The Dietary Approaches to Stop Hypertension (DASH) dietary pattern, which emphasizes fruit, vegetables, fat-free/low-fat dairy, whole grains, nuts and legumes, and limits saturated fat, cholesterol, ...red and processed meats, sweets, added sugars, salt and sugar-sweetened beverages, is widely recommended by international diabetes and heart association guidelines.
To summarize the available evidence for the update of the European Association of the Study of Diabetes (EASD) guidelines, we conducted an umbrella review of existing systematic reviews and meta-analyses using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach of the relation of the DASH dietary pattern with cardiovascular disease and other cardiometabolic outcomes in prospective cohort studies and its effect on blood pressure and other cardiometabolic risk factors in controlled trials in individuals with and without diabetes.
MEDLINE and EMBASE were searched through 3 January 2019. We included systematic reviews and meta-analyses assessing the relation of the DASH dietary pattern with cardiometabolic disease outcomes in prospective cohort studies and the effect on cardiometabolic risk factors in randomized and non-randomized controlled trials. Two independent reviewers extracted relevant data and assessed the risk of bias of individual studies. The primary outcome was incident cardiovascular disease (CVD) in the prospective cohort studies and systolic blood pressure in the controlled trials. Secondary outcomes included incident coronary heart disease, stroke, and diabetes in prospective cohort studies and other established cardiometabolic risk factors in controlled trials. If the search did not identify an existing systematic review and meta-analysis on a pre-specified outcome, then we conducted our own systematic review and meta-analysis. The evidence was summarized as risk ratios (RR) for disease incidence outcomes and mean differences (MDs) for risk factor outcomes with 95% confidence intervals (95% CIs). The certainty of the evidence was assessed using GRADE.
We identified three systematic reviews and meta-analyses of 15 unique prospective cohort studies (
= 942,140) and four systematic reviews and meta-analyses of 31 unique controlled trials (
= 4,414) across outcomes. We conducted our own systematic review and meta-analysis of 2 controlled trials (
= 65) for HbA1c. The DASH dietary pattern was associated with decreased incident cardiovascular disease (RR, 0.80 (0.76⁻0.85)), coronary heart disease (0.79 (0.71⁻0.88)), stroke (0.81 (0.72⁻0.92)), and diabetes (0.82 (0.74⁻0.92)) in prospective cohort studies and decreased systolic (MD, -5.2 mmHg (95% CI, -7.0 to -3.4)) and diastolic (-2.60 mmHg (-3.50 to -1.70)) blood pressure, Total-C (-0.20 mmol/L (-0.31 to -0.10)), LDL-C (-0.10 mmol/L (-0.20 to -0.01)), HbA1c (-0.53% (-0.62, -0.43)), fasting blood insulin (-0.15 μU/mL (-0.22 to -0.08)), and body weight (-1.42 kg (-2.03 to -0.82)) in controlled trials. There was no effect on HDL-C, triglycerides, fasting blood glucose, HOMA-IR, or CRP. The certainty of the evidence was moderate for SBP and low for CVD incidence and ranged from very low to moderate for the secondary outcomes.
Current evidence allows for the conclusion that the DASH dietary pattern is associated with decreased incidence of cardiovascular disease and improves blood pressure with evidence of other cardiometabolic advantages in people with and without diabetes. More research is needed to improve the certainty of the estimates.
The Diabetes and Nutrition Study Group (DNSG) of the European Association for the Study of Diabetes (EASD) conducted a review of existing systematic reviews and meta-analyses to explain the ...relationship between different dietary patterns and patient-important cardiometabolic outcomes. To update the clinical practice guidelines for nutrition therapy in the prevention and management of diabetes, we summarize the evidence from these evidence syntheses for the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), Portfolio, Nordic, liquid meal replacement, and vegetarian dietary patterns. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the quality of evidence. We summarized the evidence for disease incidence outcomes and risk factor outcomes using risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs), respectively. The Mediterranean diet showed a cardiovascular disease (CVD) incidence (RR: 0.62; 95%CI, 0.50, 0.78), and non-significant CVD mortality (RR: 0.67; 95%CI, 0.45, 1.00) benefit. The DASH dietary pattern improved cardiometabolic risk factors (
< 0.05) and was associated with the decreased incidence of CVD (RR, 0.80; 95%CI, 0.76, 0.85). Vegetarian dietary patterns were associated with improved cardiometabolic risk factors (
< 0.05) and the reduced incidence (0.72; 95%CI: 0.61, 0.85) and mortality (RR, 0.78; 95%CI, 0.69, 0.88) of coronary heart disease. The Portfolio dietary pattern improved cardiometabolic risk factors and reduced estimated 10-year coronary heart disease (CHD) risk by 13% (-1.34% (95%CI, -2.19 to -0.49)). The Nordic dietary pattern was correlated with decreased CVD (0.93 (95%CI, 0.88, 0.99)) and stroke incidence (0.87 (95%CI, 0.77, 0.97)) and, along with liquid meal replacements, improved cardiometabolic risk factors (
< 0.05). The evidence was assessed as low to moderate certainty for most dietary patterns and outcome pairs. Current evidence suggests that the Mediterranean, DASH, Portfolio, Nordic, liquid meal replacement and vegetarian dietary patterns have cardiometabolic advantages in populations inclusive of diabetes.
To update the European Association for the Study of Diabetes (EASD) clinical practice guidelines for nutrition therapy, we conducted a systematic review and meta-analysis of randomized controlled ...trials to summarize the evidence for the effect of vegetarian dietary patterns on glycemic control and other established cardiometabolic risk factors in individuals with diabetes.
We searched MEDLINE, EMBASE, and Cochrane databases through February 26, 2018 for randomized controlled trials ≥3 weeks assessing the effect of vegetarian dietary patterns in individuals with diabetes. The primary outcome was HbA1c. Secondary outcomes included other markers of glycemic control, blood lipids, body weight/adiposity, and blood pressure. Two independent reviewers extracted data and assessed risk of bias. Data were pooled by the generic inverse variance method and expressed as mean differences (MD) with 95% CIs. Heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). The overall certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.
Nine trials (n = 664 participants) met the eligibility criteria. Vegetarian dietary patterns significantly lowered HbA1c (MD = −0.29% 95% CI: −0.45, −0.12%), fasting glucose (MD = −0.56 mmol/L 95% CI: −0.99, −0.13 mmol/L), LDL-C (MD = −0.12 mmol/L 95% CI: −0.20, −0.04 mmol/L), non-HDL-C (MD = −0.13 mmol/L 95% CI: −0.26, −0.01 mmol/L), body weight (MD = −2.15 kg 95% CI: −2.95, −1.34 kg), BMI (MD = −0.74 kg/m2 95% CI: −1.09, −0.39 kg/m2) and waist circumference (MD = −2.86 cm 95% CI: −3.76, −1.96 cm). There was no significant effect on fasting insulin, HDL-C, triglycerides or blood pressure. The overall certainty of evidence was moderate but was low for fasting insulin, triglycerides and waist circumference.
Vegetarian dietary patterns improve glycemic control, LDL-C, non-HDL-C, and body weight/adiposity in individuals with diabetes, supporting their inclusion for diabetes management. More research is needed to improve our confidence in the estimates.
NCT02600377.
The role of sugar-sweetened beverages (SSBs) that contain free or bound fructose in the pathogenesis of hypertension remains unclear.
We conducted a systematic review and meta-analysis of prospective ...cohort studies to quantify the association between fructose-containing SSBs and risk of hypertension.
MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, and the Cochrane registry were searched from conception through 11 November 2014. Two independent reviewers extracted data and assessed the quality of studies (with the use of the Newcastle-Ottawa Scale). Risk estimates of extreme quantiles of SSB intake (lowest compared with highest) for hypertension incidence were generated with the use of generic inverse-variance methods with random-effects models and expressed as risk ratios with 95% CIs. Heterogeneity was assessed with the Cochran Q statistic and quantified with the I(2) statistic.
Six prospective cohort studies (n = 240,508) with 79,251 cases of hypertension observed over ≥3,197,528 person-years of follow-up were included. SSB consumption significantly increased the risk of developing hypertension by 12% (risk ratio: 1.12; 95% CI: 1.06, 1.17) with evidence of significant heterogeneity (I(2) = 62%, P = 0.02) when highest ≥1 serving (6.7, 8, or 12 oz)/d and lowest (none) quantiles of intake were compared. With the use of a dose-response analysis, a significant 8.2% increase in risk of every additional SSB per day from none to ≥1 SSB/d (β = 0.0027, P < 0.001) was identified. Limitations include unexplained heterogeneity and residual confounding. The results may also have been subject to collinearity effects from aspects of a Western dietary pattern.
SSBs were associated with a modest risk of developing hypertension in 6 cohorts. There is a need for high-quality randomized trials to assess the role of SSBs in the development of hypertension and its complications. This study was registered at clinicaltrials.gov as NCT01608620.
The glycemic index concept is an extension of the fiber hypothesis, suggesting that fiber consumption reduces the rate of nutrient influx from the gut. The glycemic index has particular relevance to ...those chronic Western diseases associated with central obesity and insulin resistance. Early studies showed that starchy carbohydrate foods have very different effects on postprandial blood glucose and insulin responses in healthy and diabetic subjects, depending on the rate of digestion. A range of factors associated with food consumption was later shown to alter the rate of glucose absorption and subsequent glycemia and insulinemia. At this stage, systematic documentation of the differences that exist among carbohydrate foods was considered essential. The resulting glycemic index classification of foods provided a numeric physiologic classification of relevant carbohydrate foods in the prevention and treatment of diseases such as diabetes. Since then, low-glycemic-index diets have been shown to lower urinary C-peptide excretion in healthy subjects, improve glycemic control in diabetic subjects, and reduce serum lipids in hyperlipidemic subjects. Furthermore, consumption of low-glycemicindex diets has been associated with higher HDL-cholesterol concentrations and, in large cohort studies, with decreased risk of developing diabetes and cardiovascular disease. Case-control studies have also shown positive associations between dietary glycemic index and the risk of colon and breast cancers. Despite inconsistencies in the data, sufficient, positive findings have emerged to suggest that the dietary glycemic index is of potential importance in the treatment and prevention of chronic diseases.
To synthesize the evidence of the effect of small doses (≤30-g/meal) of fructose and its epimers (allulose, tagatose, and sorbose) on the postprandial glucose and insulin response to ...carbohydrate-containing meals.
MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched through to April 9, 2019. We included randomized (RCTs) and non-randomized acute, single-meal, controlled feeding trials that added ≤30-g of fructose or its epimers either prior to or with a carbohydrate-containing meal compared with the same meal alone. Outcomes included the incremental area under the curve (iAUC) for glucose and insulin, the Matsuda Insulin Sensitivity Index, and the Early Insulin Secretion Index. Data were expressed as ratio of means (RoM) with 95% CIs and pooled using the inverse variance method. The overall certainty of the evidence was evaluated using GRADE.
Forty trial comparisons (n = 400) were included (none for sorbose). Allulose significantly reduced the postprandial iAUC glucose response by 10% (0.90 0.84 to 0.96, P < 0.01). Tagatose significantly reduced the postprandial iAUC insulin response by 25% (0.75 0.62 to 0.91, P < 0.01) and showed a non-significant 3% reduction in the postprandial iAUC glucose response (0.97 0.94 to 1.00, P = 0.07). There was no effect of fructose on any outcome. The certainty of the evidence was graded as low to moderate for fructose, moderate for allulose, and low for tagatose.
Small doses of allulose and tagatose, but not fructose, lead to modest improvements on postprandial glucose and insulin regulation. There is a need for long-term RCTs to confirm the sustainability of these improvements.
Comprehensive lifestyle management is a fundamental aspect of diabetes care. Clinical practice guidelines for the nutritional management of diabetes have evolved considerably over the last 25 years ...shifting from a focus on single nutrients to food- and dietary pattern-based recommendations. Use of meal replacements as a temporary short-term strategy to induce weight loss and then transitioning to a healthier dietary pattern (e.g., Mediterranean or Portfolio) for weight loss maintenance fits well with this new shift in focus of clinical practice guidelines. As adherence is the most important determinant for attaining the benefits of any diet, health professionals should recommend evidence-based dietary patterns (including meal replacements) that align best with the patient's values, preferences, and treatment goals.
Certain nutrients and phytochemicals in almonds may confer protection against cardiovascular disease, but little is known about factors that influence their bioavailability. A crucial and relevant ...aspect is the amount of these dietary components available for absorption in the intestine, which is a concept referred to as bioaccessibility.
We investigated the role played by cell walls in influencing the bioaccessibility of intracellular lipid from almond seeds.
Quantitative analyses of nonstarch polysaccharides (NSPs) and phenolic compounds of cell walls were performed by gas-liquid chromatography and HPLC, respectively. In a series of experiments, the effects of mechanical disruption, chewing, and digestion on almond seed microstructure and intracellular lipid release were determined. In the digestibility study, fecal samples were collected from healthy subjects who had consumed diets with or without almonds. Almond seeds and fecal samples were examined by microscopy to identify cell walls and intracellular lipid.
Cell walls were found to be rich in NSPs, particularly arabinose-rich polysaccharides, with a high concentration of phenolic compounds detected in the seed coat cell wall. During disruption of almond tissue by mechanical methods or chewing, only the first layer of cells at the fractured surface was ruptured and able to release lipid. In fecal samples collected from subjects consuming the almond diet, we observed intact cotyledonary cells, in which the cell walls encapsulated intracellular lipid. This lipid appeared susceptible to colonic fermentation once the cotyledonary cell walls were breached by bacterial degradation.
The cell walls of almond seeds reduce lipid bioaccessibility by hindering the release of lipid available for digestion.
Background: Many of the benefits of soy have been attributed to soy isoflavones. Objective: The objective was to determine the effects of high- and low-isoflavone soy-protein foods on both lipid and ...nonlipid risk factors for coronary artery disease (CAD). Methods: Forty-one hyperlipidemic men and postmenopausal women participated in a study with three 1-mo diets: a low-fat dairy food control diet and high- (50 g soy protein and 73 mg isoflavones daily) and low- (52 g soy protein and 10 mg isoflavones daily) isoflavone soyfood diets. All 3 diets were very low in saturated fat (< 5% of energy) and cholesterol (< 50 mg/d). Fasting blood samples were drawn and blood pressure was measured at the start and end of each diet. Results: No significant differences were seen between the high- and low-isoflavone soy diets. Compared with the control diet, however, both soy diets resulted in significantly lower total cholesterol, estimated CAD risk, and ratios of total to HDL cholesterol, LDL to HDL cholesterol, and apolipoprotein B to A-I. No significant sex differences were observed, except for systolic blood pressure, which in men was significantly lower after the soy diets than after the control diet. On the basis of blood lipid and blood pressure changes, the calculated CAD risk was significantly lower with the soy diets, by 10.1 +/- 2.7%. Conclusion: Substitution of soyfoods for animal products, regardless of isoflavone concentration, reduces the CAD risk because of both modest reductions in blood lipids and reductions in oxidized LDL, homocysteine, and blood pressure.
BACKGROUND: Cholesterol-lowering foods may be more effective when consumed as combinations rather than as single foods. OBJECTIVES: Our aims were to determine the effectiveness of consuming a ...combination of cholesterol-lowering foods (dietary portfolio) under real-world conditions and to compare these results with published data from the same participants who had undergone 4-wk metabolic studies to compare the same dietary portfolio with the effects of a statin. DESIGN: For 12 mo, 66 hyperlipidemic participants were prescribed diets high in plant sterols (1.0 g/1000 kcal), soy protein (22.5 g/1000 kcal), viscous fibers (10 g/1000 kcal), and almonds (23 g/1000 kcal). Fifty-five participants completed the 1-y study. The 1-y data were also compared with published results on 29 of the participants who had also undergone separate 1-mo metabolic trials of a diet and a statin. RESULTS: At 3 mo and 1 y, mean (±SE) LDL-cholesterol reductions appeared stable at 14.0 ± 1.6% (P < 0.001) and 12.8 ± 2.0% (P < 0.001), respectively (n = 66). These reductions were less than those observed after the 1-mo metabolic diet and statin trials. Nevertheless, 31.8% of the participants (n = 21 of 66) had LDL-cholesterol reductions of >20% at 1 y (x ± SE: -29.7 ± 1.6%). The LDL-cholesterol reductions in this group were not significantly different from those seen after their respective metabolically controlled portfolio or statin treatments. A correlation was found between total dietary adherence and LDL-cholesterol change (r = -0.42, P < 0.001). Only 2 of the 26 participants with <55% compliance achieved LDL-cholesterol reductions >20% at 1 y. CONCLUSIONS: More than 30% of motivated participants who ate the dietary portfolio of cholesterol-lowering foods under real-world conditions were able to lower LDL-cholesterol concentrations >20%, which was not significantly different from their response to a first-generation statin taken under metabolically controlled conditions.
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