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Research Nut: Cashews

Should we go nuts about nuts?

Rohrmann, S., D. Faeh, 2013. Should we go nuts about nuts? BMC Medicine. 11:165.

Since the beginning of the 1990s, increasing evidence supports beneficial effects of nut consumption on health. A new analysis of the Spanish PREDIMED trial, published in BMC Medicine, has expanded our knowledge. The study showed that individuals eating nuts more than three times per week died less often from cardiovascular disease and cancer than non-consumers. The study also adds an important finding that previous epidemiological studies could not provide: a protective effect on premature mortality was only seen in the intervention group in which nut consumption increased during the 4.8 years of follow-up, not in the intervention group with additional olive oil consumption or in the control group. Nut consumption actually decreased during follow-up in the latter two groups. Questions remain to be answered on the quantity of nuts to be consumed for health benefits, on possible mechanisms of action, and on whether some types of nuts should be favored.

Frequency of nut consumption and mortality risk in the PREDIMED nutrition intervention trial.

Guasch-Ferré, M., M. Bulló, M.Á. Martínez-González, E. Ros, D. Corella, R. Estruch, M. Fitó, F. Arós, J. Wärnberg, M. Fiol, J. Lapetra, E. Vinyoles, R.M. Lamuela-Raventós, L. Serra-Majem, X. Pintó, V. Ruiz-Gutiérrez, J. Basora, J. Salas-Salvadó, on behalf of the PREDIMED study group, 2013. Frequency of nut consumption and mortality risk in the PREDIMED nutrition intervention trial. BMC Med. 11:164.

Background: Prospective studies in non-Mediterranean populations have consistently related increasing nut consumption to lower coronary heart disease mortality. A small protective effect on all-cause and cancer mortality has also been suggested. To examine the association between frequency of nut consumption and mortality in individuals at high cardiovascular risk from Spain, a Mediterranean country with a relatively high average nut intake per person. Methods: We evaluated 7,216 men and women aged 55 to 80 years randomized to 1 of 3 interventions (Mediterranean diets supplemented with nuts or olive oil and control diet) in the PREDIMED (‘PREvención con DIeta MEDiterránea’) study. Nut consumption was assessed at baseline and mortality was ascertained by medical records and linkage to the National Death Index. Multivariable-adjusted Cox regression and multivariable analyses with generalized  estimating equation models were used to assess the association between yearly repeated measurements of nut consumption and mortality. Results: During a median follow-up of 4.8 years, 323 total deaths, 81 cardiovascular deaths and 130 cancer deaths occurred. Nut consumption was associated with a significantly reduced risk of all-cause mortality (P for trend <0.05, all). Compared to non-consumers, subjects consuming nuts >3 servings/week (32% of the cohort) had a 39% lower mortality risk (hazard ratio (HR) 0.61; 95% CI 0.45 to 0.83). A similar protective effect against cardiovascular and cancer mortality was observed. Participants allocated to the Mediterranean diet with nuts group who consumed nuts >3 servings/week at baseline had the lowest total mortality risk (HR 0.37; 95% CI 0.22 to 0.66). Conclusions: Increased frequency of nut consumption was associated with a significantly reduced risk of mortality in a Mediterranean population at high cardiovascular risk.

Threshold dose distributions for 5 major allergenic foods in children.

Blom, W.M., B.J. Vlieg-Boerstra, A.G. Kruizinga, S. van der Heide, G.F. Houben, A.E.J. Dubois, 2013. Threshold dose distributions for 5 major allergenic foods in children. J Allergy Clin Immunol. 131:172-9.

Background: For most allergenic foods, insufficient threshold dose information within the population restricts the advice on levels of unintended allergenic foods which should trigger precautionary labeling on prepackaged foods. Objective: We wanted to derive threshold dose distributions for major allergenic foods and to elaborate the protein doses at which a proportion of the allergic population is likely to respond. Methods: For 7 allergenic foods double-blind, placebo-controlled food challenges (DBPCFCs) with a positive outcome for allergic reactions were selected from the clinical database of children routinely tested to diagnose food allergy at the University Medical Center Groningen. For each allergen 2 population threshold distributions were determined with the individual minimal eliciting dose and the preceding dose of each DBPCFC for objective symptoms and any symptom (either subjective or objective). Results: Individual positive DBPCFCs were available for peanut (n = 135), cow’s milk (n = 93), hen’s egg (n = 53), hazelnut (n = 28), and cashew nut (n = 31). Fewer children were challenged with soy (n = 10) or walnut (n = 13). Threshold dose distributions showed a good statistical and visual fit. The protein dose at which 5% of the allergic population is likely to respond with objective reactions was 1.6 mg for peanut, 1.1 mg for cow’s milk, 1.5 mg for hen’s egg, 7.4 mg for cashew nut, and 0.29 mg for hazelnut. Thresholds for any symptom were on average 2 to 6 times lower than for objective symptoms. The 95% upper and lower confidence intervals of the threshold distributions were overlapping. The peanut threshold distribution on objective symptoms was similar to the distribution of another European center. Conclusions: Threshold distribution curves and eliciting doses are a powerful tool to compare different allergenic foods and for informing policy on precautionary labeling.

Estimated daily flavonoid and stilbene intake from fruits, vegetables, and nuts and associations with lipid profiles in Chinese adults.

Li, G., Y. Zhu, Y. Zhang, J. Lang, Y. Chen, W. Ling, 2013. Estimated daily flavonoid and stilbene intake from fruits, vegetables, and nuts and associations with lipid profiles in Chinese adults. J Acad Nutr Diet. 113:786-794.

Background: The scientific evidence for the association of daily flavonoid and stilbene intakes with cardiovascular risk factors in Chinese adults has not been reported previously. Objective: The aim of the study was to assess daily flavonoid and stilbene intakes and evaluate these compounds’ association with cardiovascular risk factors such as serum lipids and carotid intima–media thickness in Chinese adults. Design: A total of 1,393 subjects participated in this cross-sectional study from July 2008 to January 2010 in China. Dietary flavonoid and stilbene intakes as well as overall dietary intakes from foods and beverages were assessed with a quantitative food frequency questionnaire. Anthropometric measurements and cardiovascular risk factors including serum lipids, uric acid, and carotid intima–media thickness were examined. The relationship between flavonoids and stilbene intakes and these cardiovascular risk factors was examined using either partial correlation coefficients or analysis of covariance. Results: The richest sources of flavonoids and stilbenes were the fruit group including apple, plum, pear, and peach, followed by the vegetable group containing lotus root and taro. The daily intake of total flavonoids, anthocyanidins, flavonols, flavones, isoflavones, and stilbene were 165.6 mg/day, 27.6 mg/day, 123.7 mg/day, 10.7 mg/day, 3.7 mg/day, and 0.3 mg/day, respectively. Higher daily consumption of anthocyanidins was associated with elevated serum high-density lipoprotein cholesterol (HDL-C) concentrations (P trend=0.001), and higher total flavonoid and flavonol intakes were associated with lower serum triglycerides (TG) concentrations (P trend=0.020 and P trend=0.035, respectively) and TG/HDL-C ratios (P trend=0.040 and P trend=0.045, respectively) in female subjects. These significant relationships were not found in male subjects. Conclusions: The daily intakes of flavonoid and stilbene were estimated in the present study, and higher dietary flavonoid intake was associated with improving lipid profile in Chinese women. The results indicate that dietary flavonoids may have beneficial effect on preventing cardiovascular diseases.

Cross-sectional assessment of nut consumption and obesity, metabolic syndrome and other cardiometabolic risk factors: The PREDIMED study.

Ibarrola-Jurado, N, M. Bulló, M. Guasch-Ferré, E. Ros, M.A. Martínez-González, D. Corella, M. Fiol, J. Wärnberg, R. Estruch, P. Román, F. Arós, E. Vinyoles, L. Serra-Majem, X. Pintó, M.I. Covas, J. Basora, J. Salas-Salvadó, on behalf of the PREDIMED Study Investigators, 2013. Cross-sectional assessment of nut consumption and obesity, metabolic syndrome and other cardiometabolic risk factors: The PREDIMED study. PLoS ONE 8(2): e57367. doi:10.1371/journal.pone.0057367.

Introduction: Prospective studies have consistently suggested that nut consumption is inversely related to fatal and nonfatal coronary heart disease. Limited data are available on the epidemiological associations between nut intake and cardiometabolic risk factors. Objective: To evaluate associations between frequency of nut consumption and prevalence of cardiometabolic risk factors [obesity, metabolic syndrome (MetS), type-2 diabetes, hypertension, and dyslipidemia] in a Mediterranean population at high cardiovascular risk. Materials and Methods: Cross-sectional study of 7,210 men and women (mean age, 67 y) recruited into the PREDIMED study. MetS was defined by the harmonized ATPIII and IDF criteria. Diabetes and hypertension were assessed by clinical diagnosis and dyslipidemia (high triglycerides, low HDL-cholesterol, and hypercholesterolemia) by lipid analyses. Nut consumption was assessed using a validated food frequency questionnaire and categorized as <1, 1–3, and >3 servings/wk. Control of confounding was done with multivariate logistic regression. Results: Compared to participants consuming <1 serving/wk of nuts, those consuming >3 servings/wk had lower adjusted odds ratios (OR) for obesity (0.61, 95% confidence interval 0.54 to 0.68; P-trend <0.001), MetS (0.74, 0.65 to 0.85; P-trend, 0.001), and diabetes (0.87, 0.78 to 0.99; P-trend = 0.043). Higher nut consumption was also associated with lower risk of the abdominal obesity MetS criterion (OR 0.68, 0.60 to 0.79; P-trend <0.001). No significant associations were observed for the MetS components high blood pressure, dyslipidemia, or elevated fasting glucose. Conclusions: Nut consumption was inversely associated with the prevalence of general obesity, central obesity, MetS, and diabetes in subjects at high cardiovascular risk.

 

Phytosterol content and fatty acid pattern of ten different nut types.

Kornsteiner-Krenn, M., K.-H. Wagner, I. Elmadfa, 2013. Phytosterol content and fatty acid pattern of ten different nut types. International Journal for Vitamin and Nutrition Research. 83:263-270. 

Ten different nut kinds (almonds, Brazil nuts, cashews, hazelnuts, macadamias, peanuts, pecans, pine nuts, pistachios, and walnuts) were evaluated for their total oil and phytosterol content as well as their fatty acid composition. The total oil content was the predominant component; mean values oscillated between 45.2 % (cashews) and 74.7 % (macadamias). Mean total phytosterol content ranged from 71.7 mg (Brazil nuts) to 271.9 mg (pistachios) per 100 g oil. ß-sitosterol was the major sterol (mean >71.7 mg/100 g oil) followed by minor contents of campesterol, ergosterol, and stigmasterol. Almonds, cashews, hazelnuts, macadamias, and pistachios were high in monounsaturated fatty acids (MUFA; > 55 %). MUFA- and polyunsaturated fatty acid (PUFA)-rich nuts were peanuts and pecans, whereas Brazil nuts, pine nuts, and walnuts had the highest PUFA content (> 50 %); the high unsaturated/saturated fatty acid ratio ranged from 4.5 to 11.8. However, the fatty acid pattern of every nut is unique.

Nut consumption is associated with a healthy dietary pattern in military men.

Mullie, M., P. Clarys, 2012. Nut consumption is associated with a healthy dietary pattern in military men. Food and Nutrition Sciences. 3:1048-1054.

The objective of the research was to determine the relation between nut consumption and dietary patterns described by Healthy Eating Index, Mediterranean Diet Score and principal component analysis. In a cross-sectional study, 1852 military men were contacted by mail. Using food-frequency questionnaires, nut consumption was recorded and stratified in weekly versus less than weekly. Three dietary indices were calculated and stratified in quintiles. For principal component analysis, the healthiest dietary pattern rich in fruits and vegetables was selected as Healthy Dietary Pattern. The highest quintiles of Healthy Eating Index, Mediterranean Diet Score and Healthy Dietary Pattern were systematically associated with the highest weekly consumption of nuts. The highest quintiles were also associated with the lowest intake of saturated fat, i.e. between 10 and 12 energy-percent compared with 17 to 19 energy-percent for the lowest quintiles. The mean daily nut consumption was less than 6 g a day, which is beneath the recommended quantity for cardiovascular protection. Nut consumption was associated with the healthiest dietary pattern, independently of the used method to determine the dietary pattern. Regular nut consumption seems to be a component of a cluster of several healthy behaviors.

Out-of-hand nut consumption is associated with improved nutrient intake and health risk markers in US children and adults: National Health and Nutrition Examination Survey 1999-2004.

O’Neil, C.E., D.R. Keast, T.A. Nicklas, V.L. Fulgoni, 2012. Out-of-hand nut consumption is associated with improved nutrient intake and health risk markers in US children and adults: National Health and Nutrition Examination Survey 1999-2004. Nutrition Research. 32:185-194.

The purpose of this study was to determine the association of out-of-hand nut (OOHN) consumption with nutrient intake, diet quality, and the prevalence of risk factors for cardiovascular disease and metabolic syndrome. Data from 24-hour recalls from individuals aged 2+ years (n = 24,385) participating in the 1999-2004 National Health and Nutrition Examination Survey were used. The population was divided into children aged 2 to 11, 12 to 18, and adults 19+ years, and each group was dichotomized into OOHN consumers and nonconsumers. Out-of-hand nut consumers were defined as those individuals consuming ¼ oz of nuts or more per d. Means, standard errors, and covariate-adjusted analyses of variance were determined using appropriate sample weights. Diet quality was determined using the Healthy Eating Index-2005. Significance was set at P < .05. The percent of OOHN consumers increased with age: 2.1% ± 0.3%, 2.6% ± 0.3%, 6.5% ± 0.5%, and 9.6% ± 0.5% those aged 2 to 11, 12 to 18, 19 to 50, and 51+ years, respectively. The 2 latter groups were combined into a single group of consumers aged 19+ years for subsequent analyses. Consumers of OOHN from all age groups had higher intakes of energy, monounsaturated and polyunsaturated fatty acids, dietary fiber, copper, and magnesium and lower intakes of carbohydrates, cholesterol, and sodium than did nonconsumers. Diet quality was higher in OOHN consumers of all age groups. In children aged 2 to 11 years, consumers had a higher prevalence of overweight/obesity. In those aged 12 to 18 years, weight and percent overweight were lower in consumers. Adult consumers had higher high-density lipoprotein cholesterol, red blood cell folate, and serum folate levels and lower insulin, glycohemoglobin, and C-reactive protein levels than did nonconsumers. Adult consumers also had a 19% decreased risk of hypertension and a 21% decreased risk of low high-density lipoprotein cholesterol levels. Data suggested that OOHN consumption was associated with improved nutrient intake, diet quality, and, in adults, a lower prevalence of 2 risk factors for metabolic syndrome. Consumption of OOHN, as part of a healthy diet, should be encouraged by health professionals.

Nut consumption is associated with decreased health risk factors for cardiovascular disease and metabolic syndrome in U.S. adults: NHANES 1999–2004.

O’Neil, C.E., D.R. Keast, T.A. Nicklas, V.L. Fulgoni, 2011. Nut consumption is associated with decreased health risk factors for cardiovascular disease and metabolic syndrome in U.S. adults: NHANES 1999–2004. Journal of the American College of Nutrition. 30(6):502–510.

Background: Few recent epidemiologic studies have assessed the effect that nut consumption (including tree nuts and peanuts) has on health risks, including metabolic syndrome (MetS). Objective: This study compared the health risk for cardiovascular disease, type 2 diabetes, and MetS of nut consumers with that of nonconsumers. Design: Adults 19+ years (n = 13,292) participating in the 1999–2004 National Health and Nutrition Examination Survey were used. Intake from 24-hour recalls was used to determine intake. Nut/tree nut consumers consumed ≥¼ ounce per day. Covariate-adjusted means, standard errors, and prevalence rates were determined for the nut consumption groups. Results: The prevalence of nut consumers was 18.6% ± 0.7% and 21.0% ± 0.9% in those 19–50 years and 51 years and older, respectively. Nut consumption was associated with a decreased body mass index (27.7 kg/m2 ± 0.2 vs 28.1 ± 0.1 kg/m2, p<0.05), waist circumference (95.6 ± 0.4 cm vs 96.4 ± 0.3 cm, p < 0.05), and systolic blood pressure (121.9 ± 0.4 mmHg vs 123.20 ± 0.3 mmHg, p < 0.01) compared with nonconsumers. Tree nut consumers also had a lower weight (78.8 ± 0.7 kg vs 80.7 ± 0.3 kg, p < 0.05). Nut consumers had a lower percentage of two risk factors for MetS: hypertension (31.5% ± 1.0% vs 34.2% ± 0.8%, p < 0.05) and low high density lipoprotein-cholesterol (HDL-C) (29.6% ± 1.0% vs 34.8% ± 0.8%, p < 0.01). Tree nut consumers had a lower prevalence of four risk factors for MetS: abdominal obesity (43.6% ± 1.6% vs 49.5% ± 0.8%, p < 0.05), hypertension (31.4% ± 1.2% vs 33.9% ± 0.8%, p < 0.05), low HDL-C (27.9% ± 1.7% vs 34.5% ± 0.8%, p < 0.01), high fasting glucose (11.4% ± 1.4% vs 15.0% ± 0.7%, p < 0.05), and a lower prevalence of MetS (21.2% ± 2.1% vs 26.6% ± 0.7%, p < 0.05). Conclusion: Nut/tree nut consumption was associated with a decreased prevalence of selected risk factors for cardiovascular disease, type 2 diabetes, and MetS.

Tree nut phytochemicals: composition, antioxidant capacity, bioactivity, impact factors. A systematic review of almonds, Brazils, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts.

Bolling, B.W., C.-Y. O. Chen, D.L. McKay, J.B. Blumberg, 2011. Tree nut phytochemicals: composition, antioxidant capacity, bioactivity, impact factors. A systematic review of almonds, Brazils, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts. Nutrition Research Reviews 24:244–275

Tree nuts contain an array of phytochemicals including carotenoids, phenolic acids, phytosterols and polyphenolic compounds such as flavonoids, proanthocyanidins (PAC) and stilbenes, all of which are included in nutrient databases, as well as phytates, sphingolipids, alkylphenols and lignans, which are not. The phytochemical content of tree nuts can vary considerably by nut type, genotype, pre- and post-harvest conditions, as well as storage conditions. Genotype affects phenolic acids, flavonoids, stilbenes and phytosterols, but data are lacking for many other phytochemical classes. During the roasting process, tree nut isoflavones, flavanols and flavonols were found to be more resistant to heat than the anthocyanins, PAC and trans-resveratrol. The choice of solvents used for extracting polyphenols and phytosterols significantly affects their quantification, and studies validating these methods for tree nut phytochemicals are lacking. The phytochemicals found in tree nuts have been associated with antioxidant, anti-inflammatory, anti-proliferative, antiviral, chemopreventive and hypocholesterolaemic actions, all of which are known to affect the initiation and progression of several pathogenic processes. While tree nut phytochemicals are bioaccessible and bioavailable in humans, the number of intervention trials conducted to date is limited. The objectives of the present review are to summarize tree nut: (1) phytochemicals; (2) phytochemical content included in nutrient databases and current publications; (3) phytochemicals affected by pre- and post-harvest conditions and analytical methodology; and (4) bioactivity and health benefits in humans.