1,721,109 research outputs found
Effects of citrus fruit juices and their bioactive components on inflammation and immunity: a narrative review
No full textThe immune system provides defence to the host against pathogenic organisms. A weak immune system increases susceptibility to infections and allows infections to become more severe. One component of the immune response is inflammation. Where inflammation is excessive or uncontrolled it can damage host tissues and cause pathology. Limitation of oxidative stress is one means of controlling inflammation. Citrus fruit juices are a particularly good source of vitamin C and folate, which both have roles in sustaining the integrity of immunological barriers and in supporting the function of many types of immune cell including phagocytes, natural killer cells, T-cells and B-cells. Vitamin C is an antioxidant and reduces aspects of the inflammatory response. Important bioactive polyphenols in citrus fruit juices include hesperidin, narirutin and naringin. Hesperidin is a glycoside of hesperetin while narirutin and naringin are glycosides of naringenin. Hesperidin, hesperetin, naringenin, naringin and narirutin have all been found to have anti-inflammatory effects in model systems, and human trials of hesperidin report reductions in inflammatory markers. In humans, orange juice was shown to limit the post- prandial inflammation induced by a high fat-high carbohydrate meal. Consuming orange juice daily for a period of weeks has been reported to reduce markers of inflammation, including C- reactive protein, as confirmed through a recent meta-analysis. A newly emerging topic is whether polyphenols from orange juice have direct anti-viral effects. In summary, micronutrients and other bioactives present in citrus fruit juices have established roles in controlling oxidative stress and inflammation and in supporting innate and acquired immune responses. Trials in humans demonstrate that orange juice reduces inflammation; its effects on innate and acquired immunity require further exploration in well-designed trials in appropriate population sub-groups such as older people. <br/
Maternal diet and its influence on the development of allergic disease
No full textThe early presentation of childhood allergies and the rise in their prevalence suggest that changes in early-life exposures may increase the predisposition. Very early-life exposures may act upon the developing foetal immune system and include infection, environmental tobacco smoke, other pollutants and nutrients provided via the mother. Three nutrients have come under close scrutiny: vitamin D, omega 3 polyunsaturated fatty acids (PUFAs) and folate (or the synthetic form, folic acid). Much of the data on these nutrients are observational although some randomised, placebo-controlled trials have been conducted with omega 3 PUFAs and one with vitamin D. Some studies with omega 3 PUFA supplements in pregnancy have demonstrated immunomodulatory effects on the neonate and a reduction in risk of early sensitisation to allergens. A few studies with omega 3 polyunsaturated fatty acid supplements in pregnancy have shown a reduction in proportion of children affected by allergic symptoms (food allergy) or in symptom severity (atopic dermatitis). Observational studies investigating the association of maternal vitamin D intake or maternal or neonatal vitamin D status have been inconsistent. One randomised, controlled trial of vitamin D supplementation during pregnancy did not show any significant effect on allergic outcome in the offspring. Studies investigating the association between maternal folic acid or folate intake or maternal or neonatal folate status and offspring risk of allergic disease have been equivocal. Further evidence is required to clarify whether increased intake of these nutrients during pregnancy influences allergic disease in the offspring. In the light of current evidence, mothers should not either increase or avoid consuming these nutrients to prevent or ameliorate allergic disease in their offspring. However, these essential nutrients each have important roles in foetal development. This is reflected in current government recommendations for intake of these nutrients by pregnant women
Fatty acids, lipid emulsions and the immune and inflammatory systems
No full textFatty acids modulate the responses of cells of the immune system. Inflammatory and immune responses in patients receiving parenteral nutrition may be modulated by the type of lipid used, which may influence clinical outcomes. Lipid emulsions based solely upon soybean oil may not be optimal because of the role of n-6 fatty acids in promoting inflammation and suppressing immune responses. Lipid emulsions with soybean oil in various combinations with medium-chain triglycerides (MCTs), olive oil and fish oil are available. Some early studies have suggested better immune function with MCT-soybean oil than with soybean oil alone, but the differences were small, and more recent studies suggested little difference between soybean oil, MCT-soybean oil and soybean oil-olive oil regarding markers of inflammation and immunity. The inclusion of fish oil in combination with one or more other oils (i.e. soybean, MCT, olive) in the parenteral regimen administered to patients following major gastrointestinal surgery reduces the post-surgery rise in inflammatory markers and the fall in cell-mediated immune markers. These changes are associated with improvements in clinical outcomes. Whether similar effects of intravenous fish oil occur in critically ill patients is not clear at present because of the small number, small size and variable findings of existing studies. The lipid component of parenteral nutrition may modify inflammatory and immune processes in ways that influence patient outcome. The inclusion of fish oil in parenteral nutrition for post-surgical patients is associated with benefits. The situation regarding critically ill patients is not clear
Neonatal lymphocyte responses in relation to subsequent allergic disease in infants born to atopic parents
No full textSIGLEAvailable from British Library Document Supply Centre-DSC:DX190717 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Omega-6 and omega-3 polyunsaturated Fatty acids and allergic diseases in infancy and childhood
No full textThere may be a causal relationship between intake of n-6 polyunsaturated fatty acids (PUFAs) and childhood allergic diseases. This can be explained by plausible biological mechanisms involving eicosanoid mediators produced from the n-6 PUFA arachidonic acid. Long chain n-3 PUFAs are found in fish and fish oils. These fatty acids act to oppose the actions of n-6 PUFAs. Thus, it is considered that n-3 PUFAs will lower the risk of developing allergic diseases. In support of this, protective associations have been reported between maternal fish intake during pregnancy and allergic outcomes in infants and children from those pregnancies. However, studies of fish intake during infancy and childhood and allergic outcomes in those infants or children are inconsistent, although some reported a protective association. Supplementing pregnant women with fish oil can induce immunologic changes in cord blood. This supplementation has been reported in some studies to decrease sensitisation to common food allergens and to lower the prevalence and severity of atopic dermatitis in the first year of life. The protective effect of maternal n-3 PUFAs may last until adolescence of the offspring. Fish oil supplementation in infancy may decrease the risk of developing some manifestations of allergic disease, although this benefit may not persist. Whether fish oil is a useful therapy in children with asthma receiving standard therapy is not clear from studies performed to date and this requires further exploratio
A review of the functional effects of pine nut oil, pinolenic acid and its derivative eicosatrienoic acid and their potential health benefits
No full textPine nut oil (PNO) is rich in a variety of unusual delta-5-non-methylene-interrupted fatty acids (NMIFAs), including pinolenic acid (PLA; all cis-5,-9,-12 18:3) which typically comprises 14 to 19% of total fatty acids. PLA has been shown to be metabolised to eicosatrienoic acid (ETA; all cis-7,-11,-14 20:3) in various cells and tissues. Here we review the literature on PNO, PLA and its metabolite ETA in the context of human health applications. PNO and PLA have a range of favourable effects on body weight as well as fat deposition through increased energy expenditure (fatty acid oxidation) and decreased food energy intake (reduced appetite). PNO and PLA improve blood and hepatic lipids in animal models and insulin sensitivity in vitro and reduce inflammation and modulate immune function in vitro and in animal models. The few studies which have examined effects of ETA indicate it has anti-inflammatory properties. Another NMIFA from PNO, sciadonic acid (all cis-5,-11,-14 20:3), has generally similar properties to PLA where these have been investigated. There is potential for human health benefits from PNO, its constituent NMIFA PLA and the PLA derivative ETA. However further studies are needed to explore the effects in humans.</p
Can early omega-3 fatty acid exposure reduce risk of childhood allergic disease?
No full textA causal link between increased intake of omega-6 (n-6) polyunsaturated fatty acids (PUFAs) and increased incidence of allergic disease has been suggested. This is supported by biologically plausible mechanisms, related to the roles of eicosanoid mediators produced from the n-6 PUFA arachidonic acid. Fish and fish oils are sources of long chain omega-3 (n-3) PUFAs. These fatty acids act to oppose the actions of n-6 PUFAs particularly with regard to eicosanoid synthesis. Thus, n-3 PUFAs may protect against allergic sensitisation and allergic manifestations. Epidemiological studies investigating the association between maternal fish intake during pregnancy and allergic outcomes in infants/children of those pregnancies suggest protective associations, but the findings are inconsistent. Fish oil provision to pregnant women is associated with immunologic changes in cord blood. Studies performed to date indicate that provision of fish oil during pregnancy may reduce sensitisation to common food allergens and reduce prevalence and severity of atopic eczema in the first year of life, with a possible persistence until adolescence. A recent study reported that fish oil consumption in pregnancy reduces persistent wheeze and asthma in the offspring at ages 3 to 5 years. Eating oily fish or fish oil supplementation in pregnancy may be a strategy to prevent infant and childhood allergic disease
Diet and immune function
Get PDFA well-functioning immune system is critical for survival. The immune system must be constantly alert, monitoring for signs of invasion or danger. Cells of the immune system must be able to distinguish self from non-self and furthermore discriminate between non-self molecules which are harmful (e.g., those from pathogens) and innocuous non-self molecules (e.g., from food). This Special Issue of Nutrients explores the relationship between diet and nutrients and immune function. In this preface, we outline the key functions of the immune system, and how it interacts with nutrients across the life course, highlighting the work included within this Special Issue. This includes the role of macronutrients, micronutrients, and the gut microbiome in mediating immunological effects. Nutritional modulation of the immune system has applications within the clinical setting, but can also have a role in healthy populations, acting to reduce or delay the onset of immune-mediated chronic diseases. Ongoing research in this field will ultimately lead to a better understanding of the role of diet and nutrients in immune function and will facilitate the use of bespoke nutrition to improve human healt
Influence of very long-chain n-3 fatty acids on plasma markers of inflammation in middle-aged men
No full textThis study investigated the effects of a moderate dose of long-chain n-3 polyunsaturated fatty acids (1.8 g eicosapentaenoic acid (EPA) plus 0.3g docosahexaenoic acid (DHA) per day) given for 8 weeks to healthy middle-aged males on cardiovascular risk factors, particularly plasma lipids and inflammatory markers. The study was double-blind and placebo-controlled. The proportion of EPA was significantly increased in plasma phosphatidylcholine (from 1.4% to 5.0% of total fatty acids; P<0.001), cholesteryl esters (from 1.2% to 4.5%; P<0.001) and triacylglycerols (from 0.3% to 1.8%; P<0.001). In contrast, the more modest increases in DHA in these lipid fractions were not significant. There was very little effect of n-3 fatty acids on the risk factors measured, apart from a reduction in plasma soluble intercellular adhesion molecule (sICAM)-1 concentration compared with placebo (P=0.05). The change in plasma sICAM-1 concentration was significantly inversely related to the change in DHA in plasma phosphatidylcholine (r=-0.675; P=0.001), but less so to the change in EPA (r=-0.406; P=0.076). Data from the present study suggest that marine oil providing 1.8 g of EPA plus 0.3g DHA/day is not sufficient to demonstrate marked effects on cardiovascular risk factors (plasma lipids and inflammatory markers) in healthy middle-aged men, although there may be a slight anti-inflammatory effect as indicated by the decrease in sICAM-1. The stronger association between changes in DHA than EPA and sICAM-1 concentrations suggest that DHA may be more anti-inflammatory than EPA. Thus, one reason why only limited effects were seen here may be that the dose of DHA provided was insufficient
Do probiotics in pregnancy reduce allergies and asthma in infancy and childhood? A systematic review
No full textThe maternal immune system is very important in the development of the foetal immune system. Probiotics have been shown to help regulate immune responses. Therefore, it is possible that the administration of probiotics to pregnant women could influence the development of the foetal immune system, reducing the likelihood of infants and children developing an allergic condition. The aim of this research was to conduct a systematic review to determine whether administering probiotics to pregnant women can reduce the incidence of allergic disease in their children. Medline, CINAHL and Embase databases were searched for randomised controlled trials (RCTs) that compared supplementation of probiotics to pregnant women to a placebo control and recorded the presentation of allergic conditions in their children. Data extracted from the study reports included their characteristics and findings. Study quality and risk of bias were assessed. From a total of 850 articles identified in the search, 6 were eligible for inclusion in this review. Two studies found no effect of maternal probiotics on the outcomes measured, two studies found that the incidence of eczema or atopic dermatitis (AD) was reduced by maternal probiotics, one study found no effect on the overall incidence of atopic sensitisation, but a reduction in a subgroup of children at high hereditary risk of allergic disease, and one study found no effect in an intention to treat analysis, but a reduction in AD in complete case analysis. The results of these studies are inconsistent but demonstrate that probiotics may have the potential to reduce infant allergies when administered prenatally, particularly in children at high risk of allergy development. There is a need for further larger-scale studies to be performed in order to provide a more definitive answer. Such studies should focus on at-risk groups.<br/
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