Archive

Research Area: Cardiovascular Health

The effects of daily intake timing of almond on the body composition and blood lipid profile of healthy adults.

Liu, Y., H.-J. Hwang, H. Ryu, Y.-S. Lee, H.-S. Kim, H. Park, 2017. The effects of daily intake timing of almond on the body composition and blood lipid profile of healthy adults. Nutrition Research and Practice. 11(6):479-486.

BACKGROUND/OBJECTIVES: Timing of almond intake during a day may result differently in the perspectives of body composition and changes of lipid profile. The current study was conducted to compare the effects of daily almond intake as a preload versus as a snack on body composition, blood lipid profile, and oxidative and inflammation indicators among young Korean adults aged 20-39 years old. SUBJECTS/METHODS: Participants were randomly assigned to one of three groups: a pre-meal almond group (PM), a snack almond group (SN) in which participants were instructed to consume 56 g of almonds either as a preload before meals or as a snack between meals, respectively, and a control group (CL) in which participants were provided high-carbohydrate iso-caloric control food. Measurements were performed at baseline, weeks 8 and 16. RESULTS: A total of 169 (M 77 / F 92) out of the 227 participants completed the study between June 2014 and June 2015 (n=58 for PM; 55 for SN; and 56 for CL). A significant decrease in body fat mass was observed in the PM group at both weeks 8 and 16 compared with the CL. There were significant intervention effects on changes of body fat mass (P=0.025), body fat percentages (P=0.019), and visceral fat levels (P<0.001). Consuming almonds as a daily snack reduced the levels of total cholesterol (P=0.043) and low-density lipoprotein (LDL) cholesterol (P=0.011) without changing high-density lipoprotein (HDL) cholesterol compared with the CL. CONCLUSION: Almond consumption as a preload modified body fat percentages, whereas snacking on almonds between meals improved blood lipid profiles.

Effect of nut consumption on vascular endothelial function: A systematic review and meta-analysis of randomized controlled trials.

Xiao, Y., W. Huang, C. Peng, J. Zhang, C. Wong, J.H. Kim, E.-K. Yeoh, 2017. Effect of nut consumption on vascular endothelial function: A systematic review and meta-analysis of randomized controlled trials. Clinical Nutrition. http://dx.doi.org/10.1016/j.clnu.2017.04.011

Objective: Nut consumption has consistently been found to be associated with a reduced risk of cardiovascular diseases (CVD) and mortality in prospective studies. However, its effect on endothelial function, a prognostic marker of CVD, is still controversial in clinical trials. This meta-analysis of randomized controlled trials (RCTs) aimed to quantitatively assess the effect of nuts on vascular endothelial function. Methods: Major electronic databases were searched for published RCTs that reported the effect of nuts on flow mediated dilation (FMD) as a measurement of endothelial function in the adult population (age eighteen years or over). We calculated the pooled estimates of weighted mean differences (WMDs) and their 95% confidence intervals (CIs) by using random-effects models. Results: A total of nine papers (10 trials) involving 374 participants were included. The pooled estimates found that nut consumption significantly improved FMD (WMD: 0.41%; 95% CI: 0.18%, 0.63%; P = 0.001). Moderate and marginally significant heterogeneity was observed among the studies (I2 = 39.5%, P = 0.094). Subgroup analyses indicated that walnuts significantly improved FMD (WMD: 0.39%; 95% CI: 0.16%, 0.63%; P = 0.001). In addition, nut consumption had a significant effect on FMD in the trials with study duration <18 weeks, nut dose <67 g/d, or subjects with baseline FMD ≥8.6%. Conclusions: Nut consumption significantly improved endothelial function. However, the beneficial effect was limited to walnuts. More studies examining the effect of other nuts on endothelial function are needed in the future.

Inclusion of almonds in a cholesterol-lowering diet improves plasma HDL subspecies and cholesterol efflux to serum in normal-weight individuals with elevated LDL cholesterol.

Berryman, C.E, J.A. Fleming, P.M. Kris-Etherton, 2017. Inclusion of almonds in a cholesterol-lowering diet improves plasma HDL subspecies and cholesterol efflux to serum in normal-weight individuals with elevated LDL cholesterol. J. Nutr. 147(8). doi: 10.3945/jn.116.245126.

Background: Almonds may increase circulating HDL cholesterol when substituted for a high-carbohydrate snack in an isocaloric diet, yet little is known about the effects on HDL biology and function. Objective: The objective was to determine whether incorporating 43 g almonds/d in a cholesterol-lowering diet would improve HDL subspecies and function, which were secondary study outcomes. Methods: In a randomized, 2-period, crossover, controlled-feeding study, a diet with 43 g almonds/d (percentage of total energy: 51% carbohydrate, 16% protein, and 32% total and 8% saturated fat) was compared with a similar diet with an isocaloric muffin substitution (58% carbohydrate, 15% protein, and 26% total and 8% saturated fat) in men and women with elevated LDL cholesterol. Plasma HDL subspecies and cholesterol efflux from J774 macrophages to human serum were measured at baseline and after each diet period. Diet effects were examined in all participants (n = 48) and in normal weight (body mass index: <25; n = 14) and overweight or obese (≥25; n = 34) participants by using linear mixed models. Results: The almond diet, compared with the control diet, increased α-1 HDL [mean ± SEM: 26.7 ± 1.5 compared with 24.3 ± 1.3 mg apolipoprotein A-I (apoA-I)/dL; P = 0.001]. In normal-weight participants, the almond diet, relative to the control diet, increased a-1 HDL (33.7 6 3.2 compared with 28.4 ± 2.6 mg apoA-I/dL), the α-1 to pre–β-1 ratio [geometric mean (95%CI): 4.3 (3.3, 5.7) compared with 3.1 (2.4,4.0)], and non–ATP-binding cassette transporter A1 cholesterol efflux (8.3% ± 0.4% compared with 7.8% ± 0.3%) and decreased pre–β-2 (3.8 ± 0.4 compared with 4.6 ± 0.4 mg apoA-I/dL) and α-3 (23.5 ± 0.9 compared with 26.9 ± 1.1 mg apoA-I/dL) HDL (P < 0.05). No diet effects were observed in the overweight or obese group. Conclusions: Substituting almonds for a carbohydrate-rich snack within a lower-saturated-fat diet may be a simple strategy to maintain a favorable circulating HDL subpopulation distribution and improve cholesterol efflux in normal-weight individuals with elevated LDL cholesterol.

The effect of almonds on vitamin E status and cardiovascular risk factors in Korean adults: a randomized clinical trial.

Jung, H., C.Y.O. Chen, J.B. Blumberg, H.K. Kwak, 2017. The effect of almonds on vitamin E status and cardiovascular risk factors in Korean adults: a randomized clinical trial. Eur. J. Nutr. doi:10.1007/s00394-0171480-5.

Purpose: Almonds have shown to beneficially modify some cardiovascular risk factors in clinical trials conducted in diverse ethnic populations but this relationship has never been tested in Koreans. Thus, we tested the impact of almonds consumed as a snack within the context of a typical Korean diet on cardiovascular risk factors. Methods: We conducted a randomized, crossover trial in a free-living setting with a 2-week run-in period, two 4-week intervention phases, and a 2-week washout period between interventions. Eighty-four overweight/obese participants (11 M/73 F; 52.4 ± 0.6 year; 25.4 ± 0.22 kg/m2) consumed either 56 g of almonds or isocaloric cookies daily for 4 weeks. Results: Mean % daily energy intake at baseline was 64.8, 21.3, and 14.9% from carbohydrate, fat, and protein, respectively. The addition of 56 g of almonds daily decreased carbohydrate energy to 55.0%, increased fat to 32.0%, and maintained protein at 14.7%. Consuming the almonds increased intake of MUFA by 192.3%, PUFA by 84.5%, vitamin E by 102.7%, and dietary fiber by 11.8% and decreased % energy from carbohydrate by 14.1%. Total caloric intake was increased by the almonds, but body weight, waist circumference, and body composition were not affected. Almonds in overweight and obese Korean adults decreased TC, LDL-C, and non-HDL-C by 5.5, 4.6, and 6.4%, respectively, compared to the cookie control (P ≤ 0.05). Almonds increased plasma α-tocopherol by 8.5% (P ≤ 0.05) from the baseline and tended to increase its value as compared to cookies (P = 0.055). Neither the almonds nor cookies altered plasma protein carbonyls, MDA or oxLDL. Of serum inflammatory markers, IL-10 was decreased by almond intake (P ≤ 0.05), and ICAM1, IL-1β, and IL-6 tended to be lower with almonds, compared to the cookies. Conclusions: Almonds at 56 g/day consumed as a snack favorably modified the Korean diet by increasing MUFA, PUFA, vitamin E, and dietary fiber intake and decreasing % energy intake from carbohydrate. Almonds also enhanced plasma α-tocopherol status and serum TC and LDL-C in overweight and obese Koreans. Thus, including almonds in typical Korean diets as a snack can help healthy overweight/obese individuals improve nutritional status and reduce their risk for CVD.

A PUFA-rich diet improves fat oxidation following saturated fat-rich meal.

Stevenson, J.L., M.K. Miller, H.E. Skillman, C.M. Paton, J.A. Cooper, 2017. A PUFA-rich diet improves fat oxidation following saturated fat-rich meal. Eur J Nutr. 56(5):1845–1857.

Purpose: To determine substrate oxidation responses to saturated fatty acid (SFA)-rich meals before and after a 7-day polyunsaturated fatty acid (PUFA)-rich diet versus control diet. Methods: Twenty-six, normal-weight, adults were randomly assigned to either PUFA or control diet. Following a 3-day lead-in diet, participants completed the pre-diet visit where anthropometrics and resting metabolic rate (RMR) were measured, and two SFA-rich HF meals (breakfast and lunch) were consumed. Indirect calorimetry was used to determine fat oxidation (Fox) and energy expenditure (EE) for 4 h after each meal. Participants then consumed a PUFA-rich diet (50% carbohydrate, 15% protein, 35% fat, of which 21% of total energy was PUFA) or control diet (50% carbohydrate, 15% protein, 35% fat, of which 7% of total energy was PUFA) for the next 7 days. Following the 7-day diet, participants completed the post-diet visit. Results: From pre- to post-PUFA-rich diet, there was no change in RMR (16.3 ± 0.8 vs. 16.4 ± 0.8 kcal/20 min) or in incremental area under the curve for EE (118.9 ± 20.6-126.9 ± 14.1 kcal/8h, ns). Fasting respiratory exchange ratio increased from pre- to post-PUFA-rich diet only (0.83 ± 0.1-0.86 ± 0.1, p < 0.05). The postprandial change in Fox increased from pre- to post-visit in PUFA-rich diet (0.03 ± 0.1-0.23 ± 0.1 g/15 min for cumulative Fox; p < 0.05), whereas controls showed no change. Conclusions: Adopting a PUFA-rich diet initiates greater fat oxidation after eating occasional high SFA meals compared to a control diet, an effect achieved in 7 days.

Effect of almond supplementation on glycemia and cardiovascular risk factors in Asian Indians in north India with type 2 diabetes mellitus: A 24-week study.

Gulati, S., A. Misra, R.M. Pandey, 2017. Effect of almond supplementation on glycemia and cardiovascular risk factors in Asian Indians in north India with type 2 diabetes mellitus: A 24-week study. Metabolic Syndrome and Related Disorders. doi:10.1089/met.2016.0066.

Background: Type 2 diabetes (T2D) statistics have reached menacing proportions in India. Appropriate dietary intervention, as part of healthy lifestyle, is imperative to curb further spread of this disease. Objectives: This pre–post intervention study was conducted in New Delhi, India, to investigate the effects of daily consumption of almonds for 24 weeks in T2D subjects, specifically on measures of glycemia and cardiovascular disease (CVD) risk factors. Methods and Study Design: In this study, the 24-week intervention period was preceded by a control diet and exercise run-in period of 3 weeks. Raw almonds (20% of energy intake) were provided to the patients for consumption along with diet and physical activity counseling. Patients were assessed for anthropometry, blood pressure, measures of glycemia (fasting blood glucose, glycosylated hemoglobin), lipids [total cholesterol (TC), triglycerides, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, lipoprotein(a)], surrogate marker of atherosclerosis (Pulse wave velocity), and marker of inflammation (high sensitivity C-reactive protein [hs-CRP]) at baseline and after the intervention period. Results: Statistically significant improvement in mean values for various parameters post intervention was as follows: waist circumference (P<0.03), waist-to-height ratio (P<0.005), TC (P<0.002), serum triglycerides (P<0.004), low-density lipoprotein cholesterol (P<0.01), glycosylated hemoglobin (P<0.04), and hs-CRP (P<0.01). A trend toward improvement in pulse wave velocity (P<0.06) was also observed. Conclusion: The study findings illustrate that incorporation of almonds in a well-balanced healthy diet leads to multiple beneficial effects on glycemic and CVDs risk factors in Asian Indian patients with T2D.

The feasibility of walnut and extra virgin olive oil supplementation in older adults.

Vitolins, M.Z., C.S. Blackwell, J.D. Williamson, C.G. Foy, S. Wilmoth, K.M. Sink, L.M. Reynolds, R.P. Byington, D.M. Reboussin, 2017. The feasibility of walnut and extra virgin olive oil supplementation in older adults. J Food Nutr Sci. 4(1):1-6.

Researchers in Spain provided randomized, controlled trial evidence that adding extra virgin olive oil (EVOO) and nuts to diets of older adults lowered cardiovascular disease risk. Supplementing these foods may represent a simple and straightforward approach to favourable dietary change with potential for dissemination to the broader public. This was an 8-week feasibility trial in which all participants were asked to supplement their ad libitum diets with both walnuts and EVOO to determine their interest in participating and to assess retention and adherence once enrolled. Inclusion criteria were broad: Adults ≥ 55 years old treated for hypertension with medication; exclusions included walnuts/EVOO allergies, homebound or diagnosis of dementia. Recruitment was assessed as number of weeks to accrue 25 participants. Adherence was assessed by participant self-report using a daily diary. Blood pressure (BP), body weight, and HDL cholesterol were measured to estimate the variability of outcomes. Results: Twenty- seven participants were recruited in 2 ½ weeks; 26 of the 27 participants remained in the study for a retention rate of 96% (95% CI: 78% – 100%). Of 216 possible diaries, 185 were returned (86%). On average, weight increased over 8 weeks by 0.8 pounds. Mean systolic BP dropped by 0.25 mmHg while mean diastolic BP decreased by 1.0 mmHg. Mean HDL increased by 1.96 mg/dL. A full-scale walnut/EVOO trial in older adults with hypertension seems realistic given our high rates of recruitment, retention, and adherence, coupled with minimal weight gain and favorable trends in BP and HDL.

 

Associations between dietary patterns and blood pressure in a clinical sample of overweight adults.

Ndanuko, R.N., L.C. Tapsell, K.E. Charlton, E.P. Neale, M.J. Batterham, 2017. Associations between dietary patterns and blood pressure in a clinical sample of overweight adults. J Acad Nutr Diet. 7(2):228-239.

Background: Dietary pattern analysis provides important evidence revealing diet-disease relationships. It may be especially useful in areas less well researched, such as diet and hypertension in clinical populations. Objective: The aim of this study was to identify the association between dietary patterns and blood pressure (BP) in a sample of overweight adults volunteering for a clinical trial for weight loss. Design: This cross-sectional analysis used baseline data from the HealthTrack study, a 12-month randomized controlled trial. Dietary intake was evaluated with 4-day food records. Participants/Setting: Participants were 328 adults recruited from the Illawarra region of New South Wales, Australia, between May 2014 and April 2015. Main Outcome Measures:  Resting BP and 24-hour urine sodium and potassium were measured. Statistical Analysis: Dietary patterns were derived by principal component analysis from 21 food groups. Multiple regression analysis was performed to assess the association between the extracted dietary patterns and BP. Results:  The participants’ mean age was 43.6±8.0 years, mean body mass index was 32.4±4.2, and mean systolic BP/diastolic BP was 124.9±14.5/73.3±9.9 mm Hg. Six major dietary patterns were identified: “nuts, seeds, fruit, and fish,” “milk and meat,” “breads, cereals, and snacks,” “cereal-based products, fats, and oils,” “alcohol, eggs, and legumes,” and “savoury sauces, condiments, and meat.” The “nuts, seeds, fruit, and fish” dietary pattern was significantly and inversely associated with systolic BP (F [7,320]=15.248; P<0.0005; adjusted R2=0.234 and diastolic BP (F [7,320]=17.351; P<0.0005; adjusted R2=0.259) and sodium-to-potassium ratio (F [7,320]=6.210; P<0.0005; adjusted R2=0.100). Conclusions: A dietary pattern rich in nuts, seeds, fruit, and fish was inversely associated with blood pressure in this clinical sample. The findings suggest that current dietary guidelines are relevant to an overweight clinical population and support the value of dietary pattern analysis when exploring the diet-disease relationship.

 

An umbrella review of nuts intake and risk of cardiovascular disease.

Schwingshackl, L., G. Hoffmann, B. Missbach, M. Stelmach-Mardas, H. Boeing, 2017. An umbrella review of nuts intake and risk of cardiovascular disease. Current Pharmaceutical Design. 23:1016-1027.

Background: Nuts have been an indispensable component of the human diet for hundreds because of their unique nutrient composition and are thought to play a beneficial part in the prevention of cardiovascular diseases. Objective: To evaluate the extent, validity and presence of evidence for studies investigating the impact of nuts intake on biomarkers of cardiovascular disease and cardiovascular events, we performed an umbrella review of all published meta-analyses synthesizing data from both observational studies and randomized controlled trials. Method: PubMed (between 1966 and April 2016) was searched for systematic reviews and meta-analyses. Methodological quality was assessed by applying the AMSTAR score (0-11 points), and the meta-evidence by applying NutriGrade, our recently developed scoring system (0-10 points). Results: In total, 14 meta-analyses were included in the umbrella review. Only 4 out of 14 reported an AMSTAR score ≥8 (high methodological quality), whereas NutriGrade meta-evidence score varied between 2 (very low meta-evidence) and 7.9 (moderate meta-evidence). There is consistent evidence from intervention trials, reporting significant reductions for total cholesterol, and from observational studies that higher intakes of nuts were associated with reduced risk of cardiovascular disease and hypertension. On the other side no effect could be observed for stroke, HDL-cholesterol, and blood pressure in the normal range.  Conclusion: In summary, the present umbrella review showed that nuts intake was associated with reduced risk of cardiovascular disease and hypertension, and lower levels of total cholesterol. The observed evidence is limited by the moderate methodological quality and very low to moderate quality of evidence.

Cashew consumption reduces total and LDL cholesterol: a randomized, crossover, controlled-feeding trial.

Mah, E., J.A. Schulz, V.N. Kaden, A.L. Lawless, J. Rotor, L.B. Mantilla, D.J. Liska, 2017.  Cashew consumption reduces total and LDL cholesterol: a randomized, crossover, controlled-feeding trial. Am J Clin. Nutr. 105(5):1070-1078.

Background: Cashews are the third most-consumed tree nut in the United States and are abundant with monounsaturated fatty acids and polyunsaturated fatty acids, which are associated with reduced cardiovascular disease risk. Although a qualified Food and Drug Administration health claim exists for nuts and heart health, cashews have been exempt from its use because cashews exceed the disqualifying amount of saturated fatty acids. Approximately one-third of the saturated fat in cashews is stearic acid, which is relatively neutral on blood lipids, thereby suggesting that cashews could have effects that are similar to those of other nuts. However, clinical data on cashews and blood lipids have been limited. Objective: We investigated the effect of reasonable intakes of cashews on serum lipids in adults with or at risk of high LDL cholesterol. Design: In a randomized, crossover, isocaloric, controlled-feeding study, 51 men and women (aged 21-73 y) with a median LDL-cholesterol concentration of 159 mg/dL (95% CI: 146, 165 mg/dL) at screening consumed typical American diets with cashews (28-64 g/d; 50% of kilocalories from carbohydrate, 18% of kilocalories from protein, and 32% of kilocalories from total fat) or potato chips (control; 54% of kilocalories from carbohydrate, 18% of kilocalories from protein, and 29% of kilocalories from total fat) for 28 d with a ≥2-wk washout period. Results: Consumption of the cashew diet resulted in a significantly greater median change from baseline (compared with the control, all P < 0.05) in total cholesterol [-3.9% (95% CI: -9.3%, 1.7%) compared with 0.8% (95% CI: -1.5%, 4.5%), respectively], LDL cholesterol [-4.8% (95% CI: -12.6%, 3.1%) compared with 1.2% (95% CI: -2.3%, 7.8%), respectively], non-HDL cholesterol [-5.3% (95% CI: -8.6%, 2.1%) compared with 1.7% (95% CI: -0.9%, 5.6%), respectively], and the total-cholesterol:HDL-cholesterol ratio [-0.0% (95% CI: -4.3%, 4.8%) compared with 3.4% (95% CI: 0.6%, 5.2%), respectively]. There were no significant differences between diets for HDL cholesterol and triglyceride. Conclusions: In comparison with a control diet, the incorporation of cashews into typical American diets decreases total cholesterol and LDL cholesterol. Results from this study provide support that the daily consumption of cashews, when substituted for a high-carbohydrate snack, may be a simple dietary strategy to help manage total cholesterol and LDL cholesterol. This study was registered at clinicaltrials.gov as NCT02769741.