Schlörmann, W., M. Birringer, V. Böhmc, K. Löber, G. Jahreis, S. Lorkowski, A.K. Müller, F. Schöne, M. Glei, 2015. Influence of roasting conditions on health-related compounds in different nuts. Food Chem. Food Chemistry 180:77–85.
Due to their health-beneficial ingredients the consumption of nuts can contribute to a healthy diet. The composition of hazelnuts, almonds, macadamia nuts, pistachios and walnuts regarding health-promoting and potentially harmful compounds was examined before and after roasting under different time and temperature conditions. Fatty acid compositions were not affected by roasting. Malondialdehyde increased with higher roasting temperatures (17-fold in walnuts). Levels of tocopherol isomers were reduced after roasting (α-T: 38%, β-T: 40%, γ-T: 70%) and hydrophilic antioxidant capacity decreased significantly in hazelnuts (1.4-fold), macadamia nuts (1.7-fold) and walnuts (3.7-fold). Increasing roasting temperatures supported the formation of significant amounts of acrylamide only in almonds (1220 μg kg-1). In general, nuts roasted at low/middle temperatures (120–160°C) exhibited best sensory properties. Therefore, desired sensory quality along with a favourable healthy nut composition may be achieved by roasting over a low to medium temperature range.
Ros, E., 2015. Nuts and CVD. Br J Nutr. 113, S111–S120.
Nuts are nutrient-dense foods with complex matrices rich in unsaturated fatty acids and other bioactive compounds, such as l-arginine, fibre, healthful minerals, vitamin E, phytosterols and polyphenols. By virtue of their unique composition, nuts are likely to beneficially affect cardiovascular health. Epidemiological studies have associated nut consumption with a reduced incidence of CHD in both sexes and of diabetes in women, but not in men. Feeding trials have clearly demonstrated that consumption of all kinds of nuts has a cholesterol-lowering effect, even in the context of healthy diets. There is increasing evidence that nut consumption has a beneficial effect on oxidative stress, inflammation and vascular reactivity. Blood pressure, visceral adiposity and the metabolic syndrome also appear to be positively influenced by nut consumption. Contrary to expectations, epidemiological studies and clinical trials suggest that regular nut consumption is not associated with undue weight gain. Recently, the PREvención con DIeta MEDiterránea randomised clinical trial of long-term nutrition intervention in subjects at high cardiovascular risk provided first-class evidence that regular nut consumption is associated with a 50% reduction in incident diabetes and, more importantly, a 30% reduction in CVD. Of note, incident stroke was reduced by nearly 50% in participants allocated to a Mediterranean diet enriched with a daily serving of mixed nuts (15 g walnuts, 7·5 g almonds and 7·5 g hazelnuts). Thus, it is clear that frequent nut consumption has a beneficial effect on CVD risk that is likely to be mediated by salutary effects on intermediate risk factors.
Njike, V.Y., R. Ayettey, P. Petraro, J.A. Treu, D.L. Katz, 2015. Walnut ingestion in adults at risk for diabetes: effects on body composition, diet quality, and cardiac risk measures. BMJ Open Diabetes Research and Care. doi:10.1136/bmjdrc-2015-000115.
Background: Despite their energy density, walnuts can be included in the diet without adverse effects on weight or body composition. The effect of habitual walnut intake on total calorie intake is not well studied. Effects on overall diet quality have not been reported. Methods: Randomized, controlled, modified Latin square parallel design study with 2 treatment arms. The 112 participants were randomly assigned to a diet with or without dietary counseling to adjust calorie intake. Within each treatment arm, participants were further randomized to 1 of the 2 possible sequence permutations to receive a walnut-included diet with 56 g (providing 366 kcal) of walnuts per day and a walnut-excluded diet. Participants were assessed for diet quality, body composition, and cardiac risk measures. Results: When compared with a walnut-excluded diet, a walnut-included diet for 6 months, with or without dietary counseling to adjust caloric intake, significantly improved diet quality as measured by the Healthy Eating Index 2010 (9.14±17.71 vs 0.40±15.13; p=0.02 and 7.02±15.89 vs -5.92±21.84; p=0.001, respectively). Endothelial function, total and low-density lipoprotein (LDL) cholesterol improved significantly from baseline in the walnut-included diet. Body mass index, percent body fat, visceral fat, fasting glucose, glycated hemoglobin, and blood pressure did not change significantly. CONCLUSION: The inclusion of walnuts in an ad libitum diet for 6 months, with or without dietary counseling to adjust calorie intake, significantly improved diet quality, endothelial function, total and LDL cholesterol, but had no effects on anthropometric measures, blood glucose level, and blood pressure.
Holt, R.R., S.J. Yim, G.C. Shearer, R.M. Hackman, D. Djurica, J.W. Newman, A.W. Shindel, C.L. Keen, 2015. Effects of short-term walnut consumption on human microvascular function and its relationship to plasma epoxide content. J Nutr Biochem. 26(12):1458-66.
Improved vascular function after the incorporation of walnuts into controlled or high fat diets has been reported, however the mechanism(s) underlying this effect of walnuts are poorly defined. The objective of the current study was to evaluate the acute and short-term effects of walnut intake on changes in microvascular function and the relationship of these effects to plasma epoxides, the cytochrome P450 derived metabolites of fatty acids. Thirty-eight hypercholesterolemic postmenopausal women were randomized to 4 weeks of 5 g or 40 g of daily walnut intake. All outcomes were measured after an overnight fast and 4 hours after walnut intake. Microvascular function, assessed as the reactive hyperemia index (RHI) was the primary outcome measure, with serum lipids and plasma epoxides as secondary measures. Compared to 5 g of daily walnut intake, consuming 40 g/d of walnuts for 4 weeks increased the RHI and Framingham RHI. Total cholesterol and low and high density-cholesterol did not significantly change after walnut intake. The change in RHI after 4 weeks of walnut intake was associated with the change in the sum of plasma epoxides (r=0.65, p = 0.002), but not with the change in the sum of plasma hydroxyeicosatetraenoic acids (HETE). Of the individual plasma epoxides, arachidonic acid derived 14(15)-epoxyeicosatrienoic acid (EpETrE) was most strongly associated with the change in microvascular function (r=0.72, p < 0.001). These data support the concept that the intake of walnut-derived fatty acids can favorably affect plasma epoxide production, resulting in improved microvascular function.
Li, Y., A. Hruby, A.M. Bernstein, S.H. Ley, D.D. Wang, S.E. Chiuve, L. Sampson, K.M. Rexrode, E.B. Rimm, W.C. Willett, F.B. Hu, 2015. Saturated fats compared with unsaturated fats and sources of carbohydrates in relation to risk of coronary heart disease: a prospective cohort study. J Am Coll Cardiol. 66(14):1538-48.
Background: The associations between dietary saturated fats and the risk of coronary heart disease (CHD) remain controversial, but few studies have compared saturated with unsaturated fats and sources of carbohydrates in relation to CHD risk. Objectives: This study sought to investigate associations of saturated fats compared with unsaturated fats and different sources of carbohydrates in relation to CHD risk. Methods: We followed 84,628 women (Nurses’ Health Study, 1980 to 2010), and 42,908 men (Health Professionals Follow-up Study, 1986 to 2010) who were free of diabetes, cardiovascular disease, and cancer at baseline. Diet was assessed by a semiquantitative food frequency questionnaire every 4 years. Results: During 24 to 30 years of follow-up, we documented 7,667 incident cases of CHD. Higher intakes of polyunsaturated fatty acids (PUFAs) and carbohydrates from whole grains were significantly associated with a lower risk of CHD comparing the highest with lowest quintile for PUFAs (hazard ratio [HR]: 0.80, 95% confidence interval [CI]: 0.73 to 0.88; p trend <0.0001) and for carbohydrates from whole grains (HR: 0.90, 95% CI: 0.83 to 0.98; p trend = 0.003). In contrast, carbohydrates from refined starches/added sugars were positively associated with a risk of CHD (HR: 1.10, 95% CI: 1.00 to 1.21; p trend = 0.04). Replacing 5% of energy intake from saturated fats with equivalent energy intake from PUFAs, monounsaturated fatty acids, or carbohydrates from whole grains was associated with a 25%, 15%, and 9% lower risk of CHD, respectively (PUFAs, HR: 0.75, 95% CI: 0.67 to 0.84; p < 0.0001; monounsaturated fatty acids, HR: 0.85, 95% CI: 0.74 to 0.97; p = 0.02; carbohydrates from whole grains, HR: 0.91, 95% CI: 0.85 to 0.98; p = 0.01). Replacing saturated fats with carbohydrates from refined starches/added sugars was not significantly associated with CHD risk (p > 0.10). Conclusions: Our findings indicate that unsaturated fats, especially PUFAs, and/or high-quality carbohydrates can be used to replace saturated fats to reduce CHD risk.
Gepner, Y., N. Bril, I. Shelef, D. Schwarzfuchs, D. Serfaty, M. Rein, N. Cohen, E. Shemesh, O. Tangi-Rosental, B. Sarusi, E. Goshen, S. Kenigsbuch, Y. Chassidim, R. Golan, S. Witkow, Y. Henkin, MJ. Stampfer, A. Rudich, I. Shai, 2015. Higher visceral adiposity is associated with an enhanced early thermogenic response to carbohydrate-rich food. Clin Nutr. 35(2):422-7.
Background: Studies examining the dynamics of the thermic effect of feeding (TEF) of specific food items and the relationship of TEF to visceral adiposity are limited. Methods: We measured resting energy expenditure (REE) and early-TEF (40-min postprandial, e-TEF) after 8-h fast by indirect calorimetry in 40 obese men, and imaged abdominal fat tissues by magnetic resonance imaging. Each participant was examined on two occasions, 3-weeks apart. At each examination we measured fasting REE and then postprandial REE following the isocaloric [∼380 kcal] consumption of either 56 gr walnuts [(8% carbohydrates; 84% fat, of which 72% polyunsaturated fat)], or 5-slices (150gr) of whole-grain bread (48% carbohydrates; 32% fat). e-TEF was calculated as the area under the curve between the fasting and postprandial tests. Results: Participants had a mean age of 45 ± 8 years, body-mass-index (BMI) = 31.1 ± 3.8 kg/m2, total abdominal fat area = 901.4 ± 240 cm2, visceral fat area (VAT) = 260 ± 102.9 cm2, fasting REE = 1854 ± 205 kcal, REE/kg = 19.39 ± 1.73 kcal/kg, and respiratory quotient (RQ, CO2 eliminated/O2 consumed) = 0.82 ± 0.04. Individuals who exhibited increased e-TEF (top ΔAUC median) to bread had higher VAT (299 cm2 vs. 223 cm2; p = 0.024) and higher BMI (32.4 kg/m2 vs. 30.0 kg/m2; p = 0.013), compared to their peers with the lower e-TEF response (ΔAUC below median). As expected, postprandial e-TEF was higher after whole-grain bread consumption [ΔAUC = +14 kcal/40min] compared to walnuts [ΔAUC = -2 kcal/40 min; p < 0.001]. Conclusions: Higher early thermic effect of high-carbohydrate food, likely reflecting digestion, early absorption and/or sympathetic tone (rather than metabolic utilization (oxidation)), associates with visceral adiposity. Future studies are required to determine if this association represents an added causality between early carbohydrate processing and visceral fat accumulation.
Austel, A., C. Ranke, N. Wagner, J. Görge, T. Ellrott, 2015. Weight loss with a modified Mediterranean-type diet using fat modification: a randomized controlled trial. Eur J Clin Nutr. 69(8):878-84
Background/Objective: There is evidence that Mediterranean diets with a high proportion of olive oil and nuts can be effective for weight management and prevention of cardiovascular disease. It might be difficult for populations with other eating habits to follow such diets. Therefore, a modified Mediterranean-type diet using fat modification through neutral and butter-flavored canola oil, walnuts and walnut oil with two portion-controlled sweet daily snacks was tested in Germany. Subjects/Methods: Randomized waiting-list control study with overweight/grade 1 obese subjects: 12-week self-help modified Mediterranean-type diet, 6 weeks of diet plans and 6 weeks of weight loss maintenance training. Trial duration was 12 months. Intervention group (IG) included 100 participants (average age of 52.4 years, weight 85.1 kg and body mass index (BMI) 30.1 kg/m2), waiting-list control group (CG) included 112 participants (52.6 years, 84.1 kg and 30.1 kg/m2). Results: Per-protocol weight loss after 12 weeks was 5.2 kg in IG vs 0.4 kg in CG (P⩽0.0001), BMI -1.8 vs -0.1 kg/m2 (P⩽0.0001), waist circumference -4.7 vs -0.9 cm (P⩽0.0001). Triglycerides, total cholesterol and LDL cholesterol improved significantly in IG but not in CG. One-year dropouts: 44% in IG and 53% in CG. Weight loss after 12 months: 4.2 kg (pooled data). Conclusions: A five-meal modified Mediterranean-type diet with two daily portion-controlled sweet snacks was effective for weight management in a self-help setting for overweight and grade 1 obese subjects. Fat modification through canola oil, walnuts and walnut oil improved blood lipids even at 12 months.
O’Neil, C.E., V.L. Fulgoni, T.A. Nicklas, 2015. Tree Nut consumption is associated with better adiposity measures and cardiovascular and metabolic syndrome health risk factors in U.S. Adults: NHANES 2005–2010. Nutrition Journal. 14:64. DOI 10.1186/s12937-015-0052-x
Introduction: Previous research has shown inconsistencies in the association of tree nut consumption with risk factors for cardiovascular disease (CVD) and metabolic syndrome (MetS). Objective: To determine the association of tree nut consumption with risk factors for CVD and for MetS in adults. Methods: NHANES 2005–2010 data were used to examine the associations of tree nut consumption with health risks in adults 19+ years (n = 14,386; 51 % males). Tree nuts were: almonds, Brazil nuts, cashews, filberts [hazelnuts], macadamias, pecans, pine nuts, pistachios, and walnuts. Group definitions were non-consumers < ¼ ounce/day and consumers of ≥ ¼ ounce/day tree nuts using data from 24-h dietary recalls. Means and ANOVA (covariate adjusted) were determined using appropriate sample weights. Using logistic regression, odds ratios of being overweight (OW)/obese (OB) (body mass index [BMI] >25/<30 and ≥30, respectively) and having CVRF or MetS, were determined. Results: Tree nut consumption was associated with lower BMI (p = 0.004), waist circumference (WC) (p = 0.008), systolic blood pressure (BP) (p = 0.001), Homeostatic Model Assessment—Insulin Resistance (p = 0.043), and higher high density lipoprotein-cholesterol (p = 0.022), compared with no consumption, and a lower likelihood of OB (−25 %), OW/OB (−23 %), and elevated WC (−21 %). Conclusions: Tree nut consumption was associated with better weight status and some CVRF and MetS components.
Yang, M., F.B. Hu, E.L. Giovannucci, M.J. Stampfer, W.C. Willett, C.S. Fuchs, K. Wu, Y. Bao, 2015. Nut consumption and risk of colorectal cancer in women. European Journal of Clinical Nutrition. doi:10.1038/ejcn.2015.66.
Background/Objectives: Increasing nut consumption has been associated with reduced risk of obesity and type II diabetes, the risk factors for colorectal cancer. However, the association between nut consumption and colorectal cancer risk is unclear. We aimed to examine the association of long-term nut consumption with risk of colorectal cancer. Subjects/Methods: We prospectively followed 75 680 women who were free of cancer at baseline in the Nurses’ Health Study, and examined the association between nut consumption and colorectal cancer risk. Nut consumption was assessed at baseline and updated every 2–4 years. Relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards models. Results: During 2 103 037 person-years of follow-up, we identified 1503 colorectal cancer cases. After adjustment for other known or suspected risk factors, women who consumed nuts 2 or more times per week (that is, 56 g per week) had a 13% lower risk of colorectal cancer compared with those who rarely consumed nuts, but the association was not statistically significant (RR: 0.87; 95%CI: 0.72–1.05; P-trend: 0.06). No association was observed for peanut butter. Conclusions: In this large prospective cohort of women, frequent nut consumption was not significantly associated with colorectal cancer risk after adjusting for other risk factors.
Mohammadifard, N., A. Salehi-Abargouei, J. Salas-Salvadó, M. Guasch-Ferré, K. Humphries, N. Sarrafzadegan, 2015. The effect of tree nut, peanut, and soy nut consumption on blood pressure: a systematic review and meta-analysis of randomized controlled clinical trials. Am J Clin Nutr. 101:966–82.
Background: Although several studies have assessed the effects of nut consumption (tree nuts, peanuts, and soy nuts) on blood pressure (BP), the results are conflicting. Objective: The aim was to conduct a systematic review and meta-analysis of published randomized controlled trials (RCTs) to estimate the effect of nut consumption on BP. Design: The databases MEDLINE, SCOPUS, ISI Web of Science, and Google Scholar were searched for RCTs carried out between 1958 and October 2013 that reported the effect of consuming single or mixed nuts (including walnuts, almonds, pistachios, cashews, hazelnuts, macadamia nuts, pecans, peanuts, and soy nuts) on systolic BP (SBP) or diastolic BP (DBP) as primary or secondary outcomes in adult populations aged $18 y. Relevant articles were identified by screening the abstracts and titles and the full text. Studies that evaluated the effects for, 2 wk or in which the control group ingested different healthy oils were excluded. Mean 6 SD changes in SBP and DBP in each treatment group were recorded for meta-analysis. Results: Twenty-one RCTs met the inclusion criteria. Our findings suggest that nut consumption leads to a significant reduction in SBP in participants without type 2 diabetes [mean difference (MD): 21.29; 95% CI: 22.35, 20.22; P = 0.02] but not in the total population. Subgroup analyses of different nut types suggest that pistachios, but not other nuts, significantly reduce SBP (MD: 21.82; 95% CI: 22.97, 20.67; P = 0.002). Our study suggests that pistachios (MD: 20.80; 95% CI: 21.43, 20.17; P = 0.01) and mixed nuts (MD: 21.19; 95% CI: 22.35, 20.03; P = 0.04) have a significant reducing effect on DBP. We found no significant changes in DBP after the consumption of other nuts. Conclusions: Total nut consumption lowered SBP in participants without type 2 diabetes. Pistachios seemed to have the strongest effect on reducing SBP and DBP. Mixed nuts also reduced DBP.
