Nutrition
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The prevalence of Alzheimer's disease, a chronic neurodegenerative condition, is increasing as is the need for effective treatments and preventions. The underlying pathology of Alzheimer's is not yet fully understood, so existing research has focused on understanding the prominent features of the disease. These include amyloid plaques, which accumulate in the brains of those with Alzheimer's disease; impaired glucose metabolism; and neuronal cell death. ⋯ Research has begun to identify early underlying mechanisms in Alzheimer's disease that could be targeted by new prevention strategies. Glycation of the ApoE protein leads to impaired transportation of important lipids, including cholesterol, to the brain, resulting in lipid deficiencies that could explain progression to the later pathologies of the disease. In this review, we hypothesize that the ketogenic diet could be an effective treatment and prevention for Alzheimer's disease, but both ketone production and carbohydrate restriction may be needed to achieve this.
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High altitudes are a challenge for human physiology and for sports enthusiasts. Several reasons lead to deterioration in performance at high altitudes. Hypoxia owing to high altitude causes a breakdown of homeostasis with imbalance in several physiological systems, including the immune system. ⋯ Although the association between exercise and hypoxia has been shown to be more severe for the body owing to the sum of stressful agents, supplementation with carbohydrates and glutamine seems to play a relevant role in mitigating immunosuppressive effects. These findings, although limited by the fact that they are the result of very few studies, shed light on a relevant theme for sports physiology and nutrition and suggest that both supplements may be useful for athletes, visitors, and workers in high-altitude regions. The aim of this review was to discuss the effects of high-altitude hypoxia on the human body from the point of view of exercise immunology because it is known that transient immunosuppression after strenuous exercise and competition should be followed by reduction in training overload and worse performance.
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Increased blood flow via vasodilation, metabolite production, and venous pooling contribute to the hyperemia and cellular swelling experienced during resistance training. It has been suggested that these effects play a role in hypertrophic adaptations. Over the past 2 decades, sport supplement products have been marketed to promote exercise hyperemia and intracellular fluid storage, thereby enhancing hypertrophy via acute swelling of myocytes. ⋯ Although we recognize that the literature is relatively scarce regarding these topics, a better comprehension and discussion of these determinants can lead to increased knowledge and might guide further research regarding the proposed mechanisms of action of the identified compounds. In this case, increased knowledge may contribute to the development of improved efficacy, new products, or direct new research to specifically investigate those secondary effects. The aim of this review was to bring into focus new perspectives associated with secondary physiological effects induced by supplementation and to determine their relevance.
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Although current guidelines for obesity treatment endorse lifestyle modifications to achieve weight loss, energy-restricted diets are still the most commonly used method for the management of overweight. Diet restriction, however, not only is ineffective in promoting long-term weight loss but also may have more costs than benefits, predisposing the individual to fat regain. Several physiological and psychological mechanisms protect the body against starvation and explain how food restriction can promote paradoxically the opposite of what it is planned to achieve, triggering changes in energy metabolism, endocrine function and, thus, body composition. New approaches that focus on behavioral treatment without diet restriction, such as nutritional coaching, are showing strong growth that arises as an innovative way to create sustainable and effective lifestyle changes.
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Vitamin C exhibits interesting properties in the context of critical illness, with benefits described in neurologic, cardiovascular, renal, and hematologic systems, both in in vitro and in animal models. Through direct effects on bacterial replication, immunomodulation, and antioxidant reserve of the organism, vitamin C directly affects the pathophysiological process of sepsis, trauma, burn, and systemic inflammation. Even if several observational trials have linked vitamin C deficiency to worse outcomes, the evidence is not such as to provide us with a distinction between causality effects or simple epiphenomenon, and the current focus is on interventional trials. ⋯ Current guidelines do not support the administration of high-dose vitamin C in critically ill patients. Future larger trials are required to support any therapy, but the low cost and safety profile can justify supplementation in the meantime. Metabolomics study will further help understand biological effect.