Annals of nutrition & metabolism
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Randomized Controlled Trial
Oxidant-Antioxidant Capacity of Dietary Guanidinoacetic Acid.
Guanidinoacetic acid (GAA) is an experimental nutritional additive under the functional group amino acids and derivatives, yet its use in human nutrition is hindered by limited data on GAA safety. In this double blind, placebo-controlled pilot study, we evaluated the effects of dietary GAA (3 g/day) administered for 2 weeks on the oxidant-antioxidant system in healthy men. ⋯ Oral GAA did not impact the cumulative action of antioxidants present in plasma, yet its SOD-boosting capacity might be considered beneficial when GAA is used as a dietary supplement. Further studies are needed to reveal the direct effects of GAA ingestion on markers of lipid and protein oxidation and on DNA damage.
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Non-celiac gluten sensitivity (NCGS) is a syndrome characterized by intestinal and extraintestinal symptoms related to the ingestion of gluten-containing food in subjects who are not affected by either celiac disease (CD) or wheat allergy (WA). The prevalence of NCGS is not clearly defined yet. Indirect evidence suggests that NCGS is slightly more common than CD, the latter affecting around 1% of the general population. ⋯ The diagnosis of NCGS should be considered in patients with persistent intestinal and/or extraintestinal complaints showing a normal result of the CD and WA serological markers on a gluten-containing diet, usually reporting worsening of symptoms after eating gluten-rich food. NCGS should not be an exclusion diagnosis only. Unfortunately, no biomarker is sensitive and specific enough for diagnostic purposes; therefore, the diagnosis of NCGS is currently based on establishing a clear-cut cause-effect relationship between the ingestion of gluten and the appearance of symptoms by a standardized double-blind, placebo-controlled gluten challenge.
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Too often, clinical practice guidelines, or similar documents, are of poor quality or are eminence based. Consequently, health care decisions might be based on biased or erroneous information. Here, issues related to standards for clinical practice guidelines that ensure the inclusion of objective, transparent, and scientifically valid information will be discussed. ⋯ No clinical practice guidelines are perfect. They vary significantly in quality and, therefore, in the trustworthiness of the yielded recommendations. Hence, it is important that one can distinguish evidence-based clinical practice guidelines from guidelines that are not based on evidence. Standards for the development of evidence-based guidelines have been developed. If strictly adhered to, this should lead to more valid and trustworthy guidelines.