The effects of twenty-one nutrients and phytonutrients on cognitive function: A narrative review

BACKGROUND AND AIM

Brain health is becoming more important to the average person as the number of people with cognitive impairments, such as Alzheimer's disease (AD), is rising significantly. The current Food and Drug Administration-approved pharmacotherapeutics for dementia neither cure nor halt cognitive decline; they just delay the worsening cognitive impairment. This narrative review summarizes the effects of nutrients and phytonutrients on cognitive function.

METHODS

A comprehensive literature search of PubMed was performed to find clinical trials in humans that assessed the effects of nutrients and phytonutrients on cognitive function published in English between 2000 and 2021. Six independent reviewers evaluated the articles for inclusion in this review.

RESULTS

Ninety-six articles were summarized in this narrative review. In total 21 categories of nutrients and phytonutrients were included, i.e., α-lipoic acid, Bacopa monnieri, B vitamins, cholinergic precursors, vitamin D, vitamin E, Ginkgo biloba, ginseng, lion's mane mushroom, N-acetyl cysteine, omega-3 fatty acids, aloe polysaccharides, Rhodiola rosea, rosemary, saffron, tart cherries, turmeric, wild yam, Withania somnifera, xanthines, and zinc. Particular noteworthy effects on cognition included memory, recollection, attention, intelligence, vocabulary, recognition, response inhibition, arousal, performance enhancement, planning, creative thinking, reaction time, vigilance, task switching, orientation to time, place, and person, reading, writing, comprehension, accuracy, learning, information processing speed, executive function, mental flexibility, daily functioning, decrease in mental fatigue, and freedom from distractibility. Some nutrients and phytonutrients also improved mood and contentedness and reduced anxiety and the need for caregiving. These effects are not completely consistent or ubiquitous across all patient populations or health statuses. Adverse effects were minimal or nonexistent.

CONCLUSION

Due to the growing population of people with cognitive impairment and the lack of effective pharmacotherapeutics, it is prudent for those afflicted or their caregivers to find alternative treatments. Our narrative review shows that many of these nutrients and phytonutrients may be promising for treating some aspects of cognitive impairment, especially for people afflicted with AD.

RELEVANCE FOR PATIENTS

As demonstrated in a number of clinical trials, healthy adults and patients with various health challenges (e.g., AD, mild cognitive impairment, multiple sclerosis, and Parkinson's disease) exhibiting a wide range of severity in cognitive defects would be best served to consider multiple nutrients and phytonutrients to improve aspects of their cognitive function.

The effects of twenty-four nutrients and phytonutrients on immune system function and inflammation: A narrative review

BACKGROUND AND AIM

Recently, optimal immune function has become a primary focus of worldwide attention not only in the prevention of chronic disease but also as one strategy to reduce the severity of acute illness. Inflammation, a process largely controlled by the immune system, has long been studied and recognized for its role in chronic disease. Optimizing immune function or managing inflammation using individual nutrients and phytonutrients is not well understood by the average person. Thus, this narrative literature review summarizes many of the more recent findings about how certain nutrients and phytonutrients affect immune function and inflammation, and how they may best be utilized considering the growing worldwide interest in this topic.

METHODS

A comprehensive literature search of PubMed was performed to find clinical trials in humans that assessed the effect of nutrients and phytonutrients on immune function and inflammation, in individuals with acute and chronic health conditions, published in English between 2000 and 2020. Two independent reviewers evaluated the articles for their inclusion.

RESULTS

Eighty-seven articles were summarized in this narrative review. In total 24 nutrients and phytonutrients were included in the study, that is, acetyl-L-carnitine, Aloe vera polysaccharides, beta-glucans, bilberry, black seed oil, coenzyme Q10, curcumin (turmeric), frankincense, garlic, ginger, hydrolyzed rice bran, isoflavones, lipoic acid, mistletoe, N-acetyl cysteine, omega-3 fatty acids, resveratrol, selenium, shiitake mushroom and its derivatives, Vitamin B12, Vitamin C, Vitamin D3 (cholecalciferol), Vitamin E (d-alpha- and gamma-tocopherol), and zinc. Some of the noteworthy immune function and anti-inflammatory responses to these interventions included modulation of nuclear factor-Kappa B, tumor necrosis factor-a, interferon-g, interleukin-6, and CD4+ T cells, among others. These findings are not completely consistent or ubiquitous across all patient populations or health status.

CONCLUSIONS

Based on this review, many nutrients and phytonutrients are capable of significantly modulating immune function and reducing inflammation, according to multiple biomarkers in clinical trials in different populations of adults with varying health statuses. Thus, dietary supplementation may serve as an adjunct to conventional pharmaceutical or medical therapies, but evaluation of risks and benefits for each person and health status is necessary. Additional larger studies are also needed to investigate the safety and efficacy of nutritional compounds in various health conditions, with emphases on potential drug-supplement interactions and clinical endpoints.

RELEVANCE FOR PATIENTS

As demonstrated in the reviewed clinical trials, patients of various health challenges with a wide range of severity may benefit from select nutrients and phytonutrients to improve their immune function and reduce inflammation.

Nutritional interventions for autism spectrum disorder

Autism spectrum disorder (ASD) is an increasingly prevalent neurodevelopmental disorder with considerable clinical heterogeneity. With no cure for the disorder, treatments commonly center around speech and behavioral therapies to improve the characteristic social, behavioral, and communicative symptoms of ASD. Gastrointestinal disturbances are commonly encountered comorbidities that are thought to be not only another symptom of ASD but to also play an active role in modulating the expression of social and behavioral symptoms. Therefore, nutritional interventions are used by a majority of those with ASD both with and without clinical supervision to alleviate gastrointestinal and behavioral symptoms. Despite a considerable interest in dietary interventions, no consensus exists regarding optimal nutritional therapy. Thus, patients and physicians are left to choose from a myriad of dietary protocols. This review, summarizes the state of the current clinical and experimental literature on nutritional interventions for ASD, including gluten-free and casein-free, ketogenic, and specific carbohydrate diets, as well as probiotics, polyunsaturated fatty acids, and dietary supplements (vitamins A, C, B6, and B12; magnesium and folate).

Cell communication by tunneling nanotubes: Implications in disease and therapeutic applications

Intercellular communication is essential for the development and maintenance of multicellular organisms. Tunneling nanotubes (TNTs) are a recently recognized means of long and short distance communication between a wide variety of cell types. TNTs are transient filamentous membrane protrusions that connect cytoplasm of neighboring or distant cells. Cytoskeleton fiber-mediated transport of various cargoes occurs through these tubules. These cargoes range from small ions to whole organelles. TNTs have been shown to contribute not only to embryonic development and maintenance of homeostasis, but also to the spread of infectious particles and resistance to therapies. These functions in the development and progression of cancer and infectious disease have sparked increasing scrutiny of TNTs, as their contribution to disease progression lends them a promising therapeutic target. Herein, we summarize the current knowledge of TNT structure and formation as well as the role of TNTs in pathology, focusing on viral, prion, and malignant disease. We then discuss the therapeutic possibilities of TNTs in light of their varied functions. Despite recent progress in the growing field of TNT research, more studies are needed to precisely understand the role of TNTs in pathological conditions and to develop novel therapeutic strategies.

Intravenous infusion of magnesium sulfate is not associated with cardiovascular, liver, kidney, and metabolic toxicity in adults

BACKGROUND

Magnesium (Mg) deficiency contributes to the pathophysiology of numerous diseases. The therapeutic use of Mg has steadily increased over time. The increased in-hospital use of intravenous (IV) magnesium sulfate (MgSO4) warrants more extensive investigation regarding the safety of the therapy. The aim of this study was to determine the safety of IV MgSO4 infusion on cardiovascular, liver, kidney, and metabolic markers in adults.

METHODS

Twelve volunteers were randomized to one of two cross-over conditions: (a) IV infusion of MgSO4 in 5% dextrose followed by IV infusion of 5% dextrose 1 week later or (b) IV infusion of 5% dextrose followed by IV infusion of MgSO4 in 5% dextrose 1 week later. An electrocardiogram was recorded continuously during the infusions. Blood was drawn pre- and post-infusion for blood count (high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides). Results: Serum Mg increased from pre- to post-infusion in the MgSO4 + 5% dextrose group (p < 0.0001). The QRS interval length increased from pre- to post-infusion in the MgSO4 + 5% dextrose group (p < 0.04). Additionally, serum glucose concentration increased in the MgSO4 + 5% dextrose group (p = 0.04). These significant findings were modeled with gender and age as covariates. No other significant differences were found.

CONCLUSIONS

The administration of IV infusion of MgSO4 (4 g/100 mL) in 5% dextrose over a 4-hour treatment period poses no significant deleterious effects on cardiovascular, liver, kidney, or metabolic function.

RELEVANCE FOR PATIENTS

IV infusion of MgSO4 may be used for certain treatment indications without significant concern for systemic or organ toxicity.

Exercise and gastrointestinal symptoms: running-induced changes in intestinal permeability and markers of gastrointestinal function in asymptomatic and symptomatic runners

PURPOSE

Athletes frequently experience gastrointestinal (GI) symptoms during training and competition. Although the prevalence of exercise-induced GI symptoms is high, the mechanisms leading to GI distress during exercise are not fully understood. The aim of this study was to identify running-induced changes in intestinal permeability and markers of GI function and investigate their association with gastrointestinal symptoms.

METHODS

We recruited 17 active runners who we allocated as either asymptomatic or symptomatic based on their history of experiencing GI symptoms during running. The participants took part in a running test where they were asked to run for 90 min at 80% of their best 10 km race speed. Intestinal permeability was measured at baseline and after the running test. Levels of serum intestinal fatty acid-binding protein (I-FABP), zonulin, bacterial lipopolysaccharide (LPS), and fecal calprotectin were also measured at baseline and after the running test.

RESULTS

Running induced a significant increase in intestinal permeability and serum I-FABP concentration but there were no differences between asymptomatic and symptomatic runners. Serum LPS activity did not change from baseline following the running test but the symptomatic group exhibited higher LPS activity at baseline compared to the asymptomatic runners.

CONCLUSIONS

Running for 90 min at a challenging pace causes small intestinal damage and increases intestinal permeability. However, these alterations in GI function do not appear to correlate with the development of GI symptoms during running.