Nutrition reviews
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Chemotherapy-induced nausea and vomiting (CINV) is a common side-effect of cytotoxic treatment. It continues to affect a significant proportion of patients despite the widespread use of antiemetic medication. In traditional medicine, ginger (Zingiber officinale) has been used to prevent and treat nausea in many cultures for thousands of years. ⋯ All studies were assessed on methodological quality and their limitations were identified. Studies were mixed in their support of ginger as an anti-CINV treatment in patients receiving chemotherapy, with three demonstrating a positive effect, two in favor but with caveats, and two showing no effect on measures of CINV. Future studies are required to address the limitations identified before clinical use can be recommended.
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Vegetarians are at risk for vitamin B(12) (B12) deficiency due to suboptimal intake. The goal of the present literature review was to assess the rate of B12 depletion and deficiency among vegetarians and vegans. Using a PubMed search to identify relevant publications, 18 articles were found that reported B12 deficiency rates from studies that identified deficiency by measuring methylmalonic acid, holo-transcobalamin II, or both. ⋯ Higher rates of deficiency were reported among vegans compared with vegetarians and among individuals who had adhered to a vegetarian diet since birth compared with those who had adopted such a diet later in life. The main finding of this review is that vegetarians develop B12 depletion or deficiency regardless of demographic characteristics, place of residency, age, or type of vegetarian diet. Vegetarians should thus take preventive measures to ensure adequate intake of this vitamin, including regular consumption of supplements containing B12.
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The field of research examining the link between dehydration and endurance performance is at the dawn of a new era. This article reviews the latest findings describing the relationship between exercise-induced dehydration and endurance performance and provides the knowledge necessary for competitive, endurance-trained athletes to develop a winning hydration strategy. Acute, pre-exercise body weight loss at or above 3% may decrease subsequent endurance performance. ⋯ During exercise lasting 1 h or less, dehydration does not decrease endurance performance, but athletes are encouraged to mouth-rinse with sports drinks. During exercise lasting longer than 1 h, in which fluid is readily available, drinking according to the dictates of thirst maximizes endurance performance. In athletes whose thirst sensation is untrustworthy or when external factors such as psychological stress or repeated food intake may blunt thirst sensation, it is recommended to program fluid intake to maintain exercise-induced body weight loss around 2% to 3%.
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Concern about the role of beverages, especially those containing sugar, in the obesity epidemic continues to escalate. Bans on sugar-sweetened beverages and chocolate milk have expanded from the school cafeteria to the ballpark and convenience store. This review describes the experience of the 2010 Dietary Guidelines Advisory Committee (DGAC) in conducting an evidence-based review of dietary exposure and health outcomes. ⋯ Fluid intake is typically not tracked in prospective, cohort longitudinal studies; thus, data are not available on fluid intake and health status from studies using the strongest epidemiologic designs. Despite public perception that beverages are linked to increased body weight compared with whole foods, evidence-based reviews of this topic do not support that liquid calories are processed differently in the body. The practical recommendation to replace caloric beverages with water as an aid to control weight is based on calorie reduction, rather than a link between added-sugar intake and obesity.
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Patients in the intensive care unit (ICU) are unable to nourish themselves orally. In addition, critical illness increases nutrient requirements as well as alters metabolism. Typically, ICU patients rapidly become malnourished unless they are provided with involuntary feeding either through a tube inserted into the GI tract, called enteral nutrition (EN), or directly into the bloodstream, called parenteral nutrition (PN). ⋯ Hence, the balanced perspective has been reached of using EN when possible but avoiding underfeeding by supplementing with PN when required. This new role for PN is currently being debated and studied. In addition, the relative merits and needs for protein, carbohydrates, lipids, and micronutrients are areas of study.