Nutrition reviews最新文献

Type 2 diabetes is an inflammatory, non-infectious disease characterized by dysfunctional pancreatic β-cells and insulin resistance. Although lifestyle, genetic, and environmental factors are associated with a high risk of type 2 diabetes, nutrition remains one of the most significant factors. Specific types and increased amounts of dietary fatty acids are associated with type 2 diabetes and its complications. Dietary recommendations for the prevention of type 2 diabetes advocate for a diet that is characterized by reduced saturated fatty acids and trans fatty acids alongside an increased consumption of monounsaturated fatty acids, polyunsaturated fatty acids, and omega-3 fatty acids. Although following the recommendations for dietary fatty acid intake is important for reducing type 2 diabetes and its related complications, the underlying mechanisms remain unclear. This review will provide an update on the mechanisms of action of fatty acids on glucose metabolism and type 2 diabetes, as well as dietary recommendations for the prevention of type 2 diabetes.

Context: Inflammation and endothelial dysfunction are important risk factors for chronic diseases, including cardiovascular diseases and related mortality.

Objective: This systematic review and meta-analysis aimed to assess the effects of 2 popular dietary patterns-a Mediterranean (MED) diet supplemented with olive oil and a low-fat diet (LFD)-on factors related to inflammation and endothelial function in adults.

Data sources and data extraction: The following online databases were searched for related studies published until August 7, 2024: PubMed/Medline, Scopus, Clarivate Analytics Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar. Two independent researchers selected the studies based on the eligibility criteria.

Data analysis: The effect sizes were expressed as Hedges' g with 95% CIs. A total of 16 eligible trials with 20 effect sizes were included in the analyses. This meta-analysis revealed that the MED diet supplemented with olive oil significantly improved all of the indicators of the study compared with the LFD, except in the case of E-selectin, in which a low and nonsignificant decrease was reported.

Conclusion: Available evidence suggests that a MED diet supplemented with olive oil compared with the LFD significantly improves inflammation and serum endothelial function in adults.

Systematic review registration: PROSPERO registration no. CRD42023485718.

This review describes the state of the art regarding the prebiotic role of chitin and the interactions of chitin and chitosan with cancer cells. Chitin is the second most abundant polysaccharide in nature and a constitutive component of crustacean shells and the exoskeleton of insects. Chitosan is the deacetylated form of chitin, which is obtained by chemical processing or the enzymatic activity of deacetylases found in microorganisms and insects. Edible insects have recently been introduced in Western countries, thus raising concerns regarding food safety and due to their chitin content and the release of chitosan during the digestive process. The roles of insect chitin and chitosan in the gastrointestinal tract, microbiome modulation, and cancer have been widely investigated. Several in vitro and in vivo studies have shown the possible microbiota modulation of chitin and its relevant communication with the immune system, thus confirming its prebiotic activity. No evidence has been provided on the cancerogenic activity of chitin; however, studies have suggested that chitin has a cytotoxic effect on cancer cell lines. Chitosan has been confirmed to exhibit apoptotic and cytotoxic activities on cancer cells in several in vitro studies on cancer cell lines and in vivo models. In conclusion, the literature does not show a direct connection between the presence of chitin or chitosan and the onset of cancer. However, cytotoxic and apoptotic activities in relation to cancerous lines have been demonstrated.

Context: Vitamin C has been used as an essential antioxidant to reduce the inflammatory response associated with pneumonia and acute respiratory distress syndrome in patients with the 2019 coronavirus disease (COVID-19), but its effect on clinical outcomes remains controversial and inconclusive.

Objective: The purpose of this study was to conduct a meta-analysis and systematic review to assess the effects of vitamin C supplementation on the severity of COVID-19 in hospitalized patients.

Data sources: Web of Science, Embase, Cochrane Library, PubMed, CNKI, CSTJ, Wan fang, and CBM databases were searched for publications between January 2020 and December 2023 that met the inclusion criteria.

Data extraction: The meta-analyses of outcomes in more than one study were performed using Review Manager software. Heterogeneity was evaluated using the I2 statistic. A randomized controlled trial, cohort studies, and retrospective studies in which vitamin C supplementation was supplemented as monotherapy or in combination, compared with placebo, no treatment, or other standard treatment without vitamin C were included.

Data analysis: After screening, 22 studies, with a total of 6831 patients, were selected for assessment. Odds ratios (ORs) with 95% CIs were calculated using fixed- and random-effects models. The meta-analysis showed significant effects of vitamin C on alleviating clinical outcomes in patients with COVID-19 (OR = 0.76, 95% CI = 0.65-0.89, P = .0007) but no shortening of the length of hospitalization (OR = 1.16, 95% CI = -0.13-2.44, P = .08) compared with the control group. Notably, vitamin C supplements significantly reduced the mortality risk (OR = 0.64, 95% CI = 0.51-0.80, P = .0001) and the incidence of severity (OR = 0.59, 95% CI = 0.43-0.80, P = .0006) in COVID-19 patients.

Conclusion: The findings suggest that vitamin C supplements may have a beneficial effect on clinical outcomes, as well as reducing severity and mortality in COVID-19 patients, but more clinical randomized controlled trials are needed to evaluate the role of vitamin C in treating COVID-19.

Systematic review registration: PROSPERO registration no. CRD42023491517.

Context: Results from observational studies and meta-analyses examining the relationship between total, fried, and nonfried potato intake and cardiometabolic disease remain conflicted.

Objective: The aim was to synthesize existing evidence on the relationships between total potato intake and specific types of potato intake with the risk of overweight/obesity, hypertension, diabetes, gestational diabetes mellitus (GDM), cardiovascular disease (CVD), coronary heart disease (CHD), and stroke.

Data sources: Systematic searches were conducted in PubMed, Embase, and Web of Science until July 13, 2023.

Data extraction: Data extracted from studies included first author, publication year, location, data source, follow-up duration (cohort studies only), demographics, sample size, cases, outcomes, exposure and outcome types, measurements, adjustments, study design, potato intake categories, and adjusted risk estimates (odds ratio, relative risk [RR], hazard ratio) with 95% CIs.

Data analysis: Random-effects models were applied to estimate the summary RRs and 95% CIs.

Results: Fifty-one articles (103 studies) were identified in the current meta-analysis. Comparing the highest with the lowest categories of total potato intake, total potato intake was not associated with hypertension (summary RR = 1.07; 95% CI: 0.95, 1.21), diabetes (1.08; 95% CI: 0.96, 1.22), GDM (1.16; 95% CI: 0.86, 1.57), CHD (1.00; 95% CI: 0.99, 1.02), CVD (0.97; 95% CI: 0.91, 1.03), or stroke (0.97; 95% CI: 0.88, 1.06); fried potato intake was not associated with overweight/obesity (1.24; 95% CI: 0.90, 1.70) or GDM (1.03; 95% CI: 0.97, 1.09) but was significantly associated with increased diabetes risk (1.16; 95% CI: 1.04, 1.30); nonfried potato intake was significantly associated with increased diabetes risk (1.05; 95% CI: 1.01, 1.10) but not hypertension (1.06; 95% CI: 0.97, 1.15).

Conclusion: Total potato intake was not associated with an increased risk of hypertension, diabetes, GDM, or cardiometabolic disease, but both fried and nonfried potato intake may increase the risk of diabetes but not other cardiometabolic diseases. Future cohort studies are needed to explore the association between different types of potato intake and cardiometabolic disease. In addition, the limited number of studies on total potato intake and overweight/obesity/heart failure, fried potato intake and CHD/stroke/heart failure, and nonfried potato intake and overweight/obesity/GDM/CHD/CVD/heart failure prevented us from conducting an analysis.

Systematic review registration: PROSPERO registration no. RD42023454244.

The natural polyphenol resveratrol (RV) has garnered fame for its extensive pharmacological properties. Although clinical studies have shown some positive results, many contradictory outcomes remain. An important obstacle to the development of therapeutic applications for RV is its low bioavailability in vivo. This may be partially attributed to biotransformation mediated by phase I and II enzymes, such as cytochrome P450s, UDP-glucuronosyltransferases, and sulfotransferases. To date, more than 20 different types of metabolites have been detected after catalysis by these enzymes. Notably, RV and some of its metabolites serve as substrates for these enzymes. Conversely, RV can directly regulate the expression or activity of these enzymes. Given the increasing number of studies investigating the bioactivity of RV, this review summarizes its physicochemical and pharmacokinetic characteristics and describes the metabolism of RV and the bioactivities of its metabolites, with emphasis on the interaction between RV and its related metabolic enzymes. In addition to hepatic metabolism, the crucial roles of RV metabolism in multiple other tissues and organs cannot be overlooked, and they reveal the relationship between RV metabolism and its biological potential.

Context: The thermic effect of food (TEF) may be a therapeutic target for the prevention and treatment of obesity.

Objective: The impact of different biological and nutritional characteristics on TEF in humans was analyzed.

Data sources: The MEDLINE/PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Latin American and Caribbean Health Sciences Literature databases were searched until November 2023 without language restrictions.

Data extraction: Clinical trials were included that offered an oral test meal to adult and elderly individuals in a fasting state and measured TEF using calorimetry. The average TEF of each group was the outcome, and the impact of the individuals' and meal characteristics on the TEF was assessed using subgroups, meta-regression, and compositional analysis.

Data analysis: The review included 133 studies, with 321 different groups. The mean TEF at 60 minutes after the test meal was 262 (95% CI, 236-288) kcal/d and decreased over time until 240 minutes after the test meal (P < .01). Male participants, individuals with normal body mass index, meals with energy content offered according to individual requirements, and meals with a mixed degree of food processing yielded a higher TEF. The total energy content of meals was the variable most strongly associated with TEF. Compositional analysis showed that the amount of lipids in meals was the only macronutrient consistently and negatively associated with TEF.

Conclusions: The TEF is influenced by specific individuals' and meal characteristics. Total energy content and the amount of lipids were the characteristics of the meals most consistently associated with TEF. However, due to important methodological differences between studies, it is difficult to determine how to use TEF as a potential therapeutic target against obesity.

Systematic review registration: PROSPERO registration no. CRD42023432504.

The microbiota in humans consists of trillions of microorganisms that are involved in the regulation of the gastrointestinal tract and immune and metabolic homeostasis. The gut microbiota (GM) has a prominent impact on the pathogenesis of metabolic syndrome (MetS). This process is reciprocal, constituting a crosstalk process between the GM and MetS. In this review, GM directly or indirectly inducing MetS via the host-microbial metabolic axis has been systematically reviewed. Additionally, the specifically altered GM in MetS are detailed in this review. Moreover, short-chain fatty acids (SCFAs), as unique gut microbial metabolites, have a remarkable effect on MetS, and the role of SCFAs in MetS-related diseases is highlighted to supplement the gaps in this area. Finally, the existing therapeutics are outlined, and the superiority and shortcomings of different therapeutic approaches are discussed, in hopes that this review can contribute to the development of potential treatment strategies.

Context: Consuming antioxidant-rich foods has been associated with potential benefits in managing chronic diseases by reducing oxidative stress and inflammation.

Objective: This systematic review aimed to evaluate the effects of Aronia melanocarpa (aronia berry or chokeberry) on human inflammation biomarkers and antioxidant enzymes.

Data sources: A systematic search was conducted across multiple databases, including PubMed, Scopus, Science Direct, and Web of Science, to identify relevant studies investigating the potential effects of aronia on human inflammation biomarkers and antioxidant enzymes between April 2022 and November 2023.

Data extraction: The selection of studies followed the PRISMA guidelines, data screening was conducted by 4 independent reviewers, and data extraction and risk-of-bias assessments were performed by 2 independent reviewers using the Cochrane Risk of Bias 2 tool.

Data analysis: A total of 1986 studies were screened, and 18 studies that met the inclusion criteria were included in a systematic review that investigated the anti-inflammatory effects of aronia on various health parameters. These studies primarily focused on the effects of aronia on cardiometabolic diseases, performance in sport, and other health parameters.

Conclusions: This study examined the effects of Aronia intervention on human health outcomes using aronia juice, extract, or oven-dried powder for a period of 4 to 13 weeks. The primary health parameters considered were C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), interleukin-8 (IL-8), interleukin-10 (IL-10), interleukin-1ß (IL-1ß), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione peroxidase (GSH-Px). The results showed that aronia had a beneficial effect on several inflammatory cytokines, including reductions in CRP, TNF-α and IL-6 concentrations, as well as elevated IL-10 levels. Moreover, positive changes have been observed in antioxidant enzyme systems, including; elevated SOD, GSH-Px and CAT activity. The findings of the presented studies provide evidence that Aronia melanocarpa may have beneficial effects on inflammatory markers.

Systematic review registration: PROSPERO registration No. CRD42022325633.

Context: Carrying the apolipoprotein ε4 allele (APOE ε4) is the strongest genetic risk factor for late-onset Alzheimer's disease. There is some evidence suggesting that APOE ε4 may modulate the influence of diet on cognitive function.

Objective: This umbrella review of systematic reviews evaluates the existing literature on the effect of dietary interventions on cognitive and brain-imaging outcomes by APOE status.

Data sources: PubMed, EMBASE, Web of Science, and Scopus were searched using terms appropriate to each area of research, from their respective starting dates of coverage until March 2023.

Data extraction: Two independent reviewers conducted data extraction and performed a quality appraisal using the Measurement Tool to Assess Systematic Reviews (AMSTAR) 2.

Data analysis: Six total reviews were included in the final analysis. Four reviews evaluated randomized controlled trials on individuals aged 50-93 years ranging the entire cognitive continuum. One review combined observational studies and clinical trials conducted on both cognitively healthy and cognitively impaired individuals (age range: 50-90), and 1 review included observational studies of both cognitively healthy and cognitively impaired adults (age range: 50-75).

Results: Both observational studies and clinical trials yielded inconclusive results attributed to both practical limitations associated with longitudinal follow-up and issues of methodological quality. Except for the Mediterranean diet, dietary interventions, such as the ketogenic diet, nutraceuticals, and supplements, were generally not effective in older APOE ε4 carriers. This review considers plausible biological mechanisms that might explain why older and cognitively impaired APOE ε4 carriers were less likely to benefit.

Conclusion: This review identifies notable gaps in the literature, such as a shortage of studies conducted in middle-aged and cognitively healthy APOE ε4 carriers assessing the impact of dietary interventions and provides suggestions for novel trial designs.