Archive

Research Area: Cardiovascular Health

Comparative effects of different types of tree nut consumption on blood lipids: a network meta-analysis of clinical trials.

Liu, K., S. Hui, B. Wang, K. Kaliannan, X. Guo, L. Liang, 2020. Comparative effects of different types of tree nut consumption on blood lipids: a network meta-analysis of clinical trials. Am J Clin Nutr. 111(1):219-227.

Background: Recent evidence has confirmed that nuts are one of the best food groups at reducing LDL cholesterol and total cholesterol (TC). However, the comparative effects of different types of nuts on blood lipids are unclear. Objectives: This network meta-analysis of randomized clinical trials aimed to assess the comparative effects of walnuts, pistachios, hazelnuts, cashews, and almonds on typical lipid profiles. Methods: We conducted literature searches to identify studies comparing ≥2 of the following diets-walnut-enriched, pistachio-enriched, hazelnut-enriched, cashew-enriched, almond-enriched, and control diets-for the management of triglycerides (TGs), LDL cholesterol, TC, and HDL cholesterol. Random-effects network meta-analyses, ranking analyses based on the surface under the cumulative ranking (SUCRA) curves, and sensitivity analyses according to the potential sources of heterogeneity across the included studies were performed for each outcome. Results: Thirty-four trials enrolling 1677 participants were included in this study. The pistachio-enriched diet was ranked best for TG (SUCRA: 85%), LDL cholesterol (SUCRA: 87%), and TC (SUCRA: 96%) reductions. For TG and TC reductions, the walnut-enriched diet was ranked as the second-best diet. Regarding LDL cholesterol reduction, the almond-enriched diet was ranked second best. The pistachio-enriched and walnut-enriched diets were more effective at lowering TG, LDL cholesterol, and TC compared with the control diet. Regarding TG and TC reductions, the pistachio-enriched diet was also more effective than the hazelnut-enriched diet. For TG reduction, the walnut-enriched diet was better than the hazelnut-enriched diet. However, these findings are limited by the low quality of evidence ratings. In addition, the quality of this network meta-analysis was limited by the small number and generally poor reporting of available studies. Conclusions: The pistachio-enriched and walnut-enriched diet could be better alternatives for lowering TGs, LDL cholesterol, and TC compared with other nut-enriched diets included in this study. The findings warrant further evaluation by more high-quality studies. This network meta-analysis was registered at www.crd.york.ac.uk/PROSPERO as CRD42019131128.

Effects of a healthy diet enriched or not with pecan nuts or extra-virgin olive oil on the lipid profile of patients with stable coronary artery disease: a randomised clinical trial.

Campos, V.P., V.L. Portal, M.M. Markoski, A.S. Quadros, Â.C. Bersch-Ferreira, J. Garavaglia, A. Marcadenti, 2020. Effects of a healthy diet enriched or not with pecan nuts or extra-virgin olive oil on the lipid profile of patients with stable coronary artery disease: a randomised clinical trial. J Hum Nutr Diet. 33(3):439-450.

Background: The present study aimed to assess the effect of a healthy diet, enriched or not with pecan nuts or extra-virgin olive oil, on the lipid profile of patients with stable coronary artery disease (CAD). Methods: This was a randomised clinical trial conducted for 12 weeks with patients aged between 40 and 80 years with stable CAD for more than 60 days. Individuals were randomised into groups [control group (CG) with 67 patients, pecan nut group (PNG) with 68 patients and olive oil group (OOG) with 69 patients]. The CG was prescribed a healthy diet according to the nutritional guidelines; the PNG was prescribed the same healthy diet plus 30 g day-1 of pecan nuts; and the OOG was prescribed a healthy diet plus 30 mL day-1 of extra-virgin olive oil. Results: In total, 204 subjects were submitted to an intention-to-treat analysis. After adjustment for baseline values and type of statin used, there was no difference regarding low-density lipoprotein (LDL)-cholesterol (primary outcome), high-density lipoprotein (HDL)-cholesterol, LDL-cholesterol/HDL-cholesterol ratio and HDL-cholesterol/triglycerides ratio according to groups. However, the PNG exhibited a significant reduction in non-HDL-cholesterol levels [PNG: 114.9 (31) mg dL-1 ; CG: 127 (33.6) mg dL-1 ; OOG: 126.6 (37.4) mg dL-1 ; P = 0.033] and in the total cholesterol/HDL-cholesterol ratio [PNG: 3.7 (0.7); CG: 4.0 (0.8); OOG: 4.0 (0.8); P = 0.044] compared to the CG and OOG. Conclusions: Supplementing a healthy diet with 30 g day-1 of pecan nuts for 12 weeks did not improve LDL-cholesterol levels but may improve other lipid profile markers in patients with stable CAD.

The effect of green Mediterranean diet on cardiometabolic risk; a randomised controlled trial.

Tsaban, G., A. Yaskolka Meir, E. Rinott, H. Zelicha, A. Kaplan, A. Shalev, A. Katz, A. Rudich, A. Tirosh, I. Shelef, I. Youngster, S. Lebovitz,  N. Israeli, M. Shabat, D. Brikner, E. Pupkin, M. Stumvoll, J. Thiery, U. Ceglarek, J.T. Heiker, A. Körner, K. Landgraf, M. von Bergen, M. Blüher, M.J. Stampfer, I. Shai, 2020. The effect of green Mediterranean diet on cardiometabolic risk; a randomised controlled trial. Heart. heartjnl-2020-317802.  doi: 10.1136/heartjnl-2020-317802.

Background: A Mediterranean diet is favourable for cardiometabolic risk. Objective To examine the residual effect of a green Mediterranean diet, further enriched with green plant-based foods and lower meat intake, on cardiometabolic risk. Methods:  For the DIRECT-PLUS parallel, randomised clinical trial we assigned individuals with abdominal obesity/dyslipidaemia 1:1:1 into three diet groups: healthy dietary guidance (HDG), Mediterranean and green Mediterranean diet, all combined with physical activity. The Mediterranean diets were equally energy restricted and included 28 g/day walnuts. The green Mediterranean diet further included green tea (3–4 cups/day) and a Wolffia globosa (Mankai strain; 100 g/day frozen cubes) plant-based protein shake, which partially substituted animal protein. We examined the effect of the 6-month dietary induction weight loss phase on cardiometabolic state. Results Participants (n=294; age 51 years; body mass index 31.3 kg/m2; waist circumference 109.7 cm; 88% men; 10-year Framingham risk score 4.7%) had a 6-month retention rate of 98.3%. Both Mediterranean diets achieved similar weight loss ((green Mediterranean −6.2 kg; Mediterranean −5.4 kg) vs the HDG group −1.5 kg; p<0.001), but the green Mediterranean group had a greater reduction in waist circumference (−8.6 cm) than the Mediterranean (−6.8 cm; p=0.033) and HDG (−4.3 cm; p<0.001) groups. Stratification by gender showed that these differences were significant only among men. Within 6 months the green Mediterranean group achieved greater decrease in low-density lipoprotein cholesterol (LDL-C; green Mediterranean −6.1 mg/dL (−3.7%), −2.3 (-0.8%), HDG −0.2 mg/dL (+1.8%); p=0.012 between extreme groups), diastolic blood pressure (green Mediterranean −7.2 mm Hg, Mediterranean −5.2 mm Hg, HDG −3.4 mm Hg; p=0.005 between extreme groups), and homeostatic model assessment for insulin resistance (green Mediterranean −0.77, Mediterranean −0.46, HDG −0.27; p=0.020 between extreme groups). The LDL-C/high-density lipoprotein cholesterol (HDL-C) ratio decline was greater in the green Mediterranean group (−0.38) than in the Mediterranean (−0.21; p=0.021) and HDG (−0.14; p<0.001) groups. High-sensitivity C-reactive protein reduction was greater in the green Mediterranean group (−0.52 mg/L) than in the Mediterranean (−0.24 mg/L; p=0.023) and HDG (−0.15 mg/L; p=0.044) groups. The green Mediterranean group achieved a better improvement (−3.7% absolute risk reduction) in the 10-year Framingham Risk Score (Mediterranean−2.3%; p=0.073, HDG−1.4%; p<0.001). Conclusions: The green MED diet, supplemented with walnuts, green tea and Mankai and lower in meat/poultry, may amplify the beneficial cardiometabolic effects of Mediterranean diet.

Walnut consumption and cardiac phenotypes: The Coronary Artery Risk Development in Young Adults (CARDIA) study.

Steffen, L.M., S.Y. Yi, D. Duprez, X. Zhou, J.M. Shikany, D.R. Jacobs Jr., 2020. Walnut consumption and cardiac phenotypes: The Coronary Artery Risk Development in Young Adults (CARDIA) study. Nutr Metab Cardiovasc Dis. 31(1):95-101.

Background and Aims: Observational studies and clinical trials have shown cardiovascular benefits of nut consumption, including walnuts. However, the relations of walnut consumption with systolic and diastolic function, risk factors for heart failure, are unknown.  We examined the associations of walnut consumption with cardiac structure and function parameters in black and white adults enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Methods and Results: After exclusions, the study population included 3,341 participants. Dietary intake was assessed using the CARDIA Diet History questionnaire at baseline, year 7 and year 20 exams.  Cardiac structure and function were measured by echocardiography at year 25. Multivariable linear regression evaluated the associations of walnut consumption with blood pressure (BP), heart rate, and cardiac phenotypes, adjusting for age, sex, race, lifestyle habits, and clinical characteristics. We found the majority of walnut consumers compared to non-consumers were females, whites, and more highly educated, and had lower waist circumference, diastolic BP, and heart rate, and higher diet quality score. Even though cardiac structure and function measures were generally within normal ranges among participants, walnut consumers had significantly better values for diastolic function parameters A wave, E/A ratio, septal and lateral e’ than non-consumers. Further adjustment for body mass index and diabetes status did not materially change the significance between walnut consumer groups. Systolic function parameters did not differ by walnut group.  Conclusion: Compared to non-consumers, walnut consumption is associated with better diastolic dysfunction in young to middle-aged adults.