Grading nutrition evidence: where to go from here?

Mediterranean Dietary Pattern for Healthy and Active Aging: A Narrative Review of an Integrative and Sustainable Approach

The global population is on a trajectory of continuous growth, with estimates projecting an increase from 7.7 billion in 2019 to approximately 9.7 billion by 2050. Longevity is also expected to rise rapidly, with advancements in healthcare contributing to increased life expectancies and an increase in the maximum lifespan. The aging process is accompanied by different changes, often leading to a decline in daily life activities and an increased susceptibility to disease. Age-related changes can cause cellular damage and subsequent cellular death. Oxidative stress and inflammation play significant roles in this process contributing to molecular damage and mitochondrial dysfunction. Active aging has been associated with improved quality of life and a reduced risk of morbidity and premature mortality. In this context, the Mediterranean diet has emerged as a promising approach to promoting healthy aging and sustainability. The phytochemical compounds within the Mediterranean diet have been linked to a lower risk of developing cardiovascular disease, type 2 diabetes, obesity, cancer and neurodegenerative diseases. The findings of peer-reviewed articles regarding the use of the Mediterranean diet as a healthy and sustainable dietary pattern written in Portuguese, Spanish or English were included in this narrative literature review. This dietary pattern's emphasis on the consumption of fresh and local food aligns with both health and environmental sustainability goals. This work provides a comprehensive review of the benefits of the Mediterranean diet and its components in a healthy aging process and highlights the importance of this dietary pattern as a sustainable approach.

Health effects of drinking 100% juice: an umbrella review of systematic reviews with meta-analyses

CONTEXT

Low fruit and vegetable intakes are major modifiable determinants of disease. One hundred percent juice may facilitate intake and deliver essential nutrients and bioactive compounds. However, the position of 100% juice in healthy eating guidelines remains controversial due to its lower dietary fiber and higher free-sugar contents compared with whole fruits and vegetables.

OBJECTIVE

To conduct an umbrella review of systematic literature reviews with meta-analyses (MAs) to summarize the health benefits of drinking 100% fruit and/or vegetable juice.

DATA SOURCES

Four databases (Medline, The Cochrane Library, EMBASE, and CINAHL) were systematically searched for MAs of 100% juice and any health outcomes.

DATA ANALYSIS

Screening, quality, risk of bias, and content overlap tools were applied, and extracted data were narratively synthesized. No eligible studies for vegetable juice were found. Fifteen systematic literature reviews (51 primary MAs, 6 dose-response, and 87 subanalyses; 50-1200 mL/day; hours to years of duration) were included. Ten MAs (19.6%) reported health benefits (4 for blood pressure, 2 for vascular function, 3 for inflammation, 1 for stroke mortality), 3 MAs (5.9%) reported adverse risks (1 each for cardiovascular disease mortality, prostate cancer, type 2 diabetes risk), while most (74.5%) reported no effect (blood lipids, body composition, liver function, metabolic health, cancers, and inflammation). Risks were limited to cohort studies and benefits were found in both cohort and intervention studies.

CONCLUSION

The findings collate evidence showing some potential health benefits associated with 100% juice consumption, with fewer potential risks. The balance of evidence does not support the exclusion of 100% juice from food-based guides to healthy eating, although caution may be warranted in certain groups or individuals, and the body of evidence is not yet conclusive.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022380588.

Association of glycaemic index and glycaemic load with type 2 diabetes, cardiovascular disease, cancer, and all-cause mortality: a meta-analysis of mega cohorts of more than 100 000 participants

BACKGROUND

There is debate over whether the glycaemic index of foods relates to chronic disease. We aimed to assess the associations between glycaemic index (GI) and glycaemic load (GL) and type 2 diabetes, cardiovascular disease, diabetes-related cancers, and all-cause mortality.

METHODS

We did a meta-analysis of large cohorts (≥100 000 participants) identified from the Richard Doll Consortium. We searched the Cochrane Library, MEDLINE, PubMed, Embase, Web of Science, and Scopus for cohorts that prospectively examined associations between GI or GL and chronic disease outcomes published from database inception to Aug 4, 2023. Full-article review and extraction of summary estimates data were conducted by three independent reviewers. Primary outcomes were incident type 2 diabetes, total cardiovascular disease (including mortality), diabetes-related cancers (ie, bladder, breast, colorectal, endometrial, hepatic, pancreatic, and non-Hodgkin lymphoma), and all-cause mortality. We assessed comparisons between the lowest and highest quantiles of GI and GL, adjusting for dietary factors, and pooling their most adjusted relative risk (RR) estimates using a fixed-effects model. We also assessed associations between diets high in fibre and whole grains and the four main outcomes. The study protocol is registered with PROSPERO, CRD42023394689.

FINDINGS

From ten prospective large cohorts (six from the USA, one from Europe, two from Asia, and one international), we identified a total of 48 studies reporting associations between GI or GL and the outcomes of interest: 34 (71%) on various cancers, nine (19%) on cardiovascular disease, five (10%) on type 2 diabetes, and three (6%) on all-cause mortality. Consumption of high GI foods was associated with an increased incidence of type 2 diabetes (RR 1·27 [95% CI 1·21-1·34]; p<0·0001), total cardiovascular disease (1·15 [1·11-1·19]; p<0·0001), diabetes-related cancer (1·05 [1·02-1·08]; p=0·0010), and all-cause mortality (1·08 [1·05-1·12]; p<0·0001). Similar associations were seen between high GL and diabetes (RR 1·15 [95% CI 1·09-1·21]; p<0·0001) and total cardiovascular disease (1·15 [1·10-1·20]; p<0·0001). Associations between diets high in fibre and whole grains and the four main outcomes were similar to those for low GI diets.

INTERPRETATION

Dietary recommendations to reduce GI and GL could have effects on health outcomes that are similar to outcomes of recommendations to increase intake of fibre and whole grain.

FUNDING

Banting and Best and the Karuna Foundation.

A Primer on Systematic Review and Meta-analysis in Diabetes Research

A systematic review is a rigorous process that involves identifying, selecting, and synthesizing available evidence pertaining to an a priori-defined research question. The resulting evidence base may be summarized qualitatively or through a quantitative analytic approach known as meta-analysis. Systematic review and meta-analysis (SRMAs) have risen in popularity across the scientific realm including diabetes research. Although well-conducted SRMAs are an indispensable tool in informing evidence-based medicine, the proliferation of SRMAs has led to many reviews of questionable quality and misleading conclusions. The objective of this article is to provide up-to-date knowledge and a comprehensive understanding of strengths and limitations of SRMAs. We first provide an overview of the SRMA process and offer ways to identify common pitfalls at key steps. We then describe best practices as well as evolving approaches to mitigate biases, improve transparency, and enhance rigor. We discuss several recent developments in SRMAs including individual-level meta-analyses, network meta-analyses, umbrella reviews, and prospective meta-analyses. Additionally, we outline several strategies that can be used to enhance quality of SRMAs and present key questions that authors, editors, and readers should consider in preparing or critically reviewing SRMAs.

Overall, plant-based, or animal-based low carbohydrate diets and all-cause and cause-specific mortality: A systematic review and dose-response meta-analysis of prospective cohort studies

INTRODUCTION

In this study, we sought to summarize the associations between overall, plant-, and animal-based low carbohydrate diet (LCD) scores and the risk of all-cause, cardiovascular disease (CVD), and cancer mortality from prospective cohort studies.

METHODS

We searched PubMed, Scopus, and Web of Science up to January 2022. We included prospective cohort studies that investigated the relationship between LCD-score and risk of overall, CVD, or cancer mortality. Two investigators assessed the studies for eligibility and extracted the data. Summary hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using a random-effects model.

RESULTS

Ten studies, with 421022 participants, were included in the analysis. In the high-versus-low meta-analysis, overall (HR:1.05,95%CI:0.97, 1.13, I2 =72.0%) and animal-based LCD-scores (HR: 1.08, 95% CI: 0.97-1.21; I2 = 88.0%) were not associated with all-cause mortality, but plant-based LCD-score was associated with a risk reduction (HR:0.87, 95%CI:0.78,0.97; I2 = 88.4%). CVD mortality was not associated with overall, plant-, or animal-based LCD-scores. Overall (HR:1.14, 95%CI:1.05,1.24; I2 = 37.4%) and animal-based LCD scores (HR:1.16,95%CI:1.02,1.31; I2 = 73.7%) were associated with a higher risk of cancer mortality, while plant-based LCD-score was not. A U-shaped relationship was revealed between overall LCD-score and all-cause and CVD mortality. The shape of relationship between LCD and cancer mortality was a linear dose-response.

CONCLUSION

In conclusion, diets with a moderate carbohydrate content were associated with the lowest risk of all-cause and CVD mortality. If the sources of macronutrients that replaced carbohydrates were plant-based, the risk of all-cause mortality was reduced linearly with lower carbohydrate content. The risk of cancer mortality increased linearly with the increase in carbohydrate content. Considering the low certainty of evidence, more robust prospective cohort studies are suggested.

Need for a nutrition-specific scientific paradigm for research quality improvement

Nutrition science has been criticised for its methodology, apparently contradictory findings and generating controversy rather than consensus. However, while certain critiques of the field are valid and informative for developing a more cogent science, there are also unique considerations for the study of diet and nutrition that are either overlooked or omitted in these discourses. The ongoing critical discourse on the utility of nutrition sciences occurs at a time when the burden of non-communicable cardiometabolic disease continues to rise in the population. Nutrition science, along with other disciplinary fields, is tasked with producing a translational evidence-base fit for the purpose of improving population and individual health and reducing disease risk. Thus, an exploration of the unique methodological and epistemic considerations for nutrition research is important for nutrition researchers, students and practitioners, to further develop an improved scientific discipline for nutrition. This paper will expand on some of the challenges facing nutrition research, discussing methodological facets of nutritional epidemiology, randomised controlled trials and meta-analysis, and how these considerations may be applied to improve research methodology. A pragmatic research paradigm for nutrition science is also proposed, which places methodology at its centre, allowing for questions over both how we obtain knowledge and research design as the method to produce that knowledge to be connected, providing the field of nutrition research with a framework within which to capture the full complexity of nutrition and diet.

Missing the forest-plot for the trees

Systematic reviews and meta-analyses are methods increasingly used in biomedical research since their introduction in the 1970s. They serve to replace other non-systematic and cherry-picked narrative reviews, which are highly variable in their approach, structure and content. Their increase in popularity parallels the increase in overall scientific output, and when properly conducted, systematic reviews can contribute highly impactful summaries of a fast-growing evidence base. Meta-analyses offer statistical summaries, called forest plots, which similarly provide a powerful synopsis unachievable by individual studies. Thus, it is not difficult to imagine why systematic reviews are published more often. Should scientists be concerned by the accelerated output of research, from systematic reviews or other? If quantity comes at the expense of quality, then yes, of course; but should important manuscripts be rationed out otherwise? A new scientific technique can seem scary at first, especially to the researcher who is unfamiliar with its application or uncertain of its validity. In that case, we should become familiar with new and popular methods, and understand their strengths and limitations. There is a rightful place for systematic reviews and meta-analyses among respectable research tools. Importantly, however, despite standard operating procedures and best practices, the quality of systematic reviews today is highly variable, warranting serious concerns for quantity exceeding quality. Therefore, the appropriate response should be to instil researchers with an appreciation for the complexity of conducting and interpreting a systematic review and meta-analysis, to create more knowledgeable authors, reviewers and editors, who collectively will improve, rather than dismiss, these important scientific contributions.

Nuts and Cardiovascular Disease Outcomes: A Review of the Evidence and Future Directions

Nuts are nutrient-rich foods that contain many bioactive compounds that are beneficial for cardiovascular health. Higher consumption of nuts has been associated with a reduced risk of several cardiovascular diseases (CVD) in prospective cohort studies, including a 19% and 25% lower risk of CVD incidence and mortality, respectively, and a 24% and 27% lower risk of coronary heart disease incidence and mortality, respectively. An 18% lower risk of stroke mortality, a 15% lower risk of atrial fibrillation, and a 19% lower risk of total mortality have also been observed. The role of nuts in stroke incidence, stroke subtypes, peripheral arterial disease and heart failure has been less consistent. This narrative review summarizes recommendations for nuts by clinical practice guidelines and governmental organizations, epidemiological evidence for nuts and CVD outcomes, nut-containing dietary patterns, potential mechanisms of nuts and CVD risk reduction, and future research directions, such as the use of biomarkers to help better assess nut intake. Although there are still some uncertainties around nuts and CVD prevention which require further research, as summarized in this review, there is a substantial amount of evidence that supports that consuming nuts will have a positive impact on primary and secondary prevention of CVD.

Effect of dietary patterns on cardiovascular risk factors in people with type 2 diabetes. A systematic review and network meta-analysis

AIMS

To identify the most effective dietary pattern for improving cardiovascular risk factors in people with type 2 diabetes.

METHODS

PubMed, Embase, the Cochrane library, SCOPUS and Web of Science were systematically searched for randomized controlled trials comparing the effects of dietary patterns on body weight, blood pressure, HbA1c and lipids after 6 and 12 months. Treatment effects were synthesized using Bayesian network meta-analysis. Six-month changes in HbA1c, SBP and LDL-C were used to estimate relative risk reductions (RRR) for cardiovascular events.

RESULTS

Seventy-three RCTs on eight different dietary patterns were included. All reduced body weight and HbA1c after 6 months, with the largest effects from the low carbohydrate (body weight -4.8 kg, 95 %credibility interval (95 %CrI) -6.5;-3.2 kg) and Mediterranean diet (HbA1c -1.0 %, 95 %CrI -15;-0.4 % vs usual diet). There were no significant 6-month blood pressure or lipid effects. Dietary patterns had non-statistically significant 12-months effects. The Mediterranean diet resulted in the largest expected RRR for cardiovascular events: -16 % (95 %CI -31;3.0) vs usual diet.

CONCLUSIONS

In patients with type 2 diabetes, all dietary patterns outperformed usual diet in improving body weight and HbA1c after 6 months and clinically relevant cardiovascular risk reduction could be achieved. There was insufficient evidence to select one optimal dietary pattern.

Red/processed meat consumption and non-cancer-related outcomes in humans: umbrella review

The associations of red/processed meat consumption and cancer-related health outcomes have been well discussed. The umbrella review aimed to summarise the associations of red/processed meat consumption and various non-cancer-related outcomes in humans. We systematically searched the systematic reviews and meta-analyses of associations between red/processed meat intake and health outcomes from PubMed, Embase, Web of Science and the Cochrane Library databases. The umbrella review has been registered in PROSPERO (CRD 42021218568). A total of 40 meta-analyses were included. High consumption of red meat, particularly processed meat, was associated with a higher risk of all-cause mortality, CVD and metabolic outcomes. Dose-response analysis revealed that an additional 100 g/d red meat intake was positively associated with a 17 % increased risk of type 2 diabetes mellitus (T2DM), 15 % increased risk of CHD, 14 % of hypertension and 12 % of stroke. The highest dose-response/50 g increase in processed meat consumption at 95 % confident levels was 1·37, 95 % CI (1·22, 1·55) for T2DM, 1·27, 95 % CI (1·09, 1·49) for CHD, 1·17, 95 % CI (1·02, 1·34) for stroke, 1·15, 95 % CI (1·11, 1·19) for all-cause mortality and 1·08, 95 % CI (1·02, 1·14) for heart failure. In addition, red/processed meat intake was associated with several other health-related outcomes. Red and processed meat consumption seems to be more harmful than beneficial to human health in this umbrella review. It is necessary to take the impacts of red/processed meat consumption on non-cancer-related outcomes into consideration when developing new dietary guidelines, which will be of great public health importance. However, more additional randomised controlled trials are warranted to clarify the causality.

Using the Hierarchies of Evidence Applied to Lifestyle Medicine (HEALM) Approach to Assess the Strength of Evidence on Associations between Dietary Patterns and All-Cause Mortality

Dietary guidelines should be underpinned by high-quality evidence. Quality assessment methods that reflect traditional evidence hierarchies prioritise evidence from randomised controlled trials (RCTs). The Hierarchies of Evidence Applied to Lifestyle Medicine (HEALM) approach is an alternative quality assessment method for research questions that for practical and/or ethical reasons, cannot be answered using RCTs. The aim of this study was to investigate how the HEALM approach could be used to assess the strength of evidence on associations between dietary patterns and all-cause mortality (a research question that is difficult to answer using RCTs). Two data sources were used: an existing systematic review of dietary patterns and all-cause mortality that synthesised evidence from observational studies; and an overview of reviews that was conducted to summarise relevant evidence from mechanistic and intervention studies. A set of four criteria were developed and used in the application of HEALM. Using different datasets in combination, the strength of evidence was rated as 'Grade B: moderate/suggestive' or 'Grade C: insufficient/inconclusive'. HEALM is a novel approach for integrating and assessing the strength of evidence from mechanistic, intervention, and observational studies. Further research is needed to address the practical challenges that were identified in the application of HEALM.

Food Insecurity and Childhood Obesity: A Systematic Review

BACKGROUND AND OBJECTIVES

Addressing food insecurity while promoting healthy body weights among children is a major public health challenge. Our objective is to examine longitudinal associations between food insecurity and obesity in US children aged 1 to 19 years.

METHODS

Sources for this research include PubMed, CINAHL, and Scopus databases (January 2000 to February 2022). We included English language studies that examined food insecurity as a predictor of obesity or increased weight gain. We excluded studies outside the United States and those that only considered the unadjusted relationship between food security and obesity. Characteristics extracted included study design, demographics, methods of food security assessment, and anthropometric outcomes.

RESULTS

Literature searches identified 2272 articles; 13 met our inclusion criteria. Five studies investigated the relationship between food insecurity and obesity directly, whereas 12 examined its relationship with body mass index or body mass index z-score. Three studies assessed multiple outcomes. Overall, evidence of associations between food insecurity and obesity was mixed. There is evidence for possible associations between food insecurity and obesity or greater weight gain in early childhood, for girls, and for children experiencing food insecurity at multiple time points. Heterogeneity in study methods limited comparison across studies.

CONCLUSIONS

Evidence is stronger for associations between food insecurity and obesity among specific subgroups than for children overall. Deeper understanding of the nuances of this relationship is critically needed to effectively intervene against childhood obesity.

Plant- and Animal-Based Protein-Rich Foods and Cardiovascular Health

PURPOSE OF REVIEW

To summarize recent evidence from randomized controlled feeding trials (RCTs) on the effects of consuming plant- and animal-based protein-rich foods on cardiovascular health of adults.

RECENT FINDINGS

Results from meta-analyses of RCTs exemplify the importance of considering relative effects of protein-rich foods, i.e., when intake of one food increases, intake of another food likely decreases. Results from short-term RCTs showed that overall diet quality is more influential for improving cardiovascular disease (CVD) risk factors than intake of a single protein-rich food, e.g., red meat. Yet, assessing long-term CVD risk associated with intake of a single protein-rich food as part of a dietary pattern is methodologically challenging. While accumulating evidence suggests gut microbiota as a potential mediator for such effects, current knowledge is preliminary and restricts causal or functional inferences. A variety of protein-rich foods, both plant- and animal-based, should be consumed as part of nutrient-dense dietary patterns to meet nutrient needs and improve cardiovascular health for adults.

Systematic Review and Meta-Analysis on the Effect of Portion Size and Ingestive Frequency on Energy Intake and Body Weight among Adults in Randomized Controlled Feeding Trials

Energy intake is the product of portion size (PS)-the energy content of an ingestive event-and ingestive frequency (IF)-the number of ingestive events per unit time. An uncompensated alteration in either PS or IF would result in a change in energy intake and body weight if maintained over time. The objective of this meta-analysis was to assess the independent effects of PS and IF on energy intake and body weight among healthy adults in randomized controlled trials (RCTs). A total of 9708 articles were identified in PubMed, Web of Science, Cochrane, and CINAHL databases. The articles were divided among 10 researchers; each article was screened for eligibility by 2-3 independent reviewers. Exclusion criteria included: populations <19 y and >65 y, unhealthy populations (i.e. participants with an acute or chronic disease), assessments <24 h and <4 wk in duration for trials investigating energy intake or body weight, respectively. Controlled feeding trials (i.e. fixed energy intake) that manipulated IF and PS in the same study intervention (IF/PS) were evaluated separately and for the body weight outcome only. Twenty-two studies (IF = 4, PS = 14, IF/PS = 4) met the inclusion criteria. There was an insufficient number of studies to assess the effect of IF, PS, or IF/PS on body weight. There was heterogeneity in the effect sizes among all comparisons (I2 ≥75%). Consuming larger portion sizes was associated with higher daily energy intake [295 kcal (202, 388), n = 24; weighted mean differences (WMD) (95% CI), n = comparisons], and increased frequency of ingestive events was associated with higher energy intake [203 kcal (76, 330), n = 10]. Results from RCTs support that larger PS and greater IF are both associated with higher energy consumption. However, there is insufficient information to determine chronic effects on body weight. This protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42018104757.

Evidence Use in the Development of the Australian Dietary Guidelines: A Qualitative Study

Dietary guidelines are important nutrition policy reference standards that should be informed by the best available evidence. The types of evidence that are reviewed and the evidence review methods that are used have implications for evidence translation. The aim of this study was to explore perceived advantages, disadvantages, and practicalities associated with the synthesis and translation of evidence from nutrient-based, food-based, and dietary patterns research in dietary guideline development. A qualitative descriptive study was conducted. Twenty-two semi-structured interviews were conducted with people involved in the development of the 2013 Australian Dietary Guidelines (ADGs). Transcripts were analysed thematically. To inform future ADGs, there was support for reviewing evidence on a range of dietary exposures (including dietary patterns, foods and food groups, nutrients and food components, and eating occasions) and health outcomes, as well as evidence on environmental sustainability and equity. At the evidence synthesis stage, practicalities associated with planning the evidence review and conducting original systematic reviews were discussed. At the evidence translation stage, practicalities associated with integrating the evidence and consulting stakeholders were described. To ensure that the best available evidence is translated into future ADGs, evidence review methods should be selected based on the exposures and outcomes of interest.

NUQUEST-NUtrition QUality Evaluation Strengthening Tools: development of tools for the evaluation of risk of bias in nutrition studies

BACKGROUND

Dietary exposure assessments are a critical issue in evaluating human nutrition studies; however, nutrition-specific criteria are not consistently included in existing bias assessment tools.

OBJECTIVES

Our objective was to develop a set of risk of bias (RoB) tools that integrated nutrition-specific criteria into validated generic assessment tools to address RoB issues, including those specific to dietary exposure assessment.

METHODS

The Nutrition QUality Evaluation Strengthening Tools (NUQUEST) development and validation process included 8 steps. The first steps identified 1) a development strategy; 2) generic assessment tools with demonstrated validity; and 3) nutrition-specific appraisal issues. This was followed by 4) generation of nutrition-specific items and 5) development of guidance to aid users of NUQUEST. The final steps used established ratings of selected studies and feedback from independent raters to 6) assess reliability and validity; 7) assess formatting and usability; and 8) finalize NUQUEST.

RESULTS

NUQUEST is based on the Scottish Intercollegiate Guidelines Network checklists for randomized controlled trials, cohort studies, and case-control studies. Using a purposive sample of 45 studies representing the 3 study designs, interrater reliability was high (Cohen's κ: 0.73; 95% CI: 0.52, 0.93) across all tools and at least moderate for individual tools (range: 0.57-1.00). The use of a worksheet improved usability and consistency of overall interrater agreement across all study designs (40% without worksheet, 80%-100% with worksheet). When compared to published ratings, NUQUEST ratings for evaluated studies demonstrated high concurrent validity (93% perfect or near-perfect agreement). Where there was disagreement, the nutrition-specific component was a contributing factor in discerning exposure methodological issues.

CONCLUSIONS

NUQUEST integrates nutrition-specific criteria with generic criteria from assessment tools with demonstrated reliability and validity. NUQUEST represents a consistent and transparent approach for evaluating RoB issues related to dietary exposure assessment commonly encountered in human nutrition studies.

Dairy Product Consumption and Cardiovascular Health: a Systematic Review and Meta-Analysis of Prospective Cohort Studies

The association between dairy product consumption and cardiovascular health remains highly debated. We quantitatively synthesized prospective cohort evidence on the associations between dairy consumption and risk of hypertension (HTN), coronary heart disease (CHD) and stroke. We systematically searched PubMed, Embase, and Web of Science through August 1st, 2020 to retrieve prospective cohort studies that reported on dairy consumption and risk of HTN, CHD or stroke. We used random-effects models to calculate the pooled relative risk (RR) and 95% confidence interval (CI) for the highest vs the lowest category of intake and for 1 serving/day increase in consumption. We rated the quality of evidence using NutriGrade. Fifty-five studies were included. Total dairy consumption was associated with a lower risk of HTN (RR for highest vs lowest level of intake: 0.91, 95% CI: 0.86-0.95, I2 = 73.5%; RR for 1 serving/day increase: 0.96, 95% CI: 0.94-0.97, I2 = 66.5%), CHD (highest vs lowest level of intake: 0.96, 95% CI: 0.92-1.00, I2 = 46.6%; 1 serving/day increase: 0.98, 95% CI: 0.95-1.00, I2 = 56.7%), and stroke (highest vs lowest level of intake: 0.90, 95% CI: 0.85-0.96, I2 = 60.8%; 1 serving/day increase: 0.96, 95% CI: 0.93-0.99, I2 = 74.7%). Despite moderate to considerable heterogeneity, these associations remained consistent across multiple subgroups. Evidence on the relationship between total dairy and risk of HTN and CHD were of moderate quality and of low quality for stroke. Low-fat dairy consumption was associated with lower risk of HTN and stroke, and high-fat dairy with a lower risk of stroke. Milk, cheese, or yogurt consumption showed inconsistent associations with the cardiovascular outcomes in high vs. low intake and dose-response meta-analyses. Total dairy consumption was associated with a modestly lower risk of hypertension, CHD and stroke. Moderate to considerable heterogeneity was observed in the estimates and the overall quality of the evidence was low to moderate.