A systematic review and dose-response meta-analysis of prospective cohort studies on coffee consumption and risk of lung cancer.

Studies on the association between coffee consumption and risk of lung cancer have been conflicting. The aim of this study was to systematically review the current evidence on the association between coffee consumption and risk of lung cancer and to quantify this association by performing a meta-analysis. A comprehensive systematic search was performed on online databases up to July 2023 investigating the association between coffee consumption and risk of lung cancer. All prospective cohort studies reporting odds ratios (ORs), rate or risk ratios (RRs), or hazard ratios (HRs) and 95% confidence intervals (CIs) in this context were included. The overall effect size was calculated using the random-effects model and statistical between-studies heterogeneity was examined using Cochrane's Q test and I2. A total of 14 prospective cohort studies were included in this systematic review and meta-analysis. We found a significant positive association between coffee consumption and risk of lung cancer (RR: 1.28; 95% CI: 1.12, 1.47). This association remained significant when we included a pooled analysis paper and excluded 5 cohort studies (RR: 1.37; 95% CI: 1.12, 1.66). We observed no proof of significant publication bias using Egger's test (P = 0.58). Moreover, dose-response analysis showed that each one cup/day increase in coffee consumption was related with a 6% higher lung cancer risk (RR: 1.06; 95% CI: 1.03, 1.09). In conclusion, we found a significant positive association between coffee consumption and risk of lung cancer.

The effect of dietary interventions on inflammatory biomarkers among people with multiple sclerosis: A protocol for systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Multiple sclerosis (MS) is a chronic neuroinflammatory disease of the central nervous system, characterized by demyelination and neurodegeneration, which has a profound impact on the quality of life. Dysregulated inflammatory processes are a major driver of MS progression, with many areas of research being dedicated to modulating inflammation in people with MS. Several dietary patterns have been associated with improvements in inflammatory biomarkers; although, the findings have been inconsistent. Thus, this study aims to evaluate the effects of dietary interventions on inflammatory markers in adults with MS. METHODS: Electronic databases, including PubMed/MEDLINE, Web of Science, Scopus, and Cochrane/Central, will be searched. Screening, selection, and extraction of data, along with quality assessment of included studies, will be done by two separate reviewers, and any potential conflicts will be settled through discussion. Two reviewers will independently assess the risk of bias in included studies using the Cochrane Risk of Bias Tool. If plausible, the results will be synthesized and pooled for meta-analysis. The overall quality of evidence of each study will be evaluated using the NutriGRADE tool, which is a modification to the Grading Recommendations Assessment, Development, and Evaluation (GRADE) developed specifically for nutrition research. DISCUSSION: Studies have demonstrated conflicting results regarding the effects of dietary interventions on serum levels of inflammatory biomarkers among people with MS. Thus, it is expected that the planned systematic review and meta-analysis will yield robust evidence on the effects of diet on inflammatory profile in the setting of MS.

Mediterranean diet and depression: reanalysis of a meta-analysis.

On the basis of comments we received from readers, we made some changes in the original version of our article about our study and re-analyzed the data. In this corrected version, we found an inverse significant association between adherence to the Mediterranean diet and risk of depression in cohort studies (overall hazard ratio, 0.81; 95% confidence interval, 0.70-0.94). In addition, combining 8 cross-sectional studies that examined the association between adherence to the Mediterranean diet and depression, we found a significant inverse association (overall odds ratio, 0.81; 95% confidence interval, 0.71-0.92).

Maternal caffeine consumption during pregnancy and risk of low birth weight: a dose-response meta-analysis of cohort studies.

BACKGROUND & OBJECTIVES: Earlier published studies on maternal caffeine intake during pregnancy in relation to the risk of low birth weight (LBW) (birth weight <2500 g) have indicated conflicting findings. Therefore, the present systematic review and meta-analysis was conducted to examine the association between maternal caffeine intake and risk of LBW. METHODS: We searched for relevant articles published up to Jan 2021 through PubMed and Scopus. For this purpose, we used MESH (Medical Subject Heading) and non-MESH keywords. Cohort studies that considered maternal caffeine intake as the exposure variable and LBW as the main outcome variable were included in the systematic review. Finally, seven cohort studies were considered in this systematic review and meta-analysis. RESULTS: Combining seven effect sizes, we found a significant positive association between maternal caffeine intake and risk of LBW (RR: 1.70; 95% CI: 1.19-2.43). We also found that each additional 100-mg per day of maternal caffeine intake was significantly associated with an increased risk of LBW (RR: 1.12; 95% CI: 1.03-1.22; Pheterogeneity = 0.020). In addition, nonlinear dose-response analysis showed a significant relationship (Pnonlinearity < 0.001) between maternal caffeine intake and risk of LBW. CONCLUSIONS: In this systematic review and meta-analysis, we found a significant positive association between maternal caffeine intake and risk of LBW.

Dietary intake of branched-chain amino acids in relation to the risk of breast cancer.

BACKGROUND: Given that, studies on the association of dietary intake of branched-chain amino acids (BCAAs) with risk of cancers, especially breast cancer, are limited, we aimed to examine the association between dietary intake of BCAAs and risk of breast cancer. METHODS: This case-control study was performed on Iranian women aged ≥ 30 years from July 2013 to July 2015. Overall 1050 women including 350 patients and 700 controls were included. Breast cancer was diagnosed by physical examination, mammography and pathological confirmation. We assessed dietary intakes using the validated 106-item Willett-format semi-quantitative dish-based food frequency questionnaire. The total intake of valine, leucine, and isoleucine from all food items in the questionnaire was used to calculate BCAAs intake. To estimate odds ratios (ORs) and 95% confidence intervals (95% CI), we used logistic regression analysis. RESULTS: After controlling for potential confounders, we found that women in the highest quartile of BCAAs had lower odds of breast cancer compared with the first quartile (OR: 0.50; 95% CI 0.34-0.72). When we stratified the analysis based on menopausal status, a significant inverse association between BCAAs intake and odds of postmenopausal breast cancer was observed (OR: 0.22; 95% CI 0.13-0.39), although this significant relationship was not found in premenopausal breast cancer (OR: 2.57; 95% CI 0.51-12.73). Also, this significant association was also observed for valine, leucine, and isoleucine separately. CONCLUSION: We found that higher dietary intake of BCAAs was significantly associated with a reduced risk of postmenopausal breast cancer.

Dietary Inflammatory Potential in relation to General and Abdominal Obesity.

Background/Aims: Limited data are available on the association of Dietary Inflammatory Potential (DIP) with general and abdominal obesity in developing countries. The aim of this study was to examine the association between DIP score with general and abdominal obesity among Iranian adults. Methods. This cross-sectional study was conducted among adults in Isfahan, Iran. Dietary intakes were assessed by using a validated, self-administrated, dish-based, semiquantitative food frequency questionnaire. DIP was calculated based on standard method. Data regarding height, weight, and waist circumference (WC) were collected using a self-reported questionnaire. Overweight or obesity was defined as body mass index (BMI) ≥25 kg/m2, and abdominal obesity was defined as WC ≥ 80 cm for women and ≥94 cm for men. Results. Mean age of study participants was 36.8 ± 8.08 years. The prevalence of general and abdominal obesity was 46.5% and 52.9%, respectively. We observed that higher DIP scores were significantly associated with a lower odds of general obesity (OR: 0.66; 95% CI: 0.58-0.74). Stratified by sex, this significant association was seen only for women (OR: 0.58; 95% CI: 0.46-0.72). In addition, no significant association was found between DIP scores and abdominal obesity. Conclusions. We found a significant inverse association between consumption of a proinflammatory diet and general obesity. In the gender-stratified analysis, this was seen in women, but not in men. There was no significant association between the DIP scores and abdominal obesity.

Association Between Dietary Total Antioxidant Capacity and Diet Quality in Adults.

Background: Diet quality is a major contributor to human health. In addition, antioxidants have a great contribution to several chronic conditions. The purpose of this study was to evaluate if dietary total antioxidant capacity (TAC) can be considered as a measure of diet quality in a Middle Eastern country. Methods: In this cross-sectional study on 6,724 Iranian adults, we used a validated food frequency questionnaire (FFQ) to assess dietary intakes. Data derived from the FFQ was used to calculate dietary TAC and well-known diet quality scores including alternate healthy eating index (AHEI) and dietary diversity score (DDS). Dietary TAC was calculated based on the ferric reducing-antioxidant power (FRAP) values reported in earlier publications. AHEI and DDS have also been constructed based on previous publications. Cross-classification was used to examine the agreement between these measures. Results: Mean age and BMI of study participants were 36.89 ± 8.08 y and 24.97 ± 3.87 kg/m2, respectively. We found that individuals in the highest tertile of dietary TAC had higher scores of AHEI (57.53 ± 0.20 vs. 52.03 ± 0.20, P < 0.001) and DDS (5.56 ± 0.03 vs. 4.15 ± 0.03, P < 0.001) compared with those in the lowest tertile. Participants' distribution on the basis of the cross-classification analysis indicated that the classifications were in exact agreement for 42.6%, within an adjacent tertile for 33.05%, and in gross misclassification for 20% of individuals. When this was examined between dietary TAC and DDS, we found that exact agreement in the classifications was for 59.2% of participants. Notably, a very low proportion of gross misclassification was seen in this regard such that only 6% of participants were classified in the opposing tertiles, indicating additional support for a good agreement. Conclusion: We found that dietary TAC might be considered as a proper measure for the assessment of diet quality because it was well correlated with well-known measures of diet quality including DDS and AHEI scores.

Association Between Red and Processed Meat Consumption and Risk of Prostate Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Debate on the potential carcinogenic effects of meat intake is open and the relationship between meat consumption and risk of prostate cancer remains uncertain. This meta-analysis was conducted to summarize earlier prospective studies on the association of meat consumption with risk of prostate cancer. METHODS: Relevant studies were identified by exploring PubMed/Medline, Scopus, Web of Science, EMBASE, and Google Scholar databases up to December 2020. Fixed-effects and random-effects meta-analyses were used for pooling the relative risks (RRs). Heterogeneity across studies was evaluated using the Q-statistic and I-square (I 2). A funnel plot and Egger's test was used to detect publication bias. Linear and non-linear dose-response analyses were performed to estimate the dose-response relations between meat intake and risk of prostate cancer. RESULTS: Twenty-five prospective studies were included in this meta-analysis. Totally, 1,900,910 participants with 35,326 incident cases of prostate cancer were investigated. Pooling the eligible effect sizes, we observed that high consumption of processed meat might be associated with an increased risk of "total prostate cancer" (RR: 1.06; 95% CI: 1.01, 1.10; I 2 = 1.5%, P = 0.43) and "advanced prostate cancer" (1.17; 1.09, 1.26; I 2 = 58.8%, P = 0.01). However, the association between processed meat and "advanced prostate cancer" was not significant in the random-effects model: 1.12 (95% CI: 0.98, 1.29). A linear dose-response analysis indicated that an increment of 50 grams per day of processed meat intake might be related to a 4% greater risk of "total prostate cancer" (1.04; 1.00, 1.08; I 2 = 0.0%, P = 0.51). "Total meat intake" was marginally associated with all outcomes of prostate cancer risk (1.04; 1.01, 1.07; I 2 = 58.4%, P < 0.001). CONCLUSIONS: This systematic review and meta-analysis of prospective studies indicated that increased consumption of "total meat" and "processed meat" might be associated with a higher risk of prostate cancer. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=230824, identifier: CRD42021230824.

Coffee and caffeine intake in relation to symptoms of psychological disorders among adults.

OBJECTIVE: Given that there is an inconsistency in the findings related to the relationship between coffee and caffeine consumption and symptoms of psychological disorders, we performed a cross-sectional analysis to examine the association between coffee and caffeine intake and symptoms of psychological disorders among adults. DESIGN: In this cross-sectional study, 3362 participants were included. We assessed the coffee and caffeine intakes using a self-completed food frequency questionnaire (FFQ). Symptoms of depression, anxiety, and psychological distress were assessed using HADS and GHQ screening tools. RESULTS: The mean age of participants in this study was 36.2±7.8 years. After controlling for potential confounders, individuals who consumed coffee weekly or more had a significantly lower odds of symptoms of depression (OR: 0.67; 95% CI: 0.46-0.96) and symptoms of anxiety (OR: 0.57; 95% CI: 0.34-0.95) compared with those who did not consume coffee. However, no significant association was found between coffee intake and symptoms of psychological distress (OR: 0.98; 95%CI: 0.68-1.42). No significant relationship was found between caffeine intake and odds of symptoms of depression (OR: 0.94; 95% CI: 0.75-1.16), symptoms of anxiety (OR: 0.90; 95% CI: 0.67-1.20), and symptoms of psychological distress (OR: 1.13; 95% CI: 0.89-1.42). CONCLUSION: Compared with lack of coffee intake, weekly or more coffee consumption might be correlated with symptoms of depression and anxiety.

A systematic review and meta-analysis of prospective cohort studies on the association between alcohol intake and risk of fracture.

Previous studies on the association between alcohol intake and risk of fracture have reached conflicting findings. The aim of this systematic review and meta-analysis of prospective cohort studies was to summarize earlier studies on the association of alcohol intake with risk of fracture. A systematic search of PubMed, Scopus, and ISI Web of Science was conducted up to November 2020. Prospective cohort studies that had considered alcohol consumption as the exposure variable and fracture as the main outcome or as one of the outcome variables were included in this systematic review. Publications in which odds ratios (ORs), rate or risk ratios (RRs), or hazard ratios (HRs) and 95% confidence intervals (CIs) were reported, were included in the meta-analysis. In total, 40 prospective cohort studies including 5,084,303 participants and 170,916 subjects with fracture were included in this systematic review; of them 38 studies with a total sample size of 5,053,117 participants and 169,560 cases of fracture were included in the meta-analysis. Using a random-effects meta-analysis, we found a significant positive association between alcohol consumption and risk of total fractures (RR: 1.35; 95% CI: 1.01, 1.81) and any fractures (RR: 1.24; 95% CI: 1.11, 1.38). However, no significant association was observed between alcohol intake and risk of hip fractures (RR: 1.19; 95% CI: 0.96, 1.48), osteoporotic fractures (RR: 2.01; 95% CI: 0.76, 5.34), vertebral fractures (RR: 0.98; 95% CI: 0.68, 1.40), and wrist fractures (RR: 0.99; 95% CI: 0.85, 1.16). In conclusion, we found that alcohol consumption was positively associated with risk of total fractures and any fractures. However, we did not observe any significant association between alcohol consumption and risk of hip, osteoporotic, vertebral, and wrist fractures.

Effect of low-carbohydrate diet on adiponectin level in adults: a systematic review and dose-response meta-analysis of randomized controlled trials.

BACKGROUND: To the best of our knowledge, no previous study has reported findings on the effects of low-carbohydrate diet (LCD) on adiponectin concentration. OBJECTIVE: The current systematic review and dose-response meta-analysis was carried out to systematically review the available controlled clinical trials about the effect of LCD on adiponectin level in adults. METHODS: Literature searches of PubMed/Medline, Scopus and Web of Sciences were conducted up to August 2019. Randomized controlled trials (RCTs) which assessed the effect of LCD on the adiponectin level were selected. RESULTS: Eleven studies, including 1047 participants (LCD = 534 and control = 513), were included in the meta-analysis. Proportion of carbohydrate from calorie was from 4 to 34%. Time of the follow-up varied between studies and ranged from 6 to 152 weeks. LCD intake mildly but significantly increased adiponectin (0.02 µg/ml, 95% CI: 0.01 to 0.03, P < 0.001). Dose-response analysis indicated a nonlinear association between the percentage of carbohydrate and change in adiponectin level from baseline (P = 0.04). After subgroup analysis based on the proportion of carbohydrate from calorie, there was a significant increase in adiponectin concentration in studies that prescribed <30% of calorie from carbohydrates (0.12 µg/ml, 95% CI: 0.07-0.18). In contrast, diets which consisted ≥30% of carbohydrates had no significant effect on adiponectin (0.50 µg/ml, 95% CI: -0.46 to 1.48). Also, meta-regression analysis revealed that age (ß = 0.04, P = 0.15), baseline BMI (ß= -0.15, P = 0.15), time of follow-up (ß = 0.01, P = 0.17), percentage of carbohydrates (ß = 0.004, P = 0.90), percentage of protein (ß= -0.12, P = 0.08), percentage of fat (ß = 0.20, P = 0.61) and baseline adiponectin (ß = 0.001, P = 0.97) are not sources of heterogeneity. CONCLUSION: This systematic review and meta-analysis demonstrated a mild but significant effect of LCD on adiponectin concentration compared to control groups.

Association between alcohol intake and overweight and obesity: a systematic review and dose-response meta-analysis of 127 observational studies.

Several studies have assessed the relationship between alcohol intake and overweight/obesity; however, the reported results are inconsistent. Therefore, the present systematic review and dose-response meta-analysis of observational studies was designed to investigate the association between alcohol intake and general and abdominal obesity among the adults. Literature search was conducted in the PubMed/Medline and Web of Science databases up to August 2020. Odds ratio (OR), risk ratio (RR), or hazard ratio (HR) with 95% confidence interval (95% CI) were used to pool effect size. To conduct dose-response meta-analysis, amount of alcohol intake was classified into three categories including light (<14 g/d), moderate (14-28 g/d), and heavy (>28 g/d). In the present study, 127 eligible studies were included. In cohort studies, there was no significant association between alcohol drinking and risk of overweight (OR: 0.93, 95% CI: 0.46 to 1.89), obesity (OR: 0.84, 95% CI: 0.52 to 1.37), overweight/obesity (OR: 1.15, 95% CI: 0.84 to 1.58), and abdominal obesity (OR: 1.13, 95% CI: 0.90 to 1.41). In cross-sectional studies, alcohol intake was associated with the increased odds of overweight (OR: 1.11, 95% CI: 1.05 to 1.18), overweight/obesity (OR: 1.23, 95% CI: 1.11 to 1.37), and abdominal obesity (OR: 1.19, 95% CI: 1.09 to 1.29); but not obesity (OR: 1.03, 95% CI: 0.95 to 1.12). Results of dose-response analysis indicated that heavy alcohol drinking was positively associated with odds of overweight (OR: 1.12, 95% CI: 1.01 to 1.24), overweight/obesity (OR: 1.32, 95% CI: 1.16 to 1.51), and abdominal obesity (OR: 1.25, 95% CI: 1.12 to 1.38) compared to non- or light alcohol drinking. There was no publication bias among studied on outcomes of interest. In conclusion, our results revealed alcohol drinkers, especially heavy alcohol drinkers, had increased odds of overweight, overweight/obesity, and abdominal obesity than non-alcohol drinker or light alcohol drinkers among cross-sectional studies but not cohort studies.

The Association between Adherence to the MIND Diet and Irritable Bowel Syndrome.

BACKGROUND AND AIMS: No earlier study examined the association between adherence to the MIND (Mediterranean-DASH Diet Intervention for Neurodegenerative Delay) diet and odds of irritable bowel syndrome (IBS). This study was conducted to examine the relationship between adherence to the MIND diet and odds of IBS among Iranian adults. METHODS: In this cross-sectional study, dietary intakes of 3,362 adults were examined using a validated Dish-Based 106-item Semi-Quantitative Food Frequency Questionnaire (DS-FFQ). The MIND diet score was constructed based on participants' dietary intakes obtained from DS-FFQ. IBS was evaluated using a modified Persian version of the Rome III questionnaire. RESULTS: Overall, 22.2% of the study population were affected by IBS (n = 748). We observed no significant relationship between adherence to the MIND diet and odds of IBS in the whole population (OR: 0.97; 95% CI: 0.71-1.31). By gender and BMI status, no significant association between adherence to the MIND diet and odds of IBS was seen. Also, no significant association was found between adherence to the MIND diet and IBS subtypes. CONCLUSION: No significant association was found between adherence to the MIND diet and odds of IBS. Further studies are needed to examine the association between dietary patterns and IBS.

The association between adherence to the MIND diet and stroke: a case-control study.

OBJECTIVES: Although some components of MIND diet were associated with stroke, no information is available on the association between adherence to the MIND diet and odds of stroke. This study was conducted to investigate the association between adherence to the MIND diet and odds of stroke among Iranian adults. METHODS: This case-control study was done on 193 hospitalized stroke cases and 195 hospital-based controls in Al-Zahra hospital, Isfahan, Iran. Dietary intakes of study participants were assessed using a validated 168-item food frequency questionnaire (FFQ). The MIND diet score was computed based on participants' dietary intakes obtained from FFQ. Stroke was confirmed by a trained neurologist using standard imaging methods. RESULTS: After controlling for age, sex, energy intake, physical activity, smoking, hypertension, diabetes, dyslipidemia, and heart disease, there was no significant association between adherence to the MIND diet and stroke (OR: 0.54; 95% CI: 0.26, 1.12). However, after further adjustment for BMI, we found that those with the greatest adherence to the MIND diet were less likely to have stroke compared with those with the lowest adherence; such that greater adherence to the MIND diet was associated with a 59% reduced odds of stroke (OR: 0.41; 95% CI: 0.18-0.94). CONCLUSION: In conclusion, we found that adherence to the MIND diet was inversely associated with odds of stroke in a case-control study. Further studies are required to confirm these findings.

Dietary glycaemic index and glycaemic load in relation to risk of breast cancer.

OBJECTIVE: Previous studies on the association between glycaemic index (GI) and glycaemic load (GL) in relation to breast cancer risk are contradictory. The aim of this study was to examine the association between dietary GI and GL and risk of breast cancer in Iranian women. DESIGN: Population-based case-control study. Dietary GI and GL were assessed using a validated Willett-format 106-item semi-quantitative FFQ. SETTING: Isfahan, Iran. PARTICIPANTS: Cases were 350 patients with newly diagnosed stage I-IV breast cancer, for whom the status of breast cancer was confirmed by physical examination and mammography. Controls were 700 age-matched apparently healthy individuals who were randomly selected from general population. RESULTS: After controlling for potential confounders, individuals in the highest tertile of dietary GI had 47 % higher odds of breast cancer than women in the lowest tertile (OR: 1·47; (95 % CI 1·02, 2·12)). Stratified analysis by menopausal status showed such association among postmenopausal women (OR: 1·51; (95 % CI 1·02, 2·23)). We found no significant association between dietary GL and odds of breast cancer either before (OR: 1·35; (95 % CI 0·99, 1·84)) or after adjustment for potential confounders (OR: 1·24; (95 % CI 0·86, 1·79)). In addition, stratified analysis by menopausal status revealed no significant association between dietary GL and odds of breast cancer. CONCLUSIONS: Our findings showed a significant positive association between dietary GI and odds of breast cancer. However, we observed no significant association between dietary GL and odds of breast cancer.

Dietary intake of branched-chain amino acids in relation to general and abdominal obesity.

PURPOSE: Despite the huge evidence on the link between dietary protein intake and obesity, limited studies have examined the role of individual amino acids in this regard. This study aimed to investigate the association between dietary total and individual BCAAs intake and odds of general and abdominal obesity in a large group of adults. METHODS: This cross-sectional study was conducted among 8691 adults aged 18-55 years in Isfahan, Iran. Dietary BCAAs were assessed using a validated dish-based 106-item semi-quantitative food frequency questionnaire (DS-FFQ). Information about weight and waist circumference was collected through a self-reported validated questionnaire. General obesity was defined as body mass index (BMI) ≥ 30 kg/m2, and abdominal obesity was defined as waist circumference (WC) ≥ 88 cm for women and ≥ 102 cm for men. RESULTS: Mean age of study participants was 36.8 ± 8.1 years. Prevalence of general obesity was 9.2% in men and 9.7% in women and that of abdominal obesity was 13.3% and 36.2% in men and women, respectively. We found that participants in the top tertile of total BCAAs intake had higher odds of general obesity compared with those in the bottom tertile (OR: 1.42; 95% CI: 1.09-1.84). Such significant association was seen in men (OR: 1.57; 95% CI: 1.05-2.34), but not in women (OR: 1.33; 95% CI: 0.94-1.89) in our stratified analysis. We found no significant association between total BCAAs intake and odds of abdominal obesity. Stratified by sex, no significant association was observed between total BCAAs intake and odds of abdominal obesity [for men: (OR: 1.10; 95% CI: 0.74-1.65) and for women: (OR: 1.08; 95% CI: 0.84-1.38)]. Assessing the association with individual BCAAs, a significant positive association was observed between dietary intake of valine (OR: 1.42; 95% CI: 1.10-1.84), leucine (OR: 1.43; 95% CI: 1.10-1.86), and isoleucine (OR: 1.42; 95% CI: 1.09-1.84) with general obesity. We observed no significant association between dietary intake of individual BCAAs intake and odds of abdominal obesity. CONCLUSION: Dietary BCAAs intake was associated with an increased odds of general obesity, in particular among men. No significant association was observed between dietary BCAAs and abdominal obesity. LEVEL OF EVIDENCE: Level V, descriptive cross-sectional study.

Dietary intakes of monounsaturated fatty acids and risk of mortality from all causes, cardiovascular disease and cancer: A systematic review and dose-response meta-analysis of prospective cohort studies.

BACKGROUND: Findings on the link between dietary intakes of monounsaturated fatty acids (MUFA) and risk of mortality are conflicting. This study aimed to summarize existing literature regarding the association between MUFA intake and risk of mortality from all causes, cardiovascular diseases (CVDs), and cancer. METHODS: PubMed, Scopus, and ISI Web of Science was systematically searched up to December 2020. Prospective cohort studies which investigated MUFA intake in relation to mortality from all causes, CVD, or cancer were eligible for this systematic review. Publications that had reported risk ratios (RRs) or hazard ratios (HRs) and 95% confidence intervals (CIs) as effect size, were considered. RESULTS: A total of 17 prospective cohort studies were included. These studies included 1022,321 participants aged ≥ 20 years in total, and 191,283 all-cause deaths, 55,437 CVD deaths, and 64,448 cancer deaths were totally reported. Combining 15 effect sizes from 11 studies, MUFA intake was inversely associated with risk of all-cause mortality (RR: 0.94; 95% CI: 0.90, 0.98; I2 =55.5; P = 0.005). Based on 17 effect sizes from 11 studies, we found no significant association between MUFA intake and risk of CVD mortality (RR: 0.95; 95% CI: 0.89, 1.01; I2 =37.0; P = 0.06). Combining 10 effect sizes from 6 studies, MUFA intake was not significantly associated with cancer mortality (RR: 0.99; 95% CI: 0.96, 1.03, I2 =13.3%, P = 0.32). Also, an additional 5% of energy from MUFA was associated with a 3% reduced risk of all-cause mortality (RR: 0.97; 95%CI: 0.96, 0.98), but not with CVD (RR: 0.98; 95%CI: 0.95, 1.01) and cancer mortality (RR: 0.99; 95%CI: 0.97, 1.01). CONCLUSIONS: MUFA intake was found to be inversely associated with risk of all-cause mortality. However, no link was found between MUFA consumption and mortality from CVD or cancer.

Association of Coffee and Caffeine Intake With Irritable Bowel Syndrome in Adults.

The aim of this study was to investigate the association between coffee and caffeine intake and odds of IBS and its severity in adult population. In this cross-sectional study, dietary intakes of 3,362 Iranian adults were examined using a validated dish-based 106-item Semi-quantitative Food Frequency Questionnaire (DS-FFQ). Coffee and caffeine intake was assessed using the DS-FFQ. IBS was assessed using a modified Persian version of Rome III questionnaire. After adjustment for potential confounders, we found that individuals who were taking coffee weekly or more had greater odds of IBS (OR:1.44; 95% CI: 1.02-2.04) than those who never drinking coffee. In addition, participants in the top tertile of caffeine intake (≥106.5 mg/d) had 47% greater odds of IBS compared to those in the bottom tertile (<69.4 mg/d) (OR: 1.47; 95% CI: 1.14-1.87). By gender, a significant association was observed between caffeine intake and odds of IBS among women (OR for those in the highest tertile vs. lowest tertile: 1.48; 95% CI: 1.10-2.00), but not in men (OR: 1.47; 95% CI: 0.94-2.30). In addition, a significant positive association was seen between caffeine intake and odds of IBS among subjects with BMI ≥ 25 kg/m2 (OR for those in the highest tertile vs. lowest tertile: 1.72; 95% CI: 1.20-2.48). There was a significant association between caffeine intake and IBS severity among subjects with BMI ≥ 25 kg/m2 (OR: 1.04; 95% CI: 1.01-2.62). In conclusion, coffee and caffeine consumption was associated with increased odds of IBS in the whole study population. The association between caffeine and odds of IBS was also significantly positive among women and overweight or obese subjects (BMI ≥ 25 kg/m2). In addition, we found a significant relationship between caffeine intake and severity of IBS symptoms among overweight or obese subjects (BMI ≥ 25 kg/m2).

Dietary acrylamide intake and risk of women's cancers: a systematic review and meta-analysis of prospective cohort studies.

This systematic review and meta-analysis was done to review earlier publications on the association between dietary acrylamide intake and risk of breast, endometrial and ovarian cancers. We performed a systematic search in the online databases of PubMed, ISI Web of Science and Scopus for relevant publications up to August 2020. Prospective cohort studies that considered dietary acrylamide as the exposure variable and breast, endometrial or ovarian cancer as the main outcome variable or as one of the outcome variables were included in this systematic review and meta-analysis. A total of fourteen cohort studies were included in the meta-analysis. We found no significant association between dietary acrylamide intake and the risk of breast (relative risk (RR) 0·95; 95 % CI 0·90, 1·01), endometrial (RR 1·03; 95 % CI 0·89, 1·19) and ovarian cancers (RR 1·02; 95 % CI 0·84, 1·24). In addition, we observed no significant association between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers in different subgroup analyses by smoking status, menopausal status, BMI status and different types of breast cancer. In conclusion, no significant association was found between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers.

Dietary intake of branched-chain amino acids in relation to depression, anxiety and psychological distress.

BACKGROUND: There is no previous study that examined the association between branched-chain amino acids (BCAAs) intake and odds of psychological disorders. The aim of this study was to investigate the association between dietary BCAAs and odds of psychological disorders including depression, anxiety, and psychological distress in a large sample of Iranian adults. METHODS: In this cross-sectional study on 3175 Iranian adults aged 18-55 years, a validated food frequency questionnaire was used to assess dietary intakes. BCAAs intake was computed by summing up the amount of valine, leucine, and isoleucine intake from all food items in the questionnaire. Psychological health was examined through the use of Iranian validated version of the Hospital Anxiety and Depression Scale (HADS). Psychological distress was assessed using General Health Questionnaire (GHQ). For depression and anxiety, scores of 8 or more on either subscale were considered as psychological disorders and scores of 0-7 were defined as "normal". In terms of psychological distress, the score of 4 or more was defined as psychological distress. RESULTS: Mean age of study participants was 36.2 ± 7.8 years. Overall, 26.4% (n = 837) of study subjects had depression, 11.9% (n = 378) had anxiety and 20.9% (n = 665) were affected by psychological distress. After controlling for potential confounders, participants in the highest tertile of total BCAAs intake had lower odds of depression (OR: 0.76; 95% CI: 0.60-0.96) and anxiety (OR: 0.66; 95% CI: 0.47-0.91) compared with those in the lowest tertile. Participants in the top tertile of valine intake had a lower odds of depression (OR: 0.76; 95% CI: 0.60-0.96) and anxiety (OR: 0.65; 95% CI: 0.47-0.90) compared with those in the bottom tertile. A significant inverse association was also seen between leucine intake and depression (OR: 0.77; 95% CI: 0.61-0.98) and anxiety (OR: 0.66; 95% CI: 0.47-0.91). In addition, a significant inverse association was observed between isoleucine intake and odds of depression (OR: 0.75; 95% CI: 0.59-0.95) and anxiety (OR: 0.62; 95% CI: 0.45-0.86). There was no significant association between isoleucine intake and odds of psychological distress. CONCLUSION: Evidence indicating an inverse association between dietary intake of BCAAs and odds of depression and anxiety was found. Prospective studies are required to confirm these findings.