Corrigendum: Safe and effective delivery of supplemental iron to healthy adults: a two-phase, randomized, double-blind trial - the safe iron study

[This corrects the article DOI: 10.3389/fnut.2023.1230061.].

Supplementation with antioxidant micronutrients in pregnant women with obesity: a randomized controlled trial

BACKGROUND/OBJECTIVE

Obesity increases maternal morbidity and adversely affects child health. Maternal inflammation may play a role in adverse outcomes. The objective of this study was to determine whether providing a higher dose of antioxidant micronutrients to pregnant women with obesity would raise concentrations of key antioxidant vitamins and impact inflammation and oxidative stress during pregnancy.

SUBJECTS/METHODS

This was a double-blind, randomized controlled trial. We recruited pregnant women with a body mass index (BMI) ≥ 30 kg/m2 at their initial prenatal visit ( < 13 weeks gestation) and collected blood and urine samples at baseline, 24-28 weeks, and 32-36 weeks to measure micronutrient concentrations (vitamin C, E, B6 and folate), markers of inflammation (C-reactive protein, interleukin-6, 8, and 1β) and oxidative stress (8-epi-PGF2α and malondialdehyde). We collected maternal and infant health data from enrollment to delivery as secondary outcomes. We enrolled 128 participants (64 in each arm), and 98 (49 in each arm) completed follow-up through delivery.

INTERVENTION

Both groups received a standard prenatal vitamin containing the recommended daily allowance of micronutrients in pregnancy. In addition, the intervention group received a supplement with 90 mg vitamin C, 30 αTU vitamin E, 18 mg vitamin B6, and 800 μg folic acid, and the control group received a placebo.

RESULTS

The intervention group had higher vit B6 (log transformed (ln), β 24-28 weeks: 0.76 nmol/L (95% CI: 0.40, 1.12); β 32-36 weeks: 0.52 nmol/L (95% CI: 0.17, 0.88)) than the control group. Vitamins C, E, erythrocyte RBC folate concentrations did not differ by randomization group. The intervention did not impact biomarkers of inflammation or oxidative stress. There were no differences in maternal or neonatal clinical outcomes by randomization group.

CONCLUSIONS

Higher concentrations of antioxidant vitamins during pregnancy increased specific micronutrients and did not impact maternal inflammation and oxidative stress, which may be related to dosing or type of supplementation provided.

CLINICAL TRIAL REGISTRATION

Clinical Trial Identification Number: NCT02802566; URL of the Registration Site: www.

CLINICALTRIALS

gov .

Vital role for primary healthcare providers: urgent need to educate the community about daily nutritional self-care to support immune function and maintain health

The importance of self-care to improve health and social well-being is well recognised. Nevertheless, there remains a need to encourage people to better understand how their body works, and how to keep it healthy. Because of its important role, part of this understanding should be based on why the immune system must be supported. This highly complex system is essential for defending against pathogens, but also for maintaining health throughout the body by preserving homeostasis and integrity. Accordingly, the immune system requires active management for optimal functioning and to reduce the risk of chronic diseases. In addition to regular exercise, healthy sleeping patterns, cultivating mental resilience, adequate nutrition through healthy and diverse dietary habits is key to the daily support of immune function. Diet and the immune system are closely intertwined, and a poor diet will impair immunity and increase the risk of acute and chronic diseases. To help elucidate the roles of primary healthcare providers in supporting individuals to engage in self-care, an international group of experts reviewed the evidence for the roles of the immune system in maintaining health and for nutrition in daily immune support, and discussed implications for population health and clinical practice.

Safe and effective delivery of supplemental iron to healthy adults: a two-phase, randomized, double-blind trial - the safe iron study

Introduction

The safety of novel forms of iron in healthy, iron-replete adults as might occur if used in population-based iron supplementation programs was examined. We tested the hypotheses that supplementation with nanoparticulate iron hydroxide adipate tartrate (IHAT), an iron-enriched Aspergillus oryzae product (ASP), or ferrous sulphate heptahydrate (FS) are safe as indicated by erythrocyte susceptibility to malarial infection, bacterial proliferation, and gut inflammation. Responses to FS administered daily or weekly, and with or without other micronutrients were compared.

Methods

Two phases of randomized, double-blinded trials were conducted in Boston, MA. Phase I randomized 160 volunteers to six treatments: placebo, IHAT, ASP, FS, and FS plus a micronutrient powder (MNP) administrated daily at 60 mg Fe/day; and FS administered as a single weekly dose of 420 mg Fe. Phase II randomized 86 volunteers to IHAT, ASP, or FS administered at 120 mg Fe/day. Completing these phases were 151 and 77 participants, respectively. The study was powered to detect effects on primary endpoints: susceptibility of participant erythrocytes to infection by Plasmodium falciparum, the proliferation potential of selected pathogenic bacteria in sera, and markers of gut inflammation. Secondary endpoints for which the study was not powered included indicators of iron status and gastrointestinal symptoms.

Results

Supplementation with any form of iron did not affect any primary endpoint. In Phase I, the frequency of gastrointestinal symptoms associated with FS was unaffected by dosing with MNP or weekly administration; but participants taking IHAT more frequently reported abdominal pain (27%, p < 0.008) and nausea (4%, p = 0.009) than those taking FS, while those taking ASP more frequently reported nausea (8%, p = 0.009). Surprisingly, only 9% of participants taking IHAT at 120 mg Fe/day (Phase II) reported abdominal pain and no other group reported that symptom.

Discussion

With respect to the primary endpoints, few differences were found when comparing these forms of iron, indicating that 28 days of 60 or 120 mg/day of IHAT, ASP, or FS may be safe for healthy, iron-replete adults. With respect to other endpoints, subjects receiving IHAT more frequently reported abdominal pain and nausea, suggesting the need for further study.

Clinical Trial Registration

ClinicalTrials.gov, NCT03212677; registered: 11 July 2017.

Nutrition, Immunosenescence, and Infectious Disease: An Overview of the Scientific Evidence on Micronutrients and on Modulation of the Gut Microbiota

The immune system is key to host defense against pathogenic organisms. Aging is associated with changes in the immune system, with a decline in protective components (immunosenescence), increasing susceptibility to infectious disease, and a chronic elevation in low-grade inflammation (inflammaging), increasing the risk of multiple noncommunicable diseases. Nutrition is a determinant of immune cell function and of the gut microbiota. In turn, the gut microbiota shapes and controls the immune and inflammatory responses. Many older people show changes in the gut microbiota. Age-related changes in immune competence, low-grade inflammation, and gut dysbiosis may be interlinked and may relate, at least in part, to age-related changes in nutrition. A number of micronutrients (vitamins C, D, and E and zinc and selenium) play roles in supporting the function of many immune cell types. Some trials report that providing these micronutrients as individual supplements can reverse immune deficits in older people and/or in those with insufficient intakes. There is inconsistent evidence that this will reduce the risk or severity of infections including respiratory infections. Probiotic, prebiotic, or synbiotic strategies that modulate the gut microbiota, especially by promoting the colonization of lactobacilli and bifidobacteria, have been demonstrated to modulate some immune and inflammatory biomarkers in older people and, in some cases, to reduce the risk and severity of gastrointestinal and respiratory infections, although, again, the evidence is inconsistent. Further research with well-designed and well-powered trials in at-risk older populations is required to be more certain about the role of micronutrients and of strategies that modify the gut microbiota-host relationship in protecting against infection, especially respiratory infection.

Perspective: Role of Micronutrients and Omega-3 Long-Chain Polyunsaturated Fatty Acids for Immune Outcomes of Relevance to Infections in Older Adults-A Narrative Review and Call for Action

The immune system is weakened by advancing age, often referred to as immunosenescence, increasing the vulnerability to, and frequently the severity of, infectious diseases in older people. This has become very apparent in the current coronavirus disease 2019 (COVID-19) pandemic for which older people are at higher risk of severe outcomes, even those who are fully vaccinated. Aging affects both the innate and adaptive immune systems and is characterized by an imbalanced inflammatory response. Increasing evidence shows that optimal status of nutrients such as vitamins C, D, and E and selenium and zinc as well as the omega-3 (n-3) fatty acids DHA and EPA can help compensate for these age-related changes. While inadequate intakes of these nutrients are widespread in the general population, this is often more pronounced in older people. Maintaining adequate intakes is a challenge for them due to a range of factors such as physical, physiological, and cognitive changes; altered absorption; and the presence of noncommunicable diseases. While nutritional requirements are ideally covered by a balanced diet, this can be difficult to achieve, particularly for older people. Fortified foods and nutritional complements are effective in achieving adequate micronutrient intakes and should be considered as a safe and cost-effective means for older people to improve their nutritional status and hence support their defense against infections. Complementing the diet with a combination of micronutrients, particularly those playing a key role in the immune system such as vitamins C, D, and E and selenium and zinc as well as DHA and EPA, is recommended for older people. Optimal nutrition to support the immune system in older people will remain essential, particularly in the face of the current COVID-19 pandemic and, thus, developing strategies to ensure adequate nutrition for the growing number of older adults will be an important and cost-effective investment in the future.

Safe and effective delivery of supplemental iron to healthy older adults: The double-blind, randomized, placebo-controlled trial protocol of the Safe Iron Study

The forms of iron currently available to correct iron deficiency have adverse effects, including infectious diarrhea, increased susceptibility to malaria, inflammation and detrimental changes to the gut microbiome. These adverse effects limit their use such that the growing burden of iron deficiency has not abated in recent decades. Here, we summarize the protocol of the "Safe Iron Study", the first clinical study examining the safety and efficacy of novel forms of iron in healthy, iron-replete adults. The Safe Iron Study is a double-blind, randomized, placebo-controlled trial conducted in Boston, MA, USA. This study compares ferrous sulfate heptahydrate (FeSO 4·H 2O) with two novel forms of iron supplements (iron hydroxide adipate tartrate (IHAT) and organic fungal iron metabolite (Aspiron™ Natural Koji Iron)). In Phase I, we will compare each source of iron administrated at a low dose (60 mg Fe/day). We will also determine the effect of FeSO 4 co-administrated with a multiple micronutrient powder and weekly administration of FeSO 4. The forms of iron found to produce no adverse effects, or adverse effects no greater than FeSO 4 in Phase I, Phase II will evaluate a higher, i.e., a therapeutic dose (120 mg Fe/day). The primary outcomes of this study include ex vivo malaria ( Plasmodium falciparum) infectivity of host erythrocytes, ex vivo bacterial proliferation (of selected species) in presence of host plasma and intestinal inflammation assessed by fecal calprotectin. This study will test the hypotheses that the novel forms of iron, administered at equivalent doses to FeSO 4, will produce similar increases in iron status in iron-replete subjects, yet lower increases in ex vivo malaria infectivity, ex vivo bacterial proliferation, gut inflammation. Ultimately, this study seeks to contribute to development of safe and effective forms of supplemental iron to address the global burden of iron deficiency and anemia. Registration: ClinicalTrials.gov identifier: NCT03212677; registered: 11 July 2017.

A Novel Combination of Fruits and Vegetables Prevents Diet-Induced Hepatic Steatosis and Metabolic Dysfunction in Mice

BACKGROUND

Epidemiological studies suggest that higher fruits and vegetables (F&V) consumption correlates with reduced risk of hepatic steatosis, yet evidence for causality and the underlying mechanisms is lacking.

OBJECTIVES

We aimed to determine the causal relation between F&V consumption and improved metabolic disorders in mice fed high-fat (HF) (Experiment-1) or normal-fat (Experiment-2) diets and its underlying mechanisms.

METHODS

Six-week-old male C57BL/6J mice were randomly grouped and fed diets supplemented at 0%-15% (wt:wt) with a freeze-dried powder composed of 24 commonly consumed F&V (human equivalent of 0-9 servings/d) for 20 wk. In Experiment-1, mice were fed an HF (45% kcal fat) diet with 0% (HF0), 5%, 10%, or 15% (HF15) F&V or a matched low-fat control diet (10% kcal fat). In Experiment-2, mice were fed an AIN-93 diet (basal) (B, 16% kcal fat) with 0% (B0), 5%, 10%, or 15% (B15) F&V supplementation. Body weight and composition, food intake, hepatic steatosis, inflammation, ceramide levels, sphingomyelinase activity, and gut microbiota were assessed.

RESULTS

In Experiment-1, mice fed the HF15 diet had lower weight gain (17.9%), hepatic steatosis (48.4%), adipose tissue inflammation, blood (24.6%) and liver (33.9%) ceramide concentrations, and sphingomyelinase activity (38.8%) than HF0 mice (P < 0.05 for all). In Experiment-2, mice fed the B15 diet had no significant changes in weight gain but showed less hepatic steatosis (28.5%), blood and adipose tissue inflammation, and lower blood (30.0%) ceramide concentrations than B0 mice (P < 0.05 for all). These F&V effects were associated with favorable microbiota changes.

CONCLUSIONS

These findings represent the first evidence for a causal role of high F&V intake in mitigating hepatic steatosis in mice. These beneficial effects may be mediated through changes in ceramide and/or gut microbiota, and suggest that higher than currently recommended servings of F&V may be needed to achieve maximum health benefits.

Safe and effective delivery of supplemental iron to healthy older adults: The double-blind, randomized, placebo-controlled trial protocol of the Safe Iron Study

The forms of iron currently available to correct iron deficiency have adverse effects, including infectious diarrhea, increased susceptibility to malaria, inflammation and detrimental changes to the gut microbiome. These adverse effects limit their use such that the growing burden of iron deficiency has not abated in recent decades. Here, we summarize the protocol of the "Safe Iron Study", the first clinical study examining the safety and efficacy of novel forms of iron in healthy, iron-replete adults. The Safe Iron Study is a double-blind, randomized, placebo-controlled trial conducted in Boston, MA, USA. This study compares ferrous sulfate heptahydrate (FeSO 4·H 2O) with two novel forms of iron supplements (iron hydroxide adipate tartrate (IHAT) and organic fungal iron metabolite (Aspiron™ Natural Koji Iron)). In Phase I, we will compare each source of iron administrated at a low dose (60 mg Fe/day). We will also determine the effect of FeSO 4 co-administrated with a multiple micronutrient powder and weekly administration of FeSO 4. The forms of iron found to produce no adverse effects or adverse effects no greater than FeSO 4 in Phase I, Phase II will evaluate a higher, i.e., a therapeutic dose (120 mg Fe/day). The primary outcomes of this study include ex vivo malaria ( Plasmodium falciparum) infectivity of host erythrocytes, ex vivo bacterial proliferation (of selected species) in presence of host plasma and intestinal inflammation assessed by fecal calprotectin. This study will test the hypotheses that the novel forms of iron, administered at equivalent doses to FeSO 4, will produce similar increases in iron status in iron-replete subjects, yet lower increases in ex vivo malaria infectivity, ex vivo bacterial proliferation, gut inflammation. Ultimately, this study seeks to contribute to development of safe and effective forms of supplemental iron to address the global burden of iron deficiency and anemia. Registration: ClinicalTrials.gov identifier: NCT03212677; registered: 11 July 2017.

Long-term moderate calorie restriction inhibits inflammation without impairing cell-mediated immunity: a randomized controlled trial in non-obese humans

Calorie restriction (CR) inhibits inflammation and slows aging in many animal species, but in rodents housed in pathogen-free facilities, CR impairs immunity against certain pathogens. However, little is known about the effects of long-term moderate CR on immune function in humans. In this multi-center, randomized clinical trial to determine CR's effect on inflammation and cell-mediated immunity, 218 healthy non-obese adults (20-50 y), were assigned 25% CR (n=143) or an ad-libitum (AL) diet (n=75), and outcomes tested at baseline, 12, and 24 months of CR. CR induced a 10.4% weight loss over the 2-y period. Relative to AL group, CR reduced circulating inflammatory markers, including total WBC and lymphocyte counts, ICAM-1 and leptin. Serum CRP and TNF-α concentrations were about 40% and 50% lower in CR group, respectively. CR had no effect on the delayed-type hypersensitivity skin response or antibody response to vaccines, nor did it cause difference in clinically significant infections. In conclusion, long-term moderate CR without malnutrition induces a significant and persistent inhibition of inflammation without impairing key in vivo indicators of cell-mediated immunity. Given the established role of these pro-inflammatory molecules in the pathogenesis of multiple chronic diseases, these CR-induced adaptations suggest a shift toward a healthy phenotype.

Fecal concentrations of bacterially derived vitamin K forms are associated with gut microbiota composition but not plasma or fecal cytokine concentrations in healthy adults

Background: Emerging evidence suggests novel roles for bacterially derived vitamin K forms known as menaquinones in health and disease, which may be attributable in part to anti-inflammatory effects. However, the relevance of menaquinones produced by gut bacteria to vitamin K requirements and inflammation is undetermined.Objective: This study aimed to quantify fecal menaquinone concentrations and identify associations between fecal menaquinone concentrations and serum vitamin K concentrations, gut microbiota composition, and inflammation.Design: Fecal and serum menaquinone concentrations, fecal microbiota composition, and plasma and fecal cytokine concentrations were measured in 80 men and postmenopausal women (48 men, 32 women, age 40-65 y) enrolled in a randomized, parallel-arm, provided-food trial. After consuming a run-in diet for 2 wk, participants were randomly assigned to consume a whole grain-rich (WG) or a refined grain-based (RG) diet for 6 wk. Outcomes were measured at weeks 2 and 8.Results: The median total daily excretion of menaquinones in feces was 850 nmol/d but was highly variable (range: 64-5358 nmol/d). The total median (IQR) fecal concentrations of menaquinones decreased in the WG diet compared with the RG diet [-6.8 nmol/g (13.0 nmol/g) dry weight for WG compared with 1.8 nmol/g (12.3 nmol/g) dry weight for RG; P < 0.01)]. However, interindividual variability in fecal menaquinone concentrations partitioned individuals into 2 distinct groups based on interindividual differences in concentrations of different menaquinone forms rather than the diet group or the time point. The relative abundances of several gut bacteria taxa, Bacteroides and Prevotella in particular, differed between these groups, and 42% of identified genera were associated with ≥1 menaquinone form. Menaquinones were not detected in serum, and neither fecal concentrations of individual menaquinones nor the menaquinone group was associated with any marker of inflammation.Conclusion: Menaquinone concentrations in the human gut appear highly variable and are associated with gut microbiota composition. However, the health implications remain unclear. This trial was registered at clinicaltrials.gov as NCT01902394.

The Alpha-Tocopherol Form of Vitamin E Boosts Elastase Activity of Human PMNs and Their Ability to Kill Streptococcus pneumoniae

Despite the availability of vaccines, Streptococcus pneumoniae remains a leading cause of life-threatening infections, such as pneumonia, bacteremia and meningitis. Polymorphonuclear leukocytes (PMNs) are a key determinant of disease course, because optimal host defense requires an initial robust pulmonary PMN response to control bacterial numbers followed by modulation of this response later in infection. The elderly, who manifest a general decline in immune function and higher basal levels of inflammation, are at increased risk of developing pneumococcal pneumonia. Using an aged mouse infection model, we previously showed that oral supplementation with the alpha-tocopherol form of vitamin E (α-Toc) decreases pulmonary inflammation, in part by modulating neutrophil migration across lung epithelium into alveolar spaces, and reverses the age-associated decline in resistance to pneumococcal pneumonia. The objective of this study was to test the effect of α-Toc on the ability of neutrophils isolated from young (22–35 years) or elderly (65–69 years) individuals to migrate across epithelial cell monolayers in response to S. pneumoniae and to kill complement-opsonized pneumococci. We found that basal levels of pneumococcal-induced transepithelial migration by PMNs from young or elderly donors were indistinguishable, suggesting that the age-associated exacerbation of pulmonary inflammation is not due to intrinsic properties of PMNs of elderly individuals but rather may reflect the inflammatory milieu of the aged lung. Consistent with its anti-inflammatory activity, α-Toc treatment diminished PMN migration regardless of donor age. Unexpectedly, unlike previous studies showing poor killing of antibody-opsonized bacteria, we found that PMNs of elderly donors were more efficient at killing complement-opsonized bacteria ex vivo than their younger counterparts. We also found that the heightened antimicrobial activity in PMNs from older donors correlated with increased activity of neutrophil elastase, a serine protease that is required to kill pneumococci. Notably, incubation with α-Toc increased PMN elastase activity from young donors and boosted their ability to kill complement-opsonized pneumococci. These findings demonstrate that α-Toc is a potent modulator of PMN responses and is a potential nutritional intervention to combat pneumococcal infection.

Substituting whole grains for refined grains in a 6-wk randomized trial favorably affects energy-balance metrics in healthy men and postmenopausal women

Background: The effect of whole grains on the regulation of energy balance remains controversial.Objective: We aimed to determine the effects of substituting whole grains for refined grains, independent of body weight changes, on energy-metabolism metrics and glycemic control.Design: The study was a randomized, controlled, parallel-arm controlled-feeding trial that was conducted in 81 men and postmenopausal women [49 men and 32 women; age range: 40-65 y; body mass index (in kg/m²): <35.0]. After a 2-wk run-in period, participants were randomly assigned to consume 1 of 2 weight-maintenance diets for 6 wk. Diets differed in whole-grain and fiber contents [mean ± SDs: whole grain-rich diet: 207 ± 39 g whole grains plus 40 ± 5 g dietary fiber/d; refined grain-based diet: 0 g whole grains plus 21 ± 3 g dietary fiber/d] but were otherwise similar. Energy metabolism and body-composition metrics, appetite, markers of glycemic control, and gut microbiota were measured at 2 and 8 wk.Results: By design, body weight was maintained in both groups. Plasma alkylresorcinols, which are biomarkers of whole-grain intake, increased in the whole grain-rich diet group (WG) but not in the refined grain-based diet group (RG) (P-diet-by-time interaction < 0.0001). Beta ± SE changes (ΔWG compared with ΔRG) in the resting metabolic rate (RMR) (43 ± 25 kcal/d; P = 0.04), stool weight (76 ± 12 g/d; P < 0.0001), and stool energy content (57 ± 17 kcal/d; P = 0.003), but not in stool energy density, were higher in the WG. When combined, the favorable energetic effects in the WG translated into a 92-kcal/d (95% CI: 28, 156-kcal/d) higher net daily energy loss compared with that of the RG (P = 0.005). Prospective consumption (P = 0.07) and glycemia after an oral-glucose-tolerance test (P = 0.10) trended toward being lower in the WG than in the RG. When nonadherent participants were excluded, between-group differences in stool energy content and glucose tolerance increased, and between-group differences in the RMR and prospective consumption were not statistically significant.Conclusion: These findings suggest positive effects of whole grains on the RMR and stool energy excretion that favorably influence energy balance and may help explain epidemiologic associations between whole-grain consumption and reduced body weight and adiposity. This trial was registered at clinicaltrials.gov as NCT01902394.

Consensus Statement Immunonutrition and Exercise

In this consensus statement on immunonutrition and exercise, a panel of knowledgeable contributors from across the globe provides a consensus of updated science, including the background, the aspects for which a consensus actually exists, the controversies and, when possible, suggested directions for future research.

Nutritional Considerations for Healthy Aging and Reduction in Age-Related Chronic Disease

A projected doubling in the global population of people aged ≥60 y by the year 2050 has major health and economic implications, especially in developing regions. Burdens of unhealthy aging associated with chronic noncommunicable and other age-related diseases may be largely preventable with lifestyle modification, including diet. However, as adults age they become at risk of "nutritional frailty," which can compromise their ability to meet nutritional requirements at a time when specific nutrient needs may be high. This review highlights the role of nutrition science in promoting healthy aging and in improving the prognosis in cases of age-related diseases. It serves to identify key knowledge gaps and implementation challenges to support adequate nutrition for healthy aging, including applicability of metrics used in body-composition and diet adequacy for older adults and mechanisms to reduce nutritional frailty and to promote diet resilience. This review also discusses management recommendations for several leading chronic conditions common in aging populations, including cognitive decline and dementia, sarcopenia, and compromised immunity to infectious disease. The role of health systems in incorporating nutrition care routinely for those aged ≥60 y and living independently and current actions to address nutritional status before hospitalization and the development of disease are discussed.

Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Zinc is essential for the regulation of immune response. T cell function declines with age. Zinc supplementation has the potential to improve the serum zinc concentrations and immunity of nursing home elderly with a low serum zinc concentration.

OBJECTIVE

We aimed to determine the effect of supplementation with 30 mg Zn/d for 3 mo on serum zinc concentrations of zinc-deficient nursing home elderly.

DESIGN

This was a randomized, double-blind, placebo-controlled study. Of 53 nursing home elderly (aged ≥65 y) who met eligibility criteria, 58% had a low serum zinc concentration (serum zinc <70 μg/dL); these 31 were randomly assigned to zinc (30 mg Zn/d) (n = 16) or placebo (5 mg Zn/d) (n = 15) groups. The primary outcome measure was change in serum zinc concentrations between baseline and month 3. We also explored the effects of supplementation on immune response.

RESULTS

Baseline characteristics were similar in the 2 groups. The difference in the mean change in serum zinc was significantly higher, by 16%, in the zinc group than in the placebo group (P = 0.007) when baseline zinc concentrations were controlled for. In addition, controlling for baseline C-reactive protein, copper, or albumin did not change the results. However, supplementation of participants with ≤60 μg serum Zn/dL failed to increase their serum zinc to ≥70 μg/dL. Zinc supplementation also significantly increased anti-CD3/CD28 and phytohemagglutinin-stimulated T cell proliferation, and the number of peripheral T cells (P < 0.05). When proliferation was expressed per number of T cells, the significant differences between groups were lost, suggesting that the zinc-induced enhancement of T cell proliferation was mainly due to an increase in the number of T cells.

CONCLUSIONS

Zinc supplementation at 30 mg/d for 3 mo is effective in increasing serum zinc concentrations in nursing home elderly; however, not all zinc-deficient elderly reached adequate concentrations. The increase in serum zinc concentration was associated with the enhancement of T cell function mainly because of an increase in the number of T cells.

Effects of 2-year calorie restriction on circulating levels of IGF-1, IGF-binding proteins and cortisol in nonobese men and women: a randomized clinical trial

Young-onset calorie restriction (CR) in rodents decreases serum IGF-1 concentration and increases serum corticosterone levels, which have been hypothesized to play major roles in mediating its anticancer and anti-aging effects. However, little is known on the effects of CR on the IGF-1 system and cortisol in humans. To test the sustained effects of CR on these key hormonal adaptations, we performed a multicenter randomized trial of a 2-year 25% CR intervention in 218 nonobese (body mass index between 22 and 27.8 kg m(-2) ) young and middle-aged (20-50 years age range) men and women. Average CR during the first 6 months was 19.5 ± 0.8% and 9.1 ± 0.7% over the next 18 months of the study. Weight loss averaged 7.6 ± 0.3 kg over the 2-years period of which 71% was fat mass loss (P < 0.0001). Average CR during the CR caused a significant 21% increase in serum IGFBP-1 and a 42% reduction in IGF-1:IGFBP-1 ratio at 2 years (P < 0.008), but did not change IGF-1 and IGF-1:IGFBP-3 ratio levels. Serum cortisol concentrations were slightly but significantly increased by CR at 1 year only (P = 0.003). Calorie restriction had no effect on serum concentrations of PDGF-AB and TGFβ-1. We conclude, on the basis of the present and previous findings, that, in contrast to rodents, humans do not respond to CR with a decrease in serum IGF-1 concentration or with a sustained and biological relevant increase in serum cortisol. However, long-term CR in humans significantly and persistently increases serum IGFBP-1 concentration.

A 2-Year Randomized Controlled Trial of Human Caloric Restriction: Feasibility and Effects on Predictors of Health Span and Longevity

BACKGROUND

Caloric restriction (CR), energy intake reduced below ad libitum (AL) intake, increases life span in many species. The implications for humans can be clarified by randomized controlled trials of CR.

METHODS

To determine CR's feasibility, safety, and effects on predictors of longevity, disease risk factors, and quality of life in nonobese humans aged 21-51 years, 218 persons were randomized to a 2-year intervention designed to achieve 25% CR or to AL diet. Outcomes were change from baseline resting metabolic rate adjusted for weight change ("RMR residual") and core temperature (primary); plasma triiodothyronine (T3) and tumor necrosis factor-α (secondary); and exploratory physiological and psychological measures.

RESULTS

Body mass index averaged 25.1 (range: 21.9-28.0 kg/m(2)). Eighty-two percent of CR and 95% of AL participants completed the protocol. The CR group achieved 11.7±0.7 %CR (mean ± standard error) and maintained 10.4±0.4% weight loss. Weight change in AL was negligible. RMR residual decreased significantly more in CR than AL at 12 months (p = .04) but not 24 months (M24). Core temperature change differed little between groups. T3 decreased more in CR at M12 and M24 (p < .001), while tumor necrosis factor-α decreased significantly more only at M24 (p = .02). CR had larger decreases in cardiometabolic risk factors and in daily energy expenditure adjusted for weight change, without adverse effects on quality of life.

CONCLUSIONS

Sustained CR is feasible in nonobese humans. The effects of the achieved CR on correlates of human survival and disease risk factors suggest potential benefits for aging-related outcomes that could be elucidated by further human studies.

Inflammation and Nutritional Science for Programs/Policies and Interpretation of Research Evidence (INSPIRE)

An increasing recognition has emerged of the complexities of the global health agenda—specifically, the collision of infections and noncommunicable diseases and the dual burden of over- and undernutrition. Of particular practical concern are both 1) the need for a better understanding of the bidirectional relations between nutritional status and the development and function of the immune and inflammatory response and 2) the specific impact of the inflammatory response on the selection, use, and interpretation of nutrient biomarkers. The goal of the Inflammation and Nutritional Science for Programs/Policies and Interpretation of Research Evidence (INSPIRE) is to provide guidance for those users represented by the global food and nutrition enterprise. These include researchers (bench and clinical), clinicians providing care/treatment, those developing and evaluating programs/interventions at scale, and those responsible for generating evidence-based policy. The INSPIRE process included convening 5 thematic working groups (WGs) charged with developing summary reports around the following issues: 1) basic overview of the interactions between nutrition, immune function, and the inflammatory response; 2) examination of the evidence regarding the impact of nutrition on immune function and inflammation; 3) evaluation of the impact of inflammation and clinical conditions (acute and chronic) on nutrition; 4) examination of existing and potential new approaches to account for the impact of inflammation on biomarker interpretation and use; and 5) the presentation of new approaches to the study of these relations. Each WG was tasked with synthesizing a summary of the evidence for each of these topics and delineating the remaining gaps in our knowledge. This review consists of a summary of the INSPIRE workshop and the WG deliberations.

The α-tocopherol form of vitamin E reverses age-associated susceptibility to streptococcus pneumoniae lung infection by modulating pulmonary neutrophil recruitment

Streptococcus pneumoniae infections are an important cause of morbidity and mortality in older patients. Uncontrolled neutrophil-driven pulmonary inflammation exacerbates this disease. To test whether the α-tocopherol (α-Toc) form of vitamin E, a regulator of immunity, can modulate neutrophil responses as a preventive strategy to mitigate the age-associated decline in resistance to S. pneumoniae, young (4 mo) and old (22-24 mo) C57BL/6 mice were fed a diet containing 30-PPM (control) or 500-PPM (supplemented) α-Toc for 4 wk and intratracheally infected with S. pneumoniae. Aged mice fed a control diet were exquisitely more susceptible to S. pneumoniae than young mice. At 2 d postinfection, aged mice suffered 1000-fold higher pulmonary bacterial burden, 2.2-fold higher levels of neutrophil recruitment to the lung, and a 2.25-fold higher rate of lethal septicemia. Strikingly, α-Toc supplementation of aged mice resulted in a 1000-fold lower bacterial lung burden and full control of infection. This α-Toc-induced resistance to pneumococcal challenge was associated with a 2-fold fewer pulmonary neutrophils, a level comparable to S. pneumoniae-challenged, conventionally fed young mice. α-Toc directly inhibited neutrophil egress across epithelial cell monolayers in vitro in response to pneumococci or hepoxilin-A3, an eicosanoid required for pneumococcus-elicited neutrophil trans-epithelial migration. α-Toc altered expression of multiple epithelial and neutrophil adhesion molecules involved in migration, including CD55, CD47, CD18/CD11b, and ICAM-1. These findings suggest that α-Toc enhances resistance of aged mice to bacterial pneumonia by modulating the innate immune response, a finding that has potential clinical significance in combating infection in aged individuals through nutritional intervention.

Obesity during pregnancy alters maternal oxidant balance and micronutrient status

OBJECTIVE

Little is known about the effect of obesity on inflammatory status in pregnant women. The objective of this study was to determine the effect of obesity on markers of inflammation, oxidative stress and micronutrient status in obese pregnant women and their infants compared with lean controls (Lc).

STUDY DESIGN

This was a prospective case-control study. A total of 15 obese (Ob; body mass index (BMI) >30 kg m(-2)) and 15 lean (BMI 18-25 kg m(-2)) women were recruited based on prepregnancy BMI. Vitamins A, B6, C, E and 25-hydroxyvitamin D (25(OH)D), zinc, red blood cell (RBC) folate, C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α and oxidized and reduced glutathione were measured from maternal blood between 24 and 28 weeks of gestation. Vitamins A, B6, C and E, 25(OH)D, zinc, red blood cell folate, CRP and IL-6 were measured from cord blood at delivery.

RESULT

Ob pregnant women have statistically significantly lower levels of vitamin B6, vitamin C, vitamin E, RBC folate, higher CRP and IL-6 levels and higher ratio of oxidized to reduced glutathione compared with Lc pregnant women. Infants born to Ob mothers did not have statistically significantly higher measures of inflammation or oxidative stress. There were no differences in micronutrient concentrations between Lc and Ob infants, but folate, vitamin B6 and zinc levels correlated strongly between mother and infant. There was no statistically significant difference in any parameter between Ob and Lc cord blood.

CONCLUSION

Ob pregnant women have increased inflammation and oxidative stress, and lower levels of nutritional antioxidant defenses compared with Lc pregnant women. We speculate that lower antioxidant defenses combined with increased oxidative stress and inflammation may contribute to the adverse outcomes associated with pregnancy in Ob women.

Obesity impairs cell-mediated immunity during the second trimester of pregnancy

OBJECTIVE

Obese pregnancy is associated with significantly higher rates of infection, which can harm both mother and fetus. The objective of this study was to determine the impact of obesity on maternal blood immune function.

STUDY DESIGN

This was a cross-sectional, case control study of 15 obese (Ob) and 15 lean (Lc) subjects. Immune cell subsets, intracellular and serum cytokine production, and lymphocyte proliferation were measured in maternal blood during the second trimester of pregnancy.

RESULTS

Obese women had a significantly lower proportion of CD8+ and NKT cells and a higher proportion of B cells, impaired cytokine production when stimulated ex vivo, and impaired ability of lymphocytes to proliferate compared with their lean counterparts.

CONCLUSION

Obese pregnancy is associated with impaired cell-mediated immunity. Because perinatal infections can have serious maternal and fetal consequences, it is imperative to better understand these mechanistic underpinnings to optimize prevention and devise targeted therapy.

Epigallocatechin-3-gallate ameliorates experimental autoimmune encephalomyelitis by altering balance among CD4+ T-cell subsets

The green tea component epigallocatechin-3-gallate (EGCG) may be beneficial in autoimmune diseases; however, the underlying mechanisms are not well understood. In this study, we determined the effect of EGCG on the development of experimental autoimmune encephalomyelitis, an animal model for human multiple sclerosis, and the underlying mechanisms. Female C57BL/6 mice were fed EGCG (0%, 0.15%, 0.3%, and 0.6% in diet) for 30 days and then immunized with specific antigen myelin oligodendrocyte glycoprotein 35-55. EGCG dose dependently attenuated clinical symptoms and pathological features (leukocyte infiltration and demyelination) in the central nervous system and inhibited antigen-specific T-cell proliferation and delayed-type hypersensitivity skin response. We further showed that EGCG reduced production of interferon-γ, IL-17, IL-6, IL-1β, and tumor necrosis factor-α; decreased types 1 and 17 helper T cells (Th1 and Th17, respectively); and increased regulatory T-cell populations in lymph nodes, the spleen, and the central nervous system. Moreover, EGCG inhibited expression of transcription factors T-box expressed in T cells and retinoid-related orphan receptor-γt, the specific transcription factor for Th1 and Th17 differentiation, respectively; the plasma levels of intercellular adhesion molecule 1; and CCR6 expression in CD4(+) T cells. These results indicate that EGCG may attenuate experimental autoimmune encephalomyelitis autoimmune response by inhibiting immune cell infiltration and modulating the balance among pro- and anti-autoimmune CD4(+) T-cell subsets. Thus, we identified a novel mechanism that underlies EGCG's beneficial effect in autoimmune disease.

Patterns of antimicrobial use for respiratory tract infections in older residents of long-term care facilities

OBJECTIVES

To describe patterns of antimicrobial use for respiratory tract infections (RTIs) in older residents of long-term care facilities (LTCFs).

DESIGN

Data from a prospective, randomized, controlled study of the effect of vitamin E supplementation on RTIs conducted from April 1998 through August 2001 were analyzed.

SETTING

Thirty-three LTCFs in the greater Boston area.

PARTICIPANTS

Six hundred seventeen subjects aged 65 and older residing in LTCFs.

MEASUREMENTS

RTIs, categorized as acute bronchitis, pneumonia, common cold, influenza-like illness, pharyngitis, and sinusitis, were studied for appropriateness of antimicrobial use, type of antibiotics used, and factors associated with their use. For cases in which drug treatment was administered, antibiotic use was rated as appropriate (when an effective drug was used), inappropriate (when a more-effective drug was indicated), or unjustified (when use of any antimicrobial was not indicated).

RESULTS

Of 752 documented episodes of RTI, overall treatment was appropriate in 79% of episodes, inappropriate in 2%, and unjustified in 19%. For acute bronchitis, treatment was appropriate in 35% and unjustified in 65% of cases. For pneumonia, treatment was appropriate in 87% of episodes. Of the most commonly used antimicrobials, macrolide use was unjustified in 43% of cases. No statistically significant differences in the patterns of antibiotic use were observed when stratified according to age, sex, race, or comorbid conditions, including diabetes mellitus, dementia, and chronic kidney disease.

CONCLUSION

Antimicrobials were unjustifiably used for one-fifth of RTIs and more than two-thirds of cases of acute bronchitis, suggesting a need for programs to improve antibiotic prescribing at LTCFs.

Metabolic syndrome in the elderly living in marginal peri-urban communities in Quito, Ecuador

OBJECTIVE

The proportion of the Latin American population aged >60 years is expected to double during the next few decades. Metabolic syndrome (MetS) is associated with high morbidity and mortality worldwide. However, little is known about MetS in Latin America in general, and in Ecuador in particular. The present study aimed to examine the prevalence of MetS and its association with blood micronutrient, homocysteine (Hcy) and C-reactive protein (CRP) concentrations in the elderly living in a low-income urban area.

DESIGN

We performed a cross-sectional study. MetS, using the International Diabetes Federation definition, dietary intake and plasma micronutrient, CRP and Hcy concentrations were assessed.

SUBJECTS

A total of 352 elderly (≥65 years) Ecuadorians.

SETTING

Quito, Ecuador.

RESULTS

MetS was prevalent (40%)--considerably more so among women (81%) than men (19%; χ² = 32·6, P < 0·0001). Further, 53 % of those without MetS exhibited two or more of its components. Micronutrient deficiencies were prevalent, including those of vitamin C, zinc, vitamin B₁₂ and folate. Vitamin C and E concentrations were inversely (OR = 0·78, 95% CI 0·71, 0·86; OR = 0·16, 95% CI 0·03, 0·81, respectively) and CRP (OR = 1·79, 95 % CI 1·04, 3·06) was positively associated with MetS.

CONCLUSIONS

The coexistence of MetS with micronutrient deficiencies suggests that elderly Ecuadorians suffer from the double burden of diseases that are increasingly being observed in less developed countries. More research is needed to determine the causal factors, but results presented suggest that these older adults would benefit from interventions to reduce the risk factors for MetS, in particular higher consumption of micronutrient-rich foods.

Interleukin 1B variant -1473G/C (rs1143623) influences triglyceride and interleukin 6 metabolism

CONTEXT

IL1b (IL1B or IL1β), a key modulator of the immune response, exerts its functions mainly via IL6 regulation. Fatty meals cause transient hypertriglyceridemia and are considered to be proinflammatory, but the extent of these responses shows high interindividual susceptibility.

OBJECTIVE

We evaluated the influence of a genetic variant located in the promoter region of IL1B (-1473G/C) on fasting and postprandial lipids and IL6.

DESIGN, SETTING, AND PARTICIPANTS

A total of 477 people over age 65 yr were genotyped for IL1B -1473G/C, and we evaluated fasting lipids depending on genotype. Then, 88 healthy young men were also genotyped and were fed a saturated fatty acid-rich meal. Serial blood samples were drawn for 11 h after the meal, and lipid fractions and IL6 were assayed. MAIN OUTCOME AND INTERVENTIONS: Fasting lipids were studied in the aged persons. Fasting and postprandial measurements of lipids and IL6 were performed in the healthy young men.

RESULTS

In the aged persons, CC subjects (minor allele homozygotes) showed higher triglyceride (P = 0.002) and cholesterol (P = 0.011) levels. Healthy young male carriers of the minor C allele showed higher postprandial triglycerides (P = 0.037), and those carried into large triglyceride-rich lipoproteins (P = 0.004). In addition, they showed higher postprandial IL6 concentrations (P = 0.008).

CONCLUSIONS

Our work shows that inflammatory genes may regulate fasting and postprandial lipids because the carriers of the minor allele of an IL gene variant have altered lipid metabolism. To reinforce these gene-phenotype findings, IL6 (the natural effector of IL1B) was increased in these persons.

Low zinc status: a new risk factor for pneumonia in the elderly?

Low zinc status may be a risk factor for pneumonia in the elderly. This special article reviews the magnitude of the problem of pneumonia (its prevalence, morbidity, and mortality) in the elderly, pneumonia's etiology, and the dysregulation of the immune system associated with increasing age. In addition, recent evidence from the literature is presented demonstrating that low zinc status (commonly reported in the elderly) impairs immune function, decreases resistance to pathogens, and is associated with increased incidence and duration of pneumonia, increased use and duration of antimicrobial treatment, and increased overall mortality in the elderly. Inadequate stores of zinc might, therefore, be a risk factor for pneumonia in the elderly. Randomized, double-blind, controlled studies are needed to determine the efficacy of zinc supplementation as a potential low-cost intervention to reduce morbidity and mortality due to pneumonia in this vulnerable population.

A trial of the effect of micronutrient supplementation on treatment outcome, T cell counts, morbidity, and mortality in adults with pulmonary tuberculosis

BACKGROUND

Tuberculosis (TB) often coincides with nutritional deficiencies. The effects of micronutrient supplementation on TB treatment outcomes, clinical complications, and mortality are uncertain.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial of micronutrients (vitamins A, B complex, C, and E, as well as selenium) in Dar es Salaam, Tanzania. We enrolled 471 human immunodeficiency virus (HIV)-infected and 416 HIV-negative adults with pulmonary TB at the time of initiating chemotherapy and monitored them for a median of 43 months.

RESULTS

Micronutrients decreased the risk ofTB recurrence by 45% overall (95% confidence interval [CI], 7% to 67%; P = .02) and by 63% in HIV-infected patients (95% CI, 8% to 85%; P = .02). There were no significant effects on mortality overall; however, we noted a marginally significant 64% reduction of deaths in HIV-negative subjects (95% CI, -14% to 88%; P = .08). Supplementation increased CD3+ and CD4+ cell counts and decreased the incidence of extrapulmonary TB and genital ulcers in HIV-negative patients. Micronutrients reduced the incidence of peripheral neuropathy by 57% (95% CI, 41% to 69%; P < .001), irrespective of HIV status. There were no significant effects on weight gain, body composition, anemia, or HIV load.

CONCLUSIONS

Micronutrient supplementation could improve the outcome in patients undergoing TB chemotherapy in Tanzania.

Serum zinc and pneumonia in nursing home elderly

BACKGROUND

Zinc plays an important role in immune function. The association between serum zinc and pneumonia in the elderly has not been studied.

OBJECTIVE

The objective was to determine whether serum zinc concentrations in nursing home elderly are associated with the incidence and duration of pneumonia, total and duration of antibiotic use, and pneumonia-associated and all-cause mortality.

DESIGN

This observational study was conducted in residents from 33 nursing homes in Boston, MA, who participated in a 1-y randomized, double-blind, and placebo-controlled vitamin E supplementation trial; all were given daily doses of 50% of the recommended dietary allowance of essential vitamins and minerals, including zinc. Participants with baseline (n = 578) or final (n = 420) serum zinc concentrations were categorized as having low (<70 microg/dL) or normal (>or=70 microg/dL) serum zinc concentrations. Outcome measures included the incidence and number of days with pneumonia, number of new antibiotic prescriptions, days of antibiotic use, death due to pneumonia, and all-cause mortality.

RESULTS

Compared with subjects with low zinc concentrations, subjects with normal final serum zinc concentrations had a lower incidence of pneumonia, fewer (by almost 50%) new antibiotic prescriptions, a shorter duration of pneumonia, and fewer days of antibiotic use (3.9 d compared with 2.6 d) (P <or= 0.004 for all). Normal baseline serum zinc concentrations were associated with a reduction in all-cause mortality (P = 0.049).

CONCLUSION

Normal serum zinc concentrations in nursing home elderly are associated with a decreased incidence and duration of pneumonia, a decreased number of new antibiotic prescriptions, and a decrease in the days of antibiotic use. Zinc supplementation to maintain normal serum zinc concentrations in the elderly may help reduce the incidence of pneumonia and associated morbidity.

Strategies, time, and costs associated with the recruitment and enrollment of nursing home residents for a micronutrient supplementation clinical trial

BACKGROUND

Concomitant with the substantial growth of the elderly population in the last decade, there has been a steady rise in the number of nursing home residents aged 65 years and older. Well designed, rigorously conducted clinical intervention trials provide an important source of data for evidence-based improvements in the medical care of nursing home residents. The information available on strategies for the recruitment and screening of participants for such studies in long-term care facilities, as well as the financial and time costs for carrying out these investigations, is limited.

METHODS

This report describes our experience in recruiting 617 nursing home residents for a multisite, double-blind, randomized, placebo-controlled trial designed to determine the efficacy of a 1-year period of vitamin E supplementation in preventing respiratory tract infections. Comparisons of the projected staffing costs and actual costs incurred are presented, using a retrospective method for the determination of unit costs.

RESULTS

Initially, 874 consents were obtained from 2815 potential participants, of which only 617 were enrolled. Each successful enrollment required an average of 15 hours of staff time at a combined personnel and supply cost of $515 per participant and a total study cost of $317,661. Several obstacles were encountered during the recruitment and enrollment process: resistance on the part of family or primary care provider; transfer out of facility; and changes in the medical condition of the patient, including death.

DISCUSSION

The results of this report should prove useful to investigators developing budgets for nursing home-based clinical trials by providing a more accurate determination of the personnel needed and the costs associated with recruitment and enrollment of participants.

Effect of a therapeutic lifestyle change diet on immune functions of moderately hypercholesterolemic humans

Hypercholesterolemia is a risk factor for coronary heart disease (CHD) and also could contribute to impaired immune response. The National Cholesterol Education Program Expert Panel recommends a therapeutic lifestyle change (TLC) diet to reduce the risk for CHD. We investigated the effects of changing from a high-fat Western diet to a low-fat diet in accordance with a TLC diet on immune functions of older adults with hypercholesterolemia to determine whether improving the lipid profile via dietary intervention would have beneficial effects on immune functions. In a double-blind study, 18 subjects consumed both a Western diet (38% fat) and a TLC diet (28% fat) for 32 days in a randomized order. Measures of cellular immune responses, including delayed-type hypersensitivity (DTH) response, in vitro lymphocyte proliferation, and interleukin (IL)-2 production, and production of proinflammatory mediators, including tumor necrosis factor-alpha, IL-6, IL-1beta, and prostaglandin E2, were determined. DTH response and lymphocyte proliferative response increased significantly (29% and 27%, respectively) after consumption of a TLC diet. Our results indicate that consumption of a TLC diet enhances T cell-mediated immune functions in older adults with elevated cholesterol level. This might be a clinically important benefit, considering the decline of T cell-mediated immune functions with aging and evidence of impaired immune function associated with hypercholesterolemia.

Metabolic aging and predicted longevity: results of a cross-sectional study in post-menopausal women

BACKGROUND AND AIMS

The extent to which general characteristics of metabolic aging contribute to differences in life span among individuals remains uncertain. The objective of this study was to examine the association of age-related physiological and metabolic variables with predicted longevity in postmenopausal women.

METHODS

Subjects were 33 healthy women aged 55-65 years. Total and resting energy expenditure, body temperature, immune function as assessed by a delayed-type hypersensitivity skin test (DTH), lipid profile, and reported dietary intake were measured.

RESULTS

There were no significant associations between longevity, energy expenditure, body temperature, lipid profile, or dietary intake. However, there was a significant association of predicted longevity with DTH (partial r=0.44, p=0.023).

CONCLUSIONS

These results suggest that immune function may predict familial differences in longevity, while energy expenditure, body temperature, lipid profile, and dietary intake are unrelated. Although the small sample size may have limited the ability to detect metabolic effects on longevity in this study, the general approach may be broadly applicable to examinations of metabolic aging in humans.

Vitamin E-enhanced IL-2 production in old mice: naive but not memory T cells show increased cell division cycling and IL-2-producing capacity

Aging is associated with reduced T cell function, as demonstrated by decreased T cell proliferation and IL-2 production. These changes respond to supplemental vitamin E both in animals and humans, in part by the reduction of T cell suppressive PGE(2), the production of which by macrophages is increased with age. To evaluate whether vitamin E has a direct PGE(2)-independent effect on T cell responses, T cells purified from the spleens of young and old mice were preincubated with vitamin E or vehicle control. Activation-induced cell division of T cells from old mice was lower than that by young, and the production of IL-2 following 48-h activation was less by T cells from old mice. There was an age-related decline in both the number of IL-2+ T cells and the amount of IL-2 produced per cell. Despite decreased IL-2 protein at 48 h, the expression of IL-2 mRNA at 6 h and IL-2 protein production at 6 and 16 h was greater by T cells from old mice compared with that of young. Age-related decline in cell division and IL-2 production at 48 h was only observed within the naive T cell subpopulation. Vitamin E increased both cell-dividing and IL-2-producing capacity of naive T cells from old mice, with no effect on memory T cells. These data indicate that naive T cells exhibit the greatest age-related defect and show for the first time that supplemental vitamin E has direct immunoenhancing effect on naive T cells from old mice.

Vitamin E and genome stability

Free radicals and reactive oxygen species (ROS) which are generated continuously cause mutagenic alterations resulting in cancer, aging and abnormalities in the nervous system. Accumulating evidence indicates that Vitamin E, the most potent lipid peroxyl radical scavenger, may reduce free radical induced chromosomal damages through inhibition of free radical formation, and activation of endonuclease that can be triggered by intracellular oxidative stress, and by increasing the rate of removal of damaged DNA. Although some studies suggest a potential usefulness of Vitamin E in the prevention of mutagenic effects caused by genotoxic free radicals, other studies report no effects. Thus the data are not conclusive enough to be used as a basis to change the current recommended dietary allowances (RDA). Future research should address molecular mechanisms underlying the protective effects of Vitamin E and develop appropriate biologically relevant biomarkers of DNA damage to further help in determining the dietary levels of Vitamin E needed to protect the genetic pool from internally and externally induced DNA damages.

Metabolic, psychological, and health correlates of dietary restraint in healthy postmenopausal women

BACKGROUND

Dietary restraint, a term used to describe the intentional control of food intake to prevent weight gain or promote weight loss, is commonly practiced by older adults, but little is known about its effects on physiology and metabolism.

METHODS

We therefore compared a wide range of parameters between groups of healthy non-obese postmenopausal women classified psychometrically as unrestrained eaters (body mass index [BMI] 23.8 +/- 0.6 [SEM] kg/m(2), n = 28) or restrained eaters (BMI 24.5 +/- 0.5, n = 39). Measurements were made of reported micronutrient intakes, cardiopulmonary function, hematology, body temperature, skin thickness, bone mass, and immune function; in addition, self-perceived health, mood, and some dimensions of eating behavior were assessed by questionnaire.

RESULTS

Macronutrient and micronutrient intakes were not significantly different between restrained and unrestrained eaters reporting energy intake to within 30% of predicted total energy expenditure. Restrained eaters had significantly lower hemoglobin (12.9 +/- 0.1 [SEM] vs 13.2 +/- 0.1 g/dl; p <.05), but values were within the normal range in both groups. In addition, restrained eaters scored significantly higher on the Eating Attitudes Test (p <.01) and drive-for-thinness (p <.001) and maturity fears (p <.05) subscores of the Eating Disorders Inventory, but values were again within the normal range. No other parameter differed significantly between groups.

CONCLUSIONS

In this normal-weight population, restrained eating was not associated with detrimental effects in a wide range of physiological, metabolic, and health characteristics. Further work is needed to determine the relevance of these results to the general population.

Interleukin-6 production does not increase with age

Investigators have reported an increase, decrease, or no effect of age on interleukin-6 (IL-6) production. Differences in experimental conditions and the health status of subjects may explain these contradicting results. Because the subjects used in most of the previous studies were not carefully screened for health, we investigated the effect of age on IL-6 production in healthy young and elderly subjects. Twenty young (aged 20-30 years) and 26 elderly (>65 years) men completed the study. Each subject was screened for good health, undergoing physical examinations and laboratory tests. Circulating IL-6 levels were not significantly different between young and elderly subjects. A subgroup of subjects representing both young and elderly volunteers had high (>1000 pg/ml) circulating levels of IL-6. However, circulating IL-6 levels were low (<100 pg/ml) in the majority of subjects in both age groups. Peripheral blood mononuclear cells (PBMC) were cultured for IL-6 production in the presence or absence of phytohemagglutinin (PHA) or concanavalin (Con)A for 48 hours. Unstimulated secretion of IL-6 by PBMC cultured in autologous plasma (AP) or fetal bovine serum (FBS) was detectable in the majority of cultures. Age did not influence this spontaneous secretion of IL-6. PBMC stimulation with PHA or ConA significantly increased IL-6 production, but age did not affect the ability of PBMC to secrete IL-6 after stimulation when cultured in FBS. IL-6 production by PBMC cultured in AP and stimulated with PHA was not affected by age. However, when stimulated with ConA, PBMC from the elderly subjects produced less IL-6 than PBMC from the young subjects. Because IL-6 has been suggested to contribute to the age-related increase in prostaglandin (PG)E2 and nitric oxide (NO) production, we investigated the effect of age on the production of IL-6 by murine peritoneal macrophages (Mphi) as well as the effect of IL-6 on the production of other Mphi inflammatory products. Similar to the findings in humans, mouse age did not influence the level of IL-6 produced by Mphi. These data suggest that in healthy subjects, increased production of IL-6 is not a normal consequence of aging. Previously reported higher IL-6 levels in elderly subjects might reflect an underlying, undiagnosed disease state. PGE2 and NO production were not affected by the addition of IL-6 to Mphi from young mice or anti-IL-6 antibody to Mphi from old mice. Thus, IL-6 does not appear to influence the Mphi production of selected inflammatory molecules.

Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a marker of oxidative stress in rheumatoid arthritis and aging: effect of progressive resistance training

Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), as a measure of oxidative stress, was measured before and after 12 weeks of progressive resistance strength training in 8 healthy elderly (65-80 yr) and eight healthy young (22-30 yr) men and women, and in eight adults (25-65 yr) with rheumatoid arthritis (RA).Training subjects exercised at 80% of their one-repetition maximum and performed eight repetitions per set, three sets per session, on a twice-weekly basis. 8-OHdG was measured at baseline and follow-up (at least 24 hr after the last exercise session) in the RA and elderly subject groups, and at baseline only in young subjects.Baseline 8-OHdG levels were greater among subjects with RA compared to both healthy young (P < 0.001) and elderly (P < 0.05) subjects. There were no changes in 8-OHdG levels in either RA or elderly subjects as a result of the strength training intervention.These results suggest that subjects with RA have higher levels of oxidative stress than young and elderly healthy individuals. Furthermore, there is no change in oxidative stress, measured by urinary 8-OHdG, in elderly healthy individuals or in subjects with RA after a 12-week strength training intervention.