Balachandran Bashyam

Effect of a Dietary Portfolio of Cholesterol-Lowering Foods Given at 2 Levels of Intensity of Dietary Advice on Serum Lipids in Hyperlipidemia: A Randomized Controlled Trial

CONTEXT Combining foods with recognized cholesterol-lowering properties (dietary portfolio) has proven highly effective in lowering serum cholesterol under metabolically controlled conditions. OBJECTIVE To assess the effect of a dietary portfolio administered at 2 levels of intensity on percentage change in low-density lipoprotein cholesterol (LDL-C) among participants following self-selected diets. DESIGN, SETTING, AND PARTICIPANTS A parallel-design study of 351 participants with hyperlipidemia from 4 participating academic centers across Canada (Quebec City, Toronto, Winnipeg, and Vancouver) randomized between June 25, 2007, and February 19, 2009, to 1 of 3 treatments lasting 6 months. INTERVENTION Participants received dietary advice for 6 months on either a low-saturated fat therapeutic diet (control) or a dietary portfolio, for which counseling was delivered at different frequencies, that emphasized dietary incorporation of plant sterols, soy protein, viscous fibers, and nuts. Routine dietary portfolio involved 2 clinic visits over 6 months and intensive dietary portfolio involved 7 clinic visits over 6 months. MAIN OUTCOME MEASURES Percentage change in serum LDL-C. RESULTS In the modified intention-to-treat analysis of 345 participants, the overall attrition rate was not significantly different between treatments (18% for intensive dietary portfolio, 23% for routine dietary portfolio, and 26% for control; Fisher exact test, P = .33). The LDL-C reductions from an overall mean of 171 mg/dL (95% confidence interval [CI], 168-174 mg/dL) were -13.8% (95% CI, -17.2% to -10.3%; P < .001) or -26 mg/dL (95% CI, -31 to -21 mg/dL; P < .001) for the intensive dietary portfolio; -13.1% (95% CI, -16.7% to -9.5%; P < .001) or -24 mg/dL (95% CI, -30 to -19 mg/dL; P < .001) for the routine dietary portfolio; and -3.0% (95% CI, -6.1% to 0.1%; P = .06) or -8 mg/dL (95% CI, -13 to -3 mg/dL; P = .002) for the control diet. Percentage LDL-C reductions for each dietary portfolio were significantly more than the control diet (P < .001, respectively). The 2 dietary portfolio interventions did not differ significantly (P = .66). Among participants randomized to one of the dietary portfolio interventions, percentage reduction in LDL-C on the dietary portfolio was associated with dietary adherence (r = -0.34, n = 157, P < .001). CONCLUSION Use of a dietary portfolio compared with the low-saturated fat dietary advice resulted in greater LDL-C lowering during 6 months of follow-up. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00438425.

The effect of strawberries in a cholesterol-lowering dietary portfolio

Effective diets reduce blood lipids and oxidative damage, both of which have been linked to the complications of diabetes and coronary heart disease. Our objective was to assess the effect of adding strawberries, as a source of antioxidants, to improve the antioxidant effect of a cholesterol-lowering diet (dietary portfolio). To this end, 28 hyperlipidemic subjects who had followed the dietary portfolio consisting of soy, viscous fiber, plant sterol, and nuts for a mean of 2.5 years were randomized to receive supplements of strawberries (454 g/d, 112 kcal) or additional oat bran bread (65 g/d, 112 kcal, approximately 2 g beta-glucan) (control) in a randomized 1-month crossover study with a 2-week washout. Strawberry supplementation resulted in a greater reduction in oxidative damage to low-density lipoprotein (LDL) measured as thiobarbituric acid-reactive substances in the LDL fraction (P = .014). At the end of the strawberry period, reductions in LDL cholesterol and in the ratio of total to high-density lipoprotein cholesterol were maintained close to 1-year values at -13.4% +/- 2.1% and -15.2% +/- 1.7%, respectively (P < .001), and were similar to the post-oat bran bread values. Strawberries also improved the palatability of the diet. We conclude that strawberry supplementation reduced oxidative damage to LDL while maintaining reductions in blood lipids and enhancing diet palatability. Added fruit may improve the overall utility of diets designed to lower coronary heart disease risk.

Effect of Lowering the Glycemic Load With Canola Oil on Glycemic Control and Cardiovascular Risk Factors: A Randomized Controlled Trial

OBJECTIVE Despite their independent cardiovascular disease (CVD) advantages, effects of α-linolenic acid (ALA), monounsaturated fatty acid (MUFA), and low-glycemic-load (GL) diets have not been assessed in combination. We therefore determined the combined effect of ALA, MUFA, and low GL on glycemic control and CVD risk factors in type 2 diabetes. RESEARCH DESIGN AND METHODS The study was a parallel design, randomized trial wherein each 3-month treatment was conducted in a Canadian academic center between March 2011 and September 2012 and involved 141 participants with type 2 diabetes (HbA1c 6.5%–8.5% [48–69 mmol/mol]) treated with oral antihyperglycemic agents. Participants were provided with dietary advice on either a low-GL diet with ALA and MUFA given as a canola oil–enriched bread supplement (31 g canola oil per 2,000 kcal) (test) or a whole-grain diet with a whole-wheat bread supplement (control). The primary outcome was HbA1c change. Secondary outcomes included calculated Framingham CVD risk score and reactive hyperemia index (RHI) ratio. RESULTS Seventy-nine percent of the test group and 90% of the control group completed the trial. The test diet reduction in HbA1c units of −0.47% (−5.15 mmol/mol) (95% CI −0.54% to −0.40% [−5.92 to −4.38 mmol/mol]) was greater than that for the control diet (−0.31% [−3.44 mmol/mol] [95% CI −0.38% to −0.25% (−4.17 to −2.71 mmol/mol)], P = 0.002), with the greatest benefit observed in those with higher systolic blood pressure (SBP). Greater reductions were seen in CVD risk score for the test diet, whereas the RHI ratio increased for the control diet. CONCLUSIONS A canola oil–enriched low-GL diet improved glycemic control in type 2 diabetes, particularly in participants with raised SBP, whereas whole grains improved vascular reactivity.

Effect of almond consumption on the serum fatty acid profile: a dose–response study

Consumption of almonds has been shown to be associated with a decreased risk of CHD, which may be related to their fatty acid (FA) composition. However, the effect of almond consumption on the serum FA composition is not known. Therefore, in the present study, we investigated whether almond consumption would alter the serum FA profile and risk of CHD, as calculated using Framinghams 10-year risk score, in a dose-dependent manner in hyperlipidaemic individuals when compared with a higher-carbohydrate control group using dietary interventions incorporating almonds. A total of twenty-seven hyperlipidaemic individuals consumed three isoenergetic (mean 1770 kJ/d) supplements during three 1-month dietary phases: (1) full-dose almonds (50–100 g/d); (2) half-dose almonds with half-dose muffins; (3) full-dose muffins. Fasting blood samples were obtained at weeks 0 and 4 for the determination of FA concentrations. Almond intake (g/d) was found to be inversely associated with the estimated Framingham 10-year CHD risk score (P= 0·026). In both the half-dose and full-dose almond groups, the proportions of oleic acid (OA) and MUFA in the TAG fraction (half-almond: OA P= 0·003; MUFA P= 0·004; full-almond: OA P< 0·001; MUFA P< 0·001) and in the NEFA fraction (half-almond: OA P= 0·01; MUFA P= 0·04; full-almond: OA P= 0·12; MUFA P= 0·06) increased. The estimated Framingham 10-year CHD risk score was inversely associated with the percentage change of OA (P= 0·011) and MUFA (P= 0·016) content in the TAG fraction. The proportions of MUFA in the TAG and NEFA fractions were positively associated with changes in HDL-cholesterol concentrations. Similarly, the estimated Framingham 10-year CHD risk score was inversely associated with the percentage change of OA (P= 0·069) and MUFA content in the NEFA fraction (P= 0·009). In conclusion, the results of the present study indicate that almond consumption increases OA and MUFA content in serum TAG and NEFA fractions, which are inversely associated with CHD lipid risk factors and overall estimated 10-year CHD risk.

The effect of a dietary portfolio compared to a DASH-type diet on blood pressure

BACKGROUND AND AIM Compared to a DASH-type diet, an intensively applied dietary portfolio reduced diastolic blood pressure at 24 weeks as a secondary outcome in a previous study. Due to the importance of strategies to reduce blood pressure, we performed an exploratory analysis pooling data from intensively and routinely applied portfolio treatments from the same study to assess the effect over time on systolic, diastolic and mean arterial pressure (MAP), and the relation to sodium (Na(+)), potassium (K(+)), and portfolio components. METHODS AND RESULTS 241 participants with hyperlipidemia, from four academic centers across Canada were randomized and completed either a DASH-type diet (control n = 82) or a dietary portfolio that included, soy protein, viscous fibers and nuts (n = 159) for 24 weeks. Fasting measures and 7-day food records were obtained at weeks 0, 12 and 24, with 24-h urines at weeks 0 and 24. The dietary portfolio reduced systolic, diastolic and mean arterial blood pressure compared to the control by 2.1 mm Hg (95% CI, 4.2 to -0.1 mm Hg) (p = 0.056), 1.8 mm Hg (CI, 3.2 to 0.4 mm Hg) (p = 0.013) and 1.9 mm Hg (CI, 3.4 to 0.4 mm Hg) (p = 0.015), respectively. Blood pressure reductions were small at 12 weeks and only reached significance at 24 weeks. Nuts, soy and viscous fiber all related negatively to change in mean arterial pressure (ρ = -0.15 to -0.17, p ≤ 0.016) as did urinary potassium (ρ = -0.25, p = 0.001), while the Na(+)/K(+) ratio was positively associated (ρ = 0.20, p = 0.010). CONCLUSIONS Consumption of a cholesterol-lowering dietary portfolio also decreased blood pressure by comparison with a healthy DASH-type diet. CLINICAL TRIAL REG. NO.: NCT00438425, clinicaltrials.gov.

Nut consumption, serum fatty acid profile and estimated coronary heart disease risk in type 2 diabetes.

BACKGROUND AND AIMS Nut consumption has been associated with decreased risk of coronary heart disease (CHD) and type 2 diabetes which has been largely attributed to their healthy fatty acid profile, yet this has not been ascertained. Therefore, we investigated the effect of nut consumption on serum fatty acid concentrations and how these relate to changes in markers of glycemic control and calculated CHD risk score in type 2 diabetes. METHODS AND RESULTS 117 subjects with type 2 diabetes consumed one of three iso-energetic (mean 475 kcal/d) supplements for 12 weeks: 1. full-dose nuts (50-100 g/d); 2. half-dose nuts with half-dose muffins; and 3. full-dose muffins. In this secondary analysis, fatty acid concentrations in the phospholipid, triacylglycerol, free fatty acid, and cholesteryl ester fractions from fasting blood samples obtained at baseline and week 12 were analyzed using thin layer and gas chromatography. Full-dose nut supplementation significantly increased serum oleic acid (OA) and MUFAs compared to the control in the phospholipid fraction (OA: P = 0.036; MUFAs: P = 0.024). Inverse associations were found with changes in CHD risk versus changes in OA and MUFAs in the triacylglycerol (r = -0.256, P = 0.011; r = -0.228, P = 0.024, respectively) and phospholipid (r = -0.278, P = 0.006; r = -0.260, P = 0.010, respectively) fractions. In the cholesteryl ester fraction, change in MUFAs was inversely associated with markers of glycemic control (HbA1c: r = -0.250, P = 0.013; fasting blood glucose: r = -0.395, P < 0.0001). CONCLUSION Nut consumption increased OA and MUFA content of the serum phospholipid fraction, which was inversely associated with CHD risk factors and 10-year CHD risk. CLINICAL TRIAL REG NO NCT00410722, clinicaltrials.gov.

Supplemental Barley Protein and Casein Similarly Affect Serum Lipids in Hypercholesterolemic Women and Men

High-protein diets have been advocated for weight loss and the treatment of diabetes. Yet animal protein sources are often high in saturated fat and cholesterol. Vegetable protein sources, by contrast, are low in saturated fat and without associated cholesterol. We have therefore assessed the effect on serum lipids of raising the protein intake by 5% using a cereal protein, barley protein, as part of a standard therapeutic diet. Twenty-three hypercholesterolemic men and postmenopausal women completed a randomized crossover study comparing a bread enriched with either barley protein or calcium caseinate [30 g protein, 8374 kJ (2000 kcal)] taken separately as two 1-mo treatment phases with a minimum 2-wk washout. Body weight and diet history were collected weekly during each treatment. Fasting blood samples were obtained at wk 0, 2, and 4. Palatability, satiety, and compliance were similar for both the barley protein- and casein-enriched breads, with no differences between the treatments in effects on serum LDL cholesterol or C-reactive protein, measures of oxidative stress, or blood pressure. Nevertheless, because no adverse effects were observed on cardiovascular risk factors, barley protein remains an additional option for raising the protein content of the diet.

Low-glycaemic index diet to improve glycaemic control and cardiovascular disease in type 2 diabetes: design and methods for a randomised, controlled, clinical trial

Introduction Type 2 diabetes (T2DM) produces macrovascular and microvascular damage, significantly increasing the risk of cardiovascular disease (CVD), renal failure and blindness. As rates of T2DM rise, the need for effective dietary and other lifestyle changes to improve diabetes management become more urgent. Low-glycaemic index (GI) diets may improve glycaemic control in diabetes in the short term; however, there is a lack of evidence on the long-term adherence to low-GI diets, as well as on the association with surrogate markers of CVD beyond traditional risk factors. Recently, advances have been made in measures of subclinical arterial disease through the use of MRI, which, along with standard measures from carotid ultrasound (CUS) scanning, have been associated with CVD events. We therefore designed a randomised, controlled, clinical trial to assess whether low-GI dietary advice can significantly improve surrogate markers of CVD and long-term glycaemic control in T2DM. Methods and analysis 169 otherwise healthy individuals with T2DM were recruited to receive intensive counselling on a low-GI or high-cereal fibre diet for 3 years. To assess macrovascular disease, MRI and CUS are used, and to assess microvascular disease, retinal photography and 24-hour urinary collections are taken at baseline and years 1 and 3. Risk factors for CVD are assessed every 3 months. Ethics and dissemination The study protocol and consent form have been approved by the research ethics board of St. Michaels Hospital. If the study shows a benefit, these data will support the use of low-GI and/or high-fibre foods in the management of T2DM and its complications. Trial Registration number NCT01063374; Pre-results.

Cross-sectional associations between dietary intake and carotid intima media thickness in type 2 diabetes: baseline data from a randomised trial

Objective To assess associations between dietary intake and carotid intima media thickness (CIMT) by carotid ultrasound (CUS), a surrogate marker of cardiovascular disease (CVD) risk, in those with type 2 diabetes. Design Cross-sectional analysis of baseline data from 325 participants from three randomised controlled trials collected in the same way. Setting Risk Factor Modification Centre, St. Michaels Hospital, Toronto, Canada. Participants 325 participants with type 2 diabetes, taking oral antidiabetic agents, with an HbA1c between 6.5% and 8.0% at screening, without a recent cardiovascular event. Main outcome measures CIMT by CUS and associations with dietary intake from 7-day food records, as well as anthropometric measures and fasting serum samples. Results CIMT was significantly inversely associated with dietary pulse intake (β=−0.019, p=0.009), available carbohydrate (β=−0.004, p=0.008), glycaemic load (β=−0.001, p=0.007) and starch (β=−0.126, p=0.010), and directly associated with total (β=0.004, p=0.028) and saturated (β=0.012, p=0.006) fat intake in multivariate regression models adjusted for age, smoking, previous CVD event, blood pressure medication, antidiabetic medication and ultrasonographer. Conclusions Lower CIMT was significantly associated with greater consumption of dietary pulses and carbohydrates and lower total and saturated fat intake, suggesting a potential role for diet in CVD risk management in type 2 diabetes. Randomised controlled trials are anticipated to explore these associations further. Trial registration number NCT01063374.

Statement of Retraction. Nuts as a Replacement for Carbohydrates in the Diabetic Diet. Diabetes Care 2011;34:1706–1711. DOI: 10.2337/dc11-0338

The authors wish to retract this article because of an unintended error in statistical applications. A subsequent reanalysis of the data has shown that a number of the findings of the study described in this publication are no longer definitively different. The corresponding author voluntarily reported these discrepancies to the editors of Diabetes Care. The decision to retract the article is supported by all the authors based on their reevaluation of the data. The decision to retract the article is also supported by the editors of the journal and the American Diabetes Association, the publisher of Diabetes Care. At a later date, the authors intend to submit a revised article to Diabetes Care for full peer review with the appropriate statistical analysis applied.