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Cupar, United Kingdom

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. © 2013 The British Dietetic Association Ltd. Source

Ruxton C.H.S.,Nutrition Communications | Derbyshire E.,Manchester Metropolitan University
Nutrition Bulletin | Year: 2010

Women's diets are of interest as they not only impact on wellbeing and risk of chronic disease in women themselves, but also influence pregnancy outcomes and infant health. UK dietary surveys show that, while some improvements have occurred, intakes of key micronutrients, particularly iron, vitamin D, calcium and folate remain below recommended levels. Women's diets are also too high in saturated fat and salt, and low in fibre, oily fish and fruits and vegetables. Evidence suggests that certain chronic conditions are influenced by dietary components, e.g. inadequate calcium and vitamin D intakes reduce bone density, salt and saturated fat increase cardiovascular disease risk, excessive alcohol intakes increase cancer risk, low intakes of long chain n-3 fatty acids may adversely affect fetal development and mental health, while adequate folic acid reduces the risk of birth defects. Focused health initiatives are needed to improve diet quality in women, particularly school-aged girls, women planning a pregnancy, those living in areas of deprivation and elderly women. Vitamin and mineral supplements, and fortified foods may have a role to play alongside dietary improvements in helping women to achieve optimal diet quality. © 2010 The Authors. Journal compilation © 2010 British Nutrition Foundation. Source

Ruxton C.H.,Nutrition Communications | Hart V.A.,Reading Scientific Services Ltd
British Journal of Nutrition | Year: 2011

There is a belief that caffeinated drinks, such as tea, may adversely affect hydration. This was investigated in a randomised controlled trial. Healthy resting males (n 21) were recruited from the general population. Following 24 h of abstention from caffeine, alcohol and vigorous physical activity, including a 10 h overnight fast, all men underwent four separate test days in a counter-balanced order with a 5 d washout in between. The test beverages, provided at regular intervals, were 4 Ã-240 ml black (i.e. regular) tea and 6 Ã-240 ml black tea, providing 168 or 252 mg of caffeine. The controls were identical amounts of boiled water. The tea was prepared in a standardised way from tea bags and included 20 ml of semi-skimmed milk. All food taken during the 12 h intervention period was controlled, and subjects remained at rest. No other beverages were offered. Blood was sampled at 0, 1, 2, 4, 8 and 12 h, and a 24 h urine sample was collected. Outcome variables were whole blood cell count, Na, K, bicarbonate, total protein, urea, creatinine and osmolality for blood; and total volume, colour, Na, K, creatinine and osmolality for urine. Although data for all twenty-one participants were included in the analysis (mean age 36 years and mean BMI 25•8 kg/m 2), nineteen men completed all conditions. Statistical analysis, using a factorial ANOVA approach within PROC MIXED, revealed no significant differences between tea and water for any of the mean blood or urine measurements. It was concluded that black tea, in the amounts studied, offered similar hydrating properties to water. © 2011 The Authors. Source

Ruxton C.H.S.,Nutrition Communications
Nutrition Bulletin | Year: 2011

Overweight and obese people appear to be at greater risk of suboptimal vitamin and mineral status compared with people of a healthy weight. Nutrients most affected include vitamin D, vitamin B12, carotenoids, folate, vitamin C and iron. The reasons are unknown but may be caused by poor diets, increased requirements or obesity-related changes to nutrient absorption, excretion or metabolism, or a combination of these. Sequestration of fat-soluble vitamins by adipose tissues is also a major factor. Although dietary assessment in obese populations is hampered by under-reporting, there is evidence that dietary patterns characterised by energy-dense, processed foods are more common in groups with a higher body mass index. Dieting practices, bariatric surgery and the use of anti-obesity drugs may compound the risk of nutrient inadequacy, although sustained weight loss helps to improve vitamin D status. A poor nutrient status could accentuate the risk of chronic diseases already experienced by overweight people on account of their excessive fat mass. There is evidence that the use of dietary supplements can improve nutrient status and have a favourable impact on disease risk markers such as lipid profiles and insulin resistance. Whether currently dieting or not, overweight people may benefit from safeguarding vitamin and mineral adequacy by taking a multi-nutrient supplement alongside an increased intake of nutrient-rich foods. © 2011 The Authors. Journal compilation © 2011 British Nutrition Foundation. Source

Ruxton C.H.,Nutrition Communications
International Journal of Food Sciences and Nutrition | Year: 2016

This report summarises the proceedings of a conference organised by the Italian Association of Hospital Cardiologists. The aim was to consider the process by which dietary guidelines (DG) are developed and the quality of evidence underpinning these guidelines, as well as debating whether or not this has resulted in DG that are effective in terms of health improvement. Key points were a caution about false positives in research, the importance of holistic DG rather than single nutrient targets, the need for appropriate disease endpoints in studies and control of confounders, a plea for less reliance on observational studies which cannot address cause-and-effect relationships and a need to bear in mind unintended consequences. Options for improving the system and the quality of evidence were discussed. © 2015 Taylor & Francis. Source

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