Consumption of red or processed meat does not predict risk factors for coronary heart disease; results from a cohort of British adults in 1989 and 1999

Objectives—To investigate whether a high consumption of red or processed meat is associated with increased risk of coronary heart disease. Subjects/Methods—The subjects were 517 men and 635 women who were members of the Medical Research Council National Survey of Health and Development, 1946 birth cohort. Assessment of diet was carried out at two time-points 1989 and 1999 with outcome measures collected in 1999. Food intake data were recorded in 5 -day diaries. Meat consumption was estimated by adding individual meat portions to the meat fractions of composite dishes. Results—There was no significant association between red or processed meat consumption in 1989 and 1999 and serum cholesterol concentrations and blood pressure measured in 1999. The combined intake of red and processed meat in 1999 had a significant positive association with blood pressure in men only. Red and processed meat intakes in 1989 separately and combined had a significant positive association with waist circumference in 1999: a 10g increase in red meat consumption accounted for a 0.3cm increase in waist circumference; p=0.04 (men), 0.05 (women). Conclusions—Consumption of red or processed meat assessed separately was not related to the major risk factors for CHD but did contribute to increased waist circumference that has also been identified as a risk factor

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

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 MRC 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 added to meat only portions. 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 41.5g/day in men and 35.7 to 30.1g/day in women. Poultry consumption rose from 21.6 to 32.2g./day in men and 18.2 to 29.4 g/day in women. Re-calculating red meat intakes resulted in the percentage of subjects in 1999 consuming more 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 B12 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

Dietary fibre and phytate; a balancing act. Results from 3 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 (non-starch polysaccharide; 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-day 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, gender and food source. There were significant changes in total NSP and phytate intake over the 3 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. This 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

Combined effusive-explosive silicic volcanism straddles the multiphase viscous-to-brittle transition

Magma is a viscoelastic fluid that can support fracture propagation when local shear stresses are high, or relax and flow when shear stresses are low. Here we present experiments to confirm this using synthetic and natural magmatic liquids across eruptive conditions and use Maxwell’s linear viscoelasticity to parameterize our results and predict the maximum stresses that can be supported during flow. This model proves universal across a large range of liquid compositions, temperatures, crystallinity and rates of strain relevant to shallow crustal magma ascent. Our results predict that the 2008 Volcán Chaitén eruption resided in the viscous field at the onset of magma ascent, but transitioned to a mixed viscous-brittle regime during degassing, coincident with the observed combined effusive-explosive behaviour during dome extrusion. Taking a realistic maximum effusive ascent rate, we propose that silicic eruptions on Earth may straddle the viscous-to-brittle transition by the time they reach the surface

Comparing effects of freezing at -196 °C and -20 °C on the viability of mastitis pathogens

The aim of this study was to compare the effects of cryopreservation at approximately -196 °C in liquid nitrogen (N) and freezing at approximately -20 °C in a freezer, on the viability and survival of eight different mastitogenic bacteria inoculated in milk. Bacteria were frozen at approximately -20 °C in a freezer and cryopreserved at approximately -196 °C in liquid nitrogen. An effective preservation method was needed for follow-up samples from cows identified in the South African National Milk Recording Scheme (NMRS) with somatic cell counts above 250 000 cells/mL milk. The organisation responsible for sample collection of the NMRS milk samples also provides producers with liquid nitrogen for their semen flasks at the collection sites. This existing mode of storage and transport could therefore be utilised. Ten samples of each organism were thawed and cultured bi-weekly until week 18 for both temperature treatments. An additional sampling was performed at week 30 for samples frozen at approximately -20 °C. Freezing and cryopreservation did not impair subsequent isolation of Streptococcus dysgalactiae, Streptococcus uberis, Enterococcus faecalis, Staphylococcus aureus (STH) (phage type lytic group III) or Sta. aureus (STA) (phage typed, other than lytic group III). Survival was indicated by the isolation of bacteria from samples, and viability by the strength of growth of the bacteria isolated. The survival of Streptococcus agalactiae decreased after week 12 and Escherichia coli after week 16 of freezing, but both organisms survived under cryogenic preservation until week 18. Coagulase-negative staphylococci survived until week 18 for both freezing and cryogenic preservation. Both storage methods could thus contribute to the improvement of a pro-active approach towards udder health management in South African dairy herds

Does initial breastfeeding lead to lower blood cholesterol in adult life? A quantitative review of the evidence

BACKGROUND: Earlier studies have suggested that infant feeding may program long-term changes in cholesterol metabolism. OBJECTIVE: We aimed to examine whether breastfeeding is associated with lower blood cholesterol concentrations in adulthood. DESIGN: The study consisted of a systematic review of published observational studies relating initial infant feeding status to blood cholesterol concentrations in adulthood (ie, aged >16 y). Data were available from 17 studies (17 498 subjects; 12 890 breastfed, 4608 formula-fed). Mean differences in total cholesterol concentrations (breastfed minus formula-fed) were pooled by using fixed-effect models. Effects of adjustment (for age at outcome, socioeconomic position, body mass index, and smoking status) and exclusion (of nonexclusive breast feeders) were examined. RESULTS: Mean total blood cholesterol was lower (P = 0.037) among those ever breastfed than among those fed formula milk (mean difference: -0.04 mmol/L; 95% CI: -0.08, 0.00 mmol/L). The difference in cholesterol between infant feeding groups was larger (P = 0.005) and more consistent in 7 studies that analyzed "exclusive" feeding patterns (-0.15 mmol/L; -0.23, -0.06 mmol/L) than in 10 studies that analyzed nonexclusive feeding patterns (-0.01 mmol/L; -0.06, 0.03 mmol/L). Adjustment for potential confounders including socioeconomic position, body mass index, and smoking status in adult life had minimal effect on these estimates. CONCLUSIONS: Initial breastfeeding (particularly when exclusive) may be associated with lower blood cholesterol concentrations in later life. Moves to reduce the cholesterol content of formula feeds below those of breast milk should be treated with cautio