Dietary intake has long been looked upon as a potentially modifiable risk factor for gallbladder disease (GBD), here defined as either having gallstones or having had surgery for gallstones. This paper reviews the epidemiological evidence for an association between dietary intake and GBD, focusing on six dietary factors that have received the most attention in studies in this area: energy intake, fatty acids, cholesterol, carbohydrates and fibre, calcium and alcohol. The objectives of this review are to evaluate the potential usefulness of altering the diet to prevent GBD and to consider future research in this area.

We reviewed all English-language epidemiological studies on diet and cholelithiasis that were cross-sectional, cohort or case–control in design and that were indexed in the Medline database from 1966 to October 1997.

A positive association was suggested with simple sugars and inverse associations with dietary fibre and alcohol. No convincing evidence was found for a role for energy intake or intake of fat or cholesterol. Variable means of ascertaining cases and inaccurate measurement of dietary intake may contribute to variation in results across studies.

Some specific components of the diet that may affect GBD include simple sugars, fibre and alcohol, but whether risk for GBD can be reduced by altering intake of a specific dietary factor has not been established. Although no specific dietary recommendations can be made to reduce risk of GBD per se, a ‘healthy’ diet aimed at reducing risk of other diseases might be expected to reduce risk for GBD as well.

The purpose of this trial was to compare three different iodine interventions.

School children aged 8–10 years were randomized into one of three groups: group A was provided with iodized salt by researchers with an iodine concentration of 25 ppm; group B purchased iodized salt from the market; and group C was similar to group B with the exception that they were given iodized oil capsules containing 400 mg iodine at the beginning of the study. Salt iodine content was measured bimonthly for 18 months and indicators of iodine deficiency were measured at baseline and 6, 9, 12 and 18 months after randomization.

The prevalence of abnormal thyroid volumes, based on the World Health Organization (WHO) body surface area reference > 97th percentile, was 18% at baseline and declined to less than 5% by 12 months in groups A and C, and to 9% after 18 months in group B. Results for goitre by palpation were similar. The median urinary iodine was 94 μgl−1 at baseline and increased in all groups to > 200 μgl−1 at the 6-month follow-up.

In this population of school children with initially a low to moderate level of iodine deficiency, the group receiving salt with 25 ppm (group A) was not iodine deficient on all indicators after 18 months of study. When the iodine content of the salt varied, such as in group B, by 18 months thyroid sizes had not yet achieved normal status.

To assess the nutritional status and dietary practices of 4–24-month-old children (under-twos) in a rural South African community.

Cross-sectional survey.

A low socioeconomic rural African community (Ndunakazi), approximately 60 km north-west of Durban, KwaZulu-Natal, South Africa.

Children (n = 115), 4–24 months old who attended growth monitoring posts in the area.

Of these under-twos, 37.3% had low vitamin A status (serum retinol < 20 μg dl−1), 65.2% were anaemic, 43.2% had serum ferritin levels < 10 μgl−1 (an indicator of low iron stores) and 15.3% were stunted. Breastfeeding was initiated by 99% of mothers. At the time of the survey, 80% of infants in the 4–12-month-old category and 56.9% of children in the 12–24-month-old category were being breastfed. Solid foods were introduced at 3.6 ± 0.8 months. Food intake reflected a high intake of carbohydrate-rich foods, and irregular intakes of fruit and vegetables, especially those rich in vitamin A. Foods of animal origin were not consumed regularly. Of these under-twos, 15.9% experienced an episode of diarrhoea during 2 weeks prior to the survey.

These under-twos had a poor vitamin A and iron status. Nutrition education, intervention programmes and feeding schemes should address micronutrient deficiencies, with the focus on the quality of the diet, rather than quantity.

To compare the effect of advice to reduce both dietary fat and sugar with advice to reduce fat alone on subsequent dietary intake in Scottish men.

A parallel design intervention study was employed to measure compliance to the two types of dietary advice. Subjects were randomly assigned to Group 1 (advice to reduce fat and non-milk extrinsic (NME) sugar), Group 2 (advice to reduce fat only, ad libitum sugar) or a control Group 0 (no advice). Compliance was assessed by two 4-day food diaries over 6 months.

The study was conducted in the Strathclyde area of Scotland.

Subjects were normal to moderately overweight Scottish men. The men recruited were non-dieting and volunteered for a ‘healthy eating’ study with the aim to improve the ‘healthiness’ of their diet.

Groups 1 and 2 achieved the dietary target for fat, reducing their mean intake to below 35% energy. Group 1 achieved a statistically significant reduction in percentage energy from NME sugar in the short term (6 weeks), decreasing their mean intake from 9.9% to 7.2% energy. This initial decrease appeared to slip back towards baseline levels at 6 months (8.1% energy from NME sugar) and was no longer significantly different from baseline. At 6 months Group 1 reported a significantly lower mean energy intake than at baseline, whereas Group 2 adjusted for an initial decrease in energy intake and by 6 months energy intakes were not significantly different from baseline intakes. Group 2 appeared to compensate for the absolute reduction in dietary fat with a slight increase in total sugars and the maintenance of NME sugar intakes.

Subjects in Group 1 complied with advice to reduce both fat and sugar over 6 weeks but to a lesser extent over 6 months. The 1.8% reduction in percentage energy from NME sugars in Group 1 at 6 months may not have reached significance due to the small sample size. Alternatively it may be that free-living populations find it hard to maintain concurrent reductions in fat and sugar owing to the well-documented inverse relationship between intakes of these macronutrients when expressed as a proportion of energy.

To examine the relationship between cigarette smoking and a range of nutrient intakes and blood status indices in older people.

National Diet and Nutrition Survey: cross-sectional survey of nationally representative sample of people aged 65 years and over.

Mainland Britain during 1994/95.

1191 people (619 male, 572 female) aged 65 years and over, of whom 920 were living in private households and 271 were living in institutions.

Cigarette smoking was inversely correlated with intakes of antioxidants and other micronutrients after adjustment for age, sex and domicile. Cigarette smoking was also inversely correlated with a number of antioxidant micronutrient status indices including plasma vitamin C and the carotenoids (but not vitamin E status indices), and with other micronutrient status indices, including plasma pyridoxal phosphate, red cell and serum folate, after adjustment for age, sex, domicile and the corresponding nutrient intake. Previous cigarette smoking or cigar/pipe smoking was not generally associated with lower nutrient intakes or status indices, however, both current and previous cigarette smoking was associated with increased concentrations of acute phase indicators. Further adjustment for total energy intake and/or sociodemographic, health and drug usage variables attenuated only a few of the associations observed.

Older people who smoke cigarettes are at increased risk of suboptimal antioxidant and other micronutrient intakes and status, but the lower intakes found in cigarette smokers only partly explain their reduced blood indices.

A national survey was developed in order to assess the difficulties and the potential benefits that the adult Spanish population perceive when they try to eat a healthier diet and also to help nutrition educators to develop relevant and specific strategies to promote healthy eating.

The study survey was carried out according to an established protocol on a representative sample of 1009 Spanish subjects over 15 years of age selected by a multi-stage procedure. This study belongs to a partnership in a pan-European survey about food, nutrition and health. The analysis was focused on the evaluation of the seven most frequently chosen barriers and benefits.

There was a trend to select as the main barriers: ‘irregular work hours’ (29.7%), ‘willpower’ (29.7%) and ‘unappealing food’ (21.3%), while ‘prevent disease’ (73.6%) was the most frequently selected benefit to healthy eating. About 20% of the subjects said they did not have any difficulty eating healthier and most people believed that healthy eating was associated with at least one benefit.

In Spain, nutrition educators should be aware that an irregular and busy lifestyle, willpower and food-related factors (such as price and unappealing foods) are the main perceived barriers to healthy eating. Conversely, the prevention and health promotion aspects are the main perceived benefits.

To examine intake of fruits and vegetables in smokers and non-smokers.

Secondary analysis using general linear modelling approaches. Food intake measured using a food frequency questionnaire approach.

The community (the population of the province of Ontario, Canada).

Members of the general public (n=38,000).

Smokers ate substantially less fruit and fruit juice then non-smokers with heavy smokers eating the least. Heavy smokers were between four and six times more likely to be eating less fruit than recommended. Similar but less marked differences were noted for vegetable intake. Smokers also obtained a larger part of their total caloric intake from fats.

While smoking cessation remains the primary target for lung cancer prevention, attention should also be given to dietary interventions in smokers in order to improve their nutrition. Such interventions might also be expected to reduce the risk of other cancers (e.g. colon cancer).

To assess the accuracy and helpfulness of labelling on products containing probiotic bacteria.

52 such products – 44 from the UK (21 supplements, 15 fermented functional foods, eight ‘health-care’ products) and eight from continental Europe – have been tested for microbiological content, and results compared to the information available on their labels. Products were stored in the dark at 4°C and analysed before their expiry or sell-by date. Careful note was taken of wording on labels, package inserts, packaging, promotional literature and catalogue descriptions, as applicable. Products were cultured on appropriate bacteriological media, and organisms grown were counted and identified.

Bioyoghurts gave no indication of numbers, and only five accurately described their bacterial content; results of culture were usually satisfactory. ‘Health-care’ products (mostly intended for the bowel) usually indicated the presence of bacteria, but the numerical content was hard to ascertain, and cultural results fell short of label claims. Supplements were sometimes incorrectly labelled in bacteriological terms, and often contained markedly reduced numbers and/or had extraneous strains and/or strains specified on the label were missing. Products from continental Europe (that were sold for specific medical indications) seemed of a higher microbiological standard. The potential pathogen Enterococcus faecium was found in nine products. The most successful of the new functional foods in Britain now contain probiotics, and probiotic preparations are prominent among the expanding range of nutritional supplements presently available to consumers.

Our findings have public health implications, and suggest that improvements are needed in labelling and quality assurance procedures for products containing probiotic organisms. The presence of the potential pathogen Enterococcus faecium (intentionally or as a contaminant) in some products calls for a review of the value of this species as a probiotic.