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Effect of Lactoferrin Supplementation on Inflammation, Immune Function, and Prevention of Respiratory Tract Infections in Humans: A Systematic Review and Meta-analysis.
Berthon, BS, Williams, LM, Williams, EJ, Wood, LG
Advances in nutrition (Bethesda, Md.). 2022;13(5):1799-1819
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Human and bovine milk contains Lactoferrin, an iron-binding glycoprotein that may modulate immune function and has antimicrobial and antioxidant properties. In this systematic review and meta-analysis, 25 heterogeneous studies were included to evaluate the efficacy of lactoferrin supplementation on systemic inflammation, immune function, and respiratory tract infections in children and adults with various inflammatory conditions. Supplementation with Lactoferrin reduced only a few inflammatory markers, and beneficial effects were observed in less than half of the studies included. However, a beneficial effect was observed when the intervention was continued for at least three months, and dosages, such as 35 mg/d to 833 mg/d in infants, and 400 mg/d to 600 mg/d in adults, were also found to be beneficial. By modulating the immune system, lactoferrin supplementation reduces respiratory tract infections in children and infants. Based on the findings of this study, healthcare professionals may be able to understand the beneficial effects of Lactoferrin supplementation on immune modulation, inflammation reduction, and respiratory tract infections when supplemented as a combination with other supplements or as Lactoferrin alone. However, it is necessary to conduct further robust research to confirm the clinical effectiveness of Lactoferrin supplementation since the current research is limited in number and heterogeneous in nature.
Abstract
Lactoferrin (Lf) is a glycoprotein present in human and bovine milk with antimicrobial and immune-modulating properties. This review aimed to examine the evidence for the effect of Lf supplementation on inflammation, immune function, and respiratory tract infections (RTIs) in humans. Online databases were searched up to December 2020 to identify relevant, English-language articles that examined the effect of Lf supplementation in human subjects of all ages, on either inflammation, immune cell populations or activity, or the incidence, duration, or severity of respiratory illness or RTIs. Twenty-five studies (n = 20 studies in adults) were included, of which 8 of 13 studies (61%) in adults reported a decrease in at least 1 systemic inflammatory biomarker. Immune function improved in 6 of 8 studies (75%) in adults, with changes in immune cell populations in 2 of 6 studies (33%), and changes in immune cell activity in 2 of 5 studies (40%). RTI outcomes were reduced in 6 of 10 studies (60%) (n = 5 in adults, n = 5 in children), with decreased incidence in 3 of 9 studies (33%), and either decreased frequency (2/4, 50%) or duration (3/6, 50%) in 50% of studies. In adults, Lf reduced IL-6 [mean difference (MD): -24.9 pg/mL; 95% CI: -41.64, -8.08 pg/mL], but not C-reactive protein (CRP) [standardized mean difference: -0.09; 95% CI: -0.82, 0.65], or NK cell cytotoxicity [MD: 4.84%; 95% CI: -3.93, 13.60%]. RTI incidence was reduced in infants and children (OR: 0.78; 95% CI: 0.61, 0.98) but not in adults (OR: 1.00; 95% CI: 0.76, 1.32). Clinical studies on Lf supplementation are limited, although findings show 200 mg Lf/d reduces systemic inflammation, while formulas containing 35-833 mg Lf/d may reduce RTI incidence in infants and children, suggesting improved immune function. Future research is required to determine optimal supplementation strategies and populations most likely to benefit from Lf supplementation. This trial was registered at PROSPERO (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021232186) as CRD42021232186.
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The Effect of a Multivitamin and Mineral Supplement on Immune Function in Healthy Older Adults: A Double-Blind, Randomized, Controlled Trial.
Fantacone, ML, Lowry, MB, Uesugi, SL, Michels, AJ, Choi, J, Leonard, SW, Gombart, SK, Gombart, JS, Bobe, G, Gombart, AF
Nutrients. 2020;12(8)
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Vitamins and minerals are essential for a healthy immune system. The prevalence of vitamin and mineral deficiencies increases with age, and this may contribute to age-related decline of the immune system. The aim of this study was to investigate whether a daily multivitamin and mineral (MVM) supplement could improve the immune function of older people. 42 healthy adults aged between 55 and 75 took part in this single-centre, two-armed, parallel, randomised, double-blinded study. Half of the group was given a MVM supplement called Redoxon Vita Immune (VI) containing the vitamins A, D, E, C, B6, B12 and folate plus iron, copper, zinc and selenium daily for 12 weeks, whilst the other half was given placebo tablets for 12 weeks. Participants were instructed to avoid certain foods high in vitamins and minerals such as oily fish, red meat, liver, and citrus fruits during the study period. Blood and saliva samples were taken from all participants at the beginning and end of the study period, to measure vitamin and mineral status and markers of immune function. Participants also kept a diary to record any illnesses or symptoms. At the end of the study, participants given the MVM supplement had increased their blood levels of vitamin C by 126% and zinc by 43%. There was no significant change in blood levels of vitamin D. There was no significant difference in the potential of blood to kill the introduced bacteria Staphylococcus aureus, or in neutrophil activity, nor were there any significant changes in blood levels of cytokines and chemokines. Participants taking the supplement did however report a shorter length, and lower severity of illnesses compared to those taking the placebo. The authors concluded that their findings support further research to test whether MVM supplementation can improve immune outcomes in older adults.
Abstract
Older adults are at increased risk for vitamin and mineral deficiencies that contribute to age-related immune system decline. Several lines of evidence suggest that taking a multi-vitamin and mineral supplement (MVM) could improve immune function in individuals 55 and older. To test this hypothesis, we provided healthy older adults with either an MVM supplement formulated to improve immune function (Redoxon® VI, Singapore) or an identical, inactive placebo control to take daily for 12 weeks. Prior to and after treatment, we measured (1) their blood mineral and vitamin status (i.e., vitamin C, zinc and vitamin D); (2) immune function (i.e., whole blood bacterial killing activity, neutrophil phagocytic activity, and reactive oxygen species production); (3) immune status (salivary IgA and plasma cytokine/chemokine levels); and (4) self-reported health status. MVM supplementation improved vitamin C and zinc status in blood and self-reported health-status without altering measures of immune function or status or vitamin D levels, suggesting that healthy older adults may benefit from MVM supplementation. Further development of functional assays and larger study populations should improve detection of specific changes in immune function after supplementation in healthy older adults. Clinical Trials Registration: ClinicalTrials.gov #NCT02876315.
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Vitamin C in Pneumonia and Sepsis
Anitra C. Carr
2020
Abstract
This chapter exert from 'Vitamin C in Health and Disease' by Anitra Carr and Jens Lykkesfeldt focuses on Vitamin C in pneumonia and sepsis. It provides details of acute lung dysfunction, the role of neutrophils and the mechanisms of action of Vitamin C in infections, including those of the respiratory tract. The complete book is available free for on-line reading from our supporter, MDPI Nutrients at this link https://www.mdpi.com/books/pdfview/book/690.
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Time-restricted eating effects on performance, immune function, and body composition in elite cyclists: a randomized controlled trial.
Moro, T, Tinsley, G, Longo, G, Grigoletto, D, Bianco, A, Ferraris, C, Guglielmetti, M, Veneto, A, Tagliabue, A, Marcolin, G, et al
Journal of the International Society of Sports Nutrition. 2020;17(1):65
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Adequate nutrition is important for elite athletes, as nutrient availability influences energy expenditure, body composition, performance and exercise-induced immune responses. Time-restricted eating (TRE) is a form of intermittent fasting that has received much interest in recent years. Previous research of TRE suggested beneficial effects on performance in untrained individuals, by allowing weight loss whilst maintaining muscle functions. These qualities are of interest for endurance cyclists hence the authors of this study sought to investigate the impact of TRE in elite cyclists. Sixteen under-23 year old, elite cyclists were randomly assigned to eat within a TRE window of 8-hr or 15hr window during a 4-week, high-level endurance training phase. Both groups consumed their full estimated energy needs and markers such as fat and fat-free mass, VO2 max, basal metabolism, blood counts, anabolic hormones and inflammatory markers were measured. As a result, TRE produced weight loss, improved body composition and increased peak power output in relation to body weight without compromising aerobic performance. Furthermore, the TRE pattern proved helpful in mitigating some of the exercise-induced suppressions of the immune system. The authors concluded that TRE could be considered as part of a performance nutrition plan in endurance athletes. Particularly where there is a need to reduce body fat mass or for the management of training-induced depression of the immune system and associated respiratory infection susceptibility. This can be of clinical relevance in the support of endurance athletes.
Abstract
BACKGROUND Although there is substantial interest in intermittent fasting as a dietary approach in active individuals, information regarding its effects in elite endurance athletes is currently unavailable. The present parallel randomized trial investigated the effects of a particular intermittent fasting approach, called time-restricted eating (TRE), during 4 weeks of high-level endurance training. METHODS Sixteen elite under-23 cyclists were randomly assigned either to a TRE group or a control group (ND). The TRE group consumed 100% of its estimated daily energy needs in an 8-h time window (from 10:00 a.m. to 6:00 p.m.) whilst energy intake in the ND group was distributed in 3 meals consumed between 7:00 a.m. and 9:00 p.m. Fat and fat-free mass were estimated by bioelectrical impedance analysis and VO2max and basal metabolism by indirect gas analyzer. In addition, blood counts, anabolic hormones (i.e. free testosterone, IGF-1) and inflammatory markers (i.e. IL-6, TNF-α) were assessed. RESULTS TRE reduced body weight (- 2%; p = 0.04) and fat mass percentage (- 1.1%; p = 0.01) with no change in fat-free mass. Performance tests showed no significant differences between groups, however the peak power output/body weight ratio (PPO/BW) improved in TRE group due to weight loss (p = 0.02). Free testosterone and IGF-1 decreased significantly (p = 0.01 and p = 0.03 respectively) in TRE group. Leucocyte count decreased in ND group (p = 0.02) whilst the neutrophils-to-lymphocytes ratio (NLR) decreased significantly (p = 0.03) in TRE group. CONCLUSIONS Our results suggest that a TRE program with an 8-h feeding window elicits weight loss, improves body composition and increases PPO/BW in elite cyclists. TRE could also be beneficial for reducing inflammation and may have a protective effect on some components of the immune system. Overall, TRE could be considered as a component of a periodized nutrition plan in endurance athletes. TRIAL REGISTRATION This trial was retrospectively registered at clinicaltrials.gov as NCT04320784 on 25 March 2020.