erythrocytes, hematocrit was positively correlated with hemoglobin and the number of erythrocytes. It is concluded that hemorrheological aspects should be considered when studying CVD among elderly people.

Indicators of iodine status among adults. Dutch Nutrition Surveillance System

To evaluate the iodine status of Dutch adults we used three different iodine status indicators, namely urinary 24-hour iodide excretion (I/24 h), iodide/creatinine ratio in 24-hour urine samples (I/Cr) and 24-hour iodide excretion per kilogram body weight (I/kg). Additionally, the habitual daily iodine intake was calculated. Men had higher mean I/24 h and mean iodine intake than women. No differences between men and women were found for mean I/Cr and mean I/kg. Relatively high (greater than or equal to 18%) prevalences of low values for the different iodine status indicators were found, especially for I/24 h. The intraindividual variance for all three indicators was high. Risk assessment regarding iodine supply, based on urinary iodide excretion, depends on the indicator used, and therefore caution is called for when drawing conclusions. Our results do not argue against the usage of I/24 h as iodine status indicator. More research is needed to solve the question whether iodine requirement depends on such factors as body size, body composition and physical activity.

Nutritional status: blood vitamins A, E, B6, B12, folic acid and carotene. Euronut SENECA investigators

This chapter describes the vitamin plasma concentration data collection, preliminary analysis and results of the Euronut SENECA study. Blood plasma was collected from approximately 2500 elderly subjects born in 1913-1918 living in 17 small towns in 11 European countries, and the plasma levels of carotene, retinol, alpha-tocopherol, vitamin B12, folic acid and pyridoxal 5'-phosphate were determined. There were very large within- and between-centre differences in vitamin levels with no definite geographical pattern emerging. The vitamin status for retinol and folic acid was adequate in all centres. The prevalence of biochemical vitamin B6 deficiency was widespread and reached over 50% in some centres. Vitamin B12 biochemical deficiency was limited to ten centres and its prevalence was 1.6%-10%. Vitamin E biochemical deficiency was found in seven centres and varied from 0.5% to 25%.

Inconsistent associations among anthropometric measurements in elderly Dutch men and women

In a national survey of 515 apparently healthy Dutch elderly people aged 65 through 79 years, interrelationships among weight, height, weight-for-height indexes (especially the Quetelet index), body fatness (assessed by skinfold measurements), and 24-hour urinary creatinine excretion were investigated in various age groups. Body weight, body height, and 24-hour urinary creatinine excretion (absolute and per kilogram body weight) were lower in older age groups. In men the correlation coefficient between weight and body fatness was .54 for the group aged 65 through 69 years and .33 for the group aged 75 through 79 years. In women the correlation between weight and percentage of body fat varied from .52 to .70 among the age groups. In comparison with results reported for younger adults, a lower correlation between the Quetelet index and body fatness was observed (r = .49 in men, r = .64 in women). The correlation of the Quetelet index with both height and urinary creatinine excretion tended to be higher in the older age groups. We concluded that some of the associations found were inconsistent and that there may be some doubt about the adequacy of the Quetelet index as a measure of body fatness among the elderly. However, no convenient alternative weight-for-height index is presently available. Perhaps circumferences are a better option to choose for elderly people.

Diet and other life-style factors in high and low socio-economic groups (Dutch Nutrition Surveillance System)

Insight into the occurrence of and the association between certain socio-economic variables and life-style characteristics is necessary for preventive nutrition and health policy. The prevalence of and the interdependencies among these variables were examined in 1930 men and 2204 women aged 19 to 85 who participated in the Dutch National Food Consumption Survey 1987-1988. Dietary data were based on a two-day record. The associations among discrete variables were analysed using log-linear models. Analysis of covariance was used to explore the effects of the aggregate socio-economic status (SES) on dietary intake and anthropometry, whereas differences in food intake and SES were assessed by the non-parametric test of Kruskal and Wallis. In comparison to subjects with a high SES in people with a low SES a higher proportion of smokers (48 vs 32 per cent) was observed, a higher prevalence of obesity (39 vs 28 per cent), a higher percentage of heavy coffee drinkers (greater than six cups per day, 23 vs 17 per cent), and more subjects who skipped breakfast (19 vs 11 per cent). In the highest SES class more subjects used nutritional supplements (18 vs 11 per cent), more subjects followed a dietary rule (five vs two per cent), such as a vegetarian diet, and a higher proportion used more than three alcoholic drinks per day (19 vs 15 per cent). A higher SES was associated with a lower fat intake, but the differences (expressed as per cent of energy intake) were rather small and even absent among women when the contribution of alcohol to energy was not taken into account. In general, dietary intake among subjects in higher SES groups tended to be closer to dietary recommendations. The results indicate that a lower SES is accompanied by a higher prevalence of several indicators of an unhealthy life-style.

Nutritional status and food consumption in 10-11 year old Dutch boys (Dutch Nutrition Surveillance System)

As part of the Dutch Nutrition Surveillance System, cardiovascular risk factors and food consumption (24 h recall) as well as haematological, Fe and vitamin status (A, B6, C) were assessed in 126 Dutch boys aged 10-11 years (response 71%). Body mass index (BMI) and the sum of four skinfolds were strongly associated (r 0.85, P less than 0.01) and 8% of the boys were overweight (BMI greater than 20.1 kg/m2). Elevated serum total cholesterol levels (greater than 4.4 mmol/l) were observed in 38%; total cholesterol and low-density-lipoprotein-cholesterol levels were strongly associated (r 0.88, P less than 0.001). Intake of fat was high (38% of energy) and too much fat was saturated (polyunsaturated: saturated 0.44, guideline: 0.5-1.0), whereas intake of carbohydrate (49% of energy) and dietary fibre was low. About 12% of the boys had insufficient Fe stores (plasma ferritin less than 12.0 micrograms/l) and the mean Fe intake (9.0 mg/d) was below recommended daily allowance (10.0 mg/d). Plasma ferritin was, however, not associated with haematological indices and no frank anaemias were observed. No marginal values were observed for vitamins A, B6 and C status. In conclusion, the main nutritional risks in boys aged 10-11 years are cardiovascular risk factors and Fe nutrition.

Nutrition and blood pressure among elderly men and women (Dutch Nutrition Surveillance System)

Associations between blood pressure and nutrition-related variables (body mass index, dietary intake, and 24-hr excretion of sodium, potassium, magnesium, and calcium in the urine) were investigated in men (n = 138) and women (n = 117) 65-79 years old not using drugs known to affect blood pressure and not on a diet. Among men, body mass index was positively and creatinine clearance was inversely associated with systolic blood pressure, whereas body mass index and urinary sodium:potassium ratio were positively associated with diastolic blood pressure. Among women, both age and urinary calcium:creatinine ratio were positively associated with systolic as well as diastolic blood pressure. Coffee consumption was positively correlated with blood pressure and urinary calcium:creatinine ratio among the women. From the results it appears that, besides "normal" weight, increased potassium intake and urinary excretion may exert a protective effect among elderly men against hypertension when sodium exposure is relatively high. The positive association between urinary calcium:creatinine ratio and blood pressure among the women may be partly due to coffee consumption.

Nutrition and serum cholesterol levels among elderly men and women (Dutch Nutrition Surveillance System)

Associations of serum cholesterol with relevant dietary intake variables (assessed with the dietary history method) and body mass index were investigated in elderly men (n = 199) and women (n = 180) 65-79 years old. All subjects were apparently healthy, nondiabetic, and not on a dietary regimen. The associations were studied separately for men and women using linear regression analysis and all possible subsets regression analysis. Among men, body mass index (kg/m2) and intake of monounsaturated fat and of alcohol were positively and consistently associated with serum total cholesterol. Among women, intake of alcohol and of saturated fat were positively associated, and intake of polysaccharides was inversely associated with serum total cholesterol. The intake of monounsaturated fatty acids was highly (r greater than .60) positively correlated with the intake of total fat and saturated fatty acids, and inversely with carbohydrates. HDL-cholesterol was positively associated with alcohol intake (significant for men only), and inversely with body mass index (women). The results indicate that the effect of dietary factors on serum cholesterol levels is probably not age-limited. Elderly people may potentially benefit from weight reduction or control, moderate alcohol consumption, and avoidance of too much dietary fat. These suggestions are in fair accordance with general population-based guidelines for a healthy diet. However, as our study was cross-sectional, causation as well as the public health impact remains to be proven.

Long-term effects of a vegetarian diet on the nutritional status of elderly people (Dutch Nutrition Surveillance System)

The health and nutritional status (anthropometry, and blood and urine biochemistry) of 44 Dutch apparently healthy vegetarians, aged 65-97 years, refraining from meat, fish, and poultry consumption, was assessed for insight into long-term consequences of ovo-lacto- or lacto-vegetarianism. The results indicate that in comparison to omnivorous elderly the vegetarian elderly (especially men) have aged successfully with respect to cardiovascular risk factors. In contrast, vegetarian elderly are at a higher risk for a marginal iron, zinc, and vitamin B12 status. Although several vegetarian elderly showed low levels of 25-hydroxyvitamin D in plasma and many had low values of 24-hr urine volume (per kg body weight), these values are not likely the result of a vegetarian diet per se. It is concluded that, although some nutrition-related risks are prevalent among vegetarian elderly, these risks can probably be prevented by lifestyle changes.

Dependence of vitamin B-6 status assessment on alcohol intake among elderly men and women (Dutch Nutrition Surveillance System)

To obtain more insight into the effect of moderate alcohol intake on vitamin B-6 status indicators, we studied the associations of alcohol intake (unadjusted and adjusted for intake of vitamin B-6 and protein) with the erythrocyte aspartate aminotransferase activation coefficient (EAST-AC) and plasma pyridoxal 5'-phosphate (PLP) level. Data obtained from men (n = 224) and women (n = 217) aged 65-79 (nationwide sample in the Netherlands) were used for this purpose. Although alcohol intake (a maximum of 21% of the energy came from alcohol) tended to be positively associated with PLP, this association never reached statistical significance (p greater than or equal to 0.05). EAST-AC was inversely associated with alcohol intake, whether or not it was adjusted for vitamin B-6 and protein intake. Similar results were found for the total EAST activity (after adding PLP) or apoenzyme activity; the basal EAST activity (before adding PLP) or holoenzyme activity was not associated with the alcohol intake. These results indicate that caution is needed in the interpretation of the specificity of EAST-AC (i.e., the degree to which EAST-AC is unaffected by other factors) as an indicator of vitamin B-6 intake.

Adequacy of a vegetarian diet at old age (Dutch Nutrition Surveillance System)

To assess the adequacy of a vegetarian diet at old age, the dietary intake (assessed through dietary history with cross-check) of 44 apparently healthy lacto-(ovo-)vegetarians, aged 65-97 years, was evaluated. Adequacy was assessed by a comparison of nutrient intake with (Dutch) recommendations and by evaluating data on nutritional status. The results were also compared with data of elderly omnivores. In contrast to elderly omnivores, percentages of energy from protein (13%), fat (37%), and carbohydrates (50%) as well as P/S ratio (0.63) were close to or within the range of Dutch guidelines regarding a healthy diet (percentages of energy from protein, fat, and carbohydrates 10-15, 30-35, and 55%, respectively: P/S ratio 0.5-1.0). For most of the micronutrients studied intake was adequate, and nutrient density of the vegetarian diet was higher than of the omnivorous diet. However, the supply of zinc (average daily intake 8.5 and 7.6 mg for men and women, respectively), iron (because of lower bioavailability of nonheme iron), vitamin B12 (women only: intake 2.3 micrograms/day), and water (daily intake less than 1600 ml for 30% of the vegetarians) need special attention, considering the relatively high prevalence of a marginal status of these nutrients. In conclusion, a lacto-(ovo-)vegetarian diet can be adequate at old age, provided that it is carefully planned, especially with respect to the supply of iron, zinc, and vitamin B12.

Effect of dietary fiber on the vitamin B6 status among vegetarian and nonvegetarian elderly (Dutch nutrition surveillance system)

To obtain more insight into the effect of dietary fiber on vitamin B6 status among elderly people, we studied dietary interrelationships as well as associations between dietary intake and plasma pyridoxal-5'-phosphate (PLP) and cofactor stimulation of aspartate aminotransferase in erythrocytes (EAST-AC) among 441 nonvegetarian (aged 65-79) and 32 vegetarian elderly (aged 65-94). EAST-AC was found to be inversely related with intake of vitamin B6 and dietary fiber in bivariate regression analyses. After adjustment for age, intake of energy, protein, and fiber, the intake of vitamin B6 was still inversely related with EAST-AC. The association between EAST-AC and dietary fiber disappeared in the multivariate analysis, whereas total protein intake proved to be positively related with EAST-AC in the multivariate analysis only. The differences between bi- and multivariate analyses are most likely due to the observed interrelationships between intake of vitamin B6, fiber, and protein. It is concluded that dietary fiber does not have a significant impact on the vitamin B6 status among Dutch elderly people, since only protein (positively) and vitamin B6 (inversely) intake appeared to be related with EAST-AC in the multivariate analysis.

Nutrition and aging: nutritional status of "apparently healthy" elderly (Dutch nutrition surveillance system)

In a nationwide survey the nutritional status was assessed of 539 apparently healthy, independently living elderly aged 65-79 years. Anthropometric data showed no energy deficits. The prevalence of anemia was 4 and 1% among men and women, respectively. Many elderly showed a low level of 25-hydroxyvitamin D in plasma (less than 31 nmol/L: men 35%; women 43%), indicating a marginal status. Although the prevalence of low blood levels of folate, pyridoxal-5'-phosphate, and total carotenoids was higher among the elderly than among younger adults, clear (clinical) signs of nutritional deficiencies were not observed. Prevalence of obesity (13%), hypercholesterolemia (38%), and hypertension (63%) was found to be high, the percentages being higher for women than for men. Several indicators of the nutritional status appeared to differ among age groups. It is concluded that few differences can be considered as being due to physiological aging, which finding should be reflected in reference values for elderly people.

Serum uric acid correlates in elderly men and women with special reference to body composition and dietary intake (Dutch Nutrition Surveillance System)

In 460 apparently healthy Dutch elderly, aged 65-79 years, serum uric acid correlates were studied by linear regression analyses, for men and women separately. Diuretic therapy, total serum cholesterol (women only) and creatinine clearance (in bivariate analysis only) were significantly associated with serum uric acid level. Positive associations of serum uric acid with body weight, body mass index, body fatness (men) and lean body mass (men) were observed, with and without adjustment for diuretic therapy, creatinine clearance and age. Serum uric acid levels, whether adjusted or not for these variables and for body mass index, were positively associated with alcohol intake (men) and consumption of meat and fish (women), and inversely with consumption of bread, margarine and milk products (women). These results indicate that limited medication with diuretics, weight control and restriction of alcohol use may help to prevent hyperuricemia in the elderly.