Phyto-oestrogens and risk of prostate cancer in Scottish men

A population-based case–control study of diet, inherited susceptibility and prostate cancer was undertaken in the lowlands and central belt of Scotland to investigate the effect of phyto-oestrogen intake and serum concentrations on prostate cancer risk. A total of 433 cases and 483 controls aged 50–74 years were asked to complete a validated FFQ and provide a non-fasting blood sample. Multivariate logistic regression analysis found significant inverse associations with increased serum concentrations of enterolactone (adjusted OR 0·40, 95 % CI 0·22, 0·71] and with the consumption of soy foods (adjusted OR 0·52, 95 % CI 0·30, 0·91). However, no significant associations were observed for isoflavone intake or serum genistein, daidzein and equol. This study supports the hypotheses that soy foods and enterolactone metabolised from dietary lignans protect against prostate cancer in older Scottish men.

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) μg/d for all participants, with higher intakes in men than in women (70 v. 61 μg/d respectively, P<0·01). The mean nutrient densities of phylloquinone intake were 9·3 and 10·5 μg/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 μg/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 (95 % CI 0·06, 2·01) and 0·24 (95 % CI 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 (r0·18 and 0·30 respectively, bothP<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 (eachP<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, α- and γ-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.

A provisional database for the silicon content of foods in the United Kingdom

Si may play an important role in bone formation and connective tissue metabolism. Although biological interest in this element has recently increased, limited literature exists on the Si content of foods. To further our knowledge and understanding of the relationship between dietary Si and human health, a reliable food composition database, relevant for the UK population, is required. A total of 207 foods and beverages, commonly consumed in the UK, were analysed for Si content. Composite samples were analysed using inductively coupled plasma–optical emission spectrometry following microwave-assisted digestion with nitric acid and H2O2. The highest concentrations of Si were found in cereals and cereal products, especially less refined cereals and oat-based products. Fruit and vegetables were highly variable sources of Si with substantial amounts present in Kenyan beans, French beans, runner beans, spinach, dried fruit, bananas and red lentils, but undetectable amounts in tomatoes, oranges and onions. Of the beverages, beer, a macerated whole-grain cereal product, contained the greatest level of Si, whilst drinking water was a variable source with some mineral waters relatively high in Si. The present study provides a provisional database for the Si content of UK foods, which will allow the estimation of dietary intakes of Si in the UK population and investigation into the role of dietary Si in human health.

The impact of inter-generational social and regional circumstances on dietary intake patterns of British adults: results from the 1946 British Birth Cohort

Objectives:

(1) To determine the extent to which an individual's childhood social circumstances and region of residence influence their dietary pattern at age 43 years and (2) to establish the extent to which an individual adopts the dietary pattern of their social and regional circumstances at age 43 years.

Design:

Longitudinal study of a social class stratified, random sample of all legitimate, singleton births in the week of 3–9 March 1946.

Settings:

England, Scotland and Wales.

Subjects:

The 3187 survey members who provided sociodemographic information at age 4 years in 1950 and sociodemographic and dietary data (48-hour dietary recall) at 43 years in 1989.

Results:

People who remained in the non-manual social class consumed significantly higher amounts of food items correlated with the factor health aware (items include high-fibre breakfast cereals, wholemeal breads, apples and bananas) than those who remained in the manual social class. Those who made the transition from manual social class in childhood to non-manual social class at age 43 years partly adopted the distinctive dietary patterns of the non-manual social classes. Consumption of items in the factors refined (items include whole-fat milk, white bread, sugar and butter) and sandwich (items include tomatoes, lettuce, onions, bacon and ham) did not differ by social class or regional mobility.

Conclusions:

This work suggests that although adult dietary patterns are developed as a result of childhood influences, these patterns can be modified as a result of social and regional transitions. Such changes in dietary patterns may influence susceptibility to disease.

Phyto-oestrogen intake in Scottish men: use of serum to validate a self-administered food-frequency questionnaire in older men

OBJECTIVE

To study dietary intake and serum concentrations of isoflavones in order to provide relative validation of isoflavone intake estimates from the Scottish Collaborative Group - Food-Frequency Questionnaire (SCG-FFQ).

DESIGN

Validation study.

SETTING

Southern Scotland.

METHOD

Dietary intake of isoflavones was estimated using the semiquantitative SCG-FFQ and rank correlation and Kappa statistics were used for the relative validation of intakes against serum isoflavone concentrations in 203 male participants who were population controls in a case-control study of diet and prostate cancer.

RESULTS

The median intake of isoflavones (daidzein and genistein) was 1.0mg/day (l-QR 0.6-1.8). The median serum concentration of genistein was 33.79 nmol/l (I-QR 14.12-64.93), nearly twice that of daidzein (18.00 nmol/l, I-QR 8.26-29.45). Equol was detected in 49% of subjects; in these subjects the median was 0.67 nmol/l (I-QR 0.34-1.51). Isoflavone intake was significantly correlated with serum concentrations of daidzein (p = 0.24, P = 0.001), genistein (p = 0.26, P < 0.001) and total isoflavonoids (sum of daidzein, genistein and equol) ( p = 0.27, P < 0.001). Whereas values for weighted Kappa ranged from 0.16 (P = 0.002) for daidzein and equol combined to 0.22 (P < 0.001) for genistein.

CONCLUSIONS

These results demonstrate the suitability of the SCG-FFQ to rank usual isoflavone intakes in older Scottish men, a population observed to have low consumption of soy foods.

Dietary silicon intake in post-menopausal women

Si has been suggested as an essential element, and may be important in optimal bone, skin and cardiovascular health. However, there are few estimates of dietary Si intakes in man, especially in a UK population. Following the development of a UK food composition database for Si, the aim of the present study was to investigate dietary intakes of Si amongst healthy women aged over 60 years and to identify important food sources of Si in their diet. Healthy, post-menopausal female subjects (>60 years of age; n 209) were recruited from the general population around Dundee, Scotland as part of an unrelated randomised controlled intervention study where dietary intake was assessed using a self-administered, semi-quantitative food-frequency questionnaire at five time-points over a 2-year period. Food composition data on the Si content of UK foods was used to determine the Si content of food items on the food-frequency questionnaire. Mean Si intake was 18.6 (sd 4.6) mg and did not vary significantly across the 2 years of investigation. Cereals provided the greatest amount of Si in the diet (about 30 %), followed by fruit, beverages (hot, cold and alcoholic beverages combined) and vegetables; together these foods provided over 75 % about Si intake. Si intakes in the UK appear consistent with those reported previously for elderly women in Western populations, but lower than those reported for younger women or for men.

Childhood obesity and socioeconomic status: a novel role for height growth limitation

OBJECTIVE

To assess prevalence and socioeconomic context of overweight and obesity in a cohort of Scottish children.

DESIGN

Cross-sectional study.

SETTING

Primary schools in Dundee, Angus, and Fife, Eastern Scotland, UK.

PARTICIPANTS

A total of 1240 boys and 1214 girls aged between 4-10 y.

MAIN OUTCOME MEASURE

Weight, height and body mass index (weight/height2).

RESULTS

Overall overweight or obesity prevalence was 24.6%, while prevalence of obesity alone was 6.1%. Individuals from schools with a high level of low-income families were 65% more likely to be overweight as judged by BMI. However, these children weighed the same as more affluent children of the same age, but were 1.26 cm shorter.

CONCLUSION

These data confirm the continued increase in childhood obesity in the UK and reveal a role for height-growth limitation in the absence of overall growth restriction, among children from low-income groups. This observation raises important questions regarding socioeconomic environmental factors in promoting the currently increasing levels of obesity.

The Pro12Ala and C-681G variants of the PPARG locus are associated with opposing growth phenotypes in young schoolchildren

AIMS/HYPOTHESIS

Peroxisome proliferator-activated receptor gamma is an important regulator of adiposity in mouse and man, and common variation in the PPARG gene has been associated with birthweight, adult obesity, insulin sensitivity and type 2 diabetes. We hypothesised that these variants may be associated with childhood obesity.

METHODS

Height and weight were recorded for 2454 prepubertal children aged between 4 and 10 years, who were then genotyped for three common variants of the PPARG locus: C-681G, Pro12Ala and C1431T.

RESULTS

No single variant of PPARG was significantly associated with height, weight or BMI. However, when modelling the variants together we detected an opposing interaction between the -681G and the Ala12 variants in height and weight, but not BMI (p=0.018, 0.013 and 0.119 respectively). The data were consistent with the Ala12 carriers being deficient in energy storage/utilisation, leading to reduced growth. In contrast, the -681G variant, which has been associated with increased adult height, was associated with accelerated growth. The two variants were in strong linkage disequilibrium. However, rare individuals bearing the isolated variants demonstrated the greatest variation from the mean, the most contrasting genotypes being associated with a variation of 7 kg in weight and 6 cm in height, standardised to 7.4-year-olds (p=0.006 and p=0.02 respectively).

CONCLUSIONS/INTERPRETATION

This study demonstrates that quantitative trait analysis of energy balance/growth and the PPARG locus is complex and requires the use of multiple genetic markers.

Dietary acid-base balance and intake of bone-related nutrients in Cambridge teenagers

OBJECTIVES

To evaluate the diet of 16-18-y-old boys and girls with particular reference to intakes of nutrients believed to affect bone health and dietary acid-base balance.

DESIGN

A 7-day food diary was completed between the months of October and December.

SETTING

Cambridge, UK.

SUBJECTS

A total of 111 boys and 101 girls aged 16-18 y who were recruited into the Cambridge Bone Studies.

MAIN OUTCOME MEASURES

Mean daily intakes of foods and selected nutrients (protein, calcium, phosphorus, magnesium, potassium, vitamins C and K) were calculated. Two estimates of acid-base balance were calculated from the diet using the formulae of Remer (net acid excretion, estimated indirectly; NAE(ind)) and Frassetto (protein/potassium ratio).

RESULTS

Mean calcium and phosphorus intakes were above the UK Reference Nutrient intake (RNI). In all, 39% of the boys and 36% of the girls had vitamin K intakes lower than 1 microg/kg body weight/day. Calcium intake was positively correlated with all other nutrients except vitamins C and K. Boys had a significantly higher estimated net acid excretion (NAE(ind)) than girls (P<0.001). Although a strong correlation (r=0.76, P<0.001) was found between the two methods, at higher acid levels a divergence was observed. A significant positive correlation was found between NAE(ind) and the weight consumed per day of milk, cheese, meat and cereal foods and a negative correlation was found with the weight of potatoes and fruit. Diet composition is such that a lower NAE(ind) is accompanied by a lower calcium intake.

CONCLUSIONS

The interpretation of the effects of calcium and other nutrients on bone cannot be considered in isolation from the other components of the diet. These results challenge some of the accepted perceptions about what constitutes an optimal diet for the promotion of bone health in adolescents.

Childhood and adult dietary vitamin E intake and cardiovascular risk factors in mid-life in the 1946 British Birth Cohort

OBJECTIVES

To determine whether dietary vitamin E intake in childhood or mid-life was predictive of adult hypertension and high waist circumference, as two important risk factors for cardiovascular disease.

DESIGN

Longitudinal study of a social class stratified random sample of all the legitimate, singleton births in the week of 3-9 March 1946.

SETTINGS

England, Scotland and Wales.

SUBJECTS

The 2980 survey members who provided information on diet, health and sociodemographic information at two time points; age 4 y in 1950 (24-h dietary recall) and 43 y in 1989 (48-h dietary recall).

MAIN OUTCOME MEASURES

Outcomes were adjusted odds ratios (ORs) for hypertension and high waist circumference at age 43 y by thirds of vitamin E intake, relative to the highest intake thirds at both ages.

RESULTS

The lowest consumers of vitamin E in both childhood and adulthood were more likely to be hypertensive (OR 1.8, 95% confidence interval (CI): 1.03-3.08) and have high waist circumference (OR 1.6, 95% CI: 1.02-2.43) than those consuming high levels at both ages. A low intake of vitamin E at just one time point was not associated with a statistically significant increased risk of hypertension or high waist circumference. Social class was also an independent and equally strong predictor of these coronary risk factors, indicating that the relation between social class and cardiovascular risks was not mediated solely by the current measures of diet and lifestyle.

CONCLUSIONS

Unique data on vitamin E intake from foods in both childhood and adulthood have indicated that relatively low intake of vitamin E at both ages predicted hypertension and high waist circumference at age 43 y.

Statistical approaches for assessing the relative validity of a food-frequency questionnaire: use of correlation coefficients and the kappa statistic

OBJECTIVE

To compare different statistical methods for assessing the relative validity of a self-administered, 150-item, semi-quantitative food-frequency questionnaire (FFQ) with 4-day weighed diet records (WR).

DESIGN

Subjects completed the Scottish Collaborative Group FFQ and carried out a 4-day WR. Relative agreement between the FFQ and WR for energy-adjusted nutrient intakes was assessed by Pearson and Spearman rank correlation coefficients, the percentages of subjects classified into the same and opposite thirds of intake, and Cohen's weighted kappa.

SUBJECTS

Forty-one men, mean age 36 (range 21-56) years, and 40 women, mean age 33 (range 19-58) years, recruited from different locations in Aberdeen, Scotland.

RESULTS

Spearman correlation coefficients tended to be lower than Pearson correlation coefficients, and were above 0.5 for 10 of the 27 nutrients in men and 17 of the 27 nutrients in women. For nutrients with Spearman correlation coefficients above 0.5, the percentage of subjects correctly classified into thirds ranged from 39 to 78%, and weighted kappa values ranged from 0.23 to 0.66.

CONCLUSIONS

Both Spearman correlation coefficients and weighted kappa values are useful in assessing the relative validity of estimates of nutrient intake by FFQs. Spearman correlation coefficients above 0.5, more than 50% of subjects correctly classified and less than 10% of subjects grossly misclassified into thirds, and weighted kappa values above 0.4 are recommended for nutrients of interest in epidemiological studies.

Nutritional supplementation in older adults: pleasantness, preference and selection of sip-feeds

OBJECTIVES

Malnourishment is common in older adults, and nutritional supplementation is used to improve body weight and well-being. Clinical reports suggest, however, that patients routinely reject sip-feeds. The present study examined the following questions: whether sip-feeds are less preferred and less likely to be selected than other energy-dense foods in healthy elders; and whether eating alone further reduces intake relative to eating in a social setting.

METHODS

Twenty-one healthy older adults (aged 60-79 years) attended the laboratory on three occasions. Subjects rated six different flavours of sip-feed and then rated the pleasantness of the taste of the favoured flavour against five other energy-dense familiar foods/drinks. Intake of these foods was measured when subjects ate alone or in a group of familiar others.

RESULTS

Favourite flavour of sip-feed compared well with other more familiar foods and was selected as part of a snack. Snack intake increased by 60% when consumed in a group setting compared with eating alone.

CONCLUSIONS

The study suggests that sip-feeds are rated as pleasant and selected by free-living elders. Rejection of sip-feeds in hospitalized elders may relate more to loss of appetite than to the taste preference for sip-feeds, and that eating alone rather than in groups of familiar others is likely to compound eating problems.

Sociodemographic inequalities in the diet of young children in the 1946 British birth cohort

OBJECTIVE

To evaluate whether there was food and nutrient equality across occupational social classes and geographical region for members of the 1946 British birth cohort at age 4 years.

DESIGN

Cross-sectional analysis of selected food groups, energy and nutrients from one-day recall diet records.

SETTING

England, Scotland and Wales in 1950.

SUBJECTS

Nationally representative sample of 4419 children aged 4 years in 1950 from the MRC National Survey of Health and Development (NSHD) (1946 Birth Cohort).

RESULTS

Significant food and nutrient inequalities occurred by region and occupational social class of the father. Disparity in fruit and vegetable consumption primarily led to the nutrient differences, especially with respect to lower vitamin C and carotene intakes in children from Scotland and from a manual social class background. Lower energy intake in Scottish children was attributable to inequality in the consumption of foods providing fat, and also to the retention of the traditional Scottish diet that included porridge and soups. Consumption of some rationed foods -- bacon, orange juice and tea -- was inequitably distributed by father's social class, but others, in particular meat and spreading fats, were consumed more uniformly. In contrast to fruits and vegetables, which showed marked sociodemographic disparities, other non-rationed foods such as bread and potatoes were consumed universally.

CONCLUSION

Local cultural norms may have played as strong a part in sociodemographic differences in the diet of children in the early 1950s as did the strict, post-war food rationing that prevailed. In consequence, nutritional equality was not achieved, and the relatively low intake of antioxidant vitamins during early childhood in certain population groups may have compromised health in the long term.

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.

Preferences for different high-energy foods in elderly medical in-patients

Malnourishment is a common finding in hospitalised elderly patients. It is often addressed by the provision of nutritional supplements, in the form of sip-feeds. Patients' intake of these is frequently inadequate. We assessed the palatability of sip-feed nutritional supplements and other high-energy foods to elderly medical in-patients. Using the Lickhert Scale, 49 subjects rated the taste of a previously selected sip-feed supplement and five other high-energy foods, cheese biscuit, plain potato crisps, chocolate, cherry-flavoured cereal bar and stout beer. Subjects rated the taste of sip-feeds as favourably as all other offered foods, with the exception of the lower rated stout beer (p = 0.0001). Taste alone is unlikely to account for the poor intake of sip-feed nutritional supplements by elderly hospital patients.

Association of dietary antioxidants and waist circumference with pulmonary function and airway obstruction

Dietary antioxidants, waist circumference, and pulmonary function were measured in the Fourth Scottish MONICA cross-sectional survey of 865 men and 971 women aged 25-64 years. Waist circumference was inversely related to forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC), even after adjustment for age, height, weight, working status, energy intake, and smoking variables in a multiple linear regression model (men: beta = -0.017 for FEV1 l/cm, p < 0.01 and beta = -0.008 for FVC, p = 0.04; women: beta = -0.009 for FEV1, p < 0.01 and beta = -0.007 for FVC, p = 0.01). After additional adjustment for waist circumference, estimated vitamin C and beta-carotene intakes were positively associated with lung function in men (vitamin C: beta = 0.102 for FEV1 l/mg/day, p = 0.03; beta-carotene: beta = 0.073 for FVC l/g/day, p = 0.02). Retinol and vitamin E were not significantly related to lung function for either sex. A case-control study of airway obstruction showed that waist circumference was significantly associated, while vitamin C could be protective. The study suggests that adequate intake of antioxidants and avoidance of increasing girth could help to preserve lung function.

Seasonal variation in plasma levels of endothelin-1 and nitric oxide

BACKGROUND

There is a seasonal variation in the incidence of stroke and coronary heart disease with admissions to hospital being higher in the colder months of the year. The mechanism whereby this winter prevalence of vascular disease occurs is still not fully understood. The aim of our study was to measure plasma levels of vasoactive compounds throughout the year to establish whether or not there were any fluctuations which could play a part in the higher winter incidence.

METHODS

We measured plasma levels of the vasoconstrictive endothelin-1 (ET) and the vasorelaxant nitric oxide (NO) throughout the year. Blood samples were collected from 176 normal individuals. Samples were collected between 8.00 and 10.00 hours after an overnight fast of at least 12 hours.

RESULTS

Results were divided into two-monthly intervals and analysed using a Kruskal-Wallis one-way analysis of variance and Mann-Whitney U tests (SPSS). We found a significant seasonal variation in both parameters. Mean levels of endothelin were highest in January/February (4.0 pg/ml) and lowest in May/June (2.3 pg/ml), whereas plasma 5 nitric oxide levels were lowest in January/February (5.7 microM) and highest in September/October (9.9 microM); p values were <0.0001 (Jan/Feb vs May/June) and 0.049 (Jan/Feb vs Sept/Oct), respectively.

CONCLUSIONS

The high levels of the vasoconstrictor endothelin combined with low levels of vasorelaxant nitric oxide may account in part for the increased incidence of stroke and coronary heart disease seen in these months.

Plasma vitamin C and food choice in the third Glasgow MONICA population survey

STUDY OBJECTIVE

To determine the contribution of different foods to the estimated intakes of vitamin C among those differing in plasma vitamin C levels, and thereby inform dietary strategies for correcting possible deficiency.

DESIGN

Cross sectional random population survey.

SETTING

North Glasgow, Scotland, 1992.

PARTICIPANTS

632 men and 635 women, aged 25 to 74 years, not taking vitamin supplements, who participated in the third MONICA study (population survey monitoring trends and determinants of cardiovascular disease).

MEASUREMENTS AND MAIN RESULTS

Dietary and sociodemographic information was collected using a food frequency and lifestyle questionnaire. Plasma vitamin C was measured in non-fasted venous blood samples and subjects categorised by cut points of 11.4 and 22.7 micromol/l as being of low, marginal or optimal vitamin C status. Food sources of dietary vitamin C were identified for subjects in these categories. Plasma vitamin C concentrations were compared among groups classified according to intake of key foods. More men (26%) than women (14%) were in the low category for vitamin C status; as were a higher percentage of smokers and of those in the older age groups. Intake of vitamin C from potatoes and chips (fried potatoes) was uniform across categories; while the determinants of optimal versus low status were the intakes of citrus fruit, non-citrus fruit and fruit juice. Optimal status was achieved by a combined frequency of fruit, vegetables and/or fruit juice of three times a day or more except in older male smokers where a frequency greater than this was required even to reach a marginal plasma vitamin C level.

CONCLUSION

Fruit, vegetables and/or fruit juice three or more times a day increases plasma vitamin C concentrations above the threshold for risk of deficiency.

Compilation of a provisional UK database for the phylloquinone (vitamin K1) content of foods

This paper reports the compilation of a food composition database for phylloquinone (vitamin K1) derived from the direct analysis of foods, recipe calculation and the assignment of values based on food similarities. All the basic and other food items used in these calculations had been analysed by HPLC and about 170 of the items had been obtained and assayed in the UK. Recipe calculations took account of the cooking method and changes in water and fat content. Currently, approximately 1501 food items with Royal Society of Chemistry/Ministry of Agriculture, Fisheries and Food food codes have been allocated a vitamin K1 value, and a further 282 new recipe codes are included in the database. Representative values from each food group are reported together with an indication of the potential variation. Detailed examples of some recipe calculations are included, and also the impact of changing the type of fat in recipes. Vitamin K1 is associated with, and most abundant in, photosynthetic tissues of plants. Accordingly, the highest concentrations (3000-6000 micrograms/kg) are found in dark-green leafy vegetables and herbs, such as kale, parsley, spinach and green cabbage. Intermediate concentrations (1000-2000 micrograms/kg) are found in plants with paler leaves such as white cabbage and lettuce or in green, non-leafy vegetables such as broccoli and brussel sprouts. Fats and oils contain variable amounts of vitamin K1 with the highest concentrations (300-1300 micrograms/kg) in soyabean, rapeseed and olive oils and the margarines based on them. Other foods such as dairy products, meat dishes and cereal-based foods (bread, biscuits, cakes, desserts etc.), although not in themselves particularly rich in vitamin K1 (< 200 micrograms/kg), may contribute significantly to intakes when consumption of green vegetables is poor. Within the scope of this present study, it has not been possible to address issues such as inter-sample variability, losses during storage or the bioavailability from different foods and further work on these aspects is needed.

Accuracy of the estimated prevalence of obesity from self reported height and weight in an adult Scottish population

STUDY OBJECTIVE

To determine whether self reported heights and weights from Scottish adults can provide an accurate assessment of obesity prevalence in the population.

DESIGN

Standardised clinic measurements of weight and height were compared against self reported values on a postal questionnaire in the fourth Scottish MONICA cross sectional study.

SETTING

A sex and five year age band stratified random population sample drawn from general practitioner registers in north Glasgow in 1995. Response rate 63% for men and 62% for women.

PARTICIPANTS

A total of 865 men and 971 women aged between 25 and 64 years.

RESULTS

Men and women under-reported their weight by a mean (SD) of 0.63 (3.45) kg and 0.95 (2.64) kg respectively, and their height by a mean (SD) of 1.3 (2.50) cm and 1.7 (2.37) cm respectively. Estimated body mass index, BMI (kg/m2) varied from true (measured) BMI by +0.19 (1.40) for men and by +0.17 (1.34) for women. The only age/sex group in which BMI was under-estimated from self reports (mean 0.2) was the 55-64 year old women. Prediction equations that explained 90% (men) and 88% (women) of the difference between self reported and measured height included age and self reported weight. The equivalent prediction equations for weight explained 93% of the difference between self reported and measured weight for men and included smoking and diabetic status, while for women 96% of the variance was explained with no further variables being significant. Sensitivity and specificity for determining clinical obesity (BMI > or = 30) were 83% and 96% respectively for men, and 89% and 97% for women.

CONCLUSIONS

This Scottish population was unique in the under-reporting of height as well as weight, which resulted in BMI estimates with low error. These data suggest that self reported weights and heights would be satisfactory for the monitoring of obesity prevalence in Scotland.

Dietary influences on bone mass and bone metabolism: further evidence of a positive link between fruit and vegetable consumption and bone health?

BACKGROUND

The role of nutritional influences on bone health remains largely undefined because most studies have focused attention on calcium intake.

OBJECTIVE

We reported previously that intakes of nutrients found in abundance in fruit and vegetables are positively associated with bone health. We examined this finding further by considering axial and peripheral bone mass and markers of bone metabolism.

DESIGN

This was a cross-sectional study of 62 healthy women aged 45-55 y. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry at the lumbar spine and femoral neck and by peripheral quantitative computed tomography at the ultradistal radial total, trabecular, and cortical sites. Bone resorption was calculated by measuring urinary excretion of pyridinoline and deoxypyridinoline and bone formation by measuring serum osteocalcin. Nutrient intakes were assessed by using a validated food-frequency questionnaire; other lifestyle factors were assessed by additional questions.

RESULTS

After present energy intake was controlled for, higher intakes of magnesium, potassium, and alcohol were associated with higher total bone mass by Pearson correlation (P < 0.05 to P < 0.005). Femoral neck BMD was higher in women who had consumed high amounts of fruit in their childhood than in women who had consumed medium or low amounts (P < 0.01). In a regression analysis with age, weight, height, menstrual status, and dietary intake entered into the model, magnesium intake accounted for 12.3% of the variation in pyridinoline excretion and 12% of the variation in deoxypyridinoline excretion. Alcohol and potassium intakes accounted for 18.1% of the variation in total forearm bone mass.

CONCLUSION

The BMD results confirm our previous work (but at peripheral bone mass sites), and our findings associating bone resorption with dietary factors provide further evidence of a positive link between fruit and vegetable consumption and bone health.

Dietary antioxidant vitamins and fiber in the etiology of cardiovascular disease and all-causes mortality: results from the Scottish Heart Health Study

In this paper, data obtained between 1984 and 1993 from 11,629 men and women as part of the Scottish Heart Health Study (Scotland, United Kingdom) were used to investigate the relation between antioxidant vitamin and fiber intakes and both incident coronary heart disease (CHD) (649 events) and all-causes mortality (591 deaths). All age-adjusted mean intakes tended to be higher in the group that experienced no event. For men, increased fiber intake was associated with decreased risk of CHD even after adjustment for a host of other major coronary risk factors; hazard ratios relative to the lowest quarter were 0.68, 0.70, and 0.64 by increasing quarter. This relation was also observed for mortality (hazard ratios of 0.62, 0.66, and 0.62). Evidence was found that higher intakes of the antioxidants were also beneficial, although the associations were weaker. For women, fiber was the only obviously influential dietary factor, with hazard ratios of 0.94, 0.60, and 0.56 for CHD and 1.25, 0.82, and 0.65 for mortality. These results suggest that the current public health drive to increase the consumption of foods rich in antioxidant vitamins and (particularly) fiber will impact on both CHD risk and the general health of the population.

Differential binding of the insecticidal lectin GNA to human blood cells

Evidence of snowdrop lectin binding to human white cells supports the need for greater understanding of the possible health consequences of incorporating plant lectins into the food chain.

Evidence for age-related differences in the fatty acid composition of human adipose tissue, independent of diet

OBJECTIVE

To test the null-hypothesis that no age difference in adipose tissue fatty acid composition exists independent of dietary fat intake.

DESIGN

A cross-sectional survey of coronary heart disease risk factors, the Scottish Heart Health Study, provided needle biopsy adipose tissue fatty acid data and food frequency-derived dietary data.

SETTING

Twenty-two Scottish Districts between 1984 and 1986.

SUBJECTS

A total of 10,359 men and women aged 40-59 y were randomly recruited in sex and five-year age bands from GP lists. A sub-set of 2308 men and 2049 women (42%) provided satisfactory adipose tissue and dietary data.

MAIN OUTCOME AND MEASURES

Multiple regression analysis (adjusting for dietary fats, body mass index and smoking, with and without menopause status for women) of the relationship between individual fatty acids in adipose tissue and age, and between age and the ratio of linoleic acid (C18:2, n-6) to gamma-linolenic acid (C18:3, n-6) as an indicator of delta-6 desaturase activity.

RESULTS

Sex-consistent changes with age occurred for linoleate (adjusted regression slope +/- s.e. for men -0.299 +/- 0.1339 and for women -0.504 +/- 0.1731) and gamma-linolenate (adjusted regression slope +/- s.e. for men -0.141 +/- 0.0341 and for women -0.154 +/- 0.0469) both P < 0.0001. These changes gave rise to a significant increase (P < or = 0.005) in the C18:2, n-6 to C18:3, n-6 ratio with age). Dihomo-gamma-linolenic acid (C20:3, n-6) and docosahexa- plus docosapentaenoic acids (C22:5 + C22:6, n-3) also increased significantly with age (P < or = 0.01). For the latter, the adjusted regression slopes were far greater for women (0.596 +/- 0.0575) than men (0.131 +/- 0.0417).

CONCLUSIONS

The results show that ageing does influence adipose tissue fatty acid composition independent of diet. The sex differences may partially be due to inadequate adjustment for changes in sex hormone status in males with ageing. Using the current indicator, a decline in the rate limiting step of beta-6 desaturation appeared to occur with age, and was greater in women than in men. These results may indicate that an increase in dietary gamma-linolenic acid (C18:3, n-6) is necessary with age to offset the relative imbalance between PUFA levels which appears to occur. However, any direct health benefit regarding the common diseases of ageing from such a strategy still remain to be clarified.

Nutritional influences on bone mineral density: a cross-sectional study in premenopausal women

The association between current and past dietary intake and bone mineral density (BMD) was investigated in 994 healthy premenopausal women aged 45-49 y. BMD was measured with dual-energy X-ray absorptiometry (DXA). Dietary intake was assessed with a food-frequency questionnaire (FFQ). Energy-adjusted nutrient intakes were grouped into quartiles and mean BMD at the lumbar spine (LS), femoral neck (FN), femoral trochanter (FT), and femoral Wards (FW) were calculated. With higher intakes of zinc, magnesium, potassium, and fiber, LS BMD was significantly higher (P < 0.05-0.006), and a significant difference in LS BMD was also found between the lowest and highest quartiles for these nutrients and vitamin C intake (P < 0.05-0.01). These results remained significant after adjustment for important confounding factors. LS BMD and FT BMD were lower in women reporting a low intake of milk and fruit in early adulthood than in women with a medium or high intake (P < 0.01). High, long-term intake of these nutrients may be important to bone health, possibly because of their beneficial effect on acid-base balance.

Does dietary trans fatty acid intake relate to the prevalence of coronary heart disease in Scotland?

Reports of the effects of trans fatty acids on coronary heart disease are inconsistent. Trans fatty acids may particularly influence coronary risk when linoleic acid levels are low, a situation which occurs in Scotland where prevalence of coronary heart disease is also very high. The link between trans fatty acid intake and prevalent coronary heart disease was therefore investigated in the Scottish Heart Health Study population. Trans fatty acid intakes were calculated from 10/359 sets of food-frequency questionnaire data obtained from the cross-sectional survey of men and women aged 40-59 years. Logistic regression analysis was used to calculate the odds ratios for prevalent coronary heart disease by fifths of dietary intake of total, natural and commercial hydrogenation-derived trans fatty acid. The group who had undiagnosed coronary heart disease at the time of survey was the pertinent group for examining the possible causative effects of trans fatty acid intake. After adjustment for the confounding factors (i.e. age, weight, height, smoking, level of physical activity, blood pressure, total energy intake and intakes of saturated fat, linoleic acid and the antioxidant vitamins) the odds of undiagnosed coronary heart disease for men, relative to the lowest intake fifth, did not differ significantly from unity by total or commercially-derived trans fatty acid intake. Odds were around 35% smaller in the higher intake fifths of naturally-derived trans fatty acids. For women, the odds of undiagnosed coronary heart disease tended to be greater in the higher fifths of total (odds ratio 1.36 (95% confidence interval 0.94, 1.89)) and hydrogenated (1.26 (0.92, 1.72)) trans fatty acid relative to the lowest fifth, but only reached significance in the third fifth of total trans fatty acid (1.36 (1.01, 1.83)). Dietary total and commercially-derived trans fatty acids failed to influence the odds of coronary heart disease for men, even though a significant increase in the ratio of low density plus very low density lipoprotein to high density lipoprotein-cholesterol occurred with trans fatty acid intake. The results, therefore, do not support a major effect of dietary trans fatty acid from commercial hydrogenation on coronary heart disease risk in these Scottish men. The results for women are less clear, and the possibility remains that individuals at the high extreme of trans fatty acid intake, who may be essential fatty acid deficient, are at enhanced risk of coronary heart disease.

Intake of sugars in relation to fatness and micronutrient adequacy

Dietary sugars have frequently been linked with excess body weight and poor quality diets. A review of the recent research in this area reveals no basis for a causative association between sugar intake and obesity. Rather, a diet which contains a high percentage of energy from carbohydrate (starch and sugars) may assist in weight loss if the proportion of energy from fat is low. Nutrient inadequacies tend to occur in susceptible groups (generally women and children) who have a low total energy intake, and this is compounded by a relatively high contribution from sugars. For general populations with an adequate caloric intake nutrient adequacy can be achieved across a wide range of dietary sugar (4-20% energy). In this respect, intakes at either extreme are sub-optimal.

Trans fatty acids in the Scottish diet. An assessment using a semi-quantitative food-frequency questionnaire

Trans fatty acids produced during hardening of oils have been associated with higher cholesterol levels and increased risk of heart disease. The potential risk from trans fatty acids may be greater in populations with relatively low intakes of essential fatty acids such as the Scots, who also have a high prevalence of heart disease. Means and ranges of trans fatty acid intakes are reported here for a Scottish population. A semi-quantitative food-frequency questionnaire was used to survey the diet of 10,359 Scottish men and women aged 40-59 years in 1984-6 as part of the baseline Scottish Heart Health Study. Trans fatty acid levels were calculated for each food item on the questionnaire and the total subdivided into that which is derived naturally (primarily by bacterial fermentation in ruminants) and that which is produced during industrial hydrogenation (hardening) of vegetable and fish oils. Means and ranges of intakes of each trans fatty acid variable were calculated by sex, age, smoking and social class groups. Mean total trans fatty acid intakes for men were 7.1 (SD 3.1) g/d, 2.7 (SD 2.9)% energy and for women were 6.4 (SD 2.9) g/d, 3.3 (SD 3.0)% energy. Industrially hydrogenated trans fatty acids made up nearly 58% of the total intake for men and 61% for women, with about 60% coming from cakes, biscuits and sweets, and 20% coming from the cheaper hard margarines. The main sources of the naturally derived trans fatty acids were red meat (27%), milk (20%), butter (18-19%) and cheese (13-16%). Differences between age, smoking and social class groups were apparent. However, apart from the social class differences of up to 1 g/d, these were so small that they are unlikely to be of any biological significance unless compounded by other factors such as marginal essential fatty acid adequacy. The possibility of trans fatty acid intakes up to 48 g/d and 12% total energy (compared with the Department of Health (1991) recommendations of 5 g/d or 2% energy) highlights the need for careful monitoring of the health risks at these high levels of intake.

Antioxidant vitamin adequacy in relation to consumption of sugars

OBJECTIVE

To investigate the prevalence of antioxidant vitamin inadequacy and low fibre intakes according to total, intrinsic, extrinsic and milk-sugar consumption groups.

DESIGN

Age- and sex-stratified cross-sectional study of coronary risk factors and diet. Based on a personal health and food frequency questionnaire with a clinic attendance for body measurements.

SETTING

Ten general practitioners' surgeries from each of 22 Scottish districts (12 Mainland Health Boards) surveyed during 1984-1986.

SUBJECTS

11,626 men and women aged 25-64 years who participated in the baseline Scottish Heart Health (SHHS) and MONICA studies. Overall response rate was 69% after one reminder letter.

MAIN OUTCOME MEASURES

Both the mean daily intakes of fibre and vitamins A (retinol and carotenes), C and E, and the percentage of each sex group who fall below the dietary reference values for each nutrient are reported according to fifths of dietary sugars. The percentage of the population variation in vitamin and fibre intake which can be explained by consumption of the different sugars is provided from multiple analysis of variance techniques.

RESULTS

Intrinsic sugar intake is positively related to antioxidant vitamin and fibre intake (correlation coefficients, r, between 0.1 and 0.61 apart from retinol, r = -0.06), due to their mutual occurrence in fresh fruits and vegetables, while consumption of milk sugars tends to be weekly inversely related to antioxidant vitamin and fibre intake (apart from vitamin C, r = 0.02-0.06). Both low and high extrinsic sugar intake seems to be associated with poorer antioxidant vitamin and fibre-containing diets compared with a consumption of extrinsic sugar of between 6.5 and 15.6% energy for men and 4.8 and 11.6% energy for women. Intake of different sugar types is related to the antioxidant nutrient adequacy of a diet independent of age, smoking habit, total energy intake, alcohol consumption, weight and height. Fibre intake is below the recommended value at all levels of dietary sugars.

CONCLUSIONS

Prevalence of antioxidant vitamin adequacy is significantly related to dietary sugar intake. However, relatively low extrinsic sugar consumption appears equally associated with a poor quality diet as does a relatively high intake. It may be concluded that the dietary reference values for sugars err on the cautions side, with respect to their effect on antioxidant nutrient adequacy.

Is it necessary to transform nutrient variables prior to statistical analyses?

The distributions of the intakes of many nutrients are skewed, yet this is often overlooked when standard statistical analyses are applied to nutrient data. The nutrient intakes of 5,123 men and 5,236 women, recorded by food frequency questionnaire in the Scottish Heart Health Study, were transformed to achieve approximately symmetric distributions. Power transformations were chosen using letter value analyses. A letter value analysis uses selected order statistics and their position around the median to assess symmetry. The effect that each transformation had on a comparison of nutrient intakes between those with and without prevalent coronary heart disease was determined from t tests on the untransformed and transformed variable. The effects of the logarithm and square root transformation and of the optimum Box-Cox transformation were also determined, and the results were compared with the nonparametric Mann-Whitney test. The conclusion of whether or not to reject the null hypotheses often varied, depending on the transformation and test used. The nonparametric test usually gave a conclusion similar to that of the t test on the letter value-transformed data, the Box-Cox-transformed variable, and after either the logarithm or square root transformation of the data, but not always both. The results from the untransformed variable were sometimes very different. Failure to account for skewness in nutrient variables may thus lead to spurious conclusions.

An investigation of the relationship between antioxidant vitamin intake and coronary heart disease in men and women using discriminant analysis

Smoking, high blood pressure and elevated blood cholesterol are the well-established 'classical' risk factors for coronary heart disease (CHD) in men and women. However, it is also well-known that there is a considerable degree of residual variation in CHD after these factors have been taken into account. Consideration of antioxidant vitamin status may help to reduce this unexplained variation. Here, discriminant analysis is applied to the baseline cross-sectional data from the Scottish Heart Health Study. The problem of possible behavioural changes after diagnosis for CHD is addressed by analysing diagnosed and undiagnosed CHD cases separately. Results show that the combined dietary intakes of the antioxidant vitamins C, E and carotene (assessed using a food frequency questionnaire) differentiate CHD prevalence as well as do the classical risk factors. For women, stepwise discriminant analysis shows that the effect of the antioxidant vitamins on CHD is removed by adjustment for the classical risk factors and age. For men, however, the antioxidant vitamins still contribute to the discriminant function. It is concluded that dietary antioxidant vitamins appear to have a significant effect on the prevalence of CHD, especially amongst men. The benefits and problems of using discriminant analysis in this practical context are discussed, including the assumptions that need to be tested.

An investigation of the relationship between antioxidant vitamin intake and coronary heart disease in men and women using logistic regression analysis

Antioxidant vitamin intake (C,E and carotene) is assessed from a food frequency questionnaire applied to 10,359 middle-aged men and women participating in the Scottish Heart Health Study. Logistic regression analysis is then used to quantify the relationship between antioxidant vitamin consumption and prevalent coronary heart disease (CHD), analysing diagnosed and undiagnosed cases separately. For men, there is a protective effect of all three antioxidants, before and after adjustment for a comprehensive set of confounding variables. For women the picture is less clear, only vitamin C is negatively associated with CHD, but the effect is removed by adjustment. The logistic regression model is also used to determine classification rules for deciding whether or not an individual has CHD. The classification error rates using the antioxidants are found to be very similar to those found using smoking, blood pressure and serum total cholesterol as classification variables. Significant interactions are found for the antioxidants with smoking, cholesterol and age. It is concluded that antioxidant vitamin intake protects against CHD for men. Logistic regression analysis is compared with discriminant analysis, and is found to have important advantages as an epidemiological tool.

Dietary composition and fat to sugar ratios in relation to obesity

The aim of this work was to investigate the relationship between dietary composition and prevalent overweight and obesity in a middle-aged Scottish population. An age and sex stratified cross-sectional study was carried out of coronary risk factors and diet. This was based on a personal health and food frequency questionnaire with a clinic attendance for body measurements which included weight and height. The subjects were 11,626 men and women aged 25-64 who participated in the baseline Scottish Heart Health and MONICA studies. Those reporting to be on slimming diets were excluded. The subjects were contacted via ten general practitioners surgeries from each of 22 Scottish districts (12 Mainland Health Boards) surveyed during 1984-1986. The following were measured: (1) the prevalence of overweight (BMI 25-28.6 for women and 25-30 for men) and obesity (BMI > 28.6 for women, and > 30 for men) according to intake fifths of carbohydrates (starch, total, extrinsic, intrinsic and milk sugars) and fat to carbohydrate ratios; (2) the percentage of the variance in BMI explained by multivariate analysis models which included each of the sugar variables and total energy intake. The overall prevalence of overweight and obesity in the Scottish population were 43 and 11% for men and 38 and 14% for women respectively. Their prevalence increased from the lowest to the highest fifth of Fat:ES intake, respectively for men and women, from 5 to 18.5% and from 13 to 26%. The prevalence of overweight and obesity declined from the lowest to the highest fifth of total carbohydrate, total (TS) and extrinsic (ES) sugar intake.(ABSTRACT TRUNCATED AT 250 WORDS)

Deficient health knowledge, diet, and other lifestyles in smokers: is a multifactorial approach required?

BACKGROUND

Data from the Scottish Heart Health Study, a random cross-sectional sample of middle-aged men and women, are used to compare health knowledge, behavior, and lifestyles between 4896 smokers and 4595 nonsmokers.

METHODS

Smokers are identified from self-reports with biochemical validation. They are compared with nonsmokers using analysis of covariance and logistic regression, adjusting for age and social class.

RESULTS

Smokers are found to have poorer dietary knowledge than nonsmokers, although both groups are well-informed on some aspects of diet. Knowledge of personal risk modifiers for coronary heart disease and recent intention to improve lifestyle are both worse among smokers. Smokers have lower intakes of the antioxidant vitamins and fiber, but higher intakes of dietary cholesterol and alcohol than nonsmokers. They also tend to have higher salt intake and eat a greater proportion of saturated fat, butter, or hard margarine, and full-fat milk. High-density lipoprotein cholesterol levels are lower, but triglycerides, fibrinogen, and, for women only, total serum cholesterol levels are higher among smokers. On the other hand, body mass index and diastolic blood pressure are lower among smokers.

CONCLUSIONS

In addition to advice to give up smoking, smokers should be counseled to improve their diet. The positive message to eat more fresh fruit and vegetables would be particularly helpful.

Coronary heart disease: prevalence and dietary sugars in Scotland

STUDY OBJECTIVE

The aim was to investigate the effects of dietary intakes of different types of sugars (extrinsic, intrinsic, and lactose) and the dietary fat to sugar ratio on prevalent coronary heart disease (CHD).

DESIGN

This was a baseline cross sectional survey of CHD risk factors.

SETTING

Twenty two Scottish health districts were surveyed between 1984 and 1986.

PARTICIPANTS

A total of 10,359 men and women aged 40-59 years were screened as part of the Scottish Heart Health Study, and a further 1267 men and women aged 25-39 and 60-64 years were screened as part of the Scottish MONICA (monitoring trends and determinants in cardiovascular disease) Study. The response rates were 74% and 64% respectively.

METHODS

Subjects completed a questionnaire which included sociodemographic, health, and food frequency information. Medical history, response to the Rose chest pain questionnaire, and results of a 12 lead ECG recording were used to categorize subjects into CHD diagnosed, previously CHD undiagnosed, or no CHD groups. The chi 2 statistic was used to determine whether the CHD groups differed in their sugar consumption, and multiple logistic regression analysis, with adjustment for other potential coronary risk factors, was used to calculate odds ratios for prevalent CHD by intake fifths of dietary sugars.

MAIN RESULTS

Men, but not women, differed in their sugar consumption by CHD group. The odds ratios showed a tendency for a U shaped relationship for extrinsic sugar intake with CHD prevalence, but no significant effect of the fat to sugar ratio (possible marker of obesity) on CHD was seen.

CONCLUSIONS

The results suggest that neither extrinsic sugar, intrinsic sugar, nor the fat to sugar ratio are significant independent predictors of prevalent CHD in the Scottish population, when the other major risk factors such as cigarette smoking, blood cholesterol concentration, and antioxidant vitamins intake are accounted for. These new data for different sugar types agree with the consensus view that total sugar intake is not a major marker of coronary heart disease.

Coffee and tea consumption and the prevalence of coronary heart disease in men and women: results from the Scottish Heart Health Study

STUDY OBJECTIVES

The aim was to determine if there was a relationship between coffee or tea consumption and the prevalence of coronary heart disease in Scotland.

DESIGN

The relationship between self reported coffee and tea consumption and the prevalence of coronary heart disease (history, symptoms, or electrocardiographic evidence) was investigated using multiple logistic regression analysis in the Scottish Heart Health Study (SHHS), a cross sectional study.

SETTING

Twenty two Scottish districts were surveyed for the SHHS between 1984 and 1986.

SUBJECTS

A total of 10,359 men and women aged 40-59 years were studied.

MEASUREMENTS AND MAIN RESULTS

Of the 9740 subjects who were assigned a category, 21.8% (2122) were classified as having indications of coronary heart disease. Men and women were combined in the odds ratio analysis because they showed almost identical patterns in the prevalence of coronary heart disease across the coffee and tea quarters (grouped according to consumption). Those who did not drink coffee had a significantly higher (p < 0.05) prevalence of coronary heart disease than the three groups for coffee drinkers. Adjustments for risk factors including cigarette smoking, total blood cholesterol, and diastolic blood pressure did not remove the significance of the odds ratios. There was a positive dose-response effect between tea consumption and coronary heart disease which was removed after adjustment for various risk factors.

CONCLUSIONS

These findings do not support a positive relationship between coffee or tea consumption and coronary heart disease in this British study where most coffee consumed is instant coffee.

Nutrient intake by duration of ex-smoking in the Scottish Heart Health Study

Information on current-, never- and ex-smokers (including duration of cessation) was obtained in a cross-sectional survey of risk factors for coronary heart disease (CHD), the Scottish Heart Health Study. Diet was also assessed by food frequency questionnaire in a total of 4265 men and 4770 women. Nutrient intakes were computed by sex and smoking group and, according to their diet, the ex-smokers were categorized as current- or never-smokers using discriminant analysis techniques. The current- and five ex-smoking groups differed negligibly in past smoking characteristics. Energy-adjusted intake of polyunsaturated fat, fibre and the antioxidant vitamins were lowest in current-smokers, and for men, intakes increased progressively with duration of ex-smoking to reach the level of never-smokers. In a similar manner, energy, sugar and alcohol decreased with duration of ex-smoking. Fewer trends were observable for women, and the diets of ex-smokers more immediately resembled that of never-smokers. Discriminant analysis for the combined nutrients correctly categorized 72 and 69% of male, and 66 and 65% of female current- and never-smokers respectively. By 4 years of smoking cessation the general dietary pattern of ex-smokers was similar to never-smokers for both sexes. Whether this represents a change in diet over time or a cohort effect is unclear, but the results do suggest that the apparent healthier diet of ex-smokers may contribute to their reduction in CHD risk compared with life-long current-smokers.

The Scottish Heart Health Study. Dietary intake by food frequency questionnaire and odds ratios for coronary heart disease risk. I. The macronutrients

Identification of the risk of coronary heart disease (CHD) from nutrients in the diet is of importance to both primary and secondary disease prevention. This paper reports the mean intakes and odds ratios for the macronutrients in groups of CHD-diagnosed, -undiagnosed and CHD-free men and women, aged 40-59 years, who participated in the Scottish Heart Health Study (n = 10,359). Diet was assessed by food frequency questionnaire and odds ratios were determined relative to the lowest quintile and adjusted for the classical CHD risk factors (+/- social class). Six per cent of the study population were CHD-diagnosed and 14.5% were identified as possible cases of undiagnosed CHD. The results suggest that change in diet as a result of diagnosis does occur, and is more pronounced in men. The effect is to give odds ratios, for diagnosed CHD, opposite to those which may be expected on the basis of current knowledge of nutrition and CHD risk. According to the intake data from the undiagnosed group, a relatively low energy intake, a high percentage of energy from protein and a moderate percentage of energy from alcohol diet are favourable factors with respect to CHD risk for men. For women, only alcohol significantly altered risk of undiagnosed CHD, and surprisingly, no measure of dietary fat showed a modifying effect on risk of undiagnosed CHD for men or for women. The implications, and influence of measurement error and variance on these results are discussed.

The Scottish Heart Health Study. Dietary intake by food frequency questionnaire and odds ratios for coronary heart disease risk. II. The antioxidant vitamins and fibre

High serum antioxidant vitamins are increasingly being associated with reduced risk of coronary heart disease (CHD). Previous studies have not addressed the relationship between dietary antioxidant vitamins and risk of CHD although diet is a key factor which modifies blood antioxidant vitamin levels. In prospective studies, high-fibre diets have also been associated with reduced CHD incidence. In this analysis CHD-diagnosed, -undiagnosed and non-CHD controls were selected from 10,359 men and women aged 40-59 who participated in a cross-sectional study of CHD risk factors. Diet was assessed by food frequency questionnaire, odds ratios were adjusted for the classical CHD risk factors (+/- social class) and calculated relative to the first quintile for each vitamin and total fibre. The antioxidant vitamins were further combined in a principal component analysis and the odds ratios for undiagnosed and diagnosed CHD were again calculated. For undiagnosed CHD, risk was significantly lower in the highest quintiles of beta-carotene, fibre and vitamin C, E and A for men, but only lower for fibre in women. Opposite trends were observed in the odds ratios for vitamin C and E and fibre for male-diagnosed CHD which possibly indicates changes in diet as a result of diagnosis. Principal component analysis showed significantly reduced risk of undiagnosed CHD in the top three quintiles for men (odds ratios 0.66, 0.67 and 0.64; P less than 0.05 in each case). A similar trend occurred for women but was non-significant. The results suggest that high dietary intake of the antioxidant vitamins may reduce risk of CHD, particularly in men, and that fibre may be equally cardio-protective in both sexes.

The Chief Scientist reports... The diets of Scottish men and women in relation to nutritional recommendations for health

Diets of middle-aged Scottish men and women were assessed by food frequency questionnaire as part of the Scottish Heart Health Study (a cross-sectional study of risk factors for coronary heart disease (CHD) in 22 regions). The data have allowed evaluation of the diets of different (high CHD risk) sub-groups with respect to nutrient composition and major nutrient sources. This paper summarises the key nutrient source findings by non-manual and manual occupational groups; discusses the Scottish diet in relation to recent recommendations for healthy eating and recommended daily allowances for antioxidant vitamins; and considers ways of achieving dietary change.

Nutrient intakes of different social-class groups: results from the Scottish Heart Health Study (SHHS)

Food frequency questionnaire and socio-demographic data were collected from over 10,000 Scottish men and women aged 40-59 years in a cross-sectional study of coronary heart disease (CHD) risk factors. Dietary intake, including the antioxidant vitamins C and E and beta-carotene, was assessed for different socio-economic groups. Trends in nutrient intakes were found with social-class (occupational) groups I-V. The non-manual-manual distinctions were clear even after standardizing for serum cotinine, and alternative classification by housing tenure and level of education did not confound the social-class effect. Total energy intake was significantly higher in the manual (men 10,363 KJ, women 7507 KJ) than in the non-manual (men 9156 KJ, women 7169 KJ) groups, and all nutrient amounts except for vitamin C, vitamin E, beta-carotene and fibre were significantly higher in the manual than the non-manual groups. Alcohol intake was lower in manual women, but higher in manual men compared with their respective non-manual groups. Sex and social-class differences were maintained after adjusting for total energy. Women in general, and manual women in particular, had the highest percentage energy from total fat (40.2) and saturated fat (18.2), while the percentage energy from polyunsaturated fat was lower in men than women, and lowest in manual men (4.4). The polyunsaturated:saturated fat (P:S) ratios were, for non-manual and manual men 0.32 and 0.31, and for non-manual and manual women 0.31 and 0.28. Fibre and antioxidant vitamin intakes, when expressed as nutrient densities, were lower in men than women, and lowest in manual men. Overall, men and women in manual occupations had a poorer-quality diet than did those in non-manual occupations. The coincident low P:S ratios and low antioxidant vitamin intakes in manual groups may contribute to an increased risk of CHD. Thus, the findings are compatible with the view that poor diet may be a contributory factor to the higher mortality rates for CHD which occur in the lower socio-economic groups.