Whole grains and adiposity: little association among British adults.

OBJECTIVES: To examine associations of whole-grain intake with body weight and adiposity in two nationally representative samples of British adults. SUBJECTS/METHODS: A total of 2064 adults aged 16-64 years in 1986-1987, 1599 adults aged 19-64 years in 2000-2001. Whole-grain intake (g day(-1) and 16-g amounts) was estimated from consumption of all foods with >or=10, >or=25 or >or=51% whole-grain content, using 7-day weighed dietary records. Body weight, body mass index (BMI) and, in 2000-2001, waist circumference (WC) were measured. BMI and WC were considered as continuous and categorical variables. For each survey, associations of whole-grain intake with body weight and anthropometric indices were examined in men and women separately, before and after adjustment for age, occupational social class, smoking habit, region, season and, in 2000-2001, misreporting. RESULTS: In 1986-1987, whole-grain intake was inversely associated with percentage of men classified using BMI as obese (P=0.008, trend), independent of other factors. However, intake was not associated with body weight or prevalence of overweight. No corresponding associations were observed among women. In 2000-2001, whole-grain intake was not associated with body weight, BMI or WC. CONCLUSIONS: Two national surveys of British adults, with detailed quantitative estimates of whole-grain intake, provide little evidence of an association of whole-grain intake with body weight or measures of adiposity.

Whole-grain intake of British young people aged 4-18 years.

Inverse associations between whole-grain food consumption and risk of CVD, some cancers and type 2 diabetes have been reported. However, there are few reports of whole-grain intake, particularly among young people. The objective of the present study was to estimate whole-grain intake in a nationally representative sample of young people aged 4-18 years living in Great Britain. Whole-grain intake was estimated using 7 d weighed dietary records from 1583 young people who participated in the cross-sectional National Diet and Nutrition Survey in 1997. Whole-grain intake was quantified from the consumption of all foods containing > or =10 % whole-grain content. Median whole-grain intake was 7 g/d (interquartile range 0-19 g/d), with a corresponding mean of 13 (sd 18) g/d. Intake was significantly lower among young people whose head of household had a manual occupation, but did not differ significantly by sex, age, region or season. There was no whole-grain intake for 27 % of participants. The percentages for less than one and less than three 16 g amounts of whole-grain intake per d were 70 and 94, respectively, while corresponding percentages based on 20 g amounts were 76 and 97. Foods with <51 % whole-grain content provided 28 % of whole-grain intake overall, with a higher percentage in older adolescents. The main sources of whole-grain intake were breakfast cereals (56 %) and bread (25 %). The present study provides the first quantification of absolute whole-grain intake from all significant food sources in any representative age group in the UK. Although there is some debate regarding the quantity of whole grains required for good health, whole-grain intake among British young people is low.

Intake and sources of phylloquinone (vitamin K(1)) in 4-year-old British children: comparison between 1950 and the 1990s.

OBJECTIVES: To compare dietary intake and sources of phylloquinone (vitamin K1) in 4-year-old British children between 1950 and the 1990s, and report their variation by sociodemographic factors. DESIGN: Nationally representative samples of 4-year-olds from the longitudinal Medical Research Council National Survey of Health and Development (NSHD) (1950) and the cross-sectional National Diet and Nutrition Surveys (NDNS, 1992/93 and 1997). SETTING: Great Britain. SUBJECTS: Subjects were 4599 children born on 3-9 March 1946 (NSHD) and 307 children in the 1990s (NDNS). RESULTS: Geometric mean dietary phylloquinone intake was significantly higher in 1950 (39 mug day(-1), 95% confidence interval (CI) 37, 40) compared with the 1990s (24 mug day(-1), 95% CI 22, 25) (P<0.001). This difference remained when intake was expressed per MJ energy intake and per kilogram body weight, and after accounting for sex, region and occupational social class of the family. In 1950, phylloquinone intake in Scotland was significantly lower than in the rest of Britain. By the 1990s these regional differences had disappeared. Food sources of phylloquinone intake changed significantly between 1950 and the 1990s, with fats and oils contributing more and vegetables less, although vegetables contributed most (60% and 48%, respectively) to phylloquinone intake in both surveys. CONCLUSIONS: Phylloquinone intakes of children have decreased significantly since 1950. With the suggested need for adequate phylloquinone intake for optimal development and maintenance of bone and the cardiovascular system, the substantially lower phylloquinone intakes reported in children of the 1990s, compared with 1950, may have implications for the health of these two systems in later adulthood.

Zinc and vitamin A intake and status in a national sample of British young people aged 4-18 y.

OBJECTIVE: To examine zinc and vitamin A intake and status and associated dietary, socio-demographic, lifestyle and physiological factors in British young people. DESIGN: National Diet and Nutrition Survey of young people aged 4-18 y. SETTING: Great Britain, 1997. SUBJECTS: Complete 7-day weighed dietary records were provided by 1520 participants, while 1193 provided blood samples. RESULTS: A total of 13 and 11% of participants respectively reported low dietary intakes of zinc and vitamin A (retinol equivalents), relative to the UK lower reference nutrient intake. These percentages were not altered significantly by including contributions to intake from supplements, mainly containing vitamin A (as retinol). Likelihood of low zinc and/or vitamin A intake was more often associated with age, sex and likely under-reporting of food consumption than with other socio-demographic and lifestyle factors. Low zinc and vitamin A intakes were generally less likely in those with higher consumption of dairy foods (mainly milk). Zinc and vitamin A status (assessed by plasma zinc and retinol concentrations) were adequate in almost all participants. Plasma zinc concentration was not significantly associated with zinc intake. Plasma retinol concentration was correlated with vitamin A intake (overall r=0.17, P<0.001; adjusted for age and plasma alpha(1)-antichymotrypsin concentration) and increased significantly with age (P<0.001) in both sexes. A significant association was found between plasma zinc and retinol concentrations in boys only (r=0.17, P=0.001). CONCLUSION: Zinc and vitamin A intakes and status were generally adequate in this national sample of British young people.

Tomato consumption and plasma lycopene concentration in people aged 65 y and over in a British national survey.

OBJECTIVE: Assessment of consumption of raw and processed tomatoes, plasma lycopene concentration and their interrelationship in a nationally representative sample of elderly British people. SETTING: : A 1994-1995 National Diet and Nutrition Survey: a nationwide cross-sectional sample of people aged 65 y and over living in mainland Britain, either in the community ("free-living", n=1275) or in institutions such as nursing homes (n=412). METHODS: Consumption of raw and processed tomatoes (including those in tomato-containing composite foods) was recorded by a 4-day dietary record for each participant. Plasma lycopene concentration was assayed by HPLC. Sociodemographic and lifestyle information was recorded by trained interviewers. RESULTS: In all, 29% of free-living people and 24% of those living in institutions did not consume any raw or processed tomatoes during the 4-day recording period. Free-living participants were more likely to consume raw tomatoes (26 vs 16%). Plasma lycopene concentration was positively associated with the weight of raw and processed tomatoes consumed, especially with processed tomatoes and their products, alcohol consumption and with plasma total (as well as HDL and non-HDL) cholesterol concentrations. Among free-living participants, increased age, cigarette smoking habit and manual occupational social class were all associated with lower plasma lycopene concentration. CONCLUSIONS: In the current population, consumption of raw and processed tomatoes varied by sociodemographic and lifestyle characteristics, and made a significant contribution to plasma lycopene concentration. Determinants of plasma lycopene concentration were age, plasma cholesterol concentration and smoking habit.

Risk factors for low iron intake and poor iron status in a national sample of British young people aged 4-18 years.

OBJECTIVE: To examine the prevalence and dietary, sociodemographic and lifestyle risk factors of low iron intake and poor iron status in British young people. DESIGN: National Diet and Nutrition Survey of young people aged 4-18 years. SETTING: Great Britain, 1997. SUBJECTS: In total, 1699 young people provided 7-day weighed dietary records, of which 11% were excluded because the participant reported being unwell with eating habits affected. Blood was obtained from 1193 participants, with iron status indicated by haemoglobin, serum ferritin and transferrin saturation. RESULTS: Iron intakes were generally adequate in most young people aged 4-18 years. However, low iron intakes (below the Lower Reference Nutrient Intake) occurred in 44% of adolescent girls (11-18 years), being less prevalent with high consumption of breakfast cereals. Low haemoglobin concentration (<115 g l-1, 4-12 years; <120 or <130 g l-1, 13+ years for girls and boys, respectively) was observed in 9% of children aged 4-6 years, pubertal boys (11-14 years) and older girls (15-18 years). Adolescent girls who were non-Caucasians or vegetarians had significantly poorer iron status than Caucasians or meat eaters, independent of other risk factors. The three iron status indices were correlated significantly with haem, but not non-haem, iron intake. CONCLUSIONS: Adolescent girls showed the highest prevalence of low iron intake and poor iron status, with the latter independently associated with non-Caucasian ethnicity and vegetarianism. Risk of poor iron status may be reduced by consuming (particularly lean red) meat or enhancers of non-haem iron absorption (e.g. fruit or fruit juice) in vegetarians.

Selenium status and associated factors in a British National Diet and Nutrition Survey: young people aged 4-18 y.

OBJECTIVE: Assessment of selenium status to provide normative reference values, and investigation of associated socio-demographic factors, in a national sample of British young people aged 4-18 y. SETTING: National Diet and Nutrition Survey-a nationwide cross-sectional sample of young people aged 4-18 y living in mainland Britain in 1997. METHODS: Selenium status was measured, mainly in fasting blood samples, by plasma selenium concentration in 1127 participants, by red blood cell (RBC) selenium concentration in 1112, and by whole-blood glutathione peroxidase (GPx) activity in 658. RESULTS: No evidence of severe selenium deficiency or toxicity was observed. Plasma selenium concentration was directly correlated with RBC selenium concentration, and both were associated directly, although less strongly, with GPx activity. Plasma and RBC selenium concentrations increased significantly with age, with RBC concentrations significantly higher in older girls than boys. Region of domicile exhibited a significant relationship. Associations also occurred with parental occupational social class, selenium concentrations being higher in more socially advantaged children. Black and Indian children had considerably higher concentrations than Caucasian children. Concentrations, especially of plasma selenium, were significantly lower in children either (or both) of whose parents were smokers, although, unexpectedly, there was no evidence that children who themselves smoked had lower levels. CONCLUSIONS: The observed associations between selenium status indices and age, gender, social class, parental smoking and ethnic group indicate a complex network of biological factors which determine selenium concentrations in blood components, and which thus need to be controlled for when using these indices to assess selenium status in young people. SPONSORSHIP: The survey was commissioned jointly by the Department of Health and the Ministry of Agriculture, Fisheries and Food, whose responsibility has since been transferred to the Food Standards Agency. Support for the further analysis presented in this paper was provided by the Department of Health.

Intake and sources of phylloquinone (vitamin K1): variation with socio-demographic and lifestyle factors in a national sample of British elderly people.

Intake and sources of phylloquinone (vitamin K1) were examined according to socio-demographic and lifestyle factors in free-living British people aged 65 years and over, from the 1994-5 National Diet and Nutrition Survey. Complete 4-d weighed dietary records were obtained from 1152 participants living in private households. Using newly-available, mainly UK-specific food content data, the weighted geometric mean intake of phylloquinone was estimated at 65 (95 % CI 62, 67) microg/d for all participants, with higher intakes in men than in women (70 v. 61 microg/d respectively, P<0.01). The mean nutrient densities of phylloquinone intake were 9.3 and 10.5 microg/MJ for men and women respectively (P<0.01), after adjusting for age group, region and smoking status. Of all the participants, 59 % had phylloquinone intakes below the current guideline for adequacy of 1 microg/kg body weight per d. Participants aged 85 years and over, formerly in manual occupations, or living in Scotland or in northern England reported lower phylloquinone intakes than their comparative groups. Overall, vegetables contributed 60 % of total phylloquinone intake, with cooked green vegetables providing around 28 % of the total. Dietary supplements contributed less than 0.5 % of phylloquinone intake. Participants living in northern England or in Scotland, in particular, derived less phylloquinone from vegetables than those living in southern England.

Plasma phylloquinone (vitamin K1) concentration and its relationship to intake in a national sample of British elderly people.

Plasma phylloquinone (vitamin K1) concentration was examined according to season, socio-demographic and lifestyle factors and phylloquinone intake in a nationally representative sample of British people aged 65 years and over from the 1994-5 National Diet and Nutrition Survey. Values for both plasma phylloquinone concentration and phylloquinone intake were available from 1076 participants (561 men, 515 women). Eight hundred and thirty-four were living in private households, 242 in residential or nursing homes. Weighted geometric mean plasma phylloquinone concentrations were 0.36 (inner 95% range [corrected] 0.06, 2.01) and 0.24 (inner 94% range [corrected] 0.06, 0.96) nmol/l in free-living and institution samples respectively. Plasma phylloquinone concentrations did not generally differ between men and women, although values in free-living people were significantly lower during autumn and winter (October to March). Plasma phylloquinone concentration was not significantly associated with age. Plasma phylloquinone concentrations were positively correlated with phylloquinone intake in free-living men and women (r 0.18 and 0.30 respectively, both P<0.001). Stepwise multiple regression analysis found that 11 % of the variation in plasma phylloquinone concentration was explained by phylloquinone intake, season and plasma triacylglycerol concentration. After adjustment for age and corresponding nutrient intakes, plasma phylloquinone concentration was significantly associated (each P<0.01) with plasma concentrations of triacylglycerol, cholesterol, retinol and 25-hydroxyvitamin D in free-living women but not men, and with plasma concentrations of carotenes, alpha- and gamma-tocopherols and lutein in free-living men and women. The possibility of concurrent low fat-soluble vitamin status in elderly populations may be a cause for concern.

Dietary intakes and nutrient status of vegetarian preschool children from a British national survey.

BACKGROUND: Dietary intakes and nutrient status were compared in meat-eaters and non-meat-eaters from the National Diet and Nutrition Survey of children aged 1.5-4.5 years. METHODS: Children (n = 1351) were categorized as 'omnivores' or 'vegetarians', according to whether they consumed meat or meat products during a 4-day dietary record. Blood samples were also obtained for analysis of haematological and biochemical nutrient status. RESULTS: Three per cent of children were 'vegetarian'. They consumed higher proportions of milk and milk products, although this was significant only in older children (P = 0.007), owing to high consumption by the high proportion of Asian children. In vegetarians, energy intakes tended to be lower in both age groups. Percentage energy from protein and fat were lower, while that from carbohydrate was higher compared with omnivores. Cholesterol intakes were lower, significantly so for younger children (P < 0.001). Intakes of micronutrients were either higher (vitamins C and E, potassium) or lower (niacin and sodium) in younger vegetarians compared with omnivores. Energy-adjusted intakes of iron and zinc did not differ significantly from those of omnivores, although both intakes were low in many children (6-20% < LRNI), particularly in the younger group. Haematological and biochemical nutrient status indices showed few differences. Serum ferritin was lower in vegetarians, significantly so in younger children (P = 0.002). Antioxidant vitamin (A, C and E) status tended to be higher in vegetarians, while vitamin B12 intakes and status were more than adequate. Apart from poorer vitamin D intake and status in older Asian vegetarians, very few ethnic differences were observed. CONCLUSIONS: Nutrient intakes and status were generally adequate in preschool children who did not eat meat. Although serum ferritin levels were inferior (particularly in vegetarians under 3 years old), the lower intakes of fat, cholesterol and sodium, and higher antioxidant vitamin intakes and status indices were potentially beneficial. Given a balanced diet, adequate nutrient intakes and status can be maintained without consuming meat.

Risk factors for poor iron status in British toddlers: further analysis of data from the National Diet and Nutrition Survey of children aged 1.5-4.5 years.

OBJECTIVE: : To examine risk factors for poor iron status in British toddlers. DESIGN: : National Diet and Nutrition Survey (NDNS) of children aged 1.5-4.5 years. SETTING: : Mainland Britain, 1992/93. SUBJECTS: : Of the 1859 children whose parents or guardians were interviewed, a weighed dietary intake was provided for 1675, and a blood sample obtained from 1003. RESULTS: : Mean haemoglobin (Hb) and ferritin levels were significantly lower in younger (1.5-2.5 years) than in older (3.5-4.5 years) children, with boys having significantly lower ferritin levels than girls. Poor iron status ferritin <10 microg l-1, or low values for both indices) was associated with lower socioeconomic and employment status. Iron status was directly associated with meat and fruit consumption and inversely with that of milk and milk products, after adjustment for age and gender. The latter association remained significant after further adjustment for sociodemographic variables, energy intake and body weight. Children consuming >400 g day-1 of milk and cream were less likely to consume foods in other groups, with those also consuming little meat, fish, fruit and nuts at greatest risk of poor iron status. Few associations were observed between poor iron status and individual nutrient intakes, and iron status was not associated with either iron intake or with consumption of a vegetarian diet. CONCLUSIONS: : Overdependence on milk, where it displaces iron-rich or iron-enhancing foods, may put toddlers at increased risk of poor iron status. However, this becomes non-significant when moderate-to-high amounts of foods known to enhance iron status (e.g. meat and/or fruit) are also consumed. Milk consumption in this age group should ideally be part of a mixed and balanced diet including all food groups, and particularly lean meat (or other iron-rich or fortified foods) and fruit. This is particularly relevant for households of lower socioeconomic and employment status.