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.

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 LCn-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 LCn-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. LCn-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 LCn-3 PUFA in these conditions remains at the experimental stage. In the case of immune function, there is little doubt that LCn-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 LCn-3 PUFA supplementation during pregnancy.

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 X3 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 o250 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 X3 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. Sponsorship: The Tea Council. The authors confirm that the sponsors played no role in the writing of this review.

The present paper reviews the literature on breakfast to consider reported associations between breakfast and nutritional, physiological and biochemical variables. The contribution of breakfast to achieving nutrition targets for fat, carbohydrate and dietary fibre intakes is also examined as are the potential effects of fortified breakfast cereals on intakes of micronutrients and nutritional status. Breakfast consumption, particularly if the meal includes a breakfast cereal, is associated with lower intakes of fat and higher intakes of carbohydrate, dietary fibre and certain micronutrients. These findings may be relevant to population groups which could be at risk from low intakes of certain micronutrients, but further clarification of benefit is needed from studies of nutritional status. Associations between breakfast consumption and lower cholesterol levels have been reported, while lower body weights have been seen amongst breakfast eaters. It is concluded that breakfast consumption is a marker for an appropriate dietary pattern in terms of both macro-and micronutrients, particularly if breakfast cereals are included in the meal. Breakfast: Micronutrients: Dietary fatMuch interest has focused on the role of breakfast in the diet, probably due to anecdotal evidence of its effects on nutrition and physiology. The result has been a plethora of studies aimed at making an objective assessment of such claims. The present paper examines studies reporting associations between breakfast and a number of important health-related issues: dietary intake, nutritional status, serum lipids, appetite and body weight. The case of breakfast cereals, which appear to be the most commonly-eaten food at breakfast, will be highlighted where it has been reported separately in the literature. The role of breakfast in the diet will be discussed in the context of dietary guidelines to reduce percentage energy from fat, increase carbohydrate and fibre intakes and ensure appropriate intakes of vitamins and minerals. BREAKFAST CONSUMPTIONReports on breakfast consumption indicate that children under 10 years old and adults over 65 years eat breakfast on a more regular basis than any other age group. Breakfast omission is most frequent in young adults and children aged between 13 and 16 years, 7 % of whom have nothing to eat before attending school (Gardner Merchant, 1996). Curry & Todd (1992) reported that only 62 % of 11-15-year-olds took breakfast every day and that 20 %

The reputed benefits of moderate caffeine consumption include improvements in physical endurance, cognitive function, particularly alertness and vigilance, mood and perception of fatigue. In contrast, there are concerns that excessive intakes increase the risks of dehydration, anxiety, headache and sleep disturbances. This paper is a review of double-blind, placebo-controlled trials published over the past 15 years to establish what range of caffeine consumption would maximise benefits and minimise risks for cognitive function, mood, physical performance and hydration. Of the 41 human studies meeting the inclusion criteria, the majority reported benefits associated with low to moderate caffeine intakes (37.5 to 450 mg per day). The available studies on hydration found that caffeine intakes up to 400 mg per day did not produce dehydration, even in subjects undergoing exercise testing. It was concluded that the range of caffeine intake that appeared to maximise benefit and minimise risk is 38 to 400 mg per day, equating to 1 to 8 cups of tea per day, or 0.3 to 4 cups of brewed coffee per day. The limitations of the current evidence base are discussed.