Nutrition reviews最新文献

Context: Vitamin E, a well-known antioxidant with numerous positive effects on human health, encompasses tocotrienol-rich fraction (TRF), a natural variant abundant in palm oil.

Objective: This systematic review analyzed findings from randomized controlled trials published until 2022 to evaluate the health impacts of palm TRF.

Data sources: A literature search was performed in Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, OVID Medline, SCOPUS, and Web of Science from inception until December 2022. Thirty studies involving 2646 patients, including both healthy individuals and those with underlying conditions, were identified.

Results: This review shows palm TRF to be a promising natural supplement against inflammation and lipid peroxidation and that can significantly enhance overall health. Additionally, the study underscores the necessity for further research to ascertain the optimal dosage, formulation, and duration of supplementation, maximizing the potential health advantages.

Conclusion: This systematic review provides evidence supporting the health benefits associated with palm TRF.

Systematic review registration: PROSPERO registration no. CRD42020204070.

Context: Oral health and food oral-processing issues emerge with functional decline in the older adult population, potentially increasing the risk of malnutrition. Impairment of oral health is associated with poorer nutrition status; however, the relationship between oral factors and the intake of each nutrient remains poorly understood.

Objective: The associations between different oral factors and nutrient intakes among community-dwelling older adults were investigated.

Data sources: A literature search from 5 databases (Web of Science, Scopus, Cochrane Library, Ovid [MEDLINE and Embase], and CINAHL) was completed on February 1, 2022. The search was limited to peer-reviewed articles published between the years 2012 and 2022.

Data extraction: Six cross-sectional studies were included in the meta-analysis. Two authors independently completed the data extraction and summarized the study characteristics, factors adjusted for in the statistical analysis, the outcome, and summary statistics of the results.

Data analysis: Meta-analyses showed evidence of a significant association between compromised oral factors (namely, denture status, chewing ability, and the number of teeth) with lower energy (weighted mean difference [WMD], -107 kcal d-1 (95% CI, -132 to -81), protein (WMD, -5.2 g d-1; 95% CI, -6.6 to -3.8), fat (WMD, -4.6 g d-1; 95% CI, -6.7 to -2.6), carbohydrate (WMD, -8.8 g d-1; 95% CI, -13.9 to -3.7), and vitamin C intakes (WMD, -12.9 mg d-1; 95% CI, -16.6 to -9.2) in older adults.

Conclusion: Oral health can be an indicator of compromised daily energy, protein, fat, carbohydrate, and vitamin C intakes in older adults. However, the small sample size of the studies included in this review and the heterogeneity among macronutrient studies should be considered. Because of the lack of studies covering all aspects of food oral processing (eg, salivary flow rate, tongue pressure), the associations between oral processing and nutrient intake were not thoroughly explored.

Systematic review registration: PROSPERO registration no. CRD42022308823.

Context: The assessment of zinc status is difficult but essential for the identification of zinc deficiency and evaluation of interventions to improve zinc status.

Objective: The purpose of this systematic review (SR) and meta-analysis was to update the previously published SR of biomarkers of zinc status, conducted by the European Micronutrient Recommendations Aligned (EURRECA) network in 2009, to answer the question: Which putative measures (biomarkers) of zinc status appropriately reflect a change in zinc intake of at least 2 weeks?

Data sources: A structured search strategy was used to identify articles published between January 2007 and September 2022 from MEDLINE (Ovid), Embase (Ovid), Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials (CENTRAL). Relevant articles were identified using previously defined eligibility criteria.

Data extraction: Data were extracted and combined with data from the previous SR.

Data analysis: A random-effects model was used to calculate pooled mean differences using STATA (StataCorp). The risk of bias and the certainty of evidence for all outcomes were assessed. Additional data on 7 of the 32 previously reported biomarkers were identified, along with data on an additional 40 putative biomarkers from studies published since 2007. Pooled data analysis confirmed that, in healthy participants, both plasma/serum zinc concentration and urinary zinc excretion responded to changes in zinc intake (plasma/serum: mean effect [95% CI], controlled studies: 2.17 µmol/L [1.73, 2.61]; P < .005, I2 = 97.8; before-and-after studies: 2.87 µmol/L [2.45, 3.30]; P < .005, I2 = 98.1%; urine zinc: 0.39 mmol/mol creatinine [0.17, 0.62]; P < .005, I2 = 81.2; 3.09 µmol/day [0.16, 6.02]; P = .039, I2 = 94.3).

Conclusion: The updated analyses support the conclusion that plasma/serum and urinary zinc respond to changes in zinc intake in studies of healthy participants. Several additional putative biomarkers were identified, but more studies are needed to assess the sensitivity and reliability.

Systematic review registration: PROSPERO no. CRD42020219843.

The elderly population is increasing worldwide every day. Age is a significant factor in the progression of neurological diseases, which can also cause cognitive decline and memory disorders. Inflammation and oxidative stress are primary drivers of senescence and disorders, particularly those associated with aging and neurodegenerative diseases. Bioactive phytochemicals are considered a promising therapeutic strategy in combating aging and age-related pathological conditions. One of the phytochemicals with diverse biological properties encompassing antioxidant, anti-inflammatory, antibacterial, antiviral, anticancer, antifungal, antidepressant, anti-allergic, and anti-aging properties is curcumin. Curcumin, a polyphenolic structure with a distinct orange hue and unique chemical properties, is derived from the roots of Curcuma longa, a member of the Zingiberaceae family, commonly known as turmeric. It has been noted that the incidence of neurodegenerative diseases is low in societies that consume curcumin widely. Therefore, this review investigates the effect of curcumin on aging and Alzheimer and Parkinson disease, which are the most prevalent age-related neurodegenerative diseases.

Context: Intermittent fasting (IF) is a diet strategy with alternate intervals of calorie reduction and normal eating. Despite its beneficial effects on weight loss and cardiometabolic risk factors, the effect of IF on liver function tests (LFTs) remains unclear.

Objective: This study aimed to investigate the effect of IF on LFTs through a systematic review and meta-analysis of randomized clinical trials.

Data sources: An electronic search was performed using predefined search terms in databases including PubMed, Scopus, and ISI Web of Science until February 2023.

Data extraction: The studies were selected according to PRISMA guidelines, and the risk of bias was assessed for the randomized controlled trials.

Data analysis: The results of this study are reported as weighted mean differences (WMDs) with 95% CIs. Fourteen RCTs were included in the meta-analysis, with a total sample size of 908. IF significantly reduced alanine aminotransferase (ALT) (WMD: -2.88, 95% CI: -4.72 to -1.04, P-value = .002) and aspartate aminotransferase (AST) levels (WMD: -1.67, 95% CI: -3.12 to -0.22, P-value = .024). The results of the subgroup analysis showed that the impact of IF was significant in both the nonalcoholic fatty liver disease and the healthy groups for ALT. The effects of IF on the serum gamma-glutamyl transpeptidase (GGT) level were significant (WMD: -3.19, 95% CI: -6.00 to -0.39, P-value = .026), but there were no significant changes in the alkaline phosphatase (ALP) level (WMD: 1.06, 95% CI: -0.23 to 2.34, P-value = .106). Furthermore, no substantial heterogeneity between studies was reported.

Conclusion: IF can improve ALT, AST, and GGT levels but not ALP enzyme levels and may have a benefit on liver function.

Systematic review registration: PROSPERO registration no. CRD42023396211.

Context: Saffron, a natural remedy with potential antidepressant and anxiolytic properties, has gained attention as a potential therapeutic option.

Objective: This systematic review and meta-analysis aimed to evaluate the comparative effectiveness of saffron versus selective serotonin reuptake inhibitors (SSRIs) in treating depression and anxiety.

Data source: Electronic databases, including PubMed, Embase, Scopus, Web of Science, and the Cochrane database, were searched from inception to April 31, 2023.

Data extraction: Randomized controlled trials (RCTs) comparing saffron intervention with SSRIs in adults with depression or anxiety were included.

Data analysis: Random-effects meta-analysis using standardized mean differences (SMDs) and risk ratio (RRs) with their 95% CIs calculated continuous and binary outcomes, respectively. Meta-analysis of 8 studies assessing depression outcomes revealed a nonsignificant difference between saffron and SSRIs in reducing depressive symptoms (SMD = 0.10l 95% CI: -0.09 to 0.29). Four studies reporting anxiety outcomes showed a nonsignificant difference between saffron and SSRIs in reducing anxiety symptoms (SMD = 0.04; 95% CI: -0.22 to 0.29). With regard to safety, participants receiving saffron had fewer adverse events than the SSRI group (risk difference: -0.06; 95% CI: -0.09, -0.04; I2: 0%).

Conclusion: Saffron could be a potential SSRI alternative to reduce depressive and anxiety symptoms with fewer adverse events. Further research with larger sample sizes and in diverse populations is warranted to validate these findings and explore potential moderators of treatment response.

Systematic review registration: PROSPERO registration no. CRD42023443236.

The 28th session of the Conference of the Parties (COP 28) to the UN Framework Convention on Climate Change brought together 85 000 climate stakeholders to leverage solutions and accelerate climate actions in 4 key areas: energy transition; issue of funding and financing of climate actions; emphasis on nature, people's lives, and livelihoods; and ensuring inclusivity for all. This commentary highlights insights at the intersection of health, climate, and food gained by the author from participating in COP 28 events. The objective is to inform policymakers, researchers, and practitioners on emerging opportunities to scale specific, measurable, achievable, relevant, and time-based (SMART) climate actions that prioritize health and boost the resilience of food and public health systems.

Functional gastrointestinal disorders (FGIDs) were highly prevalent and involve gastrointestinal discomfort characterized by non-organic abnormalities in the morphology and physiology of the gastrointestinal tract. According to the Rome IV criteria, irritable bowel syndrome and functional dyspepsia are the most common FGIDs. Complementary and alternative medicines are employed by increasing numbers of individuals around the world, and they include herbal and dietary supplements, acupuncture, and hypnosis. Of these, herbal and dietary supplements seem to have the greatest potential for relieving FGIDs, through multiple modes of action. However, despite the extensive application of natural extracts in alternative treatments for FGIDs, the safety and effectiveness of food and orally ingested food-derived extracts remain uncertain. Many randomized controlled trials have provided compelling evidence supporting their potential, as detailed in this review. The consumption of certain foods (eg, kiwifruit, mentha, ginger, etc) and food ingredients may contribute to the alleviation of symptoms associated with FGID,. However, it is crucial to emphasize that the short-term consumption of these components may not yield satisfactory efficacy. Physicians are advised to share both the benefits and potential risks of these alternative therapies with patients. Furthermore, larger randomized clinical trials with appropriate comparators are imperative.

Circadian rhythms in humans are biological rhythms that regulate various physiological processes within a 24-hour time frame. Critical illness can disrupt the circadian rhythm, as can environmental and clinical factors, including altered light exposure, organ replacement therapies, disrupted sleep-wake cycles, noise, continuous enteral feeding, immobility, and therapeutic interventions. Nonpharmacological interventions, controlling the ICU environment, and pharmacological treatments are among the treatment strategies for circadian disruption. Nutrition establishes biological rhythms in metabolically active peripheral tissues and organs through appropriate synchronization with endocrine signals. Therefore, adhering to a feeding schedule based on the biological clock, a concept known as "chrononutrition," appears to be vitally important for regulating peripheral clocks. Chrononutritional approaches, such as intermittent enteral feeding that includes overnight fasting and consideration of macronutrient composition in enteral solutions, could potentially restore circadian health by resetting peripheral clocks. However, due to the lack of evidence, further studies on the effect of chrononutrition on clinical outcomes in critical illness are needed. The purpose of this review was to discuss the role of chrononutrition in regulating biological rhythms in critical illness, and its impact on clinical outcomes.

Context: Current evidence on the effect of a low-fat (LF) diet on depression scores has been inconsistent.

Objective: To explore the effect of an LF diet on depression scores of adults by systematic review and meta-analysis of randomized controlled trials (RCTs).

Data sources: The PubMed, ISI Web of Science, Scopus, and CENTRAL databases were searched from inception to June 7, 2023, to identify trials investigating the effect of an LF diet (fat intake ≤30% of energy intake) on the depression score.

Data extraction: Random-effects meta-analyses were used to estimate pooled summary effects of an LF diet on the depression score (as Hedges g).

Data analysis: Finding from 10 trials with 50 846 participants indicated no significant change in depression score following LF diets in comparison with usual diet (Hedges g = -0.11; 95% CI, -0.25 to 0.03; P = 0.12; I2 = 70.7% [for I2, 95% CI, 44%, 85%]). However, a significant improvement was observed in both usual diet and LF diets when the content of protein was 15-20% of calorie intake (LF, normal protein diet: n = 5, Hedges g = -0.21, 95% CI, -0.24 to -0.01, P = 0.04, I2 = 0%; usual, normal protein diet: n = 3, Hedges g = -0.28, 95% CI, -0.51 to -0.05, P = 0.01, I2 = 0%). Sensitivity analysis also found the depression score improved following LF diet intervention in participants without baseline depression.

Conclusion: This study revealed that LF diet may have small beneficial effect on depression score in the studies enrolled mentally healthy participants. Moreover, achieving to adequate dietary protein is likely to be a better intervention than manipulating dietary fat to improve depression scores. However, it is not clear whether this effect will last in the long term. Conducting more studies may change the results due to the low-certainty of evidence.

Systematic review registration: CRD42023420978 (https://www.crd.york.ac.uk/PROSPERO).