Dietary antioxidant vitamins and fiber in the etiology of cardiovascular disease and all-causes mortality: results from the Scottish Heart Health Study

Total and different dietary fiber subtypes and the risk of all-cause, cardiovascular, and cancer mortality: a dose-response meta-analysis of prospective cohort studies

We aimed to conduct a comprehensive review of the association between dietary fiber and the risk of mortality. We did a systematic search in PubMed, Scopus, and Web of Science up to November 2022 to find prospective cohort studies of the relationship between total and subtypes of dietary fiber and the risk of all-cause, cardiovascular (CVD), and cancer mortality in the general population. The hazard ratios (HRs) and 95% CIs were calculated using a random-effects model. A total of 28 studies with 1 613 885 participants were included. Higher intake of total and subtypes of dietary fiber including cereal, vegetable, legume, soluble, and insoluble fiber, but not fruit fiber, was associated with a lower risk of all-cause mortality, with HRs ranging from 0.77 for insoluble fiber to 0.93 for legume fiber. Similar findings were observed for CVD mortality, where higher intake of total and all subtypes of dietary fiber was each associated with a lower risk. Higher intake of total, cereal, vegetable, and insoluble fiber was also associated with a lower risk of cancer mortality. No association was found between the intake of fruit, legume, and soluble fiber and cancer mortality. Dose-response meta-analyses suggested an inverse association between total fiber intake and the risk of all-cause, CVD, and cancer mortality. The certainty of evidence was rated moderate for the association of total fiber with all-cause, CVD, and cancer mortality. In conclusion, our findings highlight the potential advantages of consuming a wide range of dietary fiber subtypes against all-cause, CVD, and cancer mortality. Registry and registry number: PROSPERO (CRD42021226816).

Dietary intake of total vegetable, fruit, cereal, soluble and insoluble fiber and risk of all-cause, cardiovascular, and cancer mortality: systematic review and dose-response meta-analysis of prospective cohort studies

Objectives

To conduct a systematic review and meta-analysis of prospective cohort studies to investigate the association between total, vegetable, fruit, cereal, soluble and insoluble fiber intake and risk of all causes, cardiovascular disease (CVD), and cancer mortality and quantitatively assess the dose-response relation.

Methods

Eligible studies were identified by searching PubMed, Embase and Web of science before August 2023. Random effects models were used to calculate summary relative risk (RR) and 95% confidence intervals (CI) and restricted cubic splines to model the linear/non-linear association.

Results

The summary RR for all-cause, CVD and cancer mortality of dietary fiber was 0.90 (95% CI: 0.86,0.93), 0.87 (0.84,0.91), 0.91 (0.88,0.93), respectively. Significant association was observed for all-cause and CVD mortality with fruit, vegetable cereal and soluble fiber intake and cancer mortality with cereal fiber intake. No significant association was found for insoluble fiber, vegetable or fruit fiber intake and cancer mortality. Dose-response analysis showed a significant non-linear relation of dietary fiber intake with all-cause mortality, and linear relation for others.

Conclusions

Higher dietary fiber including different type and food sources of fiber intake were associated with lower risk of mortality. Our findings provide more comprehensive evidence on dietary fiber intake with mortality.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier: CRD42022338837.

Antioxidant potential of diet – Association between dietary antioxidant index and odds of coronary heart disease: A case-control study

BACKGROUND: Oxidative stress and chronic inflammation are among the leading causes of coronary heart disease (CHD). Studies investigated the relationship between dietary antioxidants and the risk/odds of CHD, and contradictory results have been reported. Dietary antioxidant index (DAI) is a novel and reliable nutritional tool that examines the diet’s overall antioxidant capacity. Its validity was examined using serum total antioxidant capacity and malondialdehyde. OBJECTIVE: This study aimed to investigate the relationship between DAI score and odds of CHD. METHODS: In this incidence case-control study, 320 individuals with a definitive diagnosis of CHD and 320 participants without CHD or related risk factors attending the same hospitals/polyclinics were selected as the case and control groups. We estimated the DAI by summing up six standardized intakes of major dietary antioxidants, including manganese, vitamin E, A, C, selenium, and zinc. RESULTS: Modeling DAI categorized according to the median (–0.38), in multi-adjusted model showed a significant protective association with the odd of CHD (OR = 0.72; 95%CI:0.51–0.99, p-value = 0.05). Also, modeling DAI as a continuous variable in multi-adjusted models (OR = 0.94;95%CI:0.90–0.95; p-value = 0.01) showed significant results. CONCLUSION: Using the DAI to investigate the relationship between dietary antioxidants and CHD can show more realistic results than a single study of antioxidants.

Amauroderma rugosum Protects PC12 Cells against 6-OHDA-Induced Neurotoxicity through Antioxidant and Antiapoptotic Effects

Amauroderma rugosum (AR) is a dietary mushroom in the Ganodermataceae family whose pharmacological activity and medicinal value have rarely been reported. In this study, the antioxidant capacity and neuroprotective effects of AR were investigated. The aqueous extract of AR was confirmed to contain phenolic compounds, polysaccharides, and triterpenes. The results of 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and total antioxidant capacity assays revealed that AR extract scavenged reactive oxygen species. Moreover, AR extract decreased the cytotoxicity, oxidative stress, mitochondrial dysfunction, and apoptosis of PC12 cells induced by 6-hydroxydopamine (6-OHDA). In addition, 6-OHDA upregulated the expressions of proapoptotic proteins and downregulated the Akt (protein kinase B)/mTOR- (mammalian target of rapamycin-) and MEK (mitogen-activated protein kinase kinase)/ERK- (extracellular signal-regulated kinases-) dependent signaling pathways. These effects of 6-OHDA were abolished or partially reversed by AR extract. Furthermore, the neuroprotective effects of AR in 6-OHDA-treated PC12 cells were significantly abolished by Akt and MEK inhibitor. Thus, AR extract possesses neuroprotective effects, probably through its antioxidant and antiapoptotic effects. These findings suggest the potential application of AR in the prevention or treatment of oxidative stress-related neurodegenerative diseases such as Parkinson's disease.

The Nutraceutical Value of Olive Oil and Its Bioactive Constituents on the Cardiovascular System. Focusing on Main Strategies to Slow Down Its Quality Decay during Production and Storage

Cardiovascular diseases represent the principal cause of morbidity and mortality worldwide. It is well-known that oxidative stress and inflammatory processes are strongly implicated in their pathogenesis; therefore, anti-oxidant and anti-inflammatory agents can represent effective tools. In recent years a large number of scientific reports have pointed out the nutraceutical and nutritional value of extra virgin olive oils (EVOO), strongholds of the Mediterranean diet, endowed with a high nutritional quality and defined as functional foods. In regard to EVOO, it is a food composed of a major saponifiable fraction, represented by oleic acid, and a minor unsaponifiable fraction, including a high number of vitamins, polyphenols, and squalene. Several reports suggest that the beneficial effects of EVOO are linked to the minor components, but recently, further studies have shed light on the health effects of the fatty fraction and the other constituents of the unsaponifiable fraction. In the first part of this review, an analysis of the clinical and preclinical evidence of the cardiovascular beneficial effects of each constituent is carried out. The second part of this review is dedicated to the main operating conditions during production and/or storage that can directly influence the shelf life of olive oil in terms of both nutraceutical properties and sensory quality.

Vitamin E: Regulatory role in the cardiovascular system

Cardiovascular disease (CVD) is one of the major causes of morbidity and mortality, all around the world. Vitamin E is an important nutrient influencing key cellular and molecular mechanisms as well as gene expression regulation centrally involved in the prevention of CVD. Cell culture and animal studies have focused on the identification of vitamin E regulated signaling pathways and involvement on inflammation, lipid homeostasis, and atherosclerotic plaque stability. While some of these vitamin E functions were verified in clinical trials, some of the positive effects were not translated into beneficial outcomes in epidemiological studies. In recent years, the physiological metabolites of vitamin E, including the liver derived (long- and short-chain) metabolites and phosphorylated (α-, γ-tocopheryl phosphate) forms, have also provided novel mechanistic insight into CVD regulation that expands beyond the vitamin E precursor. It is certain that this emerging insight into the molecular and cellular action of vitamin E will help to design further studies, either in animal models or clinical trials, on the reduction of risk for CVDs. This review focuses on vitamin E-mediated preventive cardiovascular effects and discusses novel insights into the biology and mechanism of action of vitamin E metabolites in CVD. © 2019 IUBMB Life, 71(4):507-515, 2019.

Dietary and circulating vitamin C, vitamin E, β-carotene and risk of total cardiovascular mortality: a systematic review and dose-response meta-analysis of prospective observational studies

OBJECTIVE

The present review aimed to quantify the association of dietary intake and circulating concentration of major dietary antioxidants with risk of total CVD mortality.

DESIGN

Systematic review and meta-analysis.

SETTING

Systematic search in PubMed and Scopus, up to October 2017.ParticipantsProspective observational studies reporting risk estimates of CVD mortality across three or more categories of dietary intakes and/or circulating concentrations of vitamin C, vitamin E and β-carotene were included. A random-effects meta-analysis was conducted.

RESULTS

A total of fifteen prospective cohort studies and three prospective evaluations within interventional studies (320 548 participants and 16 974 cases) were analysed. The relative risks of CVD mortality for the highest v. the lowest category of antioxidant intakes were as follows: vitamin C, 0·79 (95 % CI 0·68, 0·89; I 2=46 %, n 10); vitamin E, 0·91 (95 % CI 0·79, 1·03; I 2=51 %, n 8); β-carotene, 0·89 (95 % CI 0·73, 1·05; I 2=34 %, n 4). The relative risks for circulating concentrations were: vitamin C, 0·60 (95 % CI 0·42, 0·78; I 2=65 %, n 6); α-tocopherol, 0·82 (95 % CI 0·76, 0·88; I 2=0 %, n 5); β-carotene, 0·68 (95 % CI 0·52, 0·83; I 2=50 %, n 6). Dose-response meta-analyses demonstrated that the circulating biomarkers of antioxidants were more strongly associated with risk of CVD mortality than dietary intakes.

CONCLUSIONS

The present meta-analysis demonstrates that higher vitamin C intake and higher circulating concentrations of vitamin C, vitamin E and β-carotene are associated with a lower risk of CVD mortality.

Dietary intake and blood concentrations of antioxidants and the risk of cardiovascular disease, total cancer, and all-cause mortality: a systematic review and dose-response meta-analysis of prospective studies

Background

High dietary intake or blood concentrations (as biomarkers of dietary intake) of vitamin C, carotenoids, and vitamin E have been associated with reduced risk of cardiovascular disease, cancer, and mortality, but these associations have not been systematically assessed.

Objective

We conducted a systematic review and meta-analysis of prospective studies of dietary intake and blood concentrations of vitamin C, carotenoids, and vitamin E in relation to these outcomes.

Design

We searched PubMed and Embase up to 14 February 2018. Summary RRs and 95% CIs were calculated with the use of random-effects models.

Results

Sixty-nine prospective studies (99 publications) were included. The summary RR per 100-mg/d increment of dietary vitamin C intake was 0.88 (95% CI: 0.79, 0.98, I2 = 65%, n = 11) for coronary heart disease, 0.92 (95% CI: 0.87, 0.98, I2 = 68%, n = 12) for stroke, 0.89 (95% CI: 0.85, 0.94, I2 = 27%, n = 10) for cardiovascular disease, 0.93 (95% CI: 0.87, 0.99, I2 = 46%, n = 8) for total cancer, and 0.89 (95% CI: 0.85, 0.94, I2 = 80%, n = 14) for all-cause mortality. Corresponding RRs per 50-μmol/L increase in blood concentrations of vitamin C were 0.74 (95% CI: 0.65, 0.83, I2 = 0%, n = 4), 0.70 (95% CI: 0.61, 0.81, I2 = 0%, n = 4), 0.76 (95% CI: 0.65, 0.87, I2 = 56%, n = 6), 0.74 (95% CI: 0.66, 0.82, I2 = 0%, n = 5), and 0.72 (95% CI: 0.66, 0.79, I2 = 0%, n = 8). Dietary intake and/or blood concentrations of carotenoids (total, β-carotene, α-carotene, β-cryptoxanthin, lycopene) and α-tocopherol, but not dietary vitamin E, were similarly inversely associated with coronary heart disease, stroke, cardiovascular disease, cancer, and/or all-cause mortality.

Conclusions

Higher dietary intake and/or blood concentrations of vitamin C, carotenoids, and α-tocopherol (as markers of fruit and vegetable intake) were associated with reduced risk of cardiovascular disease, total cancer, and all-cause mortality. These results support recommendations to increase fruit and vegetable intake, but not antioxidant supplement use, for chronic disease prevention.

Dietary Antioxidants, Circulating Antioxidant Concentrations, Total Antioxidant Capacity, and Risk of All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Observational Studies

The associations of various dietary or circulating antioxidants with the risk of all-cause mortality in the general population have not been established yet. A systematic search was performed in PubMed and Scopus, from their inception up to October 2017. Prospective observational studies reporting risk estimates of all-cause mortality in relation to dietary intake and/or circulating concentrations of antioxidants were included. Random-effects meta-analyses were conducted. Forty-one prospective observational studies (total n = 507,251) involving 73,965 cases of all-cause mortality were included. The RRs of all-cause mortality for the highest compared with the lowest category of circulating antioxidant concentrations were as follows: total carotenes, 0.60 (95% CI: 0.46, 0.74); vitamin C, 0.61 (95% CI: 0.53, 0.69); selenium, 0.62 (95% CI: 0.45, 0.79); β-carotene, 0.63 (95% CI: 0.57, 0.70); α-carotene, 0.68 (95% CI: 0.58, 0.78); total carotenoids, 0.68 (95% CI: 0.56, 0.80); lycopene, 0.75 (95% CI: 0.54, 0.97); and α-tocopherol, 0.84 (95% CI: 0.77, 0.91). The RRs for dietary intakes were: total carotenoids, 0.76 (95% CI: 0.66, 0.85); total antioxidant capacity, 0.77 (95% CI: 0.73, 0.81); selenium, 0.79 (95% CI: 0.73, 0.85); α-carotene, 0.79 (95% CI: 0.63, 0.94); β-carotene, 0.82 (95% CI: 0.77, 0.86); vitamin C, 0.88 (95% CI: 0.83, 0.94); and total carotenes, 0.89 (95% CI: 0.81, 0.97). A nonsignificant inverse association was found for dietary zinc, zeaxanthin, lutein, and vitamin E. The nonlinear dose-response meta-analyses demonstrated a linear inverse association in the analyses of dietary β-carotene and total antioxidant capacity, as well as in the analyses of circulating α-carotene, β-carotene, selenium, vitamin C, and total carotenoids. The association appeared to be U-shaped in the analyses of serum lycopene and dietary vitamin C. The present study indicates that adherence to a diet with high antioxidant properties may reduce the risk of all-cause mortality. Our results confirm current recommendations that promote higher intake of antioxidant-rich foods such as fruit and vegetables.

Dietary fiber intake and mortality in a Mediterranean population: the "Seguimiento Universidad de Navarra" (SUN) project

PURPOSE

To prospectively assess the association of dietary fiber intake (from different dietary sources) with all-cause mortality in a Mediterranean cohort.

METHODS

We assessed 19,703 participants of the SUN (Seguimiento Universidad de Navarra) cohort (mean follow-up: 10.1 years). A validated 136-item FFQ was administered at baseline. We used Cox proportional hazards models adjusted for multiple socio-demographic, anthropometric, lifestyle factors, and prevalent conditions at baseline.

RESULTS

We observed 323 deaths during 198,341 person-years of follow-up. A significantly inverse linear trend in Cox models was observed for the association of total dietary fiber intake and all-cause mortality after adjustment for confounders (p for trend 0.017). Each additional intake of 5 g/1000 kcal of dietary fiber was associated with a 9% relative reduction in all-cause mortality risk (HR 0.91, 95% CI 0.84-0.99). Considering separate dietary sources in separate models, a significant inverse trend was apparent for fiber derived from vegetables (p for trend 0.001), but it was non-significant for fiber derived from fruit, legumes, cereals, or other sources. Soluble fiber was significantly inversely associated with all-cause mortality in the fully adjusted model (p for trend 0.007), and insoluble fiber was marginally significant (p for trend 0.08).

CONCLUSIONS

A higher intake of total dietary fiber, and particularly fiber from vegetables, was related to a reduced all-cause mortality in our Mediterranean cohort. Dietary messages to increase the consumption of dietary patterns rich in fiber-rich foods should be broadly disseminated to decrease the alarming rate of chronic diseases and its derived mortality.

Perfil nutricional e benefícios do azeite de abacate (Persea americana ): uma revisão integrativa

Resumo O objetivo do presente estudo foi realizar uma revisão integrativa sobre a qualidade do perfil lipídico e dos compostos bioativos presentes no azeite de abacate, bem como sobre os seus potenciais benefícios para a saúde humana. Foram identificados trabalhos publicados nas bases de dados Scopus, PubMed, Lilacs, SciELO e Web of Science, além de Biblioteca Digital de Teses e Dissertações. A pesquisa encontrou dados referentes ao perfil lipídico e ao teor de substâncias bioativas presentes no azeite de abacate extraído das variedades Margarida, Quintal, Fortuna, Ouro Verde, Hass e Fuerte. O azeite de abacate caracteriza-se por apresentar, em média, teores elevados de ácidos graxos monoinsaturados (60%), teor intermediário de ácidos graxos saturados (24%) e baixo teor de ácidos graxos poli-insaturados (16%). O ácido graxo oleico (ômega-9) é o de maior concentração (aproximadamente 55%). Os principais esteróis, tocoferóis e carotenoides encontrados foram β-sitosterol, α-tocoferol e luteína, respectivamente. O azeite de abacate possui propriedades físico-químicas semelhantes às do azeite de oliva. Em modelos animais, é capaz de prevenir a disfunção mitocondrial cerebral e hepática induzida pelo diabetes, associado à diminuição de estresse oxidativo, LDL-c e peroxidação lipídica. Seus benefícios são atribuídos principalmente às concentrações de ácido oleico, por sua atividade cardioprotetora, ao β-sitosterol, por sua propriedade anti-inflamatória, e ao α-tocoferol e à luteína, pela propriedade antioxidante. Assim, o azeite de abacate se destaca pelo teor elevado de ácidos graxos monoinsaturados e de compostos bioativos, como tocoferóis, carotenoides e fitoesteróis. Análises em modelos animais, aliadas às análises de qualidade e segurança, atestam os benefícios e a possibilidade de introdução do referido azeite para uso comestível, substituindo óleos de qualidade inferior e criando nova alternativa gastronômica ao consumidor.

Nutritional Health Considerations for Persons with Spinal Cord Injury

Chronic spinal cord injury (SCI) often results in morbidity and mortality due to all-cause cardiovascular disease (CVD) and comorbid endocrine disorders. Several component risk factors for CVD, described as the cardiometabolic syndrome (CMS), are prevalent in SCI, with the individual risks of obesity and insulin resistance known to advance the disease prognosis to a greater extent than other established risks. Notably, adiposity and insulin resistance are attributed in large part to a commonly observed maladaptive dietary/nutritional profile. Although there are no evidence-based nutritional guidelines to address the CMS risk in SCI, contemporary treatment strategies advocate more comprehensive lifestyle management that includes sustained nutritional guidance as a necessary component for overall health management. This monograph describes factors in SCI that contribute to CMS risks, the current nutritional profile and its contribution to CMS risks, and effective treatment strategies including the adaptability of the Diabetes Prevention Program (DPP) to SCI. Establishing appropriate nutritional guidelines and recommendations will play an important role in addressing the CMS risks in SCI and preserving optimal long-term health.

Dietary Antioxidant Micronutrients and All-Cause Mortality: The Japan Collaborative Cohort Study for Evaluation of Cancer Risk

Background

Oxidative stress, the imbalance between pro- and antioxidants, has been implicated in the etiology and pathophysiology of the incidence and mortality of many diseases. We aim to investigate the relations of dietary intakes of vitamin C and E and main carotenoids with all-cause mortality in Japanese men and women.

Methods

The Japan Collaborative Cohort Study for Evaluation of Cancer Risk had 22,795 men and 35,539 women, aged 40–79 years at baseline (1988–1990), who completed a valid food frequency questionnaire and were followed up to the end of 2009.

Results

There were 6,179 deaths in men and 5,355 deaths in women during the median follow-up of 18.9 years for men and 19.4 years for women. Multivariate hazard ratios for the highest versus lowest quintile intakes in women were 0.83 (95% confidence interval [CI], 0.76–0.90; P for trend < 0.0001) for vitamin C, 0.85 (95% CI, 0.78–0.93; P for trend < 0.0001) for vitamin E, 0.88 (95% CI, 0.81–0.96; P for trend = 0.0006) for β-carotene, and 0.90 (95% CI, 0.82–0.98; P for trend = 0.0002) for β-cryptoxanthin. The joint effect of any two of these highly correlated micronutrients showed significant 12–17% reductions in risk in the high-intake group compared with the low-intake group in women. These significant associations were also observed in the highest quintile intakes of vitamin C, vitamin E, and β-carotene in female non-smokers but were not observed in female smokers, male smokers, and non-smokers.

Conclusions

Higher dietary intakes of antioxidant vitamins may reduce the risk of all-cause mortality in middle-aged Japanese women, especially female non-smokers.

Dietary Fiber and Telomere Length in 5674 U.S. Adults: An NHANES Study of Biological Aging

The relationship between fiber intake and telomere length was evaluated using a cross-sectional design and an NHANES sample of 5674 U.S. adults. Another purpose was to test the impact of potential confounders on the association. Fiber consumption was measured using a 24 h recall and telomere length was indexed using the quantitative polymerase chain reaction method. Overall, the U.S. adults had low fiber intake (median: 6.6 g per 1000 kcal)—less than one-half the recommendation of the Dietary Guidelines for Americans. With age, gender, race, housing status, and misreported energy intake controlled, the relationship between fiber intake per 1000 kcal and telomere length was linear (F = 9.5, p = 0.0045). Specifically, for each 1 g increment in fiber intake per 1000 kcal, telomeres were 8.3 base pairs longer. Because each additional year of chronological age was associated with telomeres that were 15.5 base pairs shorter, results suggest that a 10 g increase in fiber intake per 1000 kcal would correspond with telomeres that are 83 base pairs longer. On average, this would equate to 5.4 fewer years of biologic aging (83 ÷ 15.5). With smoking, BMI, alcohol use, and physical activity controlled, as well as the other covariates, each 10 g increment in fiber accounted for telomeres that were 67 base pairs longer (F = 7.6, p = 0.0101), a biologic aging difference of about 4.3 years. In conclusion, significant fiber consumption accounts for longer telomeres and less biologic aging than lower levels of fiber intake.

Dietary antioxidant vitamins intake and mortality: A report from two cohort studies of Chinese adults in Shanghai

Background

Few studies have evaluated dietary antioxidant vitamins intake in relation to risk of mortality in Asia.

Methods

We examined the associations between total carotene, vitamin C, and vitamin E from diet and risk of mortality from all causes, cancer, and cardiovascular disease in 134,358 participants (59,739 men and 74,619 women) from the Shanghai Men's Health Study and Shanghai Women's Health Study, two prospective cohort studies of middle-aged and elderly Chinese adults in urban Shanghai. Participants were followed up for a median period of 8.3 and 14.2 years for men and women, respectively. Hazard ratios (HRs) and 95% confidence interval (CIs) were estimated using Cox proportional hazards regression models.

Results

During the 495,332 and 1,029,198 person-years of follow-up for men and women, respectively, there were 10,079 deaths (4170 men and 5909 women). For men, compared with the lowest quintiles, the multivariable-adjusted risk reductions in the highest categories were 17% (HR 0.83; 95% CI, 0.76–0.92) for dietary total carotene and 17% (HR 0.83; 95% CI, 0.75–0.91) for dietary vitamin C. Associations were weaker in women than in men, though they were still statistically significant (highest versus lowest quintiles of dietary total carotene, HR 0.87; 95% CI, 0.80–0.95; dietary vitamin C: HR 0.83; 95% CI, 0.77–0.91). Significant inverse associations were observed between dietary total carotene, vitamin C, and risk of cardiovascular disease mortality but not cancer mortality.

Conclusion

This study suggests that total carotene and vitamin C intake from diet were inversely associated with deaths from all causes and cardiovascular disease in middle-aged or elderly people in China.

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Dietary vitamin C and carotene were inversely associated with total deaths in China.

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These associations were more pronounced for cardiovascular disease mortality.

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Dietary antioxidant vitamins might not be associated with cancer mortality risk.

Dietary, circulating beta-carotene and risk of all-cause mortality: a meta-analysis from prospective studies

Observational studies evaluating the relation between dietary or circulating level of beta-carotene and risk of total mortality yielded inconsistent results. We conducted a comprehensive search on publications of PubMed and EMBASE up to 31 March 2016. Random effect models were used to combine the results. Potential publication bias was assessed using Egger’s and Begg’s test. Seven studies that evaluated dietary beta-carotene intake in relation to overall mortality, indicated that a higher intake of beta-carotene was related to a significant lower risk of all-cause mortality (RR for highest vs. lowest group = 0.83, 95%CI: 0.78–0.88) with no evidence of heterogeneity between studies (I² = 1.0%, P = 0.416). A random-effect analysis comprising seven studies showed high beta-carotene level in serum or plasma was associated with a significant lower risk of all-cause mortality (RR for highest vs. lowest group = 0.69, 95%CI: 0.59–0.80) with low heterogeneity (I² = 37.1%, P = 0.145). No evidence of publication bias was detected by Begg’s and Egger’s regression tests. In conclusion, dietary or circulating beta-carotene was inversely associated with risk of all-cause mortality. More studies should be conducted to clarify the dose-response relationship between beta-carotene and all-cause mortality.

Cereal fibre intake and risk of mortality from all causes, CVD, cancer and inflammatory diseases: a systematic review and meta-analysis of prospective cohort studies

Dietary fibre intake has been associated with a lower risk of mortality; however, findings on the association of different sources of dietary fibre with mortality are conflicting. We performed a systematic review and meta-analysis of the prospective cohort studies to assess the relation between cereal fibre intake and cause-specific mortality. Medline/PubMed, SCOPUS, EMBASE, ISI web of Science and Google scholar were searched up to April 2015. Eligible prospective cohort studies were included if they provided hazard ratios (HR) or relative risks (RR) and corresponding 95 % CI for the association of cereal fibre intake and mortality from all causes, CVD, cancer and inflammatory diseases. The study-specific HR were pooled by using the random-effects model. In total, fourteen prospective studies that examined the association of cereal fibre intake with mortality from all causes (n 48 052 death), CVD (n 16 882 death), cancer (n 19 489 death) and inflammatory diseases (n 1092 death) were included. The pooled adjusted HR of all-cause mortality for the highest v. the lowest category of cereal fibre intake was 0·81 (95 % CI 0·79, 0·83). Consumption of cereal fibre intake was associated with an 18 % lower risk of CVD mortality (RR 0·82; 95 % CI 0·78, 0·86). Moreover, an inverse significant association was observed between cereal fibre intake and risk of death from cancer (RR 0·85; 95 % CI 0·81, 0·89). However, no significant association was seen between cereal fibre intake and inflammation-related mortality. This meta-analysis provides further evidence that cereal fibre intake was protectively associated with mortality from all causes, CVD and cancer.

Antioxidants in Cardiovascular Therapy: Panacea or False Hope?

Oxidative stress is a key feature of the atherothrombotic process involved in the etiology of heart attacks, ischemic strokes, and peripheral arterial disease. It stands to reason that antioxidants represent a credible therapeutic option to prevent disease progression and thereby improve outcome, but despite positive findings from in vitro studies, clinical trials have failed to consistently show benefit. The aim of this review is to re-appraise the concept of antioxidants in the prevention and management of cardiovascular disease. In particular, the review will explore the reasons behind failed antioxidant strategies with vitamin supplements and will evaluate how flavonoids might improve cardiovascular function despite bioavailability that is not sufficiently high to directly influence antioxidant capacity. As well as reaching conclusions relating to those antioxidant strategies that might hold merit, the major myths, limitations, and pitfalls associated with this research field are explored.

Association between dietary fiber and lower risk of all-cause mortality: a meta-analysis of cohort studies

Although in vitro and in vivo experiments have suggested that dietary fiber might have beneficial effects on health, results on the association between fiber intake and all-cause mortality in epidemiologic studies have been inconsistent. Therefore, we conducted a meta-analysis of prospective cohort studies to quantitatively assess this association. Pertinent studies were identified by searching articles in PubMed and Web of Knowledge through May 2014 and reviewing the reference lists of the retrieved articles. Study-specific risk estimates were combined using random-effects models. Seventeen prospective studies (1997-2014) that had a total of 67,260 deaths and 982,411 cohort members were included. When comparing persons with dietary fiber intakes in the top tertile with persons whose intakes were in the bottom tertile, we found a statistically significant inverse association between fiber intake and all-cause mortality, with an overall relative risk of 0.84 (95% confidence interval: 0.80, 0.87; I(2) = 41.2%). There was a 10% reduction in risk for per each 10-g/day increase in fiber intake (relative risk = 0.90; 95% confidence interval: 0.86, 0.94; I(2) = 77.2%). The combined estimate was robust across subgroup and sensitivity analyses. No publication bias was detected. A higher dietary fiber intake was associated with a reduced risk of death. These findings suggest that fiber intake may offer a potential public health benefit in reducing all-cause mortality.

Antioxidant vitamin intake and mortality: the Leisure World Cohort Study

To assess the relationship between antioxidant vitamin intake and all-cause mortality in older adults, we examined these associations using data from the Leisure World Cohort Study, a prospective study of residents of the Leisure World retirement community in Laguna Hills, California. In the early 1980s, participants (who were aged 44-101 years) completed a postal survey, which included details on use of vitamin supplements and dietary intake of foods containing vitamins A and C. Age-adjusted and multivariate-adjusted (for factors related to mortality in this cohort—smoking, alcohol intake, caffeine consumption, exercise, body mass index, and histories of hypertension, angina, heart attack, stroke, diabetes, rheumatoid arthritis, and cancer) hazard ratios for death were calculated using Cox regression for 8,640 women and 4,983 men (median age at entry, 74 years). During follow-up (1981-2013), 13,104 participants died (median age at death, 88 years). Neither dietary nor supplemental intake of vitamin A or vitamin C nor supplemental intake of vitamin E was significantly associated with mortality after multivariate adjustment. A compendium that summarizes previous findings of cohort studies evaluating vitamin intake and mortality is provided. Attenuation in the observed associations between mortality and antioxidant vitamin use after adjustment for confounders in our study and in previous studies suggests that such consumption identifies persons with other mortality-associated lifestyle and health risk factors.

Fiber consumption and all-cause, cardiovascular, and cancer mortalities: a systematic review and meta-analysis of cohort studies

The present meta-analysis aimed to investigate fiber consumption and all-cause mortality, and cause-specific mortality. MEDLINE and web of science database were searched for cohort studies published from inception to August 2014. Studies were included if they provided a hazard ratio (HR) and corresponding 95% CI for mortality in relation to fiber consumption.We found that, compared with those who consumed lowest fiber, for individuals who ate highest fiber, mortality rate was lower by 23% (HR, 0.77; 95% CI, 0.72-0.81) for CVD, by 17% (HR, 0.83; 95% CI, 0.74-0.91) for cancer, by 23% (HR, 0.77; 95% CI, 0.73-0.81) for all-cause mortality. For each 10 g/day increase in fiber intake, the pooled HR was estimated to be 0.89 (95% CI, 0.86-0.93) for all-cause mortality, 0.80 (95% CI, 0.72-0.88) for CHD mortality, and 0.66 (95% CI, 0.40-0.92) for IHD mortality, 0.91 (95% CI, 0.88-0.94) for cancer. Dietary fiber and CVD mortality showed a strong dose-response relation. Apparently, fiber consumption is inversely associated with all-cause mortality and CVD, IHD, cancer mortality.

Fiber intake and all-cause mortality in the Prevención con Dieta Mediterránea (PREDIMED) study

BACKGROUND

Few observational studies have examined the effect of dietary fiber intake and fruit and vegetable consumption on total mortality and have reported inconsistent results. All of the studies have been conducted in the general population and typically used only a single assessment of diet.

OBJECTIVE

We investigated the association of fiber intake and whole-grain, fruit, and vegetable consumption with all-cause mortality in a Mediterranean cohort of elderly adults at high cardiovascular disease (CVD) risk by using repeated measurements of dietary information and taking into account the effect of a dietary intervention.

DESIGN

We followed up 7216 men (55-75 y old) and women (60-75 y old) at high CVD risk in the Prevención con Dieta Mediterránea (PREDIMED) trial for a mean of 5.9 y. Data were analyzed as an observational cohort. Participants were initially free of CVD. A 137-item validated food-frequency questionnaire administered by dietitians was repeated annually to assess dietary exposures (fiber, fruit, vegetable, and whole-grain intakes). Deaths were identified through the continuing medical care of participants and the National Death Index. An independent, blinded Event Adjudication Committee adjudicated causes of death. Cox regression models were used to estimate HRs of death during follow-up according to baseline dietary exposures and their yearly updated changes.

RESULTS

In up to 8.7 y of follow-up, 425 participants died. Baseline fiber intake and fruit consumption were significantly associated with lower risk of death [HRs for the fifth compared with the first quintile: 0.63 (95% CI: 0.46, 0.86; P = 0.015) and 0.59 (95% CI: 0.42, 0.82; P = 0.004), respectively]. When the updated dietary information was considered, participants with fruit consumption >210 g/d had 41% lower risk of all-cause mortality (HR: 0.59; 95% CI: 0.44, 0.78). Associations were strongest for CVD mortality than other causes of death.

CONCLUSION

Fiber and fruit intakes are associated with a reduction in total mortality. PREDIMED was registered at controlled-trials.com as ISRCTN35739639.

Dietary approaches for management of cardio-vascular health- a review

Dietary patterns of consumers have changed and the importance of diet as a therapeutic adjunct in the form of nutraceuticals has become the trend of the millennium. Major contributory factor behind this trend is the idea of improving health by modifying the diet that is more attractive to the health conscious consumer as compared to drugs. According to a recent report of WHO, prevalence of cardio vascular disease has increased progressively in the past few years. It has been estimated that one-fifth of deaths in India are due to coronary heart disease that is inflicting at a much younger age in Indians than in the West. Such an insight suggests that cardiac health needs protection. Food products containing functional ingredients that are useful in controlling various different diseases are expected to provide health benefits. Recent research indicates that foods rich in omega-3 fatty acids, antioxidant vitamins and fibres may be beneficial for cardio-vascular health.

Dietary fiber intake and total mortality: a meta-analysis of prospective cohort studies

Greater intake of dietary fiber has been associated with lower risk of several chronic diseases. Some observational studies have examined the association between dietary fiber intake and total mortality, but the results were inconclusive. We conducted a meta-analysis of data from prospective cohort studies to quantitatively assess the association. Eligible studies were identified by searching the PubMed and Embase databases for all articles published through November 30, 2013, and by reviewing the reference lists of retrieved articles. Study-specific estimates adjusting for potential confounders were combined to calculate a pooled relative risk and 95% confidence interval using a random-effects model. Seven prospective cohort studies of dietary fiber intake and total mortality, including 62,314 deaths among 908,135 participants, were identified. The pooled adjusted relative risk of total mortality for the highest category of dietary fiber intake versus the lowest was 0.77 (95% confidence interval: 0.74, 0.80). In a dose-response meta-analysis, the pooled adjusted relative risk for a 10-g/day increment of dietary fiber intake was 0.89 (95% confidence interval: 0.85, 0 92). By source of fiber, cereal and, to a lesser extent, vegetable fiber were significantly associated with lower total mortality, while fruit fiber showed no association. In conclusion, high dietary fiber intake may reduce the risk of total mortality.

Regulatory metabolites of vitamin E and their putative relevance for atherogenesis

Vitamin E is likely the most important antioxidant in the human diet and α-tocopherol is the most active isomer. α-Tocopherol exhibits anti-oxidative capacity in vitro, and inhibits oxidation of LDL. Beside this, α-tocopherol shows anti-inflammatory activity and modulates expression of proteins involved in uptake, transport and degradation of tocopherols, as well as the uptake, storage and export of lipids such as cholesterol. Despite promising anti-atherogenic features in vitro, vitamin E failed to be atheroprotective in clinical trials in humans. Recent studies highlight the importance of long-chain metabolites of α-tocopherol, which are formed as catabolic intermediate products in the liver and occur in human plasma. These metabolites modulate inflammatory processes and macrophage foam cell formation via mechanisms different than that of their metabolic precursor α-tocopherol and at lower concentrations. Here we summarize the controversial role of vitamin E as a preventive agent against atherosclerosis and point the attention to recent findings that highlight a role of these long-chain metabolites of vitamin E as a proposed new class of regulatory metabolites. We speculate that the metabolites contribute to physiological as well as pathophysiological processes.

Acute effects of raisin consumption on glucose and insulin reponses in healthy individuals

Raisins are popular snacks with a favourable nutrient profile, being high in dietary fibre, polyphenols and a number of vitamins and minerals, in addition to being rich in fructose. In light of evidence demonstrating improvements in glycaemic control with moderate fructose intake and low-glycaemic index (GI) fruits, our aim was to determine the GI, insulin index (II) and postprandial responses to raisins in an acute feeding setting. A total of ten healthy participants (four male and six female) consumed breakfast study meals on four occasions over a 2- to 8-week period: meal 1: white bread (WB) (108 g WB; 50 g available carbohydrate) served as the control and was consumed on two separate occasions; meal 2: raisins (R50) (69 g raisins; 50 g available carbohydrate); and meal 3: raisins (R20) (one serving, 28 g raisins; 20 g available carbohydrate). Postprandial glucose and insulin were measured over a 2 h period for the determination of GI, glycaemic load (GL) and II. The raisin meals, R50 and R20, resulted in significantly reduced postprandial glucose and insulin responses when compared with WB (P < 0·05). Furthermore, raisins were determined to be low-GI, -GL and -II foods. The favourable effect of raisins on postprandial glycaemic response, their insulin-sparing effect and low GI combined with their other metabolic benefits may indicate that raisins are a healthy choice not only for the general population but also for individuals with diabetes or insulin resistance.

Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis

OBJECTIVE

To investigate dietary fibre intake and any potential dose-response association with coronary heart disease and cardiovascular disease.

DESIGN

Systematic review of available literature and dose-response meta-analysis of cohort studies using random effects models.

DATA SOURCES

The Cochrane Library, Medline, Medline in-process, Embase, CAB Abstracts, ISI Web of Science, BIOSIS, and hand searching.

ELIGIBILITY CRITERIA FOR STUDIES

Prospective studies reporting associations between fibre intake and coronary heart disease or cardiovascular disease, with a minimum follow-up of three years and published in English between 1 January 1990 and 6 August 2013.

RESULTS

22 cohort study publications met inclusion criteria and reported total dietary fibre intake, fibre subtypes, or fibre from food sources and primary events of cardiovascular disease or coronary heart disease. Total dietary fibre intake was inversely associated with risk of cardiovascular disease (risk ratio 0.91 per 7 g/day (95% confidence intervals 0.88 to 0.94)) and coronary heart disease (0.91 (0.87 to 0.94)). There was evidence of some heterogeneity between pooled studies for cardiovascular disease (I(2)=45% (0% to 74%)) and coronary heart disease (I(2)=33% (0% to 66%)). Insoluble fibre and fibre from cereal and vegetable sources were inversely associated with risk of coronary heart disease and cardiovascular disease. Fruit fibre intake was inversely associated with risk of cardiovascular disease.

CONCLUSIONS

Greater dietary fibre intake is associated with a lower risk of both cardiovascular disease and coronary heart disease. Findings are aligned with general recommendations to increase fibre intake. The differing strengths of association by fibre type or source highlight the need for a better understanding of the mode of action of fibre components.

Circulating 25OHD, dietary vitamin D, PTH, and calcium associations with incident cardiovascular disease and mortality: the MIDSPAN Family Study

CONTEXT

Observational studies relating circulating 25-hydroxyvitamin D (25OHD) and dietary vitamin D intake to cardiovascular disease (CVD) have reported conflicting results.

OBJECTIVE

Our objective was to investigate the association of 25OHD, dietary vitamin D, PTH, and adjusted calcium with CVD and mortality in a Scottish cohort.

DESIGN AND SETTING

The MIDSPAN Family Study is a prospective study of 1040 men and 1298 women from the West of Scotland recruited in 1996 and followed up for a median 14.4 yr.

PARTICIPANTS

Locally resident adult offspring of a general population cohort were recruited from 1972-1976.

MAIN OUTCOME MEASURES

CVD events (n = 416) and all-cause mortality (n = 100) were evaluated.

RESULTS

25OHD was measured using liquid chromatography-tandem mass spectrometry in available plasma (n = 2081). Median plasma 25OHD was 18.6 ng/ml, and median vitamin D intake was 3.2 μg/d (128 IU/d). Vitamin D deficiency (25OHD <15 ng/ml) was present in 689 participants (33.1%). There was no evidence that dietary vitamin D intake, PTH, or adjusted calcium were associated with CVD events or with mortality. Vitamin D deficiency was not associated with CVD (fully adjusted hazard ratio = 1.00; 95% confidence interval = 0.77-1.31). Results were similar after excluding patients who reported an activity-limiting longstanding illness at baseline (18.8%) and those taking any vitamin supplements (21.7%). However, there was some evidence vitamin D deficiency was associated with all-cause mortality (fully adjusted hazard ratio = 2.02; 95% confidence interval = 1.17-3.51).

CONCLUSION

Vitamin D deficiency was not associated with risk of CVD in this cohort with very low 25OHD. Future trials of vitamin D supplementation in middle-aged cohorts should be powered to detect differences in mortality outcomes as well as CVD.

Fiber intake and total and cause-specific mortality in the European Prospective Investigation into Cancer and Nutrition cohort

BACKGROUND

Previous studies have shown that high fiber intake is associated with lower mortality. However, little is known about the association of dietary fiber with specific causes of death other than cardiovascular disease (CVD).

OBJECTIVE

The aim of this study was to assess the relation between fiber intake, mortality, and cause-specific mortality in a large European prospective study of 452,717 men and women.

DESIGN

HRs and 95% CIs were estimated by using Cox proportional hazards models, stratified by age, sex, and center and adjusted for education, smoking, alcohol consumption, BMI, physical activity, total energy intake, and, in women, ever use of menopausal hormone therapy.

RESULTS

During a mean follow-up of 12.7 y, a total of 23,582 deaths were recorded. Fiber intake was inversely associated with total mortality (HR(per 10-g/d increase): 0.90; 95% CI: 0.88, 0.92); with mortality from circulatory (HR(per 10-g/d increase): 0.90 and 0.88 for men and women, respectively), digestive (HR: 0.61 and 0.64), respiratory (HR: 0.77 and 0.62), and non-CVD noncancer inflammatory (HR: 0.85 and 0.80) diseases; and with smoking-related cancers (HR: 0.86 and 0.89) but not with non-smoking-related cancers (HR: 1.05 and 0.97). The associations were more evident for fiber from cereals and vegetables than from fruit. The associations were similar across BMI and physical activity categories but were stronger in smokers and participants who consumed >18 g alcohol/d.

CONCLUSIONS

Higher fiber intake is associated with lower mortality, particularly from circulatory, digestive, and non-CVD noncancer inflammatory diseases. Our results support current recommendations of high dietary fiber intake for health maintenance.

Greater whole-grain intake is associated with lower risk of type 2 diabetes, cardiovascular disease, and weight gain

Whole-grain and high fiber intakes are routinely recommended for prevention of vascular diseases; however, there are no comprehensive and quantitative assessments of available data in humans. The aim of this study was to systematically examine longitudinal studies investigating whole-grain and fiber intake in relation to risk of type 2 diabetes (T2D), cardiovascular disease (CVD), weight gain, and metabolic risk factors. We identified 45 prospective cohort studies and 21 randomized-controlled trials (RCT) between 1966 and February 2012 by searching the Cumulative Index to Nursing and Allied Health Literature, Cochrane, Elsevier Medical Database, and PubMed. Study characteristics, whole-grain and dietary fiber intakes, and risk estimates were extracted using a standardized protocol. Using random effects models, we found that compared with never/rare consumers of whole grains, those consuming 48-80 g whole grain/d (3-5 serving/d) had an ~26% lower risk of T2D [RR = 0.74 (95% CI: 0.69, 0.80)], ~21% lower risk of CVD [RR = 0.79 (95% CI: 0.74, 0.85)], and consistently less weight gain during 8-13 y (1.27 vs 1.64 kg; P = 0.001). Among RCT, weighted mean differences in post-intervention circulating concentrations of fasting glucose and total and LDL-cholesterol comparing whole-grain intervention groups with controls indicated significantly lower concentrations after whole-grain interventions [differences in fasting glucose: -0.93 mmol/L (95% CI: -1.65, -0.21), total cholesterol: -0.83 mmol/L (-1.23, -0.42); and LDL-cholesterol: -0.82 mmol/L (-1.31, -0.33)]. [corrected] Findings from this meta-analysis provide evidence to support beneficial effects of whole-grain intake on vascular disease prevention. Potential mechanisms responsible for whole grains' effects on metabolic intermediates require further investigation in large intervention trials.

Prebiotics and the health benefits of fiber: current regulatory status, future research, and goals

First defined in the mid-1990s, prebiotics, which alter the composition and activity of gastrointestinal (GI) microbiota to improve health and well-being, have generated scientific and consumer interest and regulatory debate. The Life Sciences Research Organization, Inc. (LSRO) held a workshop, Prebiotics and the Health Benefits of Fiber: Future Research and Goals, in February 2011 to assess the current state of the science and the international regulatory environment for prebiotics, identify research gaps, and create a strategy for future research. A developing body of evidence supports a role for prebiotics in reducing the risk and severity of GI infection and inflammation, including diarrhea, inflammatory bowel disease, and ulcerative colitis as well as bowel function disorders, including irritable bowel syndrome. Prebiotics also increase the bioavailability and uptake of minerals and data suggest that they reduce the risk of obesity by promoting satiety and weight loss. Additional research is needed to define the relationship between the consumption of different prebiotics and improvement of human health. New information derived from the characterization of the composition and function of different prebiotics as well as the interactions among and between gut microbiota and the human host would improve our understanding of the effects of prebiotics on health and disease and could assist in surmounting regulatory issues related to prebiotic use.

Antioxidant-induced stress

Antioxidants are among the most popular health-protecting products, sold worldwide without prescription. Indeed, there are many reports showing the benefits of antioxidants but only a few questioning the possible harmful effects of these "drugs". The normal balance between antioxidants and free radicals in the body is offset when either of these forces prevails. The available evidence on the harmful effects of antioxidants is analyzed in this review. In summary, a hypothesis is presented that "antioxidant-induced stress" results when antioxidants overwhelm the body's free radicals.

The antioxidant paradox in diabetes mellitus

There is ample empiric evidence to indicate that oxidative stress contributes to the pathogenesis of coronary artery disease and has a key role in the onset and progression of diabetes and its complications. Diabetes leads to depletion of the cellular antioxidant defense system and is associated with an increase in the production of free radicals. Oxidative stress can be the result of multiple pathways. Some of these are related to substrate-driven overproduction of mitochondrial reactive oxygen species, advanced glycation end product formation, glucose autoxidation, and depletion of micronutrients and cellular elements with antioxidative properties. There are numerous observational studies in the literature showing a beneficial outcome of the consumption of antioxidant vitamins. However, the interventional trials portray a different picture. The divide between the robust experimental evidence of the pathogenetic role of increased oxidative load in diabetes and the overwhelming failure of antioxidants to show any health benefits in clinical trials may well be characterized as the "antioxidant paradox."

Concordance of randomized and nonrandomized studies was unrelated to translational patterns of two nutrient-disease associations

OBJECTIVE

There are several examples in nutrition of discordance between the results of observational studies and randomized controlled trials (RCTs). We hypothesized that this discordance is attributable to differences in the translational paths of nutrient-disease associations. Translational paths can be assessed using citation analysis.

STUDY DESIGN AND SETTING

We compared the characteristics of citation networks using examples, where RCTs and observational studies agreed (long-chain n-3 polyunsaturated fatty acids [n-3 PUFA]) or disagreed (vitamin E). We performed systematic reviews in each example, constructed citation networks, and compared them with respect to the number of articles and citation relationships between them, as well as the distribution of articles' hub and authority scores.

RESULTS

For n-3 PUFA, meta-analyses of 14 RCTs and 10 observational studies both suggested that higher intake was associated with lower cardiovascular mortality. For vitamin E, the meta-analysis of 14 RCTs excluded a clinically significant effect, whereas 14 observational studies reported a significant inverse association. The respective citation networks consisted of 392 (n-3 PUFA) and 351 (vitamin E) articles. No differences between the characteristics of the two networks were identified. There was no evidence that the observational studies predated RCTs in the translational process in either example.

CONCLUSION

In the two examples, citation network characteristics do not predict concordance in the results of observational studies and RCTs.

Dietary fiber intake and mortality in the NIH-AARP diet and health study

BACKGROUND

Dietary fiber has been hypothesized to lower the risk of coronary heart disease, diabetes, and some cancers. However, little is known of the effect of dietary fiber intake on total death and cause-specific deaths.

METHODS

We examined dietary fiber intake in relation to total mortality and death from specific causes in the NIH (National Institutes of Health)-AARP Diet and Health Study, a prospective cohort study. Diet was assessed using a food-frequency questionnaire at baseline. Cause of death was identified using the National Death Index Plus. Cox proportional hazard models were used to estimate relative risks and 2-sided 95% confidence intervals (CIs).

RESULTS

During an average of 9 years of follow-up, we identified 20 126 deaths in men and 11 330 deaths in women. Dietary fiber intake was associated with a significantly lowered risk of total death in both men and women (multivariate relative risk comparing the highest with the lowest quintile, 0.78 [95% CI, 0.73-0.82; P for trend, <.001] in men and 0.78 [95% CI, 0.73-0.85; P for trend, <.001] in women). Dietary fiber intake also lowered the risk of death from cardiovascular, infectious, and respiratory diseases by 24% to 56% in men and by 34% to 59% in women. Inverse association between dietary fiber intake and cancer death was observed in men but not in women. Dietary fiber from grains, but not from other sources, was significantly inversely related to total and cause-specific death in both men and women.

CONCLUSIONS

Dietary fiber may reduce the risk of death from cardiovascular, infectious, and respiratory diseases. Making fiber-rich food choices more often may provide significant health benefits.

Protective effects of vitamin E against hypercholesterolemia-induced age-related diseases

Hypercholesterolemia is a major risk factor for age-related diseases such as atherosclerosis and Alzheimer's disease (AD). Changes in human plasma cholesterol levels results from the interaction between multiple genetic and environmental factors. The accumulation of excess cholesterol in blood vessels leads to atherosclerosis. Many studies on this field show that differential expression of oxidative stress-related proteins, lipid metabolism-related enzymes, and receptors response to atherogenic diet. Additionally, excess brain cholesterol has been associated with increased formation and deposition of amyloid-β peptide from amyloid precursor protein which may contribute to the risk and pathogenesis of AD. To consider genetically, more than 50 genes have been reported to influence the risk of late-onset AD. Some of these genes might be also important in cholesterol metabolism and transport. Epidemiological studies have shown an association between high intake and high serum concentrations of antioxidant vitamins like vitamin E and lower rates of ischemic heart diseases. It has been known that vitamin E also inhibits smooth muscle cell proliferation by non-antioxidant mechanism. On the basis of the previous results, vitamin E has been accepted as an important protective factor against hypercholesterolemia-induced age-related diseases.

Vitamin E and risk of cardiovascular diseases: a review of epidemiologic and clinical trial studies

Cardiovascular diseases are the leading cause of worldwide mortality. There is strong epidemiologic evidence for a beneficial effect of vitamin E on cardiovascular disease risk. However, conflicting results have been reported by intervention studies. To assess the potential benefit of vitamin E intake on the risk of cardiovascular diseases, fifty-nine published reports from observational studies, retrospective and prospective, randomised clinical trials, meta-analyses as well as pooling analyses were reviewed. The paper provides a detailed discussion about design, quality and limitations of these studies with regard to the evidence of the hypothesized relationship between vitamin E and cardiovascular diseases.

Vitaminas e minerais com propriedades antioxidantes e risco cardiometabólico: controvérsias e perspectivas

No processo celular de obtenção de energia, são gerados compostos chamados espécies reativas de oxigênio (ERO) que, em excesso, podem causar danos celulares. Estresse oxidativo resulta do desequilíbrio no estado de óxido-redução a favor da oxidação. Dos mecanismos de defesa antioxidante, participam enzimas endógenas e algumas vitaminas e minerais. A vitamina E encontra-se no plasma e na partícula de LDL, protegendo lipídeos da oxidação. Estudos observacionais relataram associação inversa entre ingestão de vitamina E e risco cardiometabólico (RCM). Entretanto, ensaios clínicos não comprovaram a eficácia de sua suplementação nos desfechos cardiometabólicos. A vitamina C participa do sistema de regeneração da vitamina E, mantendo o potencial antioxidante plasmático. Dados sobre os benefícios de sua suplementação na redução do risco cardiometabólico são inconclusivos. A atividade antioxidante dos carotenoides é responsável, em parte, por seu papel protetor contra doenças cardiovasculares e cânceres. A suplementação desse nutriente também não trouxe resultados consistentes no que se refere à redução do RCM. A participação do zinco e do selênio na defesa antioxidante vem sendo estudada mais recentemente, mas a sua suplementação em indivíduos com níveis séricos normais e ingestão adequada na dieta desses minerais não parece ser necessária. De um modo geral, há muita controvérsia sobre o papel desses micronutrientes no RCM. Estudos epidemiológicos sugerem que o consumo de substâncias antioxidantes provenientes da dieta ou dietas ricas em frutas e hortaliças diminui o RCM. Mais estudos são necessários antes de se recomendar o uso de antioxidantes isolados na forma de suplementos para tal finalidade.

A Review of the Role of Soluble Fiber in Health with Specific Reference to Wheat Dextrin

Dietary fiber is widely recognized to have a beneficial role in overall health, but only at adequate levels (25 − 38 g/day for healthy adults). Wheat dextrin in particular is a soluble fiber that can easily be added to the diet and is widely used in the food industry. There is some debate about whether increased intake of soluble fibers leads to health benefits. This paper reviews the evidence regarding the physiological effects and potential health benefits of the addition of soluble dietary fibers, with specific reference to wheat dextrin, based on a search of PubMed. The evidence suggests that soluble fibers help to regulate the digestive system, may increase micronutrient absorption, stabilize blood glucose and lower serum lipids, may prevent several gastrointestinal disorders, and have an accepted role in the prevention of cardiovascular disease. It is concluded that supplementation with soluble fibers (e.g. wheat dextrin) may be useful in individuals at risk of a lower than recommended dietary fiber intake.

Toll-like receptor 2 is essential for the sensing of oxidants during inflammation

RATIONALE

The mechanisms by which oxidants are sensed by cells and cause inflammation are not well understood.

OBJECTIVES

This study aimed to determine how cells "sense" soluble oxidants and how this is translated into an inflammatory reaction.

METHODS

Monocytes, macrophages, or HEK293 cells (stably transfected with human Toll-like receptor [TLR]2, TLR2/1, TLR2/6, or TLR4/MD2-CD14) were used. CXC ligand-8 (CXCL8) levels were measured using ELISA. Phosphorylated IL-1 receptor-associated kinase 1 levels were measured using Western blot. TLR2(-/-) and TLR4(-/-) mice were challenged with oxidants, and inflammation was measured by monitoring cell infiltration and KC levels.

MEASUREMENTS AND MAIN RESULTS

Oxidants evoked the release of CXCL8 from monocytes/macrophages; this was abrogated by pretreatment with N-acetylcysteine or binding antibodies to TLR2 and was associated with the rapid phosphorylation of IL-1 receptor-associated kinase 1. Oxidants added to HEK293 cells transfected with TLR2, TLR1/2, or TLR2/6 but not TLR4/MD2-CD14 or control HEK nulls resulted in the release of CXCL8. Oxidant challenge delivered intraperitoneally (2-24 hours) or by inhalation to the lungs (3 days) resulted in a robust inflammation in wild-type mice. TLR2(-/-) mice did not respond to oxidant challenge in either model. TLR4(-/-) mice responded as wild-type mice to oxidants at 2 hours but as TLR2(-/-) mice at later time points.

CONCLUSIONS

Oxidant-TLR2 interactions provide a signal that initiates the inflammatory response.

Dietary fiber intake in relation to coronary heart disease and all-cause mortality over 40 y: the Zutphen Study

BACKGROUND

Little is known about the effects of dietary fiber intake on long-term mortality.

OBJECTIVE

We aimed to study recent and long-term dietary fiber intake in relation to coronary heart disease and all-cause mortality.

DESIGN

The effects of recent and long-term dietary fiber intakes on mortality were investigated in the Zutphen Study, a cohort of 1,373 men born between 1900 and 1920 and examined repeatedly between 1960 and 2000. During that period, 1,130 men died, 348 as a result of coronary heart disease. Hazard ratios were obtained from time-dependent Cox regression models.

RESULTS

Every additional 10 g of recent dietary fiber intake per day reduced coronary heart disease mortality by 17% (95% CI: 2%, 30%) and all-cause mortality by 9% (0%, 18%). The strength of the association between long-term dietary fiber intake and all-cause mortality decreased from age 50 y (hazard ratio: 0.71; 95% CI: 0.55, 0.93) until age 80 y (0.99; 0.87, 1.12). We observed no clear associations for different types of dietary fiber.

CONCLUSIONS

A higher recent dietary fiber intake was associated with a lower risk of both coronary heart disease and all-cause mortality. For long-term intake, the strength of the association between dietary fiber and all-cause mortality decreased with increasing age.