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Dietary Antioxidants: Immunity and Host Defense
Abstract
Natural antioxidants may be defined as molecules that prevent cell damage against free radicals and are critical for maintaining optimum health in both animals and humans. In all living systems, cells require adequate levels of antioxidant defenses in order to avoid the harmful effect of an excessive production of reactive oxygen species (ROS) and to prevent damage to the immune cells. During the inflammatory processes, the activation of phagocytes and/or the action of bacterial products with specific receptors are capable of promoting the assembly of the multicomponent flavoprotein NADPH oxidase, which catalyzes the production of high amounts of the superoxide anion radical (O(2)(-)). Under these particular circumstances, neutrophils and macrophages are recognized to produce superoxide free radicals and H(2)O(2), which are essential for defence against phagocytized or invading microbes. In this state, antioxidants are absolutely necessary to regulate the reactions that release free radicals. Antioxidant nutrients commonly included in the diet such as vitamin E, vitamin C, β-carotene, selenium, copper, iron and zinc improve different immune function exhibiting an important protective role in infections caused by bacteria, viruses or parasites. As a result, dietary antioxidants have been related to modulate the host susceptibility or resistance to infectious pathogens. Overall, numerous studies have suggested that the development of tolerance, and control of inflammation are strongly correlated with specific immune mechanisms that may be altered by an inadequate supply of either macronutrients or micronutrients. Therefore, the present paper will review the effects of dietary antioxidants on immune cell function and the impact on protection against infectious microorganisms.
... (34) Many reviews indicated that copper has a redox property, and could protect the basic elements of the cell, including lipids, protein, and DNA, from in situ produced reactive oxygen species and oxygen free radicals, which could be useful for people's physical health. (35) However, few studies observed the associations between dietary copper and liver cancer risk. Our study found an inverse association between consumption of dietary copper and liver cancer risk while disappeared after correcting for multiple comparisons. ...
Although dietary factors have been examined as potential risk factors for liver cancer, the evidence is still inconclusive. Using a diet-wide association analysis, our research evaluated the associations of 126 foods and nutrients on the risk of liver cancer in a Chinese population. We obtained the diet consumption of 72,680 women in the Shanghai Women’s Health Study using baseline dietary questionnaires. The association between each food and nutrient and liver cancer risk was quantified by Cox regression model. A false discovery rate of 0.05 was used to determine the foods and nutrients which need to be verified. Totally 256 incident liver cancer cases were identified in 1,267,391 person-years during the follow-up duration. At the statistical significance level (P ≤ 0.05), higher intakes of cooked wheaten foods, pear, grape and copper were inversely associated with liver cancer risk, while spinach, leafy vegetables, eggplant and carrots showed the positive associations. After considering multiple comparisons, no dietary variable was associated with liver cancer risk. Similar findings were seen in the stratification, secondary and sensitivity analyses. Our findings observed no significant association between dietary factors and liver cancer risk after considering multiple comparisons in Chinese women. More evidence is needed to explore the associations between diet and female liver cancer occurrence.
... Band males face higher metabolic demands and spend less time successfully feeding compared to natal males [14]. Less time spent feeding can reduce the intake of antioxidants and minerals such as zinc and selenium, which are important for enzymatic antioxidant function [95]. Elevated metabolic demands may contribute to the observed oxidative stress differences, as increased metabolism can lead to greater free radical production [96,97]. ...
Oxidative stress plays a crucial role in mediating life-history processes, where it can compromise survival and reproduction through harmful alterations to DNA, lipids, and proteins. In this study, we investigated oxidative stress in Cape ground squirrels (Xerus inauris), a longer-lived African ground squirrel species with a high reproductive skew and unique life history strategies. We measured oxidative stress as total antioxidant capacity (TAC), total oxidant status (TOS), and an oxidative stress index (OSI) in blood plasma from individuals of approximately known ages. Our results reveal a distinct pattern of decreasing oxidative stress with age, consistent across both sexes. Females exhibited lower OSI and TOS levels than males. Males employing different life-history strategies, namely natal (staying at home), had significantly lower oxidative stress compared to the band (roaming male groups), likely due to variations in metabolic rate, activity, and feeding rates. However, both strategies exhibited reduced oxidative stress with age, though the underlying mechanisms require further investigation. We propose that selection pressures favoring survival contributed to the observed reduction in oxidative stress with age, potentially maximizing lifetime reproductive success in this species.
... 38 Zinc is also essential for lymphocyte proliferation and differentiation before acquiring effector functions Figure 2). 39,40,41 Additionally, Zn influences the function of macrophages by impacting toll-like receptor-triggered proinflammatory and type I interferon responses and nitric oxide synthesis. 34,42,43 Copper has a vital role in mitochondrial energy production and various enzymatic reactions crucial for basal metabolism. ...
Trace minerals (TM) have a crucial role in cattle reproduction. Although microelements are required in small amounts, their bioavailability is essential for the cow reproductive physiology, and for adequate fertility and productivity. They are particularly important for antioxidant protection against cellular damage (e.g. gametes and embryonic cells), hormone synthesis, and pregnancy maintenance. Oral TM supplementation is a common and highly recommended management practice in cattle operations. However, there is substantial variability in TM bioavailability in animals receiving oral TM supplementation. The strategic use of injectable TM supplementation (without replacing traditional oral TM supplements) before episodes of marked stress (e.g. parturition), higher metabolic demand with TM depletion (e.g. last trimester of pregnancy), active immune response (e.g. uterine involution or vaccination), and before breeding helps to maintain adequate TM and oxidative status during critical points of the reproductive program. This manuscript reviews the research-based evidence regarding the effects of TM supplementation on bovine reproduction and its impact on beef and dairy cattle reproductive performance.
... However, the high polyunsaturated fatty acid content in seafood makes it highly susceptible to oxidation, leading to rapid degradation in sensory and nutritional quality, resulting in rancidity and off-flavours without proper handling. During traditional cooking, especially at high temperatures, water-soluble nutrients like vitamins, minerals, and antioxidants are often lost through evaporation or exudation, impacting the nutritional value of the food (Puertollano et al., 2011). Additionally, proteins may lose their water-holding capacity (WHC) due to shrinkage of myofibrillar proteins, affecting texture and juiciness (Schellekens, 1996). ...
Seafood's short shelf life is due to its high-water activity, neutral pH, and rich nutrient content. Sous vide technology, originating from the French phrase "under vacuum," is a method of cooking in which fish and fishery products are sealed in vacuum-packed bags and cooked at precisely controlled low temperatures over extended periods. Vacuum packaging prevents recontamination, oxidation, aerobic bacterial growth, and moisture loss while preserving aroma compounds. However, the anaerobic environment may promote the growth of spore-forming pathogens. This review aims to explore the current state of sous vide technology applied to fish and fishery products. It highlights its benefits, such as enhanced texture, flavour preservation, and retention of nutritional quality. Additionally, the paper examines the potential challenges associated with sous vide cooking, such as microbial safety and packaging concerns, while also offering insights into future research opportunities and commercial applications. This is an open access article under the terms of the https://creativecommons.org/licenses/by/4.0/ License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
... These essential nutrients play a major role in reducing and controlling oxidative stress by protecting the immune system and enhancing resistance against infectious microbes such as bacteria, viruses, and parasites. The beneficial effects of these two antioxidant vitamins on the immune system are described in several reviews [10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Relevant to this work, supplementation of vitamins C and E decreased O 2 •− concentration in the bloodstream and improved antioxidant activity by enhancing NADPH oxidase and superoxide dismutase activity [4]. ...
In this study, we examine the cooperative effect between vitamins C and E that mitigates oxidative stress by using experimental and computational methods. We performed superoxide scavenging experiments on each vitamin individually and their combination using rotating ring–disk electrode voltammetry. The results indicate that vitamins E and C together produce more effective scavenging of superoxide as evaluated by a steeper slope in the efficiency graph, −7.2 × 104, compared to that of vitamin E alone, −1.8 × 103, or vitamin C alone, −1.3 × 104. Density Functional Theory calculations agree with our experimental results, and we describe a mechanism for the antioxidant action of individual vitamins E and C, plus the synergistic action when both vitamins interact. This process involves the restoration of vitamin E by vitamin C and includes π-π interactions between superoxide and scavengers. The overall result produces an increase in scavenging superoxide radicals when both vitamins act together.
... Natural antioxidants present in food include polyphenol compounds, antioxidant vitamins (vitamins C, E, and A), and trace elements (selenium, zinc, manganese, copper, and iron). These substances participate directly or indirectly in the fight against reactive oxygen species [7,8]. ...
Because of its high antioxidant activity, chokeberry can be used both in the prevention and treatment of various metabolic disorders. In this study, for the first time, the synergistic effects of chokeberry juice and chokeberry fiber on selected metabolic and anthropometric parameters were assessed during a 90-day intervention including 102 people (67 women and 35 men). After 60 days of intervention with chokeberry juice, statistically significant increases in the muscle mass and antioxidant potential of the serum were observed. In turn, there were decreases in the waist circumference, systolic blood pressure, diastolic blood pressure, heart rate, glycated hemoglobin, glucose, LDL cholesterol, eGFR, and ALT level. The addition of chokeberry fiber for the next 30 days resulted in stabilizations of the diastolic blood pressure, glycated hemoglobin, glucose, and waist circumference, as well as reductions in the values of the heart rate, LDL cholesterol, insulin, and AST level. After 90 days, a significant increase in the FRAP value was also observed. This intervention indicates that chokeberry products may have a beneficial effect on metabolic health and serve as a foundation for developing functional foods.
Trichinellosis is a foodborne parasitic infection, where the Trichinella spiralis larvae invade, grow and dwell in muscle cells, transforming them into nurse cells for nutrient supply and protective shelter. The present study evaluated the prophylactic and therapeutic impact of the antioxidants selenium (Se) and vitamin E (Vit E), alone and in combinations with albendazole (ALB), on muscular phase of experimental Trichinella spiralis infection in mice. Forty-eight Swiss albino mice were divided into 3 main groups: control, prophylactic, and therapeutic groups, with further subgrouping according to the received treatment. Larval count, inflammation around the encapsulated larvae, and oxidative stress markers were assessed. All groups receiving treatment showed a significant reduction in larvae count/gm muscle compared to the infected control group. In the prophylactic group, combined VitE-Se achieved the highest reduction, 58.4% and 51% in the diaphragm and intercostals, respectively. Whereas in the therapeutic group combined VitE-Se-ALB showed the maximum reduction rates of 90.4% and 84.4% in the diaphragm and intercostals, respectively. Varying grades of cellular inflammatory infiltration were detected around the capsule in various groups, with marked reduction in degree of inflammation in all combination groups containing ALB. Oxidative stress markers malondialdehyde (MDA) and superoxide dismutase (SOD) levels showed a significant decrease in treated muscle tissues, the lowermost level was detected in the VitE-Se-ALB combination group. In conclusion, combined Vit E-Se reduced muscle larval burden in the prophylactic group, potentiated the antiparasitic action of ALB in the therapeutic group, and demonstrated anti-inflammatory and antioxidant effects.
We conducted a pilot, open-label study to assess the effect of short-term β-carotene administration (180 mg/d with meals for 4 weeks) on the plasma human immunodeficiency virus (HIV) RNA levels and
CD4+ lymphocyte counts in 21 HIV-infected patients. We found that plasma HIV RNA levels and CD4+ lymphocyte counts did not change following this short course of β-carotene supplementation. Patients with lower serum concentrations of β-carotene before supplementation were no more likely to have an increase in their CD4+ lymphocyte count or plasma HIV RNA copy number than were those with higher concentrations. No correlation was found between
pre- or postsupplementation β-carotene or vitamin A concentrations and pre- or postsupplementation CD4+ lymphocyte counts or plasma HIV RNA titers. This study provides no support for β-carotene supplementation for HIV-infected subjects with normal baseline serum levels of β-carotene and vitamin A.
Background
Antioxidant supplementation is thought to improve immunity and thereby reduce infectious morbidity. However, few large trials in elderly people have been conducted that include end points for clinical variables.Objective
To determine the effects of long-term daily supplementation with trace elements (zinc sulfate and selenium sulfide) or vitamins (beta carotene, ascorbic acid, and vitamin E) on immunity and the incidence of infections in institutionalized elderly people.Methods
This randomized, double-blind, placebo-controlled intervention study included 725 institutionalized elderly patients (>65 years) from 25 geriatric centers in France. Patients received an oral daily supplement of nutritional doses of trace elements (zinc and selenium sulfide) or vitamins (beta carotene, ascorbic acid, and vitamin E) or a placebo within a 2×2 factorial design for 2 years.Main Outcome Measures
Delayed-type hypersensitivity skin response, humoral response to influenza vaccine, and infectious morbidity and mortality.Results
Correction of specific nutrient deficiencies was observed after 6 months of supplementation and was maintained for the first year, during which there was no effect of any treatment on delayed-type hypersensitivity skin response. Antibody titers after influenza vaccine were higher in groups that received trace elements alone or associated with vitamins, whereas the vitamin group had significantly lower antibody titers (P<.05). The number of patients without respiratory tract infections during the study was higher in groups that received trace elements (P=.06). Supplementation with neither trace elements nor vitamins significantly reduced the incidence of urogenital infections. Survival analysis for the 2 years did not show any differences between the 4 groups.Conclusions
Low-dose supplementation of zinc and selenium provides significant improvement in elderly patients by increasing the humoral response after vaccination and could have considerable public health importance by reducing morbidity from respiratory tract infections.
Rats fed iron deficient and adequate diets were infected by intraperitoneal injection of Streptococcus pneumoniae 6302 to study the effect of iron deficiency on susceptibility. The rats were inoculated with an 0.5 ml dose of various inoculum dilutions and mortality was recorded over four days. At each dilution of inoculum, the control rats showed greater resistance to infection than the iron deficient rats. The results, based on the calculated LD50 rate, showed that iron deficient rats were 1,000 times more susceptible to the infection than control rats.
Different epidemiological, experimental or clinical studies have intensely examined the fundamental role of different dietary lipids in the regulation of immune system functions. Biochemical or metabolic activities have classically been attributed to fatty acids, which are important for the cell biological functions, because they serve as a main source of metabolic energy; as the substrates for cell membrane biogenesis, contributing to the physical and biological properties; as covalent modifiers of protein structure; as precursors for synthesis of many intracellular signalling molecules (biological lipids mediators like prostaglandins (PG), leukotrienes (LT), resolvins and lipoxins); and as regulators of gene expression. However, fatty acids are also important mediators of immune system functions. This chapter reviews the studies reporting the impact of dietary lipids on the immune response, which have allowed a better understanding of the influence of olive oil on the host natural resistance to pathogenic agents. Although the effects of olive oil on the immune functions are less known, currently, there is enough evidence for corroborating the protective and beneficial effects of olives on human health and particularly on the immune response.
AIM: To evaluate the safety and efficacy of vitamin E in children with chronic hepatitis B.
METHODS: We randomly assigned patients with chronic hepatitis B, positive for hepatitis B e antigen (HBeAg), to receive either vitamin E or placebo once daily for 6 mo in a 3:1 ratio and double-blind manner. The primary end point was HBeAg seroconversion, defined as the loss of HBeAg, undetectable levels of serum hepatitis B virus DNA, and the appearance of antibodies against HBeAg 12 mo after therapy.
RESULTS: At baseline visit, 49 patients had normal and 43 had increased serum aminotransferase levels. Twenty-nine patients did not respond to previous treatment with interferon-α or lamivudine. Seventy-six children completed the study; 16 were non-compliant (n = 7), lost to follow-up (n = 7), or started another antiviral treatment (n = 3). Intention-to-treat analysis showed HBeAg seroconversion in 16 children (23.2%) treated with vitamin E and two (8.7%) in the placebo group (P = 0.13). Vitamin E was well tolerated.
CONCLUSION: There is only a tendency that vitamin E may promote HBeAg seroconversion. Therefore larger studies are needed to clarify the role of antioxidants in the therapy of chronic hepatitis B.
Several small short-term intervention studies have suggested that beta-carotene supplementation in HIV-infected patients can increase the number of various immune cells including CD4 cells. This prospective double-blinded study was designed to investigate whether beta-carotene supplementation would result in this immuno-enhancement in a larger number of patients over a longer time period.
HIV-positive patients were randomly assigned to receive either 60 mg beta-carotene orally three times daily or a matched placebo. In addition, all patients received a multivitamin supplement. Patients were evaluated at baseline, 1 month, and 3 months for T-cell quantitative subsets, natural killer cells, HIV p24 antigen, beta-carotene levels, complete blood counts and chemistry batteries. Body weights and Karnofsky scores were evaluated at each visit.
Seventy-two patients signed informed consent forms and entered the study. Except for serum beta-carotene concentration, there were no statistically significant differences (P < 0.05) between the treatment (60 mg beta-carotene three times daily and multivitamins) and placebo (placebo and multivitamins) groups at baseline or after either 1 or 3 months of treatment.
Earlier studies suggesting that beta-carotene supplementation increased levels of immune cells in HIV-infected patients were not replicated in this study. The addition of a multivitamin supplement to both arms of this study may have masked any difference between the two groups. However, on the basis of the results of this study, we would not recommend supplementation with high doses of beta-carotene for HIV-infected patients.
Nutritional deficiency of zinc is widespread throughout the developing world. Zinc deficient subjects experience increased susceptibility to a variety of infections. Zinc deficiency in an experimental human model caused an imbalance between Th1 and Th2 functions. Production of IFN- and IL-2 (products of TH1) were decreased, whereas production of IL-4, IL-6 and IL-10 (products of Th2) were not affected due to zinc deficiency. Zinc deficiency decreased NK cell lytic activity and percentage of precursors of cytolytic T cells. In HUT-78, a Th0 cell line, zinc deficiency decreased gene expression of deoxythymidine kinase (TK), delayed cell cycle and decreased cell growth. Gene expression of IL-2 and IL-2 receptors (both and β) and binding of NF-kB to DNA were decreased by zinc deficiency in HUT-78. In HL-60, a monocytic-macrophage cell line, zinc deficiency increased production and gene expression of TNF-, IL-1β and IL-8. These cytotoxic cytokines are known to produce increased free radicals. Thus zinc may function as an important anti-oxidant. In conclusion, decreased production of IL-2 in zinc deficiency may be due to decreased activation of NF-kB and subsequent decreased gene expression of IL-2 and IL-2 receptor . Our studies show that zinc deficiency affects cell-mediated immunity and leads to activation of monocytes-macrophages and may play an important role as an antioxidant. J. Trace Elem. Exp. Med. 13:1–20, 2000. © 2000 Wiley-Liss, Inc.
The immune system is extremely sensitive to oxidative damage. Many immune cells produce reactive oxygen species as part of the body’s defence against infection and depend on adequate protection by antioxidants for optimal function. Many antioxidants can be obtained directly from the diet (e.g. vitamin C, vitamin E, carotenoids and polyphenolic flavonoids) or require micronutrients as integral components of protective enzymes (e.g. selenium, copper and zinc). Whilst a balanced diet should provide sufficient protection, periods of infection, inflammatory conditions or cigarette smoking may tip the balance in favour of oxidative stress. This review summarises some of the mechanisms by which antioxidants may affect immune status.
