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Molecular Psychiatry Jul 2019With depression being the psychiatric disorder incurring the largest societal costs in developed countries, there is a need to gather evidence on the role of nutrition... (Meta-Analysis)
Meta-Analysis
With depression being the psychiatric disorder incurring the largest societal costs in developed countries, there is a need to gather evidence on the role of nutrition in depression, to help develop recommendations and guide future psychiatric health care. The aim of this systematic review was to synthesize the link between diet quality, measured using a range of predefined indices, and depressive outcomes. Medline, Embase and PsychInfo were searched up to 31 May 2018 for studies that examined adherence to a healthy diet in relation to depressive symptoms or clinical depression. Where possible, estimates were pooled using random effect meta-analysis with stratification by observational study design and dietary score. A total of 20 longitudinal and 21 cross-sectional studies were included. These studies utilized an array of dietary measures, including: different measures of adherence to the Mediterranean diet, the Healthy Eating Index (HEI) and Alternative HEI (AHEI), the Dietary Approaches to Stop Hypertension, and the Dietary Inflammatory Index. The most compelling evidence was found for the Mediterranean diet and incident depression, with a combined relative risk estimate of highest vs. lowest adherence category from four longitudinal studies of 0.67 (95% CI 0.55-0.82). A lower Dietary Inflammatory Index was also associated with lower depression incidence in four longitudinal studies (relative risk 0.76; 95% CI: 0.63-0.92). There were fewer longitudinal studies using other indices, but they and cross-sectional evidence also suggest an inverse association between healthy diet and depression (e.g., relative risk 0.65; 95% CI 0.50-0.84 for HEI/AHEI). To conclude, adhering to a healthy diet, in particular a traditional Mediterranean diet, or avoiding a pro-inflammatory diet appears to confer some protection against depression in observational studies. This provides a reasonable evidence base to assess the role of dietary interventions to prevent depression. This systematic review was registered in the PROSPERO International Prospective Register of Systematic Reviews under the number CRD42017080579.
Topics: Adolescent; Adult; Aged; Cardiovascular Diseases; Cross-Sectional Studies; Depression; Diet; Diet Therapy; Diet, Mediterranean; Female; Health Status; Humans; Hypertension; Male; Middle Aged; Nutrients; Risk Factors
PubMed: 30254236
DOI: 10.1038/s41380-018-0237-8 -
Current Nutrition Reports Dec 2022Although plant-based diets are recommended for cancer prevention, their role in cancer survival is still uncertain. The purpose of this systematic review is to summarize... (Review)
Review
PURPOSE OF REVIEW
Although plant-based diets are recommended for cancer prevention, their role in cancer survival is still uncertain. The purpose of this systematic review is to summarize the association between postdiagnosis plant-based diets and prognosis in cancer survivors.
RECENT FINDINGS
There is indication that higher intake of plant-based foods was associated with improved prognosis in cancer survivors. For colorectal cancer survival, a better prognosis was observed for a high intake of whole grains and fibre. For breast cancer survival, a higher intake of fruit, vegetable and fibre and a moderate intake of soy/isoflavone were associated with beneficial outcomes. A higher vegetable fat intake was related to improved prognosis in prostate cancer survivors. Emerging evidence suggests benefits of postdiagnosis plant-based diets on prognosis in cancer survivors. However, given the high heterogeneity between studies, further research in cancer survivors, considering clinical factors (e.g. treatment, stage) and methodological aspects (e.g. timing of dietary assessment), is needed.
Topics: Male; Humans; Vegetables; Diet; Fruit; Plants; Breast Neoplasms; Diet, Vegetarian
PubMed: 36138327
DOI: 10.1007/s13668-022-00440-1 -
Diabetes Research and Clinical Practice Sep 2021To compare the safety of intermittent fasting (IF) with that of continuous energy-restricted diets (CERD) in patients with T2DM and metabolic syndrome who were... (Meta-Analysis)
Meta-Analysis Review
Intermittent fasting versus continuous energy-restricted diet for patients with type 2 diabetes mellitus and metabolic syndrome for glycemic control: A systematic review and meta-analysis of randomized controlled trials.
AIMS
To compare the safety of intermittent fasting (IF) with that of continuous energy-restricted diets (CERD) in patients with T2DM and metabolic syndrome who were overweight or obese and assess their effects on glycemic control and weight loss.
MATERIALS AND METHODS
We searched MEDLINE (Ovid), Embase, and SINOMED databases up to September 13, 2020. The major outcome was glycemic control and secondary outcomes were change in weight, fasting insulin, and lipid profile.
RESULTS
Of 84 retrieved studies, 5 met our inclusion criteria. Of these, four studies comprising 355 participants were included in the meta-analysis. Based on changes in HbA1c (-0.06, 95% confidence interval [CI] -0.27 to 0.16) and fasting plasma glucose (-0.27, 95% CI -0.76 to 0.22), IF and CERD had similar effects on glycemic control. Moreover, IF had a better effect on weight loss (-1.70, 95% CI -3.28 to -0.11 kg). Patients in both groups experienced similar improvements in fasting insulin and lipid profile as well as similar hypoglycemic events.
CONCLUSIONS
IF is a safe diet pattern and could be implemented for patients with T2DM or metabolic syndrome. Further studies with a larger sample size are needed to verify the effectiveness and safety of IF in patients with T2DM.
Topics: Blood Glucose; Diabetes Mellitus, Type 2; Diet; Fasting; Humans; Metabolic Syndrome; Randomized Controlled Trials as Topic
PubMed: 34391831
DOI: 10.1016/j.diabres.2021.109003 -
Clinical Nutrition (Edinburgh, Scotland) Oct 2019There is a large body of evidence which supports the role of inflammation in the pathophysiology of mental health disorders, including depression. Dietary patterns have... (Meta-Analysis)
Meta-Analysis
BACKGROUND & AIMS
There is a large body of evidence which supports the role of inflammation in the pathophysiology of mental health disorders, including depression. Dietary patterns have been shown to modulate the inflammatory state, thus highlighting their potential as a therapeutic tool in disorders with an inflammatory basis. Here we conduct a systematic review and meta-analysis of current literature addressing whether there is a link between the inflammatory potential of a diet and risk of depression or depressive symptoms.
METHODS
A systematic literature search was performed to identify studies that reported an association between the inflammatory potential of the diet and risk of depressive symptoms or diagnosis of depression. Random effect models were used to meta-analyse effect sizes. Quality assessment, publication bias, sensitivity and subgroup analyses were also performed.
RESULTS
Eleven studies, with a total of 101,950 participants at baseline (age range: 16-72 years old), were eligible for review. A significant association between a pro-inflammatory diet and increased risk of depression diagnosis or symptoms was evident, relative to those on an anti-inflammatory diet (OR: 1.40, 95% confidence intervals: 1.21-1.62, P < 0.001). No publication bias was detected; however, some study heterogeneity was evident (I = 63%, P < 0.001). Subgroup analyses suggested the main source of study heterogeneity was the study design (cross-sectional or longitudinal) and the effect measure used (odds ratio, hazard ratio or relative risk).
CONCLUSION
These results provide an association between pro-inflammatory diet and risk of depression. Thus, adopting an anti-inflammatory diet may be an effective intervention or preventative means of reducing depression risk and symptoms.
Topics: Adolescent; Adult; Aged; Anti-Inflammatory Agents; Depressive Disorder; Diet; Female; Humans; Inflammation; Male; Middle Aged; Young Adult
PubMed: 30502975
DOI: 10.1016/j.clnu.2018.11.007 -
Critical Reviews in Food Science and... 2022Cognitive decline is a rapidly increasing public health concern. A healthy diet has potential in preserving brain and maintaining cognitive health. This systematic...
Cognitive decline is a rapidly increasing public health concern. A healthy diet has potential in preserving brain and maintaining cognitive health. This systematic review was designed to evaluate the relationship between Mediterranean-DASH diet intervention for neurodegenerative delay (MIND) diet and cognitive functioning in older adults. PubMed, SCOPUS, Embase, Cochrane Library, and Google Scholar databases were searched to extract original studies on humans published until July 2020, without date restrictions. Articles that evaluated the association between MIND diet and cognitive performance in older adults were included. Duplicated and irrelevant studies were screened out and data were obtained through critical analysis. Quality of the articles and risk of bias was assessed by Newcastle-Ottawa and Cochrane Collaboration's quality assessment tools. Of the 135 studies retrieved, 13 articles (9 cohort, 3 cross-sectional, and 1 RCT studies) were included in the final review. All of the included studies indicated that adherence to the MIND diet was positively associated with specific domains, but not all, of cognition and global cognitive function (78% of the studies) in older adults. MIND diet was superior to other plant-rich diets including Mediterranean, Dietary Approaches to Stop Hypertension, Pro-Vegetarian and Baltic Sea diets, for improving cognition. Adherence to the MIND diet may possibly be associated with an improved cognitive function in older adults. MIND diet may be superior to other plant-rich diets for improving cognition.
Topics: Aged; Cognition; Cognitive Dysfunction; Cross-Sectional Studies; Diet; Diet, Mediterranean; Dietary Approaches To Stop Hypertension; Humans
PubMed: 33989093
DOI: 10.1080/10408398.2021.1925220 -
Nutrients Mar 2023The purpose of this study was to summarize the evidence from epidemiological studies concerning associations between diet and the effectiveness of treatment for lung... (Review)
Review
The purpose of this study was to summarize the evidence from epidemiological studies concerning associations between diet and the effectiveness of treatment for lung cancer. For this review, a literature search has been conducted in the EMBASE and PubMed databases, including papers published between 1977 and June 2022. The term "lung cancer" was used in conjunction with "diet". Footnotes from the selected papers were also analyzed. The present study is in line with the recommendations included in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The review included studies involving adults, including randomized controlled trials (RCTs) and cohort and observational studies. In total, 863 papers were found, with duplicates excluded. Ultimately, 20 papers were reviewed. The present systematic review indicates that vitamin A, ascorbic acid (vitamin C), vitamin E, selenium, and zinc-as antioxidants-can strengthen the body's antioxidant barrier. Furthermore, preoperative immunonutrition may not only improve perioperative nutritional status following induction chemoradiotherapy in lung cancer surgery patients but also reduce the severity of postoperative complications. Similarly, a protein supply may exert a beneficial effect on human health by increasing average body weight and muscle mass. Omega-3 fatty acid content in the diet and the consumption of their main source, fish, may have some regulatory effect on inflammation in patients with lung cancer treated with chemotherapy and radiotherapy. In addition, -3 fatty acids inhibit tumor cell proliferation and may reduce the toxicity of chemotherapy. Increased energy and protein intake are strongly associated with improved quality of life, functional outcomes, hand grip strength, symptoms, and performance in patients with lung cancer. The use of a supportive diet should be the standard of care, alongside pharmaceutical therapy, in treatment for patients with lung cancer.
Topics: Adult; Animals; Humans; Diet; Antioxidants; Vitamins; Ascorbic Acid; Lung Neoplasms; Fatty Acids, Omega-3; Lung
PubMed: 36986207
DOI: 10.3390/nu15061477 -
Critical Reviews in Food Science and... 2021It is known that nutritional composition of breast milk is, to a certain extent, related to maternal diet. The question of nutritional adequacy of mothers' milk is often...
It is known that nutritional composition of breast milk is, to a certain extent, related to maternal diet. The question of nutritional adequacy of mothers' milk is often raised whenever a vegetarian or vegan diet during the lactation process is concerned. For this reason, in some countries, the recruitment of vegan lactating women as milk donors is excluded by milk banks. The purpose of this systematic review is to summarize existing knowledge on variability of specific nutrients in breastmilk of mothers adhering to a plant-based diet. The databases, including MEDLINE (Pubmed) and Scopus, were used to identify relevant publications. Data extraction and analysis were conducted following a PRISMA protocol. Thirteen publications concerning the impact of dietary pattern and levels of animal-origin food intake on breast milk composition were included. The systematic review has shown that all non-vegetarian, vegetarian and vegan mothers produce breast milk of comparable nutritional value. Several differences are primarily attributed to fatty acids and some micro-components, primarily vitamin B12. Regardless of dietary choices, nourishment and adequate nutrition have a significant impact on human milk composition - on the basis of the current evidence, vegetarian and vegan mothers are capable of producing nutritionally valuable milk for their infants, as far as the appropriate supplementation compensating for breastfeeding mother's nutritional requirements is provided. Dietary choices should not be a permanent exclusion criterion for donor candidates in human milk banks.
Topics: Animals; Breast Feeding; Diet; Diet, Vegan; Diet, Vegetarian; Female; Humans; Infant; Lactation; Milk, Human; Vegans
PubMed: 32319307
DOI: 10.1080/10408398.2020.1753650 -
Nutrition & Dietetics: the Journal of... Feb 2020Negative body image increases the risk of engaging in unhealthy dieting and disordered eating patterns. This review evaluated the impact of habitual social media...
AIM
Negative body image increases the risk of engaging in unhealthy dieting and disordered eating patterns. This review evaluated the impact of habitual social media engagement or exposure to image-related content on body image and food choices in healthy young adults (18-30 years).
METHODS
A systematic search of six databases of observational literature published 2005-2019, was conducted (PROSPERO Registration No. CRD42016036588). Inclusion criteria were: studies reporting social media engagement (posting, liking, commenting) or exposure to image-related content in healthy young adults. Outcomes were: body image (satisfaction or dissatisfaction) and food choices (healthy eating, dieting/restricting, overeating/binging). Two authors independently screened, coded and evaluated studies for methodological quality.
RESULTS
Thirty studies were identified (n = 11 125 participants). Quantitative analysis (n = 26) identified social media engagement or exposure to image-related content was associated with higher body dissatisfaction, dieting/restricting food, overeating, and choosing healthy foods. Qualitative analysis (n = 4) identified five themes: (i) social media encourages comparison between users, (ii) comparisons heighten feelings about the body, (iii) young adults modify their appearance to portray a perceived ideal image, (iv) young adults are aware of social media's impact on body image and food choices, however, (v) external validation via social media is pursued. Most studies (n = 17) controlled for some confounding variables (age, gender, BMI, ethnicity).
CONCLUSIONS
Social media engagement or exposure to image-related content may negatively impact body image and food choice in some healthy young adults. Health professionals designing social media campaigns for young adults should consider image-related content, to not heighten body dissatisfaction.
Topics: Adolescent; Adult; Body Image; Body Mass Index; Choice Behavior; Databases, Factual; Diet; Diet, Healthy; Diet, Reducing; Female; Food Preferences; Humans; Hyperphagia; Male; Observational Studies as Topic; Social Media; Young Adult
PubMed: 31583837
DOI: 10.1111/1747-0080.12581 -
Clinical Nutrition (Edinburgh, Scotland) Sep 2022Lifestyle interventions that focus on reduced energy intake and improved dietary pattern are the mainstay of non-alcoholic fatty liver disease (NAFLD) management.... (Meta-Analysis)
Meta-Analysis
BACKGROUND & AIMS
Lifestyle interventions that focus on reduced energy intake and improved dietary pattern are the mainstay of non-alcoholic fatty liver disease (NAFLD) management. However, it remains unclear which dietary approaches are most beneficial and promote greatest adherence. We aimed to synthesise data from randomised and clinical controlled trials, describing the effects of Mediterranean Diet and Calorie Restriction interventions on NAFLD surrogate markers, in adults.
METHODS
We searched MEDLINE, Embase, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials (October 2021). Study quality was assessed using the Cochrane Collaboration's tools: risk of bias for randomised controlled trials, and risk of bias in non-randomised studies of interventions. Meta-analyses were performed using a random effects model, and the I statistic was used to assess heterogeneity.
RESULTS
Of 4041 records identified, 26 articles with 3037 participants met the inclusion criteria, including studies on calorie-restricted interventions (CRI) (n 9), Mediterranean diet (MD) interventions (n 13) and MD component interventions (n 4). Studies were heterogeneous regarding intervention components, assessment of liver status and diet outcomes. 3 studies reported zero attrition and mean attrition rate for the remaining 23 studies was 14%. Post-intervention meta-analyses revealed that dietary interventions reduced alanine aminotransferase (ALT) (P < 0.001), aspartate aminotransferase (AST) (P = 0.004), Fatty Liver Index (FLI) (P < 0.001), hepatic steatosis (HS) (P = 0.02), and liver stiffness (P = 0.01). CRI had favourable effects on ALT (P < 0.001), HS (P < 0.001) and liver stiffness (P = 0.009). MD reduced ALT (P = 0.02), FLI (P < 0.001) and liver stiffness (P = 0.05). There was a dose-response relationship between degree of calorie restriction and beneficial effects on liver function and weight loss, suggesting that this approach should remain the cornerstone of NAFLD management. In addition, diet composition changes have potential for improving NAFLD and the limited data suggest that MD may be an effective diet therapy.
CONCLUSION
These results support the current guidelines in NAFLD. However, further studies, which robustly evaluate the effects of interventions on dietary intake, acceptability and sustainability of the interventions, and quality of life and other patient-related outcomes are needed to support effective care delivery.
Topics: Adult; Humans; Caloric Restriction; Diet, Mediterranean; Life Style; Non-alcoholic Fatty Liver Disease; Quality of Life; Controlled Clinical Trials as Topic
PubMed: 35947894
DOI: 10.1016/j.clnu.2022.06.037 -
The Cochrane Database of Systematic... Jan 2022Debates on effective and safe diets for managing obesity in adults are ongoing. Low-carbohydrate weight-reducing diets (also known as 'low-carb diets') continue to be... (Review)
Review
BACKGROUND
Debates on effective and safe diets for managing obesity in adults are ongoing. Low-carbohydrate weight-reducing diets (also known as 'low-carb diets') continue to be widely promoted, marketed and commercialised as being more effective for weight loss, and healthier, than 'balanced'-carbohydrate weight-reducing diets.
OBJECTIVES
To compare the effects of low-carbohydrate weight-reducing diets to weight-reducing diets with balanced ranges of carbohydrates, in relation to changes in weight and cardiovascular risk, in overweight and obese adults without and with type 2 diabetes mellitus (T2DM).
SEARCH METHODS
We searched MEDLINE (PubMed), Embase (Ovid), the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science Core Collection (Clarivate Analytics), ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) up to 25 June 2021, and screened reference lists of included trials and relevant systematic reviews. Language or publication restrictions were not applied.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) in adults (18 years+) who were overweight or living with obesity, without or with T2DM, and without or with cardiovascular conditions or risk factors. Trials had to compare low-carbohydrate weight-reducing diets to balanced-carbohydrate (45% to 65% of total energy (TE)) weight-reducing diets, have a weight-reducing phase of 2 weeks or longer and be explicitly implemented for the primary purpose of reducing weight, with or without advice to restrict energy intake. DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts and full-text articles to determine eligibility; and independently extracted data, assessed risk of bias using RoB 2 and assessed the certainty of the evidence using GRADE. We stratified analyses by participants without and with T2DM, and by diets with weight-reducing phases only and those with weight-reducing phases followed by weight-maintenance phases. Primary outcomes were change in body weight (kg) and the number of participants per group with weight loss of at least 5%, assessed at short- (three months to < 12 months) and long-term (≥ 12 months) follow-up.
MAIN RESULTS
We included 61 parallel-arm RCTs that randomised 6925 participants to either low-carbohydrate or balanced-carbohydrate weight-reducing diets. All trials were conducted in high-income countries except for one in China. Most participants (n = 5118 randomised) did not have T2DM. Mean baseline weight across trials was 95 kg (range 66 to 132 kg). Participants with T2DM were older (mean 57 years, range 50 to 65) than those without T2DM (mean 45 years, range 22 to 62). Most trials included men and women (42/61; 3/19 men only; 16/19 women only), and people without baseline cardiovascular conditions, risk factors or events (36/61). Mean baseline diastolic blood pressure (DBP) and low-density lipoprotein (LDL) cholesterol across trials were within normal ranges. The longest weight-reducing phase of diets was two years in participants without and with T2DM. Evidence from studies with weight-reducing phases followed by weight-maintenance phases was limited. Most trials investigated low-carbohydrate diets (> 50 g to 150 g per day or < 45% of TE; n = 42), followed by very low (≤ 50 g per day or < 10% of TE; n = 14), and then incremental increases from very low to low (n = 5). The most common diets compared were low-carbohydrate, balanced-fat (20 to 35% of TE) and high-protein (> 20% of TE) treatment diets versus control diets balanced for the three macronutrients (24/61). In most trials (45/61) the energy prescription or approach used to restrict energy intake was similar in both groups. We assessed the overall risk of bias of outcomes across trials as predominantly high, mostly from bias due to missing outcome data. Using GRADE, we assessed the certainty of evidence as moderate to very low across outcomes. Participants without and with T2DM lost weight when following weight-reducing phases of both diets at the short (range: 12.2 to 0.33 kg) and long term (range: 13.1 to 1.7 kg). In overweight and obese participants without T2DM: low-carbohydrate weight-reducing diets compared to balanced-carbohydrate weight-reducing diets (weight-reducing phases only) probably result in little to no difference in change in body weight over three to 8.5 months (mean difference (MD) -1.07 kg, (95% confidence interval (CI) -1.55 to -0.59, I = 51%, 3286 participants, 37 RCTs, moderate-certainty evidence) and over one to two years (MD -0.93 kg, 95% CI -1.81 to -0.04, I = 40%, 1805 participants, 14 RCTs, moderate-certainty evidence); as well as change in DBP and LDL cholesterol over one to two years. The evidence is very uncertain about whether there is a difference in the number of participants per group with weight loss of at least 5% at one year (risk ratio (RR) 1.11, 95% CI 0.94 to 1.31, I = 17%, 137 participants, 2 RCTs, very low-certainty evidence). In overweight and obese participants with T2DM: low-carbohydrate weight-reducing diets compared to balanced-carbohydrate weight-reducing diets (weight-reducing phases only) probably result in little to no difference in change in body weight over three to six months (MD -1.26 kg, 95% CI -2.44 to -0.09, I= 47%, 1114 participants, 14 RCTs, moderate-certainty evidence) and over one to two years (MD -0.33 kg, 95% CI -2.13 to 1.46, I= 10%, 813 participants, 7 RCTs, moderate-certainty evidence); as well in change in DBP, HbA1c and LDL cholesterol over 1 to 2 years. The evidence is very uncertain about whether there is a difference in the number of participants per group with weight loss of at least 5% at one to two years (RR 0.90, 95% CI 0.68 to 1.20, I = 0%, 106 participants, 2 RCTs, very low-certainty evidence). Evidence on participant-reported adverse effects was limited, and we could not draw any conclusions about these. AUTHORS' CONCLUSIONS: There is probably little to no difference in weight reduction and changes in cardiovascular risk factors up to two years' follow-up, when overweight and obese participants without and with T2DM are randomised to either low-carbohydrate or balanced-carbohydrate weight-reducing diets.
Topics: Adult; Body Weight; Carbohydrates; Diet, Carbohydrate-Restricted; Energy Intake; Female; Heart Disease Risk Factors; Humans; Male
PubMed: 35088407
DOI: 10.1002/14651858.CD013334.pub2