Whole-grain foods and chronic disease: evidence from epidemiological and intervention studies

Cereal-based foods are key components of the diet and they dominate most food-based dietary recommendations in order to achieve targets for intake of carbohydrate, protein and dietary fibre. Processing (milling) of grains to produce refined grain products removes key nutrients and phytochemicals from the flour and although in some countries nutrients may be replaced with mandatory fortification, overall this refinement reduces their potential nutritional quality. There is increasing evidence from both observational and intervention studies that increased intake of less-refined, whole-grain (WG) foods has positive health benefits. The highest WG consumers are consistently shown to have lower risk of developing CVD, type 2 diabetes and some cancers. WG consumers may also have better digestive health and are likely to have lower BMI and gain less weight over time. The bulk of the evidence for the benefits of WG comes from observational studies, but evidence of benefit in intervention studies and potential mechanisms of action is increasing. Overall this evidence supports the promotion of WG foods over refined grain foods in the diet, but this would require adoption of standard definitions of 'whole grain' and 'whole-grain foods' which will enable innovation by food manufacturers, provide clarity for the consumer and encourage the implementation of food-based dietary recommendations and public health strategies

Advantages and pitfalls of different types of studies for investigations of the impact of food on health

Several types of studies can be used to elucidate various aspects of the effect of food on human health. The main categories are: • Epidemiological (observational) studies with humans. These can be prospective, where the diet is recorded and health indicators are moni-tored after the first recording, or retrospective, where people who have a disease are identified and it is then investigated if their diet has been different from those who did not get the same disease. • Intervention studies with animals or humans, where the outcome is differences in indicators of health between groups eating different controlled diets. • In vitro studies, where specific aspects of the mechanisms of the effects of food or food com-ponents are studied in cell cultures, isolated or-gans or on enzyme activities. Each type of study is useful for elucidation of certain types or aspects of hypotheses. They also differ in terms of sensitivity (precision) and accuracy (risk of confounding with other influences than the food it-self). A thorough understanding of the effect of a food on human health requires that all three types of stud-ies give corresponding and predictable results

Sources of total, non-milk extrinsic, and intrinsic and milk sugars in the diets of older adults living in sheltered accommodation

The WHO recommends limiting non-milk extrinsic sugars (NMES) consumption to ≤ 10 % energy to reduce the risk of unhealthy weight gain and dental caries, and to restrict frequency of intake to ≤ 4 times/d to reduce risk of dental caries. Older adults, especially those from low-income backgrounds, are at increased risk of dental caries, yet there is little information on sugars intake (frequency of intake and food sources) in this age group. The aim of this report is to present baseline data from a community-based dietary intervention study of older adults from socially deprived areas of North East England, on the quantity and sources of total sugars, NMES, and intrinsic and milk sugars, and on frequency of NMES intake. Dietary intake was assessed using two 3-d estimated food diaries, completed by 201 participants (170 female, thirty-one male) aged 65–85 years (mean 76·7 (sd 5·5) years) recruited from sheltered housing schemes. Total sugars represented 19·6 %, NMES 9·3 %, and intrinsic and milk sugars 10·3 % of daily energy intake. Eighty-one (40·3 %) exceeded the NMES intake recommendation. Mean frequency of NMES intake was 3·4 times/d. The fifty-three participants (26·4 %) who exceeded the frequency recommendation ( ≤ 4 times/d) obtained a significantly greater percentage of energy from NMES compared with those participants who met the recommendation. The food groups ‘biscuits and cakes’ (18·9 %), ‘soft drinks’ (13·1 %) and ‘table sugar’ (11·1 %) made the greatest contributions to intakes of NMES. Interventions to reduce NMES intake should focus on limiting quantity and frequency of intake of these food groups

Fat composition of organic and conventional retail milk in northeast England

This study of UK retail milk identified highly significant variations in fat composition. The survey, conducted over 2 yr replicating summer and winter, sampled 22 brands, 10 of which indicated organic production systems. Results corroborate earlier farm-based findings considering fat composition of milk produced under conventional and organic management. Organic milk had higher concentrations of beneficial fatty acids (FA) than conventional milk, including total polyunsaturated fatty acids (PUFA; 39.4 vs. 31.8 g/kg of total FA), conjugated linoleic acid cis-9,trans-11 (CLA9; 7.4 v 5.6 g/kg of FA), and α-linolenic acid (α-LN; 6.9 vs. 4.4 g/kg of FA). As expected, purchase season had a strong effect on fat composition: compared with milk purchased in winter, summer milk had a lower concentration of saturated fatty acids (682 vs. 725 g/kg of FA) and higher concentrations of PUFA (37.6 vs. 32.8 g/kg of FA), CLA9 (8.1 vs. 4.7 g/kg of FA), and α-LN (6.5 vs. 4.6 g/kg of FA). Differences identified between sampling years were more surprising: compared with that in yr 2, milk purchased in year 1 had higher concentrations of PUFA (37.5 vs. 32.9 g/kg of FA), α-LN (6.0 vs. 5.1 g/kg of FA), and linoleic acid (19.9 vs. 17.5 g/kg of FA) and lower concentrations of C16:0 and C14:0 (332 vs. 357 and 110 vs. 118 g/kg of FA, respectively). Strong interactions were identified between management and season as well as between season and year of the study. As in the earlier farm studies, differences in fat composition between systems were greater for summer compared with winter milk. Large between-year differences may be due to changes in weather influencing milk composition through forage availability, quality, and intake. If climate change predictions materialize, both forage and dairy management may have to adapt to maintain current milk quality. Considerable variation existed in milk fat composition between brands

Comparing Tea Leaf Products and Other Forages for In-vitro Degradability, Fermentation, and Methane for Their Potential Use as Natural Additives for Ruminants

Tea leaves are a rich source of plant secondary metabolites such as tannins and saponins that have the potential to manipulate rumen fermentation and to lessen methane (CH4) production.Samples of green tea (GTL), black tea (BTL), their spent leaves after water extraction (SGTL and SBTL), ryegrass hay (RH), ryegrass silage (RS), paddy straws (PS), barley straws (BS), and wheat straws (WS) were compared for their rumen in-vitro organic matter degradability (IVOMD, g/kg DM), pH, ammonia (NH3, mg/L), total volatile fatty acids (tVFA, mmol/L), total gas production (tGP, L/kg OM), and methane output (CH4,L/kg OM) after 28h incubation with buffered rumen fluid under anaerobic conditions at 39oC in glass syringes. One-way ANOVA on Minitab 16 was used to examine differences between products at P<0.05 for four replicate samples. There were no differences between tea leaf products, RH and RS but the straws tended to have lower IVOMD compared with tea leaf products and other forages. GTL produced the lowest NH3 followed by BTL, SGTL, SBTL, and other forages. There were no differences between most tea leaf products, RH, RS, and the straws for tVFA concentration but PS and WS produced the lowest tVFA. GTL, SGTL, and RH had higher tGP than BTL, SBTL, and the straws but they had a lower tGP than RS. GTL, BTL, and SBTL produced similar levels of CH4 as the straws but this was less than RS and SGTL. The results suggest that if tea leaf products are included in the straw-based diets as natural feed additives, they may improve degradability, tVFA, NH3,and tGP production without increasing CH4 output. Low NH3 production for tea leaf products could be the sign of more by-pass protein to be absorbed in small intestine.Keywords: Tea leafproducts, in-vitro measurements, and ruminants

Biologische Qualität: Mögliche Auswirkungen biologisch erzeugter Lebensmittel auf die menschliche Gesundheit

The greatly increased market share of organic food, has prompted increasing interest in investigating whether there are actual differences in the effects of organic and conventional food on health. Previous studies have focussed on composition analyses and have therefore not been able to provide definitive proof for differences between these two food production systems in terms of long-term impact on human health. Also the designs of some of these studies were inadequate to provide proof for definite composition differences. There are virtually no human dietary intervention and cohort studies, which can provide definite proof for potential health impacts. When taking into account the present knowledge in nutrition, toxicology, physiology and ecological science, there are ample examples that the methods used for production of food do impact on food composition or other aspects of food quality, and that these differences are large enough to make a real difference for the consumer in terms of health. Fertilisation methods affect the composition of plant foods, and also the risks of contamination by mycotoxin-producing fungi. Feed and housing similarly affect the composition and microbiology of animal foods. Our understanding of what is good or bad for health advances continuously, and in several cases new data have overturned old dogmas, which were revealed to have been based on (wrong) assumptions rather than good science. For example, probably due to the generally lower availability of nitrogen to the plants, levels of certain secondary metabolites in organic fresh plant foods are consistently higher than in corresponding conventional products (typically 10-50% more). Based on epidemiological data, the increase in life expectancy by a doubling of the intake of (conventional) vegetables has been estimated to 1-2 years. So if the bioactive secondary metabolites are responsible for this effect, changing to organic vegetables without changing intake will increase the life span by 1-12 months. While the differences between production methods are likely to cause general differences in food quality between organic and conventional products, many of the methods that benefit food quality are not necessarily restricted to either organic or conventional systems. Understanding the links between production methods and food quality therefore allows improvement of the products of any system, whether organic or conventional

Effect of dietary starch level and high rumen-undegradable protein on endocrine-metabolic status, milk yield, and milk composition in dairy cows during early and late lactation

Diet composition defines the amount and type of nutrients absorbed by dairy cows. Endocrine-metabolic interactions can influence these parameters, and so nutrient availability for the mammary gland can significantly vary and affect milk yield and its composition. Six dairy cows in early and then late lactation received, for 28 d in a changeover design, 2 diets designed to provide, within the same stage of lactation, similar amounts of rumen fermentable material but either high starch plus sugar (HS) content or low starch plus sugar content (LS). All diets had similar dietary crude protein and calculated supply of essential amino acids. Dry matter intake within each stage of lactation was similar between groups. Milk yield was similar between groups in early lactation, whereas a higher milk yield was observed in late lactation when feeding HS. At the metabolic level, the main difference observed between the diets in both stages of lactation was lower blood glucose in cows fed LS. The lower glucose availability during consumption of LS caused substantial modifications in the circulating and postprandial pattern of metabolic hormones. Feeding LS versus HS resulted in an increase in the ratio of bovine somatotropin to insulin. This increased mobilization of lipid reserves resulted in higher blood concentrations of nonesterified fatty acids and β-hydroxybutyrate, which contributed to the higher milk fat content in both stages of lactation in the LS group. This greater recourse to body fat stores was confirmed by the greater loss of body weight during early lactation and the slower recovery of body weight in late lactation in cows fed LS. The lower insulin to glucagon ratio observed in cows fed LS in early and late lactation likely caused an increase in hepatic uptake and catabolism of amino acids, as confirmed by the higher blood urea concentrations. Despite the higher catabolism of amino acids in LS in early lactation, similar milk protein output was observed for both diets, suggesting similar availability of amino acids for peripheral tissue and mammary gland. The latter could be the result of sparing of amino acids at the gut level due to starch that escaped from the rumen, and to the balanced amino acid profile of digestible protein. This last aspect appears worthy of further research, with the aim to enhance the efficiency of protein metabolism of dairy cows, reducing environmental nitrogen pollution without affecting milk yield potential

Biological activity of alginate and its effect on pancreatic lipase inhibition as a potential treatment for obesity

Alginates are classed as a dietary fibre and have been shown to inhibit digestive enzymes in vitro, and therefore could be used as an obesity treatment. The current study aims to assess whether alginate in a bread vehicle maintains its inhibition properties despite cooking and digestion, and may therefore be used as a potential treatment for obesity. After 180 min in a model gut that replicates digestion in the mouth, stomach and small intestines alginate bread (AB), control bread (CB), CB with Manucol® DM alginate, free DM alginate and model gut solution were collected. DM, LFR 5/60 and SF200 were heated at 37 °C and 200 °C, with DM also heated at 50, 100 and 150 °C. Samples from the model gut and heated alginate were assessed for molecular size and inhibition properties using viscosity, gel filtration and a lipase turbidity assay. AB does not significantly increase viscosity in the model gut. Viscosity of alginate reduces beyond 100 °C, although alginate retains its inhibition properties up to 150 °C. Cooking into the bread does not reduce the molecular size of the alginate or affect its inhibition properties. These data demonstrate the robustness of alginates lipase inhibition despite the cooking process and digestion. Therefore adding alginate to a bread vehicle may have the potential in the treatment for obesity

Acceptability of alginate enriched bread and its effect on fat digestion in humans

Lifestyle interventions and physical activity remain the cornerstone of obesity management, as pharmacological therapies (orlistat) are associated with gastrointestinal (GI) side effects. Combining orlistat with fibers can reduce side effects, improving compliance. Therefore, a fiber that inhibits lipase without side effects could help treat obesity. The aims of the present work were to assess whether alginate enriched bread could inhibit fat digestion, and assess the acceptability of alginate bread and its effect on GI wellbeing. A double-blind, randomised, controlled cross-over pilot study (NCT03350958) assessed the impact of an alginate bread meal on; lipid content in ileal effluent and circulating triacylglycerol levels. This was compared against the same meal with non-enriched (control) bread. GI wellbeing and acceptability of alginate bread was compared to control bread through daily wellbeing questionnaires and food diaries (NCT03477981). Control bread followed by alginate bread were consumed for two weeks respectively. Consumption of alginate bread reduced circulating triacylglycerol compared to control (2% reduction in AUC) and significantly increased lipid content in ileal effluent (3.8 g ± 1.6 after 210 min). There were no significant changes to GI wellbeing when comparing alginate bread to control bread. A significant increase in the feeling of fullness occurred with alginate bread compared to baseline and the first week of control bread consumption. This study showed that sustained consumption of alginate enriched bread does not alter GI wellbeing and can decrease lipolysis, increasing lipid leaving the small intestine. Further studies are required to demonstrate that reduced fat digestion through the action of alginate can reduce fat mass or body weight

Dietary exposure biomarker-lead discovery based on Metabolomics analysis of urine samples

Although robust associations between dietary intake and population health are evident from conventional observational epidemiology, the outcomes of large-scale intervention studies testing the causality of those links have often proved inconclusive or have failed to demonstrate causality. This apparent conflict may be due to the well-recognised difficulty in measuring habitual food intake which may lead to confounding in observational epidemiology. Urine biomarkers indicative of exposure to specific foods offer information supplementary to the reliance on dietary intake self-assessment tools, such as FFQ, which are subject to individual bias. Biomarker discovery strategies using non-targeted metabolomics have been used recently to analyse urine from either short-term food intervention studies or from cohort studies in which participants consumed a freely-chosen diet. In the latter, the analysis of diet diary or FFQ information allowed classification of individuals in terms of the frequency of consumption of specific diet constituents. We review these approaches for biomarker discovery and illustrate both with particular reference to two studies carried out by the authors using approaches combining metabolite fingerprinting by MS with supervised multivariate data analysis. In both approaches, urine signals responsible for distinguishing between specific foods were identified and could be related to the chemical composition of the original foods. When using dietary data, both food distinctiveness and consumption frequency influenced whether differential dietary exposure could be discriminated adequately. We conclude that metabolomics methods for fingerprinting or profiling of overnight void urine, in particular, provide a robust strategy for dietary exposure biomarker-lead discovery.</jats:p