Meta-analysis Of Prospective Cohort Studies Research Articles

Cigarette smoking and prostate cancer: A systematic review and meta-analysis of prospective cohort studies.

Cigarette smoking is a well-known cancer-causing behavior and a leading cause of death from cancer. However, according to previously published research and meta-analyses, cigarette smoking has a significant inverse association with prostate cancer incidence. Therefore, this study aims to investigate this association based on updated evidence by conducting a systematic review and meta-analysis. A search for relevant articles was performed in PubMed and Scopus databases to obtain the pooled relative risk (RR) and the corresponding 95% confidence intervals (CIs) for the risk of prostate cancer incidence among smokers compared to non-smokers. Our search was limited to prospective cohort studies. A total of 17 cohort studies were included in the systematic review. Fifteen studies were included in the meta-analysis and showed that cigarette smoking has an inverse association with prostate cancer incidence with a relative risk of 0.84 (95% CI: 0.78-0.91). From all cohorts included in this systematic review, five studies examined the association between current smokers and the risk of death from prostate cancer. Therefore, a meta-analysis of these cohort studies was performed and showed that current smokers had a 42% higher risk of death from prostate cancer when compared to non-smokers with a relative risk of 1.42 (95% CI: 1.20-1.68). Data from observational studies suggest that cigarette smoking has an inverse association with prostate cancer incidence. However, smokers have an increased risk of death from prostate cancer. Important to realize that this lower risk for smokers might be attributed to low prostate cancer screening uptake among smokers, misclassification bias, or selection bias from the included original studies. In summary, our results indicate that the incidence of prostate cancer is lower among smokers. Nevertheless, smokers who develop the disease have a significantly worse prognosis.

Economic burden of excessive sedentary behaviour in Canada.

To estimate health care and health-related productivity costs associated with excessive sedentary behaviour (> 8 h/day and > 9 h/day) in Canadian adults. Three pieces of information were used to estimate costs: (1) the pooled relative risk estimates of adverse health outcomes consistently shown to be associated with excessive sedentary behaviour, gathered from meta-analyses of prospective cohort studies; (2) the prevalence of excessive sedentary behaviour in Canadian men and women, obtained using waist-worn accelerometry in a nationally representative sample of adults (Canadian Health Measures Survey 2018-2019); and (3) the direct (health care) and indirect (lost productivity due to premature mortality) costs of the adverse health outcomes, selected using the Economic Burden of Illness in Canada 2010 data. The 2010 costs were then adjusted to 2021 costs to account for inflation, population growth, and higher average earnings. A Monte Carlo simulation was conducted to account for uncertainty in the model. The total costs of excessive sedentary behaviour in Canada were $2.2 billion (8 h/day cut-point) and $1.8 billion (9 h/day cut-point) in 2021, representing 1.6% and 1.3% of the overall burden of illness costs, respectively. The two most expensive chronic diseases attributable to excessive sedentary behaviour were cardiovascular disease and type 2 diabetes. A 10% decrease in excessive sedentary behaviour (from 87.7% to 77.7%) would save an estimated $219 million per year in costs. Excessive sedentary behaviour significantly contributes to the economic burden of illness in Canada. There is a need for evidence-based and cost-effective strategies that reduce excessive sedentary behaviour in the population.

Economic burden of low cardiorespiratory fitness in Canada

The objective of this study was to estimate health care and health-related productivity costs associated with low cardiorespiratory fitness (CRF) in Canadian adults. We also estimated costs that would be avoided by a 10 percentage point prevalence reduction in low CRF. A prevalence-based approach was used to estimate the economic costs associated with low CRF. Three pieces of information were used: (1) the pooled relative risk estimates of adverse health outcomes consistently associated with low CRF obtained from meta-analyses of prospective cohort studies; (2) the prevalence of low CRF in Canadian men and women obtained from a nationally representative sample; and (3) the direct (health care) and indirect (lost productivity due to premature mortality) costs of the adverse health outcomes based on the Economic Burden of Illness in Canada data. We estimated the total annual economic burden of low CRF in Canadian adults at CAD$3.6 billion, representing 2.7% of the overall Canadian burden of illness costs in 2021. The three most expensive chronic diseases attributable to low CRF were type 2 diabetes (CAD$1.3 billion), heart disease (CAD$701 million), and depression/anxiety (CAD$565 million). Prescription drug expenditures and hospital care expenditures were the main contributors to the total economic burden. An absolute 10% reduction in the prevalence of low CRF (from 45.5% to 35.5%) would save an estimated CAD$644 million per year in costs. In conclusion, low CRF is an important contributor to the economic burden of illness in Canada. Evidence-based and cost-effective strategies that aim to increase CRF at the population level may help alleviate health care costs and improve health.

Circulating Vitamin D Level and Risk of Sudden Cardiac Death and Cardiovascular Mortality: A Dose-Response Meta-Analysis of Prospective Studies.

We conducted a comprehensive meta-analysis of prospective cohort studies to analyze the effect of circulating vitamin D level on the risk of sudden cardiac death (SCD) and cardiovascular disease (CVD) mortality. Prospective cohort studies evaluating the association between circulating vitamin D and risk of SCD and CVD mortality were systematically searched in the PubMed and Embase. Extracted data were analyzed using a random effects model and results were expressed in terms of hazard ratio (HR) and 95% confidence interval (CI). Restricted cubic spline analysis was used to estimate the dose-response relationships. Of the 1,321 records identified using the search strategy, a total of 19 cohort studies were included in the final meta-analysis. The pooled estimate of HR (95% CI) for low vs. high circulating vitamin D level was 1.75 (1.49-2.06) with I² value of 30.4%. In subgroup analysis, strong effects of circulating vitamin D were observed in healthy general population (pooled HR, 1.84; 95% CI, 1.43-2.38) and the clinical endpoint of SCD (pooled HRs, 2.68; 95% CI, 1.48-4.83). The dose-response analysis at the reference level of < 50 nmol/L showed a significant negative association between circulating vitamin D and risk of SCD and CVD mortality. Our meta-analysis of prospective cohort studies showed that lower circulating vitamin D level significantly increased the risk of SCD and CVD mortality.

Alcohol consumption and the risk of heart failure: the Suita Study and meta-analysis of prospective cohort studies.

Alcohol consumption is a modifiable lifestyle, but its role in heart failure (HF) development is controversial. Herein, we investigated the prospective association between alcohol consumption and HF risk. A total of 2,712 participants (1,149 men and 1,563 women) from the Suita Study were followed up every two years. Cox regression was applied to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of HF risk for heavy drinking (≥46 g/day in men or ≥23 g/day in women) and never drinking compared to light drinking (<23 g/day in men or <11.5 g/day in women). Then, we combined the results of the Suita Study with those from other eligible prospective cohort studies in a meta-analysis using the random-effects model. In the Suita Study, within a median follow-up period of 8 years, 319 HF cases (162 in men and 157 in women) were detected. In men, but not women, never and heavy drinking carried a higher risk of HF than light drinking: HRs (95% CIs) = 1.65 (1.00, 2.73) and 2.14 (1.26, 3.66), respectively. Alike, the meta-analysis showed a higher risk of HF among heavy drinkers: HR (95% CI) = 1.37 (1.15, 1.62) and abstainers: HR (95% CI) = 1.18 (1.02, 1.37). We indicated a J-shaped association between alcohol consumption and HF risk among Japanese men. The results of the meta-analysis came in line with the Suita Study. Heavy-drinking men should be targeted for lifestyle modification interventions.

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

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

Effect of Milk and Cultured Milk Products on Type 2 Diabetes: A Global Systematic Review and Meta-analysis of Prospective Cohort Studies

Effect of Milk and Cultured Milk Products on Type 2 Diabetes: A Global Systematic Review and Meta-analysis of Prospective Cohort Studies

Dose-Response Meta-Analysis on Risk of Diabetes in Relation to Red and Processed Meat Consumption - Asian Populations, 2006-2021.

Red and processed meat consumption has been positively related to an increased risk of diabetes in Western populations. However, the results remain inconclusive within Asian populations. This dose-response meta-analysis of prospective cohort studies conducted in East Asian populations reveals a positive relation between the consumption of processed meat and increased risk of diabetes. Furthermore, a U-shaped association was identified between the consumption of unprocessed red meat and the risk of diabetes. This research presents substantive evidence advocating for the reduction of processed and unprocessed red meat consumption as a viable strategy for mitigating the risk of diabetes in East Asian populations.

Long-Term Consumption of 10 Food Groups and Cardiovascular Mortality: A Systematic Review and Dose Response Meta-Analysis of Prospective Cohort Studies.

A large body of evidence exists on diet and cardiovascular mortality, but limited studies have investigated the long-term intake of food groups, which may have cumulative effects on cardiovascular health in the long term. This review therefore evaluated the relationship between the long-term consumption of 10 food groups and cardiovascular mortality. We conducted a systematic search in Medline, Embase, Scopus, CINAHL, and Web of Science till January 2022. Of the 5318 studies initially identified, 22 studies with a total of 70,273 participants with cardiovascular mortality were included. Summary HRs and 95% CIs were estimated using a random effects model. We found that a long-term high intake of whole grains (HR: 0.87; 95% CI: 0.80, 0.95; P = 0.001), fruits and vegetables (HR: 0.72; 95% CI: 0.61, 0.85; P < 0.0001), and nuts (HR: 0.73; 95% CI: 0.66, 0.81; P < 0.00001) significantly reduced cardiovascular mortality. Each 10-gram increase in whole grain consumption per day was associated with a 4% reduction in the risk of cardiovascular mortality, whereas each 10-gram increase in red/processed meat consumption per day was associated with a 1.8% increase in the risk of cardiovascular mortality. Compared with the lowest intake category, red/processed meat consumption in the highest category was associated with an increased risk of cardiovascular mortality (HR: 1.23; 95% CI: 1.09, 1.39; P = 0.006). High intake of dairy products (HR: 1.11; 95% CI: 0.92, 1.34; P = 0.28), and legumes (HR: 0.86; 95% CI: 0.53, 1.38; P = 0.53) were not associated with cardiovascular mortality. However, in the dose-response analysis, each 10-gram increase in legume intake per week was associated with a 0.5% reduction in cardiovascular mortality. We conclude that the long-term high intake of whole grains, vegetables, fruits, nuts, and a low intake of red/processed meat are associated with reduced cardiovascular mortality. More data on the long-term effects of legumes on cardiovascular mortality are encouraged. This study was registered at PROSPERO as CRD42020214679.

The Association between Hypertension and Insomnia: A Bidirectional Meta-Analysis of Prospective Cohort Studies.

Studies on bidirectional associations between hypertension and insomnia are inconclusive. The purpose of this meta-analysis was to systematically review and summarize the current evidence from epidemiological studies that evaluated this relationship. PubMed, Embase, China National Knowledge Infrastructure (CNKI), Wan Fang, and VIP databases were searched for studies published up to May 2021. Prospective cohort studies that reported the relationship between hypertension and insomnia in adults were included. Data were extracted or provided by the authors according to the prevalence rate, incidence rate, unadjusted or adjusted odds ratio (OR), and 95% confidence interval (CI). Heterogeneity was assessed by I2 statistics. ORs were pooled by using random-effects models. A total of 23 prospective studies were identified. Twenty cohort studies recorded OR-adjusted value with the outcome for hypertension (OR = 1.11, 95% CI: 1.07-1.16; I2 = 83.9%), and three cohort studies reported OR-adjusted value with the outcome for insomnia (OR = 1.20, 95%CI: 1.08-1.32; I2 = 35.1%). Subgroup analysis showed that early morning awakening and composite insomnia were significantly associated with hypertension. The result indicates a possible bidirectional association between hypertension and insomnia. Early identification and prevention of insomnia in hypertension patients are needed, and vice versa.

Sugar-sweetened beverage consumption and weight gain in children and adults: a systematic review and meta-analysis of prospective cohort studies and randomized controlled trials

BackgroundSugar-sweetened beverages (SSBs) have been implicated in fueling the obesity epidemic. ObjectivesThis study aimed to update a synthesis of the evidence on SSBs and weight gain in children and adults. MethodsMEDLINE, Embase, and Cochrane databases were searched through September 8, 2022, for prospective cohort studies and randomized controlled trials (RCTs) that evaluated intake of SSBs in relation to BMI and body weight in children and adults, respectively. Eligible interventions were compared against a noncaloric control. Study-level estimates were pooled using random-effects meta-analysis and presented as β-coefficients with 95% CIs for cohorts and weighted mean differences (MDs) with 95% CIs for RCTs. ResultsWe identified 85 articles including 48 in children (40 cohorts, n = 91,713; 8 RCTs, n = 2783) and 37 in adults (21 cohorts, n = 448,661; 16 RCTs, n = 1343). Among cohort studies, each serving/day increase in SSB intake was associated with a 0.07-kg/m2 (95% CI: 0.04 kg/m2, 0.10 kg/m2) higher BMI in children and a 0.42-kg (95% CI: 0.26 kg, 0.58 kg) higher body weight in adults. RCTs in children indicated less BMI gain with SSB reduction interventions compared with control (MD: −0.21 kg/m2; 95% CI: −0.40 kg/m2, −0.01 kg/m2). In adults, randomization to addition of SSBs to the diet led to greater body weight gain (MD: 0.83 kg; 95% CI: 0.47 kg, 1.19 kg), and subtraction of SSBs led to weight loss (MD: −0.49 kg; 95% CI: −0.66 kg, −0.32 kg) compared with the control groups. A positive linear dose–response association between SSB consumption and weight gain was found in all outcomes assessed. ConclusionsOur updated systematic review and meta-analysis expands on prior evidence to confirm that SSB consumption promotes higher BMI and body weight in both children and adults, underscoring the importance of dietary guidance and public policy strategies to limit intake. This meta-analysis was registered at the International Prospective Register of Systematic Reviews as CRD42020209915.

Consumption of whole grains and refined grains and associated risk of cardiovascular disease events and all-cause mortality: a systematic review and dose-response meta-analysis of prospective cohort studies

BackgroundAlthough relationships between the intake of whole grains and refined grains and the incidence of cardiovascular disease (CVD) events and all-cause mortality have been investigated, the conclusions have been inconclusive. ObjectivesWe aimed to comprehensively summarize the evidence about the correlation between consuming whole grains and refined grains and risks of CVD events and all-cause mortality and to evaluate the meta-evidence quality. MethodsWe searched PubMed, Embase, and Web of Science until 15 March, 2022. Random-effects models were employed to calculate summary relative risks (RRs) and 95% confidence intervals (CIs). We explored potential linear or nonlinear relationships using restricted cubic splines. The NutriGrade tool was employed to rate meta-evidence quality. ResultsTwenty-four articles (68 studies; 46 for whole grains and 22 for refined grains) with 1,624,407 participants were included. Per 30-g increase in daily whole grain consumption, the RRs and 95% CIs of stroke, coronary heart disease (CHD), heart failure (HF), CVD, and all-cause mortality were 0.98 (0.96, 1.00), 0.94 (0.92, 0.97), 0.97 (0.89, 1.07), 0.92 (0.88, 0.96), and 0.94 (0.92, 0.97), respectively. Whole grain consumption was linearly associated with CHD (Pnonlinearity = 0.231) and nonlinearly associated with CVD (Pnonlinearity = 0.002) and all-cause mortality (Pnonlinearity = 0.001). Except for a positive correlation between refined grain consumption and all-cause mortality in the restricted cubic spline, no significant influence of refined grain intake on stroke, CHD, HF, and CVD was detected. The meta-evidence quality for the association of whole grain consumption with stroke, CHD, HF, CVD, and all-cause mortality was moderate, moderate, low, high, and high, respectively. For refined grains, all meta-evidence was of low quality. ConclusionsConsuming whole grains, rather than refined grains, can assist in preventing CHD, CVD, and all-cause mortality. Relationships between consumption of refined grains and health outcomes should be interpreted cautiously because of the low quality of meta-evidence.

Abstract 10535: Relation of Multiple Low-Risk Lifestyle Behaviors With Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

Introduction: The association of combined low-risk lifestyle behaviors (LRLBs) with cardiovascular disease (CVD) and all-cause mortality has not been systematically quantified. Objective: We undertook a systematic review and dose-response meta-analysis to assess the association of combined LRLBs with CVD and all-cause mortality. Methods: MEDLINE, EMBASE and Cochrane were searched up to December 29, 2021. Prospective cohort studies reporting the association between a minimum of 3 combined LRLBs (including healthy diet) with CVD, coronary heart disease (CHD) and stroke incidence and mortality were included. Independent reviewers extracted data and assessed study quality. Highest vs. lowest LRLB score was pooled using random effects. Heterogeneity was assessed (Cochran Q) and quantified (I 2 ). Global dose response meta-analysis (DRM) for maximum adherence was estimated using one-stage linear mixed model. The certainty of the evidence was assessed using GRADE. Results: 116 cohort comparisons (n=9,775,191) involving 382,922 cases were included. Comparing highest with lowest adherence LRLBs were associated with lower risk of CHD incidence (RR, 0.29 [95% CI, 0.21, 0.42]), stroke incidence (0.56 [0.50, 0.62]), CVD incidence (0.47 [0.37, 0.58]), CHD mortality (0.32 [0.25, 0.41]), stroke mortality (0.37 [0.30, 0.46]), CVD mortality (0.41 [0.34, 0.49]) and all-cause mortality (0.46 [0.41 to 0.52]). DRM analysis showed a linear association between LRLBs and all outcomes reaching a global DRM between 59-76% protection. LRLBs were defined with variable ranges as a healthy body weight (body mass index &lt;30kg/m 2 ), healthy diet (healthy diet score &gt;median), regular physical activity (1/week to &gt;30 minutes/day), smoking cessation (never smoked or smoking cessation), light alcohol intake (≤30g/day) and adequate sleep (5.5-9 hours). The certainty of the evidence was graded as moderate to high owing to downgrades for inconsistency and/or upgrades for a large magnitude of effect and significant dose-response gradient. Conclusions: Pooled analyses show that the combination of LRLBs was associated with a substantial lower risk of CVD outcomes and all-cause mortality. The available evidence provides a very good indication of the benefit of combined LRLBs.

Effect of Coffee Consumption on Risk of Coronary Heart Disease in a Systematic Review and Meta-Analysis of Prospective Cohort Studies

Previous prospective studies have reported inconsistent findings on the association between coffee consumption and the risk of coronary heart disease (CHD). This study aimed to investigate their association using a meta-analysis of prospective studies. We searched PubMed and EMBASE for prospective cohort studies of the association between coffee consumption and the risk of CHD in the general population. We conducted a random-effects meta-analysis and also subgroup meta-analyses by various factors. Of 870 studies searched from databases, 32 prospective cohort studies were included in the final analysis. In the main meta-analysis of all studies, no significant association between coffee consumption and the risk of CHD was observed (relative risk [RR] 1.05, 95% confidence interval [CI] 0.97 to 1.14, I2=64.9%). In the subgroup meta-analyses by gender, coffee consumption significantly increased the risk of CHD in men (RR 1.19, 95% CI 1.05 to 1.35, n=17), whereas a nonsignificantly decreased risk of CHD was observed in women (RR 0.91, 95% CI 0.77 to 1.08, n=11). Also, in the subgroup meta-analyses by follow-up period, coffee consumption significantly increased the risk of CHD in the follow-up of 20years or longer (RR 1.16, 95% CI 1.06 to 1.27, n=4) regardless of gender. In conclusion, in the current meta-analysis of prospective studies, we found that, overall, no significant association between coffee consumption and the risk of CHD was observed. However, coffee consumption showed a differential effect by gender, with an increased risk of CHD in men and a potentially decreased risk in women.

Important Food Sources of Sugars and Type 2 Diabetes: A Systematic Review and Meta-analysis of Prospective Cohort Studies

It is unclear if the high-risk relation of sugar-sweetened beverages (SSBs) with type 2 diabetes (T2D) holds for other food sources of fructose-containing sugars (FCS). We undertook a systematic review and meta-analysis of prospective cohort studies to answer this question.

Economic burden of insomnia symptoms in Canada

ObjectiveTo estimate health care and productivity costs associated with insomnia symptoms in Canadian adults. MethodsThree pieces of information were needed to calculate estimates based on a prevalence-based approach: (1) the pooled relative risk estimates of health outcomes consistently associated with insomnia symptoms obtained from recent meta-analyses of prospective cohort studies; (2) the direct (health care) and indirect (lost productivity due to premature mortality) costs of these health outcomes using the Economic Burden of Illness in Canada information; and (3) the prevalence of insomnia symptoms in Canadian men (18.1%) and women (29.5%) obtained from a nationally-representative survey. ResultsThe direct, indirect, and total costs of insomnia symptoms in Canada in 2021 were $1.9 billion, $12.6 million, and $1.9 billion, respectively. This value represents 1.9% of the overall burden of illness costs for 2021 in Canada. The 2 most expensive chronic diseases attributable to insomnia symptoms were type 2 diabetes ($754 million) and depression ($706 million). The main contributor to the costs for type 2 diabetes and depression was prescription drugs. A 5% decrease in insomnia symptoms (from 23.8% to 18.8%) would result in an estimated $353 million in avoided costs while a 5% increase in insomnia symptoms (from 23.8% to 28.8%) would result in an estimated $333 million in additional expenditures yearly. ConclusionsInsomnia symptoms greatly contribute to the economic burden of illness in Canada. Reducing the prevalence of insomnia symptoms would reduce its societal burden.

Playing a musical instrument and the risk of dementia among older adults: a systematic review and meta-analysis of prospective cohort studies

BackgroundEngaging in leisure activities was suggested to protect older adults from dementia. However, the association between playing a musical instrument and the risk of dementia is not well-established. This study aimed to investigate this association in older adults using a systematic review and meta-analysis of prospective cohort studies.MethodsPooled hazard ratio (HR) and 95% confidence interval (CI) of having dementia for older adults playing a musical instrument were calculated using the random-effects model. We performed the I2 statistic to detect heterogeneity across studies and the test for funnel plot asymmetry to assess publication bias. The risk of bias assessment was conducted using the modified Newcastle–Ottawa Scale.ResultsA total of three prospective cohort studies were found eligible: two from the U.S. and one from Japan. Playing a musical instrument, in the meta-analysis, was significantly associated with a decreased risk of dementia (HR = 0.64; 95% CI: 0.41, 0.98) among older adults. No signs of significant heterogeneity across studies (I2 = 23.3% and p-heterogeneity = 0.27) or publication bias (z= -1.3 and p-publication bias = 0.18) were identified.ConclusionPlaying a musical instrument was associated with a decreased risk of dementia among older adults. Older adults should be encouraged to engage in leisure activities, especially playing musical instruments.

Fish consumption and the risk of dementia: Systematic review and meta-analysis of prospective studies

Accumulating evidence supports some health benefits of nutrients in fish, but evidence from comprehensive investigation of fish consumption and the risk of dementia is limited. We performed a systematic review and meta-analysis of prospective cohort studies to investigate this association. Papers relevant to our study published by 2021 were searched using PubMed, Embase, Cochrane library, and Web of Science databases. Pooled relative risks (RRs) of the association between fish consumption and dementia risk were calculated using a random-effects model. Seven prospective cohort studies with a total of 30,638 subjects were included in the meta-analysis. Overall, people with high fish consumption had a significantly lower risk of dementia compared to those with low fish consumption. In addition, the dose-response meta-analysis also supported the inverse association. The inverse association tended to be stronger in studies conducted in Asia. The findings of the meta-analysis of prospective cohort studies provide quantitative evidence for an inverse association between fish consumption and the risk of dementia. Further research on consumption of specific types of fish with respect to the risk of dementia are needed to provide more informative recommendations to the public.

Effect of olive oil consumption on cardiovascular disease, cancer, type 2 diabetes, and all-cause mortality: A systematic review and meta-analysis

Some large prospective studies on olive oil consumption and risk of chronic disease suggested protective effects. We conducted an outcome-wide systematic review and meta-analysis of prospective cohort studies and randomized controlled trials (RCT) assessing the association between olive oil consumption and the primary risk of 4 different outcomes: cardiovascular disease (CVD), cancer, type 2 diabetes (T2D) or all-cause mortality through January 2022. Thirty-six studies were included in the systematic review and twenty-seven studies (24 prospective cohorts and 3 different reports from one RCT) were assessed in 4 quantitative random-effects meta-analyses. They included a total of 806,203 participants with 49,223 CVD events; 1,285,064 participants with 58,892 incident cases of cancer; 680,239 participants with 13,389 incident cases of T2D; and 733,420 participants with 174,081 deaths. Olive oil consumption was most frequently measured with validated food frequency questionnaires. Studies follow-up ranged between 3.7 and 28 years. A 16% reduced risk of CVD (relative risk [RR]: 0.84; 95% confidence interval [CI]: 0.76 to 0.94), standardized for every additional olive oil consumption of 25g/d was found. No significant association with cancer risk was observed (RR: 0.94; 95% CI: 0.86 to 1.03, per 25g/d). Olive oil consumption was associated with a 22% lower relative risk of T2D (RR: 0.78; 95% CI: 0.69 to 0.87, per 25g/d) without evidence of heterogeneity. Similarly, it was inversely associated with all-cause mortality (RR: 0.89; 95% CI: 0.85 to 0.93, per 25g/d). Only the results for T2D were homogeneous. Specific sources of heterogeneity for the other 3 outcomes were not always apparent. Prospective studies supported a beneficial association of olive oil consumption with CVD, T2D and all-cause mortality, but they did not show any association with cancer risk.

Endometrial Cancer Risk Reduction by Coffee Consumption: Meta-Analysis of Prospective Cohort Studies

Endometrial Cancer Risk Reduction by Coffee Consumption: Meta-Analysis of Prospective Cohort Studies