Haem and non-haem iron intake through 17 years of adult life of a British Birth Cohort

Implicit attitudes and explicit cognitions jointly predict a reduced red meat intake: a three-wave longitudinal study

Background: Despite nutritional benefits, a high consumption of red meat is not without risks as it is linked to the development of certain types of cancer as well as to other non-communicable diseases, such as type II diabetes or cardiovascular diseases. Moreover, the production of meat has negative effects on the environment. Therefore, a transition to a less meat-based diet could be beneficial. It is unclear how explicit cognitions towards red meat consumption and implicit attitudes jointly influence intention and consumption. We tested the additive pattern (both types of cognitions explain unique variance) and interactive pattern (both types interact in the prediction).

Method: At baseline (T0; N = 1790) and one (T1; n = 980) and three months thereafter (T2; n = 556), explicit cognitions, red meat consumption, and implicit attitudes were assessed among a Dutch sample.

Results: Only explicit cognitions were associated with red meat consumption. Implicit attitudes moderated the effect of self-efficacy on T0-RMC; negative implicit attitudes strengthened this effect. T0-intention was associated with explicit cognitions and implicit attitudes. Additionally, negative implicit attitudes strengthened the effect of social norms on T0 and T2-intention. Regarding red meat consumption, support for the interactive pattern was found. For intention there was support for the interactive and additive pattern.

Conclusion: Interventions aiming to reduce red meat consumption in the general public might profit from changing implicit attitudes in addition to explicit cognitions.

Can an iron-rich staple food help women to achieve dietary targets in pregnancy?

Habitual iron intakes during pregnancy are typically lower than dietary guidelines, a risk for iron deficiency. The aim of this study was to determine whether regular consumption of bread naturally rich in iron could help women to achieve dietary targets. Thirty-three primiparous mothers were randomized to eat 3-4 slices of iron-rich or control bread daily for 6 weeks. Two 24-h-prompted (multiple-pass) dietary recalls were completed, and validated algorithms were used to determine the amount of 'available iron' from the diet. Regular consumption of iron-rich bread helped pregnant women to achieve UK dietary recommendations; the quantity of bread consumed by the participants contributed 27% versus 9% UK Reference Nutrient Intake (RNI) (14.8 mg/d) in the intervention versus the control group. Levels of total 'available iron' were similar in both groups and correlated positively with total dietary iron (r = 0.78, P = 0.0001), vitamin C (r = 0.43, P = 0.017) and non-haem iron (r = 0.77, P = 0.0001). Findings from this study show that iron-rich staple foods can help women reach dietary targets for iron. This is an area of great potential that could be of particular benefit to low-income/ethnically diverse population groups who have some of the lowest iron intakes. Further research using fortified staple foods containing higher levels of iron is now warranted to establish physiological benefits.

Dietary fibre and phytate--a balancing act: results from three time points in a British birth cohort

An investigation was carried out to determine whether there were significant changes in the intake of dietary fibre (NSP) and phytate of adult men and women in the UK from 1982 (aged 36 years) to 1999 (aged 53 years). The 1253 subjects studied were members of the Medical Research Council National Survey of Health and Development; a longitudinal study of a nationally representative cohort of births in 1946. Food intake was recorded in a 5 d diary at age 36 years in 1982, 43 years in 1989 and 53 years in 1999. The food composition database was amended with revised values for phytate. Outcome measures were mean intakes of total NSP and phytate by year, sex and food source. There were significant changes in total NSP and phytate intake over the three time points. Intakes of NSP rose significantly between 1982 and 1999 for men and women but phytate intakes rose significantly only between 1989 and 1999. Cereal foods were the most important source of both NSP and phytate. Between 1989 and 1999 there was a significant increase in the contribution from pasta, rice and other grains. The present study shows that an increase in dietary fibre that is in accordance with dietary guidelines would almost inevitably be accompanied by a rise in phytate. The increased dietary phytate is discussed in relation to its recognised inhibition of mineral absorption and its merits with regard to protection against some cancers and other diseases of an ageing population.

Meat consumption after disaggregation of meat dishes in a cohort of British adults in 1989 and 1999 in relation to diet quality

BACKGROUND/OBJECTIVES

The aim of the study was to quantify more precisely the meat intake of a cohort of adults in the UK by disaggregating composite meat dishes.

SUBJECTS/METHODS

Subjects were members of the Medical Research Council National Survey of Health and Development, 1946 birth cohort. Five-day diaries were collected from 2256 men and women in 1989 and 1772 men and women in 1999. From the details provided, composite meat dishes were broken down into their constituent parts and the meat fraction was added to meat portions only. Meat intake was classified as red meat, processed meat and poultry.

RESULTS

Meat consumption without disaggregation of meat dishes resulted in a mean overestimation of 50% in men and 33% in women. Red meat consumption fell between 1989 and 1999 from 51.7 to 41.5 g per day in men and 35.7 to 30.1 g per day in women. Poultry consumption rose from 21.6 to 32.2 g per day in men and 18.2 to 29.4 g per day in women. Re-calculating red meat intakes resulted in the percentage of subjects in 1999 consuming more than the recommendation of the World Cancer Research Fund falling from 30 to 12%. Increasing consumption of red and processed meat was associated with increased intakes of energy, fat, haem iron, zinc and vitamin B(12), and lower intake of fibre. Increased sodium intake was associated with increased consumption of processed meat.

CONCLUSIONS

Disaggregation of meat dishes provided a more precise estimate of meat consumption. The quantity of red or processed meat in the diet was reflected in the nutrient content of the entire diet.