Glutathione is a tripeptide that plays a pivotal role in critical physiological processes resulting in effects relevant to diverse disease pathophysiology such as maintenance of redox balance, reduction of oxidative stress, enhancement of metabolic detoxification, and regulation of immune system function. The diverse roles of glutathione in physiology are relevant to a considerable body of evidence suggesting that glutathione status may be an important biomarker and treatment target in various chronic, age-related diseases. Yet, proper personalized balance in the individual is key as well as a better understanding of antioxidants and redox balance. Optimizing glutathione levels has been proposed as a strategy for health promotion and disease prevention, although clear, causal relationships between glutathione status and disease risk or treatment remain to be clarified. Nonetheless, human clinical research suggests that nutritional interventions, including amino acids, vitamins, minerals, phytochemicals, and foods can have important effects on circulating glutathione which may translate to clinical benefit. Importantly, genetic variation is a modifier of glutathione status and influences response to nutritional factors that impact glutathione levels. This narrative review explores clinical evidence for nutritional strategies that could be used to improve glutathione status.

Research into human biotransformation and elimination systems continues to evolve. Various clinical and in vivo studies have been undertaken to evaluate the effects of foods and food-derived components on the activity of detoxification pathways, including phase I cytochrome P450 enzymes, phase II conjugation enzymes, Nrf2 signaling, and metallothionein. This review summarizes the research in this area to date, highlighting the potential for foods and nutrients to support and/or modulate detoxification functions. Clinical applications to alter detoxification pathway activity and improve patient outcomes are considered, drawing on the growing understanding of the relationship between detoxification functions and different disease states, genetic polymorphisms, and drug-nutrient interactions. Some caution is recommended, however, due to the limitations of current research as well as indications that many nutrients exert biphasic, dose-dependent effects and that genetic polymorphisms may alter outcomes. A whole-foods approach may, therefore, be prudent.

Plant-based diets are associated with reduced risk of lifestyle-induced chronic diseases. The thousands of phytochemicals they contain are implicated in cellular-based mechanisms to promote antioxidant defense and reduce inflammation. While recommendations encourage the intake of fruits and vegetables, most people fall short of their target daily intake. Despite the need to increase plant-food consumption, there have been some concerns raised about whether they are beneficial because of the various ‘anti-nutrient’ compounds they contain. Some of these anti-nutrients that have been called into question included lectins, oxalates, goitrogens, phytoestrogens, phytates, and tannins. As a result, there may be select individuals with specific health conditions who elect to decrease their plant food intake despite potential benefits. The purpose of this narrative review is to examine the science of these ‘anti-nutrients’ and weigh the evidence of whether these compounds pose an actual health threat.

Background: Pancreatic enzyme replacement therapy frequently fails to correct intestinal fat malabsorption completely in cystic fibrosis (CF) patients. The reason for this failure is unknown. Objective: We investigated whether fat malabsorption in CF patients treated with pancreatic enzymes is caused by insufficient lipolysis of triacylglycerols or by defective intestinal uptake of long-chain fatty acids. Design: Lipolysis was determined on the basis of breath 13 CO 2 recovery in 10 CF patients receiving pancreatic enzyme replacement therapy after they ingested 1,3-distearoyl,2[1- 13 Results: Fecal fat excretion ranged from 5.1 to 27.8 g/d (x -± SD: 11.1 ± 7.0 g/d) and fat absorption ranged from 79% to 93% (89 ± 5%). There was no relation between breath 13 CO 2 recovery and dietary fat absorption (r = 0.04) after ingestion of [ 13 C]MTG. In contrast, there was a strong relation between 8-h plasma [ 13 C]LA concentrations and dietary fat absorption (r = 0.88, P < 0.001). Conclusion: Our results suggest that continuing fat malabsorption in CF patients receiving enzyme replacement therapy is not likely due to insufficient lipolytic enzyme activity, but rather to incomplete intraluminal solubilization of long-chain fatty acids, reduced mucosal uptake of long-chain fatty acids, or both. Am J Clin Nutr 1999;69:127-34. KEY WORDSBreath test, mixed triacylglycerol, [13 C]linoleic acid, fat malabsorption, fat balance, lipolysis, stable isotopes, cystic fibrosis, recommended dietary allowance, children, long-chain fatty acids INTRODUCTIONIn humans, triacylglycerols composed of long-chain fatty acids constitute 92-96% of dietary fats (1). Absorption of these fats is by 2 main processes. Lipolysis, by lipolytic enzymes originating predominantly in the pancreas, leads to hydrolysis of triacylglycerols into fatty acids and 2-monoacylglycerols. Second, intestinal uptake involves the formation of mixed micelles composed of bile components and lipolytic products, followed by the disintegration of the mixed micelles in the unstirred water layer and the translocation of the lipolytic products across the intestinal epithelium (1-4).Most cystic fibrosis (CF) patients malabsorb dietary fats because of pancreatic insufficiency, which leads to impaired lipolysis (5, 6). The symptoms of pancreatic insufficiency, such as steatorrhea and poor growth, can be alleviated by oral supplementation with pancreatic enzymes. However, despite recent improvements in the pharmacokinetics of these supplements, many patients continue to experience a certain degree of steatorrhea (7-9), with 10-20% of the dietary fat they consume being malabsorbed. It has not been elucidated whether this malabsorption is due to insufficient pancreatic enzyme replacement therapy. This possibility is likely because decreased pancreatic bicarbonate secretion may negatively affect enzyme activity by sustaining a low pH in the duodenum (10, 11). At a low duodenal pH, the release of enzymes from the microcapsules is inhibited and denaturation of the enzymes is stimul...