BackgroundPlant-based diets have been recommended to reduce the risk of type 2 diabetes (T2D). However, not all plant foods are necessarily beneficial. We examined the association of an overall plant-based diet and hypothesized healthful and unhealthful versions of a plant-based diet with T2D incidence in three prospective cohort studies in the US.Methods and FindingsWe included 69,949 women from the Nurses’ Health Study (1984–2012), 90,239 women from the Nurses’ Health Study 2 (1991–2011), and 40,539 men from the Health Professionals Follow-Up Study (1986–2010), free of chronic diseases at baseline. Dietary data were collected every 2–4 y using a semi-quantitative food frequency questionnaire. Using these data, we created an overall plant-based diet index (PDI), where plant foods received positive scores, while animal foods (animal fats, dairy, eggs, fish/seafood, poultry/red meat, miscellaneous animal-based foods) received reverse scores. We also created a healthful plant-based diet index (hPDI), where healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, vegetable oils, tea/coffee) received positive scores, while less healthy plant foods (fruit juices, sweetened beverages, refined grains, potatoes, sweets/desserts) and animal foods received reverse scores. Lastly, we created an unhealthful plant-based diet index (uPDI) by assigning positive scores to less healthy plant foods and reverse scores to healthy plant foods and animal foods.We documented 16,162 incident T2D cases during 4,102,369 person-years of follow-up. In pooled multivariable-adjusted analysis, both PDI and hPDI were inversely associated with T2D (PDI: hazard ratio [HR] for extreme deciles 0.51, 95% CI 0.47–0.55, p trend < 0.001; hPDI: HR for extreme deciles 0.55, 95% CI 0.51–0.59, p trend < 0.001). The association of T2D with PDI was considerably attenuated when we additionally adjusted for body mass index (BMI) categories (HR 0.80, 95% CI 0.74–0.87, p trend < 0.001), while that with hPDI remained largely unchanged (HR 0.66, 95% CI 0.61–0.72, p trend < 0.001). uPDI was positively associated with T2D even after BMI adjustment (HR for extreme deciles 1.16, 95% CI 1.08–1.25, p trend < 0.001). Limitations of the study include self-reported diet assessment, with the possibility of measurement error, and the potential for residual or unmeasured confounding given the observational nature of the study design.ConclusionsOur study suggests that plant-based diets, especially when rich in high-quality plant foods, are associated with substantially lower risk of developing T2D. This supports current recommendations to shift to diets rich in healthy plant foods, with lower intake of less healthy plant and animal foods.

Background Plant-based diets are recommended for coronary heart disease (CHD) prevention. However, not all plant foods are necessarily beneficial for health. Objectives To examine associations between plant-based diet indices and CHD incidence. Methods We included 73,710 women in Nurses’ Health Study (NHS) (1984–2012), 92,329 women in NHS2 (1991–2013), and 43,259 men in Health Professionals Follow-up Study (1986–2012), free of chronic diseases at baseline. We created an overall plant-based diet index (PDI) from repeated semi quantitative food-frequency questionnaire data, by assigning positive scores to plant foods and reverse scores to animal foods. We also created a healthful PDI (hPDI) where healthy plant foods (whole grains, fruits/vegetables, nuts/legumes, oils, tea/coffee) received positive scores, while less-healthy plant foods (juices/sweetened beverages, refined grains, potatoes/fries, sweets) and animal foods received reverse scores. To create an unhealthful PDI (uPDI), we gave positive scores to less-healthy plant foods and reverse scores to animal and healthy plant foods. Results Over 4,833,042 person-years of follow-up, we documented 8,631 incident CHD cases. In pooled multivariable analysis, higher adherence to PDI was independently inversely associated with CHD (HR comparing extreme deciles: 0.92, 95% CI: 0.83–1.01; p trend=0.003). This inverse association was stronger for hDPI (HR: 0.75, 95% CI: 0.68–0.83; p trend<0.001). Conversely, uPDI was positively associated with CHD (HR: 1.32, 95% CI: 1.20–1.46; p trend<0.001). Conclusions Higher intake of a plant-based diet index rich in healthier plant foods is associated with substantially lower CHD risk, while a plant-based diet index that emphasizes less-healthy plant foods is associated with higher CHD risk.

Dietary guidelines provide evidence-based statements on food choices to meet nutritional requirements and reduce the risk of prevailing chronic disease. They involve a substantial amount of research translation, and their implementation has important health consequences. Foods, however, are complex combinations of nutrients and other compounds that act synergistically within the food and across food combinations. In addition, the evidence base underpinning dietary guidelines accesses research that reflects different study designs, with inherent strengths and limitations. We propose a systematic approach for the review of evidence that begins with research on dietary patterns. This research will identify the combinations of foods that best protect, or appear deleterious to, health. Next, we suggest that evidence be sought from research that focuses on the effects of individual foods. Finally, nutrient-based research should be considered to explain the mechanisms by which these foods and dietary patterns exert their effects, take into account the effects of ingredients added to the food supply, and enable assessments of dietary sufficiency. The consideration of individual nutrients and food components (e.g., upper limits for saturated fat, added sugar, and sodium) provides important benchmarks for evaluating overall diet quality. The concepts of core and discretionary foods (nutrient-rich and nutrient-poor foods, respectively) enable distinctions between foods, and this has implications for the relation between food policy and food manufacturing. In summary, evidence supporting healthy dietary patterns provides the foundation for the development of dietary guidelines. Further reference to individual foods and nutrients follows from the foundation of healthy dietary patterns.

Nutritional epidemiology has recently been criticized on several fronts, including the inability to measure diet accurately, and for its reliance on observational studies to address etiologic questions. In addition, several recent meta-analyses with serious methodologic flaws have arrived at erroneous or misleading conclusions, reigniting controversy over formerly settled debates. All of this has raised questions regarding the ability of nutritional epidemiologic studies to inform policy. These criticisms, to a large degree, stem from a misunderstanding of the methodologic issues of the field and the inappropriate use of the drug trial paradigm in nutrition research. The exposure of interest in nutritional epidemiology is human diet, which is a complex system of interacting components that cumulatively affect health. Consequently, nutritional epidemiology constantly faces a unique set of challenges and continually develops specific methodologies to address these. Misunderstanding these issues can lead to the nonconstructive and sometimes naive criticisms we see today. This article aims to clarify common misunderstandings of nutritional epidemiology, address challenges to the field, and discuss the utility of nutritional science in guiding policy by focusing on 5 broad questions commonly asked of the field.

Plant-based diets, defined in terms of low frequency of animal food consumption, have been increasingly recommended for their health benefits. Numerous studies have found plant-based diets, especially when rich in high quality plant foods such as whole grains, fruits, vegetables, and nuts, to be associated with lower risk of cardiovascular outcomes and intermediate risk factors. This review summarizes the current evidence base examining the associations of plant-based diets with cardiovascular endpoints, and discusses the potential biological mechanisms underlying their health effects, practical recommendations and applications of this research, and directions for future research. Healthful plant-based diets should be recommended as an environmentally sustainable dietary option for improved cardiovascular health.

Background Considerable controversy exists regarding the association between coffee consumption and cardiovascular disease (CVD) risk. A meta-analysis was performed to assess the dose-response relationship of long-term coffee consumption with CVD risk. Methods and Results Pubmed and EMBASE were searched for prospective cohort studies of the relationship between coffee consumption and CVD risk, which included coronary heart disease, stroke, heart failure, and CVD mortality. Thirty-six studies were included with 1,279,804 participants and 36,352 CVD cases. A non-linear relationship of coffee consumption with CVD risk was identified (P for heterogeneity = 0.09, P for trend < 0.001, P for non-linearity < 0.001). Compared with the lowest category of coffee consumption (median: 0 cups/d), the relative risk of CVD was 0.95 (95% CI, 0.87 to 1.03) for the highest (median: 5 cups/d) category, 0.85 (0.80 to 0.90) for the second highest (median: 3.5 cups/d), and 0.89 (0.84 to 0.94) for the third highest category (median: 1.5 cups/d). Looking at separate outcomes, coffee consumption was non-linearly associated with both CHD (P for heterogeneity = 0.001, P for trend < 0.001, P for non-linearity < 0.001) and stroke risks (P for heterogeneity = 0.07, P for trend < 0.001, P for non-linearity< 0.001) (P for trend differences > 0.05). Conclusions A non-linear association between coffee consumption with CVD risk was observed in this meta-analysis. Moderate coffee consumption was inversely significantly associated with CVD risk, with the lowest CVD risk at 3 to 5 cups/d, and heavy coffee consumption was not associated with elevated CVD risk.

Conclusions: Outcomes for repair of ruptured abdominal aortic aneurysms (rAAA) might be improved by wider use of local anesthesia for EVAR and by recognizing that a minimum blood pressure of 70 mmHg may be too low a threshold for permissive hypotension.Summary: Most data on outcomes of patients with rAAAs are singlecenter studies and as such may be too small to identify clinical factors that could improve overall patient outcomes. The IMPROVE study is a pragmatic multicenter randomized clinical trial in which eligible patients with a clinical diagnosis of rAAA were allocated to a strategy of endovascular repair of RAAAA (EVAR) or to open repair. IMPROVE showed no difference in 30-day mortality with a strategy incorporating EVAR for repair of a rAAAA compared to a strategy of open repair for ruptured abdominal aortic aneurysm (IMPROVE trial investigators, Brit Med J 2014;348:f7661). In this paper the IMPROVE investigators sought to analyze influences of time and manner of hospital presentation, fluid volume status, type of anesthesia, type of endovascular repair and time to aneurysm repair on 30-day mortality for rAAA. This was a prespecified plan of analyses to include only the patients who underwent aneurysm repair for a proven diagnosis of rAAA . Adjustments were made for potential confounding factors. In IMPROVE, 568 of 613 randomized patients had a symptomatic or rAAA and diagnostic accuracy was 91%. Patients randomized outside routine working hours had higher operative mortality (adjusted odds ratio, 1.47, 95% CI, 1.00-2.17). There was no difference in mortality rates between those patients admitted directly to a trial center versus those transferred to a trail center from a referring institution. Lowest systolic blood pressure was strongly and independently associated with 30-day mortality (51% among those with systolic blood pressures below 70 mmHg). In addition, patients who received EVAR under local anesthesia alone had reduced 30-day mortality compared to those who had EVAR under general anesthesia (adjusted odds ratio, 0.27; 95% CI, 0.10-0.70). In patients with confirmed rupture the time from randomization to the operating suite was not associated with 30-day mortality (P ¼ .415).Comment: The data indicate that blood pressure of 70 mmHg may be too low for optimal results in a patient with rAAA and permissive hypotensive levels should be above this. In addition, when EVAR is used to treat a rAAAA it may be best to do it, if possible, under local anesthesia. Finally, given the fact that results for repair of rAAA are no worse for a patient who is transferred than for those with a primary presentation to a specialist center, along with the fact that patients undergoing off-hours repair do more poorly suggests that a skilled multidisciplinary vascular team including specialists anesthesia services is likely to provide the best results for repair of a rAAA in any individual region. Outcomes for patients with rAAA therefore may be best served by a policy of regionalization of care for such patients to speci...

This paper summarizes the literature on the impact of state subsidized or social health insurance schemes that have been offered, mostly on a voluntary basis, to the informal sector in low-and middle-income countries. A substantial number of papers provide estimations of average treatment on the treated effect for insured persons. We summarize papers that correct for the problem of self-selection into insurance and papers that estimate the average intention to treat effect. Summarizing the literature was difficult because of the lack of (1) uniformity in the use of meaningful definitions of outcomes that indicate welfare improvements and (2) clarity in the consideration of selection issues. We find the uptake of insurance schemes, in many cases, to be less than expected. In general, we find no strong evidence of an impact on utilization, protection from financial risk, and health status. However, a few insurance schemes afford significant protection from high levels of out-of-pocket expenditures. In these cases, however, the impact on the poor is weaker. More information is needed to understand the reasons for low enrollment and to explain the limited impact of health insurance among the insured.