Archive

Research Area: Cardiovascular Health

Replacing saturated fats with unsaturated fats from walnuts or vegetable oils lowers atherogenic lipoprotein classes without increasing lipoprotein(a).

Tindall, A.M., P.M. Kris-Etherton, K.S. Petersen, 2020. Replacing saturated fats with unsaturated fats from walnuts or vegetable oils lowers atherogenic lipoprotein classes without increasing lipoprotein(a). J Nutr. pii: nxz313. doi: 10.1093/jn/nxz313. [Epub ahead of print]

Bachground: Walnuts have established lipid-/lipoprotein-lowering properties; however, their effect on lipoprotein subclasses has not been investigated. Furthermore, the mechanisms by which walnuts improve lipid/lipoprotein concentrations are incompletely understood. Objectives: We aimed to examine, as exploratory outcomes of this trial, the effect of replacing SFAs with unsaturated fats from walnuts or vegetable oils on lipoprotein subclasses, cholesterol efflux, and proprotein convertase subtilisin/kexin type 9 (PCSK9). Methods: A randomized, crossover, controlled-feeding study was conducted in individuals at risk of cardiovascular disease (CVD) (n = 34; 62% men; mean ± SD age 44 ± 10 y; BMI: 30.1 ± 4.9 kg/m2). After a 2-wk run-in diet (12% SFAs, 7% PUFAs, 12% MUFAs), subjects consumed the following diets, in randomized order, for 6 wk: 1) walnut diet (WD) [57-99 g/d walnuts, 7% SFAs, 16% PUFAs [2.7% α-linolenic acid (ALA)], 9% MUFAs]; 2) walnut fatty acid-matched diet [7% SFAs, 16% PUFAs (2.6% ALA), 9% MUFAs]; and 3) oleic acid replaces ALA diet (ORAD) [7% SFAs, 14% PUFAs (0.4% ALA); 12% MUFAs] (all percentages listed are of total kilocalories ). Serum collected after the run-in (baseline) and each diet period was analyzed for lipoprotein classes and subclasses (vertical auto profile), cholesterol efflux, and PCSK9. Linear mixed models were used for data analysis. Results: Compared with the ORAD, total cholesterol (mean ± SEM -8.9± 2.3 mg/dL; -5.1%; P < 0.001), non-HDL cholesterol (-7.4 ± 2.0 mg/dL; -5.4%; P = 0.001), and LDL cholesterol (-6.9 ± 1.9 mg/dL; -6.5%; P = 0.001) were lower after the WD; no other pairwise differences existed. There were no between-diet differences for HDL-cholesterol or LDL-cholesterol subclasses. Lipoprotein(a) [Lp(a)], cholesterol efflux, and PCSK9 were unchanged after the diets. Conclusions: In individuals at risk of CVD, replacement of SFAs with unsaturated fats from walnuts or vegetable oils improved lipid/lipoprotein classes, including LDL-cholesterol, non-HDL cholesterol, and total cholesterol, without an increase in Lp(a). These improvements were not explained by changes in cholesterol efflux capacity or PCSK9.

Angiopoietin-1 protects 3T3-L1 preadipocytes from saturated fatty acid-induced cell death.

Son, Y., J.M. Cox, J.L. Stevenson, J.A. Cooper, C.M. Paton, 2020. Angiopoietin-1 protects 3T3-L1 preadipocytes from saturated fatty acid-induced cell death. Nutr Res. 76:20-28.

Cross talk between endothelial cells and adipocytes is vital to adipocyte functions, but little is known about the mechanisms or factors controlling the process. Angiogenesis is a critical component linking the endothelium to healthy adipogenesis, yet it is not known if or how it is involved in adipocyte physiology. Therefore, the purpose of this study was to determine the effect of angiopoietin-1 (Ang-1) and -2 (Ang-2) as well as their receptor, Tie-2, on adipocyte physiology. 3T3-L1 pre- and mature adipocytes were found to express Ang-1, Ang-2, and Tie-2, which decrease upon polyunsaturated fatty acid treatment. Furthermore, 3T3-L1 cells treated with recombinant Ang-1 or Ang-2 increased expression of the antiapoptotic gene Bcl-x and decreased expression of the proapoptotic gene Casp-8. Next, preadipocytes were treated with saturated fatty acids (SFAs) to induce cell stress. SFA-mediated splicing of X-box-binding protein-1 was reduced by co-treatment with Ang-1, and cell viability was improved in the presence of SFAs + Ang-1. Taken together, these results indicate that Ang-1 may protect preadipocytes from SFA-induced apoptosis and endoplasmic reticulum stress.

Changes in nut consumption and subsequent cardiovascular disease risk among US men and women: 3 large prospective cohort studies.

Liu, X., M. Guasch-Ferré, J.P. Drouin-Chartier, D.K. Tobias, S.N. Bhupathiraju, K.M. Rexrode, W.C. Willett, Q. Sun, Y. Li, 2020. Changes in nut consumption and subsequent cardiovascular disease risk among US men and women: 3 large prospective cohort studies.
J Am Heart Assoc. 9(7):e013877. doi: 10.1161/JAHA.119.013877. Epub 2020 Apr 1.

Background: we aim to evaluate the association of within-individual changes in consumption of total and specific types of nuts and the subsequent risk of incident cardiovascular disease (CVD) in US men and women. Methods and Results: We included 34 103 men from the HPFS (Health Professionals Follow-Up Study) (1986-2012), 77 815 women from the NHS (Nurses’ Health Study) (1986-2012), and 80 737 women from the NHS II (1991-2013). We assessed nut consumption every 4 years using validated food frequency questionnaires. We used multivariable Cox proportional hazards regression models to examine the association between 4-year changes in nut consumption and risk of confirmed CVD end points in the subsequent 4 years. Per 0.5 serving/day increase in total nut consumption was associated with lower risk of CVD (relative risk [RR], 0.92; 95% CI, 0.86-0.98), coronary heart disease (RR, 0.94; 95% CI, 0.89-0.99), and stroke (RR, 0.89; 95% CI, 0.83-0.95). Compared with individuals who remained nonconsumers in a 4-year interval, those who had higher consumption of total nuts (≥0.5 servings/day) had a lower risk of CVD (RR, 0.75; 95% CI, 0.67-0.84), coronary heart disease (RR, 0.80; 95% CI, 0.69-0.93), and stroke (RR, 0.68; 95% CI, 0.57-0.82) in next 4 years. Individuals who decreased nut consumption by ≥0.50 servings/day had a higher risk of developing CVD (RR, 1.14; 95% CI, 0.99-1.32), coronary heart disease (RR, 1.06; 95% CI, 0.88-1.28), and stroke (RR, 1.28; 95% CI, 1.02-1.60) when compared with those who maintained their nut consumption. Conclusions: Increasing total consumption of nuts and intake of individual types of nuts (eg, walnuts, other tree nuts, and peanuts) was associated with a subsequent lower risk of CVD. These data support the role of nut intake in the primary prevention of CVD.

Effect of tree nuts consumption on serum lipid profile in hyperlipidemic individuals: A systematic review.

Altamimi, M., S. Zidan, M. Badrasawi, 2020. Effect of tree nuts consumption on serum lipid profile in hyperlipidemic individuals: A systematic review. Nutrition and Metabolic Insights.  13: 1–10.

Many epidemiological studies have regularly connected nuts intake with decreased risk for coronary heart disease. The primary mechanism by which nuts protect against cardiovascular disease is through the improvement of lipid and apolipoprotein profile. Therefore, numerous dietary intervention studies investigated the impact of nut consumption on blood lipid levels. Many studies have shown that nut intake can enhance the lipid profile in a dose-response way among individuals with increased serum lipids. This systematic review examines the effectiveness of nuts on the lipid profile among patients with dyslipidemia from different age groups. A total of 29 interventional studies from 5 databases met the inclusion criteria. In all, 20 studies were randomized controlled clinical trials, whereas 9 were crossover-controlled clinical trials. Participants included in the studies were different in terms of age, sex and, serum lipid profile. The studies were inconsistent in the type of tree nuts, duration, dose, and the nut forms. All studies indicated changes in the lipid profile after the intervention particularly on the total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, total cholesterol/high-density lipoprotein. Interventional periods ranged from 3 weeks up to 12 months with doses ranged from 15 to 126gm. In conclusion, this review provides an evidence of favorable effect of nuts consumption of serum lipid profile.

The effect of almonds consumption on blood pressure: A systematic review and dose-response meta-analysis of randomized control trials.

Li, Z., A.S. Bhagavathula, M. Batavia, C. Clark, H.M. Abdulazeem, J. Rahmani, F. Yin, 2020. The effect of almonds consumption on blood pressure: A systematic review and dose-response meta-analysis of randomized control trials. 32(2):1757-1763.

Almond is rich in antioxidants and phytochemicals such as methylquercetin, protocatechuic acid, catechin, flavonoids, p-hydroxybenzoic acid, resveratrol, vanillic acid, and kaempferol. The aim of the present study was to systematically review and dose-response meta-analyses the effects of almond consumption on systolic and diastolic blood pressure (SBP/DBP), respectively, in Randomized Controlled Trials (RCTs). A systematic search was performed in PubMed/MEDLINE, web of sciences and SCOPUS by 2 researchers, independently to identify randomised controlled trials up to July 2019. There were no time or language restrictions. PRISMA guidelines were followed in conducting this meta-analysis. Fifteen studies with 21 arms, containing 853 participants, reported SBP as an outcome measure. Pooled results showed significant reduction in SBP (WMD: -0.90 mmHg, 95% CI: -1.74, -0.06, Pheterogeneity = 0.94) by almond intervention. There is no significant effect from almond consumption on DBP (WMD: 0.67 mmHg, 95% CI: -1.93, 0.60, Pheterogeneity = 0.001). Meta-regression analysis showed dose of used almond (g/d) as source of heterogeneity between results of DBP. In conclusion results of this meta-analysis showed reduce effect of almonds on systolic blood pressure.

Snacking on whole almonds for six weeks increases heart rate variability during mental stress in healthy adults: A randomized controlled trial.

Dikariyanto, V., L. Smith, P.J. Chowienczyk, S.E. Berry, W.L. Hall, 2020. Snacking on whole almonds for six weeks increases heart rate variability during mental stress in healthy adults: A randomized controlled trial. Nutrients. 12,1828; doi:10.3390/nu12061828.

Cardiac autonomic regulation can be indirectly measured by heart rate variability (HRV). Low HRV, which can be induced by mental stress, is a predictor of risk of sudden cardiac death. Few studies have investigated cause-and-effect relationships between diet and HRV. Nut consumption is associated with CVD risk reduction, but the impact on HRV, particularly in response to stress, is unclear. Men and women (30–70 y) with above average risk of developing CVD were randomly assigned in a 6-week randomized, controlled, parallel arm trial to consume either whole almond or isocaloric control snacks (20% of daily estimated energy requirement). Control snacks contained the average nutrient profile of UK snacks. Five-minute periods of supine heart rate (HR) and HRV were measured at resting and during mental stress (Stroop color-word test) at baseline and six weeks. High frequency (HF) power, which reflects parasympathetic regulation of HR, was increased following almonds during the mental stress task relative to control (mean difference between groups 124 ms2; 95% CI 11, 237; p = 0.031, n = 105), but other indices were unaffected. Snacking on whole almonds instead of typical snacks may reduce risk of CVD partly by ameliorating the suppression of HRV during periods of mental stress.

Snacking on whole almonds for 6 weeks improves endothelial function and lowers LDL cholesterol but does not affect liver fat and other cardiometabolic risk factors in healthy adults: the ATTIS study, a randomized controlled trial.

Dikariyanto, V., L. Smith, L. Francis, M. Robertson, E. Kusaslan, M. O’Callaghan-Latham, C. Palanche, M. D’Annibale, D. Christodoulou, N. Basty, B. Whitcher, H. Shuaib, G. Charles-Edwards, P.J. Chowienczyk, P.R. Ellis, S.E.E. Berry, W.L. Hall, 2020. Snacking on whole almonds for 6 weeks improves endothelial function and lowers LDL cholesterol but does not affect liver fat and other cardiometabolic risk factors in healthy adults: the ATTIS study, a randomized controlled trial. Am J Clin Nutr. 00:1– 12.

Background: There is convincing evidence that daily whole almond consumption lowers blood LDL cholesterol concentrations, but effects on other cardiometabolic risk factors such as endothelial function and liver fat are still to be determined. Objectives: We aimed to investigate whether isoenergetic substitution of whole almonds for control snacks with the macronutrient profile of average snack intakes, had any impact on markers of cardiometabolic health in adults aged 30–70 y at above-average risk of cardiovascular disease (CVD). Methods: The study was a 6-wk randomized controlled, parallel-arm trial. Following a 2-wk run-in period consuming control snacks (mini-muffins), participants consumed either whole roasted almonds (n = 51) or control snacks (n = 56), providing 20% of daily estimated energy requirements. Endothelial function (flow-mediated dilation), liver fat (MRI/magnetic resonance spectroscopy), and secondary outcomes as markers of cardiometabolic disease risk were assessed at baseline and end point. Results: Almonds, compared with control, increased endothelium-dependent vasodilation (mean difference 4.1%-units of measurement; 95% CI: 2.2, 5.9), but there were no differences in liver fat between groups. Plasma LDL cholesterol concentrations decreased in the almond group relative to control (mean difference −0.25 mmol/L; 95% CI: −0.45, −0.04), but there were no group differences in triglycerides, HDL cholesterol, glucose, insulin, insulin resistance, leptin, adiponectin, resistin, liver function enzymes, fetuin-A, body composition, pancreatic fat, intramyocellular lipids, fecal SCFAs, blood pressure, or 24-h heart rate variability. However, the long-phase heart rate variability parameter, very-low-frequency power, was increased during nighttime following the almond treatment compared with control (mean difference 337 ms2; 95% CI: 12, 661), indicating greater parasympathetic regulation. Conclusions: Whole almonds consumed as snacks markedly improve endothelial function, in addition to lowering LDL cholesterol, in adults with above-average risk of CVD. This trial was registered at clinicaltrials.gov as NCT02907684.

Whole almond consumption is associated with better diet quality and cardiovascular disease risk factors in the UK adult population: National Diet and Nutrition Survey (NDNS) 2008–2017.

Dikariyanto, V., S.E. Berry, L. Francis, L. Smith, W.L. Hall, 2020. Whole almond consumption is associated with better diet quality and cardiovascular disease risk factors in the UK adult population: National Diet and Nutrition Survey (NDNS) 2008–2017. Eur J Nutr. 60(2):643-654.

Purpose: This work aimed to estimate whole almond consumption in a nationally representative UK survey population and examine associations with diet quality and cardiovascular disease (CVD) risk. Methods: Four-day food record data from the National Diet and Nutrition Survey (NDNS) 2008–2017 (n = 6802, age≥19 year) were analyzed to investigate associations between whole almond consumption and diet quality, measured by the modified Mediterranean Diet Score (MDS) and modified Healthy Diet Score (HDS), and CVD risk markers, using survey-adjusted multivariable linear regression. Results: Whole almond consumption was reported in 7.6% of the population. Median intake in whole almond consumers was 5.0 g/day (IQR 9.3). Consumers had higher diet quality scores relative to non-consumers; higher intakes of protein, total fat, monounsaturated, n-3 and n-6 polyunsaturated fats, fiber, folate, vitamin C, vitamin E, potassium, magnesium, phosphorus, and iron; and lower intakes of trans-fatty acids, total carbohydrate, sugar, and sodium. BMI and WC were lower in whole almond consumers compared to non-consumers: 25.5 kg/m2 (95% CI 24.9, 26.2) vs 26.3 kg/m2 (25.9, 26.7), and 88.0 cm (86.2, 89.8) vs 90.1 cm (89.1, 91.2), respectively. However, there were no dose-related fully adjusted significant associations between increasing almond intake (g per 1000 kcal energy intake) and lower CVD risk markers. Conclusions: Almond intake is low in the UK population, but consumption was associated with better dietary quality and lower CVD risk factors. Habitual consumption of whole almonds should be encouraged as part of a healthy diet.

Anti-atherosclerotic and cardiovascular protective benefits of Brazilian nuts.

C.K.B. Ferrari, 2020. Anti-atherosclerotic and cardiovascular protective benefits of Brazilian nuts. Front Biosci (Schol Ed). 12:38-56.

Brazil nuts are rich in magnesium, selenium, arginine and other amino acids, dietary fiber, tocopherols (vitamin E), phytosterols, linoleic acid, linolenic acid, sitosterols, monounsaturated and polyunsaturated fatty acids, polyphenols and other amino acids. Due to such a rich mixture of nutrients, Brazil nuts protect LDL from peroxidation, and improve endothelial function, blood pressure, lipid metabolism, and decrease endothelial inflammatory markers, DNA oxidation, and blood lipids (cholesterol, LDL, triglycerides). Here, we review and propose biological mechanisms by which bioactive compounds of Brazil nuts afford protections against atherosclerosis and cardiovascular diseases. Just a few nuts per day provide sufficient cardiovascular benefits, including protection against development and progression of atherosclerosis.

The effects of cashew nut intake on lipid profile and blood pressure: A systematic review and meta-analysis of randomized controlled trials.

Jalali, M., M. Karamizadeh, G.A. Ferns, M. Zare, S.P. Moosavian, M. Akbarzadeh, 2020. The effects of cashew nut intake on lipid profile and blood pressure: A systematic review and meta-analysis of randomized controlled trials. Complement Ther Med. 50:102387. doi:10.1016/j.ctim.2020.102387. 

Background: Dyslipidemia and hypertension are important risk factors for cardiovascular disease (CVD). Some studies have suggested that the consumption of nuts may reduce CVD risk. Objective: The present systematic review and meta-analysis was conducted to investigate the efficacy of cashew nut consumption on lipid profile and blood pressure. Methods: PubMed, Embase, Scopus, Web of Science and Cochrane Library were systematically searched to identify randomized control trials (RCTs) examining the effects of cashew nut intake on serum triglycerides (TG), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), serum total cholesterol (TC), systolic blood pressure (SBP) or diastolic blood pressure (DBP) until 15 November 2019. A random-effects model was used to pool weighted mean difference (WMD) and 95 % confidence intervals (CI). Potential publication bias was assessed using Egger’s test. Sensitivity analysis was performed to assess the impact of each individual study on the pooled results. Results: A meta-analysis on 392 participants showed that cashew nut consumption had no significant effects on lipid profile and DBP. However, there was a significant reduction in SBP (WMD = -3.39, 95 % CI = [-6.13, -0.65], P = 0.01, I2 = 0.0 %) in the group receiving cashew nut compared to the controls. There was no significant publication bias in the meta-analysis. A sensitivity analysis showed that omitting each study did not change the significance of results. Conclusion: This meta-analysis demonstrated that cashew nut consumption might reduce SBP but has no effects on lipid profile and DBP.