Animal board invited review: The contribution of red meat to adult nutrition and health beyond protein.

Red meat has been a critical part of human diets for millennia, providing a source of high-quality protein, micronutrients and essential fatty acids. However, as societies evolved and industrialisation reshaped our food systems, there has been a noticeable shift in meat-eating trends driven by concerns about the environmental impact of meat production and its potential risk to health. Yet, despite falling out of favour with some dietary experts and influencers, meat has an important role in a healthy diet and most adults still consume it. This article explores the nutritional value of red meat, authorised nutrition and health claims, how red meat fits into diet, providing the example of the United Kingdom (UK), and the health benefits and risks associated with both eating and avoiding red meat. Benefits of red meat include nutrient density and bioavailability while risks include colorectal cancer at high intakes of processed meats, based on observational studies. Benefits of meat-free diets include a lower risk of chronic diseases, based on observational studies, while risks include nutrient inadequacy, higher bone fracture risk and low protein quality. Hence, a wholesale shift to plant-based diets may not benefit adults who are vulnerable to sub-optimal nutrient intakes, such as women of child-bearing age and the elderly. More evidence from randomised controlled trials is recommended to fully understand the benefits and risks of both meat-containing and meat-free diets.

Scientific evidence and daily food for a better life: Milan, 19 June 2015.

This paper presents a report of a nutrition conference held at EXPO 2015 in Milan. Over the course of a day, seven speakers from four continents discussed the evidence and scientific processes that underpin the development of dietary guidelines, highlighting issues and challenges at each stage. These include the quality of studies associating disease outcomes with diet, specifically a reliance on observational studies, short duration of intervention trials, low statistical power and lack of follow-up. Concerns were raised over the oversimplification of dietary messages which promote carbohydrates in general without evidence of benefit, while restricting fats when meta-analyses suggests that different fatty acids have different effects on disease risk. The merits of food-based dietary guidelines and holistic dietary patterns were described, whereas the impact of increasing or reducing consumption of individual food groups or macronutrients remains unclear. The meeting ended with a restatement of the importance of dietary guidelines, and associated education, to improve public health, but a plea was made to ensure that the process of setting guidelines is evidence based, responsive and considers the impact of the whole diet.

Role of fatty acids and micronutrients in healthy ageing: a systematic review of randomised controlled trials set in the context of European dietary surveys of older adults.

BACKGROUND: Ageing is a multifaceted and inevitable process involving a decline in health and well-being that could be ameliorated by dietary modification. We review and discuss the evidence for nutritional interventions that may support healthy ageing. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to identify randomised controlled trials investigating the role(s) of fatty acids and micronutrients in relation to markers of healthy ageing. RESULTS: European dietary surveys suggest that diets in elderly people are generally high in saturated fat, whereas intakes of vitamin D, magnesium, potassium, zinc and copper are below recommended levels. Thirty-four studies meeting the criteria were found, with 12 of these investigating the role of fatty acids and 22 considering intakes of micronutrients in relation to healthy ageing. Overall, these studies suggested that certain nutrients were consistent with healthy ageing; for example, omega-3 fatty acids were helpful for cognitive health, whereas combinations of calcium, vitamin D and K were linked with better bone health. CONCLUSIONS: Vitamin, mineral and fatty acid intakes are in need of improvement to help elderly populations achieve optimal diet quality and support healthy ageing. This could involve the judicious use of supplements alongside dietary advice. Additional research is needed to determine optimal nutrient doses, combinations and forms in relation to desired health outcomes.

The suitability of caffeinated drinks for children: a systematic review of randomised controlled trials, observational studies and expert panel guidelines.

BACKGROUND: The increased availability of caffeinated drinks raises questions about the level of caffeine that is appropriate for children, as well as the benefits and risks associated with their consumption. METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, this systematic review evaluates evidence from randomised controlled trials investigating the effects of caffeine on cognition, behaviour, mood and exercise performance in children. Observational studies and expert panel guidelines are also discussed. RESULTS: One hundred and nine studies were found, with 11 randomised controlled trials and 13 observational studies meeting the criteria. High caffeine intakes (e.g. >5 mg kg(-1) body weight day(-1)) were associated with an increased risk of anxiety and withdrawal symptoms. However, smaller amounts were not linked with such effects and may benefit cognitive function and sports performance based on adult studies. The evidence suggests that children and adolescents should limit daily caffeine consumption to 2.5 mg kg(-1) body weight day(-1), equating to one or two cups of tea or one small cup of coffee. Lower contributors of caffeine, such as tea, may be more appropriate for children because they contribute to daily fluid intakes and provide flavonoids. By contrast, caffeinated soft drinks may be less suitable options for children as a result of their acidity, higher caffeine content, presence of added sugar (in some cases) and absence of bioactive compounds. CONCLUSIONS: More studies are needed to determine the intakes that represent a risk and whether there may be benefits for alertness and sports performance with moderate intakes of caffeine.

Is sugar consumption detrimental to health? A review of the evidence 1995-2006.

Many countries set quantitative targets for added sugars, justifying this by expressing concern about the likely impact of sugar on weight control, dental health, diet quality, or metabolic syndrome. This review considers whether current intakes of sugar are harmful to health, and analyses recent literature using a systematic approach to collate, rank, and evaluate published studies from 1995-2006. Results from high quality obesity studies did not suggest a positive association between body mass index and sugar intake. Some studies, specifically on sweetened beverages, highlighted a potential concern in relation to obesity risk, although these were limited by important methodological issues. Diet adequacy appeared to be achieved across sugar intakes of 6 to 20% energy, depending on subject age. Studies on metabolic syndrome reported no adverse effects of sugar in the long-term, even at intakes of 40-50% energy. The evidence for colorectal cancer suggested an association with sugar, but this appeared to have been confounded by energy intake and glycemic load. There was no credible evidence linking sugar with attention-deficit, dementia, or depression. Regarding dental caries, combinations of sugar amount/frequency, fluoride exposure, and food adhesiveness were more reliable predictors of caries risk than the amount of sugar alone. Overall, the available evidence did not support a single quantitative sugar guideline covering all health issues.

Risk of malnutrition in a sample of acute and long-stay NHS Fife in-patients: an audit.

BACKGROUND: Hospital malnutrition (undernutrition) continues to attract concern. The implementation of standards for food and fluids in Scotland provided the stimulus for an audit of current practices in NHS Fife hospitals in order to provide baseline data with which to evaluate progress. METHODS: One hundred and fifty in-patients were recruited from wards likely to yield those with a high risk of malnutrition. Using patient records and anthropometry, data were collected on weight, weight change, body mass index (BMI), mid-upper-arm circumference (MUAC), dietetic referral, therapeutic diets and patients' perceptions of nutritional status. Malnutrition was estimated by comparing BMI, weight change and MUAC with the Malnutrition Universal Screening Tool (MUST) and standards published by the Scottish Intercollegiate Guidelines Network (SIGN). RESULTS: Depending upon the standard used, the minimum risk of malnutrition varied from 14 to 25%. The prevalence was lower than that reported previously, although methods were not directly comparable. Obesity was also evident with 42% of patients having a BMI > 25. Mean weight change from admission to audit was +0.4 kg, with a wide range (-11 kg to +13 kg). Most patients identified as malnourished were referred to the dietitian or given nutritional support. CONCLUSIONS: Fewer patients were at risk of malnutrition than expected. However, improving the provision of food and fluids remains a priority in Fife as malnutrition and eating problems can occur across the entire BMI spectrum.

Black tea--helpful or harmful? A review of the evidence.

OBJECTIVE: To consider whether consumption of black tea has a positive or negative impact on health. DESIGN: Databases were searched for relevant epidemiological and clinical studies published between 1990 and 2004. RESULTS: Clear evidence was found for coronary heart disease (CHD), where an intake of > or = 3 cups per day related to risk reduction. The mechanism could involve the antioxidant action of tea polyphenols. While experimental models have suggested that flavonoids attenuated cancer risk, epidemiological studies failed to demonstrate a clear effect for tea, although there is moderate evidence for a slightly positive or no effect of black tea consumption on colorectal cancer. Studies on cancer were limited by sample sizes and insufficient control of confounders. There is moderate evidence suggestive of a positive effect of black tea consumption on bone mineral density although studies were few. There is little evidence to support the effect of tea on dental plaque inhibition but evidence to support the contribution of tea to fluoride intakes and thus theoretical protection against caries. There was no credible evidence that black tea (in amounts typically consumed) was harmful. Normal hydration was consistent with tea consumption when the caffeine content was < 250 mg per cup. A moderate caffeine intake from tea appeared to improve mental performance, although sample sizes were small. There was no evidence that iron status could be harmed by tea drinking unless populations were already at risk from anaemia. CONCLUSIONS: There was sufficient evidence to show risk reduction for CHD at intakes of > or = 3 cups per day and for improved antioxidant status at intakes of one to six cups per day. A maximum intake of eight cups per day would minimise any risk relating to excess caffeine consumption. Black tea generally had a positive effect on health.

Feasibility and benefits of implementing a Slimming on Referral service in primary care using a commercial weight management partner.

OBJECTIVES: To assess participation in a costed Slimming on Referral service and identify factors associated with success. STUDY DESIGN: Simple intervention offering participation in a new service to 100 eligible patients. The setting was two Derby general practices, one inner city and one suburban. PARTICIPANTS: One hundred and seven patients (mean age 50 years) attending general practice for non-obesity reasons. INCLUSION CRITERIA: BMI > or = 30, age > or = 18 years, not pregnant, no recent commercial weight management group membership, willingness to attempt weight loss. METHODS: Patients were offered free attendance at a local Slimming World group for 12 consecutive weeks. Body weight and height were measured at baseline, and questionnaires established perceived health, motivation to lose weight, employment, concerns, responsibilities and well-being. Weight was measured at each group visit. The main outcome measures were: (1) changes in body weight at 12 and 24 weeks, (2) social and demographic factors associated with barriers to enrolment, continued attendance and successful weight loss. RESULTS: Ninety-one (85%) patients attended a group, with 62 completing 12 weeks. Average weight loss in participants was 5.4 kg (6.4% baseline weight). Forty-seven then chose to self-fund, with 34 (37% original group) completing a further 12 weeks. Average weight loss over the total 24 weeks was 11.1 kg (11.3% baseline weight). Regular attendance was affected by income, financial concerns (independent of actual income), age, perceived importance of weight loss and initial weight loss success. Well-being of patients significantly improved between baseline and both 12 and 24 weeks. CONCLUSIONS: Collaboration with an appropriate commercial weight management organization offers a feasible weight management option that is either similar to, or better than, other options in terms of attrition, efficacy and cost.

Vulnerable patients with a fractured neck of femur: nutritional status and support in hospital.

BACKGROUND AND AIM: Malnutrition has serious consequences for recovery and increases the risk of complications in hospital patients. Fractured neck of femur (NOF) patients may be particularly at risk because of their old age and frail state of health. We conducted an observational study to evaluate the nutritional state and the nutritional support, which was provided to this group during their stay in hospital. METHODS: Twenty-five consecutive people admitted to an orthopaedic ward with a fractured NOF at Charing Cross Hospital, London were recruited. Anthropometric measures, biochemical indices, 3 days dietary intake and dietetic referral rates were collected. RESULTS: Patients had a significantly lower body mass index (BMI) compared with the mean BMI for sex and age in an elderly UK population (21.97 +/- 1.06 versus 26.73 +/- 0.03 kg m(-2); P < 0.005). They took just 58.6% of their energy requirements in hospital (4219 +/- 319 versus 7199 +/- 202 kJ mean(-1) daily intake over 3 days in week 2). Using the hospitals own nutritional risk assessment tool 56% of patients were found to be at risk of malnutrition on admission, which increased to 68% after 2-3 weeks. Of these 64% were referred to a dietitian and were given nutritional supplements. Nutritional assessment revealed that their nutritional status worsened during stay. CONCLUSIONS: This group of patients with fractured NOF is likely to be malnourished on admission and to show a rapid deterioration in its nutrition status during admission. Energy needs were not met in up to 50% of patients. These results reinforce the need to screen, supplement and monitor fractured NOF patients.

The impact of long-chain n-3 polyunsaturated fatty acids on human health.

A considerable literature has been published on the health benefits of fish, oil-rich fish and fish oils and their constituent long-chain (LC) n-3 PUFA. Evidence from epidemiological studies highlights the cardioprotective attributes of diets rich in fish, especially oil-rich fish. Data from intervention trials are consistent in suggesting that LC n-3 PUFA lower the risk of CVD, probably by the multiple mechanisms of lowering serum triacylglycerols, improving the LDL:HDL ratio, anti-arrhythmic effects on heart muscle, improved plaque stability, anti-thrombotic effects and reduced endothelial activation. Research indicates LC n-3 PUFA provision has an impact during development, and there is preliminary evidence that docosahexaenoic acid supplementation during pregnancy could optimise brain and retina development in the infant. LC n-3 PUFA are also postulated to ameliorate behavioural and mental health disturbances such as depression, schizophrenia, dementia and attention deficit hyperactivity disorder. However, despite some positive evidence in each of these areas, use of LC n-3 PUFA in these conditions remains at the experimental stage. In the case of immune function, there is little doubt that LC n-3 PUFA have a positive effect. Although intervention trials in rheumatoid arthritis show strong evidence of benefit, evidence for efficacy in other inflammatory conditions, including Crohn's disease, ulcerative colitis, psoriasis, lupus, multiple sclerosis, cystic fibrosis and asthma, is inconsistent or inadequate. More promising evidence in some conditions may come from studies which attempt to modify the fetal environment using LC n-3 PUFA supplementation during pregnancy.

The health benefits of omega-3 polyunsaturated fatty acids: a review of the evidence.

The UK dietary guidelines for cardiovascular disease acknowledge the importance of long-chain omega-3 polyunsaturated fatty acids (PUFA) - a component of fish oils - in reducing heart disease risk. At the time, it was recommended that the average n-3 PUFA intake should be increased from 0.1 to 0.2 g day(-1). However, since the publication of these guidelines, a plethora of evidence relating to the beneficial effects of n-3 PUFAs, in areas other than heart disease, has emerged. The majority of intervention studies, which found associations between various conditions and the intake of fish oils or their derivatives, used n-3 intakes well above the 0.2 g day(-1) recommended by Committee on Medical Aspects of Food Policy (COMA). Furthermore, in 2004, the Food Standards Agency changed its advice on oil-rich fish creating a discrepancy between the levels of n-3 PUFA implied by the new advice and the 1994 COMA guideline. This review will examine published evidence from observational and intervention studies relating to the health effects of n-3 PUFAs, and discuss whether the current UK recommendation for long-chain n-3 PUFA needs to be revisited.

An investigation of the role of oro-sensory stimulation in sugar satiety?

OBJECTIVE: To investigate whether oral factors stimulated by the presence of sucrose in the mouth are involved in the suppression of appetite following sucrose ingestion. DESIGN: Ten male and 10 female healthy volunteers participated in four experimental conditions designed to provide differing levels of oro-sensory stimulation. Appetite and energy intake from a test meal were measured after subjects chewed and ingested sucrose-containing pastilles over a 10 min period, consumed a sucrose-containing jelly over a 5 min period, consumed a sucrose-containing drink within 2 min and drank plain water within 2 min. The three sucrose-containing preloads were similar in nutrient composition, each containing 251 kJ. RESULTS: Ratings of hunger and fullness did not differ between the four conditions following ingestion of the preloads. However, energy intake from a test lunch was significantly reduced after consuming the pastilles when compared with the plain water and equicaloric sweet drink conditions. CONCLUSION: These results suggest that enhanced oro-sensory stimulation from chewing the sweet food was involved in the suppression of food intake.