Parental smoking and the nutrient intake and food choice of British teenagers aged 16-17 years.

STUDY OBJECTIVE: To examine the association between parental smoking habits and the nutrient intake and food choice of teenagers aged 16-17 years, allowing for differences in teenage smoking and the social class and regional distribution of the participants. DESIGN: Data were collected from the 1970 longitudinal birth cohort, cross-sectionally at 16-17 years. The smoking habits of teenagers were evaluated from a questionnaire completed by the subjects themselves, and the smoking habits of parents by interview. The nutrient and food intakes of teenagers were quantitatively assessed using a four day unweighed dietary diary. SETTING: The participants were distributed throughout Britain. PARTICIPANTS: A subsample of 1222 males and 1735 females was isolated from respondents to the 1970 birth cohort 16-17 year data collection sweep undertaken in 1986-87. MAIN RESULTS: Parental smoking habits were associated with different dietary patterns among teenagers regardless of whether the teenagers themselves smoked. Dietary differences noted were similar to those observed previously among smokers, with lower intakes of fibre, vitamin C, vitamin E, folates, and magnesium in particular reported among both males and females in households where parents were smokers. These lower intakes were associated with lower intakes of fruit juices, wholemeal bread, and some vegetables. CONCLUSION: Teenagers who lived with parents who smoked had different nutrient and food intakes to those with non-smoking parents, and teenagers exposed to parental smoking appeared to have similar dietary patterns to teenagers who themselves smoked

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 µmol/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.


Keywords: vitamin C; food frequency; fruit; vegetable

Ventilatory function and winter fresh fruit consumption in a random sample of British adults.

The relation between ventilatory function and the reported frequency of consumption of fresh fruit and fruit juice was studied among 1502 lifelong non-smokers and 1357 current smokers aged 18-69 with no history of chronic respiratory disease. Forced expiratory volume in one second (FEV1) was assessed by turbine spirometry. As winter fruit consumption was more widely dispersed than summer consumption and few subjects ate fruit more frequently in the winter, winter fruit consumption was taken as an indicator of habitual (year round) consumption. After adjustment for sex, age, height, cigarette consumption, region of residence, and household socioeconomic group, FEV1 was associated with winter fruit consumption. The mean adjusted FEV1 among those who never drank fresh fruit juice and ate fresh fruit less than once a week during the winter was 78 ml lower (95% confidence interval 24-132 ml) than the mean for the other subjects. A similar difference was found in all age-sex groups and among both current smokers and lifelong non-smokers. Antioxidant and other actions of vitamin C may protect against pulmonary emphysema, or reduce bronchoconstrictor responses to environmental pollutants