Kendall, C.W.C., A. Esfahani, J. Truan, K. Srichaikul, D.J.A. Jenkins, 2010. Health benefits of nuts in prevention and management of diabetes. Asia Pac J Clin Nutr. 19(1):110-116.
The effects of tree nuts on risk factors for coronary heart disease (CHD), in particular blood lipids, have been investigated in a number of studies and the beneficial effects are now recognized. The beneficial effects of nuts on CHD in cohort studies have also been clearly demonstrated. However, while there is also reason to believe the unique micro- and macronutrient profiles of nuts may help to control blood glucose levels, relatively few studies have investigated their role in diabetes control and prevention. Nuts are low in available carbohydrate, have a healthy fatty acid profile, and are high in vegetable protein, fiber and magnesium. Acute feeding studies indicate that when eaten alone nuts have minimal effects on raising postprandial blood glucose levels. In addition, when nuts are consumed with carbohydrate rich foods, they blunt the postprandial glycemic response of the carbohydrate meal. Despite the success of these acute studies, only a limited number of trials have been conducted with nuts in type 2 diabetes. These studies have either been of insufficient duration to observe changes in HbA1c, as the standard measure of glycemic control, or have been underpowered. Therefore, more long-term clinical trials are required to examine the role of nuts on glycemic control in patients with prediabetes and diabetes. Overall, there are good reasons to justify further exploration of the use of nuts in the prevention of diabetes and its microand macrovascular complications.
Casas-Agustench, P., M. Bulló, J. Salas-Salvadó, 2010. Nuts, inflammation and insulin resistance. Asia Pac J Clin Nutr. 19(1):124-130.
The beneficial effects of nut consumption on cardiovascular disease (CVD) have been widely documented. These protective effects are mainly attributed to the role of nuts in the metabolism of lipids and lipoproteins. As chronic inflammation is a key early stage in the atherosclerotic process that predicts future CVD events and is closely related to the pathogenesis of insulin resistance, many recent studies have focused on the potential effect of nut consumption on inflammation and insulin resistance. Through different mechanisms, some components of nuts such as magnesium, fiber, α-linolenic acid, L-arginine, antioxidants and MUFA may protect against inflammation and insulin resistance. This review evaluates the epidemiologic and experimental evidence in humans demonstrating an association between nut consumption and these two emergent cardio-protective mechanisms.
Sabaté, J., M. Wien, 2010. Nuts, blood lipids and cardiovascular disease. Asia Pac J Clin Nutr. 19(1):131-136.
The aim of this paper is to evaluate nut-related epidemiological and human feeding study findings and to discuss the important nutritional attributes of nuts and their link to cardiovascular health. Frequent nut consumption has been found to be protective against coronary heart disease in five large epidemiological studies across two continents. A qualitative summary of the data from four of these studies found an 8.3% reduction in risk of death from coronary heart disease for each weekly serving of nuts. Over 40 dietary intervention studies have been conducted evaluating the effect of nut containing diets on blood lipids. These studies have demonstrated that intake of different kinds of nuts lower total and LDL cholesterol and the LDL: HDL ratio in healthy subjects or patients with moderate hypercholesterolaemia, even in the context of healthy diets. Nuts have a unique fatty acid profile and feature a high unsaturated to saturated fatty acid ratio, an important contributing factor to the beneficial health effects of nut consumption. Additional cardioprotective nutrients found in nuts include vegetable protein, fiber, α-tocopherol, folic acid, magnesium, copper, phytosterols and other phytochemicals.
Babio, N., M. Bulló, J. Basora, M.A. Martínez-González, J. Fernández-Ballart, F. Márquez-Sandoval, C. Molina, J. Salas-Salvadó; Nureta-PREDIMED Investigators, 2009. Adherence to the Mediterranean diet and risk of metabolic syndrome and its components. Nutr Metab Cardiovasc Dis. 19(8):563-70.
BACKGROUND AND AIMS: The role of diet in the aetiology of metabolic syndrome (MetS) is not well understood. The aim of the present study was to evaluate the relationship between adherence to the Mediterranean diet (MedDiet) and MetS. METHODS AND RESULTS: A cross-sectional study was conducted with 808 high cardiovascular risk participants of the Reus PREDIMED Centre. MetS was defined by the updated National Cholesterol and Education Program Adult Treatment Panel III criteria. An inverse association between quartiles of adherence to the MedDiet (14-point score) and the prevalence of MetS (P for trend<0.001) was observed. After adjusting for age, sex, total energy intake, smoking status and physical activity, participants with the highest score of adherence to the MedDiet (>/=9 points) had the lowest odds ratio of having MetS (OR [95% CI] of 0.44 [0.27-0.70]) compared to those in the lowest quartile. Participants with the highest MedDiet adherence had 47 and 54% lower odds of having low HDL-c and hypertriglyceridemia MetS criteria, respectively, than those in the lowest quartile. Some components of the MedDiet, such as olive oil, legumes and red wine were associated with lower prevalence of MetS. CONCLUSION: Higher adherence to a Mediterranean diet is associated with a significantly lower odds ratio of having MetS in a population with a high risk of cardiovascular disease.
Taylor, S.L., R.W.R. Crevel, D. Sheffield, J. Kabourek, J. Baumert, 2009. Threshold dose for peanut: Risk characterization based upon published results from challenges of peanut-allergic individuals. Food Chem Toxicol. 47:1198–1204.
Population thresholds for peanut are unknown. However, lowest- and no-observed adverse effect levels (LOAELs and NOAELs) are published for an unknown number of peanut-allergic individuals. Publications were screened for LOAELs and NOAELs from blinded, low-dose oral challenges. Data were obtained from 185 peanut-allergic individuals (12 publications). Data were analyzed by interval-censoring survival analysis and three probability distribution models fitted to it (Log-Normal, Log-Logistic, and Weibull) to estimate the ED10. All three models described the data well and provided ED10’s in close agreement: 17.6, 17.0, and 14.6 mg of whole peanut for the Log-Normal, Log-Logistic, and Weibull models, respectively. The 95% lower confidence intervals for the ED10’s were 9.2, 8.1, and 6.0 mg of whole peanut for the Log-Normal, Log-Logistic, and Weibull models, respectively. The modeling of individual NOAELs and LOAELs identified from three different types of published studies – diagnostic series, threshold studies, and immunotherapy trials – yielded significantly different whole peanut ED10’s of 11.9 mg for threshold studies, 18.0 mg for diagnostic series and 65.5 mg for immunotherapy trials; patient selection and other biases may have influenced the estimates. These data and risk assessment models provide the type of information that is necessary to establish regulatory thresholds for peanut.
Casas-Agustench, P., P. Lopez-Uriarte, M. Bullo’, E. Ros, J.J. Cabre’-Vila, J. Salas-Salvado’, 2009. Effects of one serving of mixed nuts on serum lipids, insulin resistance and inflammatory markers in patients with the metabolic syndrome. Nutrition, Metabolism & Cardiovascular Diseases. doi:10.1016/j.numecd.2009.08.005.
Background and aims: Knowledge of the effect of nut consumption on metabolic syndrome (MetS) components is limited. We assessed the effects of nut intake on adiposity, serum lipids, insulin resistance, and inflammatory biomarkers in patients with MetS. Methods and results: In a randomized, parallel-group, 12-week feeding trial, 50 patients with MetS were given recommendations for a healthy diet with or without supplementation with 30 g/day of raw nuts (15 g walnuts, 7.5 g almonds and 7.5 g hazelnuts) (Nut and Control diet groups, respectively). Adiposity measures, serum lipids, insulin, Homeostasis Model Assessment (HOMA), interleukin-6 (IL-6) and other inflammatory biomarkers, and 48-h fecal fat were determined basally and at study’s completion. Moderate weight loss, decreased adiposity, and lower blood pressure occurred similarly after both diets. The Control, but not the Nut diet, was associated with significant (P < 0.05) reduction of LDL-cholesterol, with mean changes of -0.36 versus -0.13 mmol/L, respectively (between-group differences, P=0.154). The Nut diet reduced fasting insulin by 2.60 µU/mL (95% CI, -4.62 to -0.59) and HOMA-insulin resistance by 0.72 (-1.28 to -0.16) (P < 0.05 versus Control diet; both). Among inflammatory markers, the Nut diet resulted in changes of median plasma IL-6 of -1.1 ng/L (-2.7 to -0.1; P=0.035 versus Control diet), but adjustment for weight loss attenuated the significance of the association. Stool fat decreased with the Control diet and slightly increased with the Nut diet (P < 0.05 for between-group differences). Conclusion: Patients with MetS show decreased lipid responsiveness but improved insulin sensitivity after daily intake of 30 g of mixed nuts.
Bes-Rastrollo, M., N.M. Wedick, M.A. Martinez-Gonzalez, T.Y. Li, L. Sampson, F.B. Hu, 2009. Prospective study of nut consumption, long-term weight change, and obesity risk in women. Am J Clin Nutr 89:1-7.
Background: Data concerning the long-term association between nut consumption and weight change in a free-living population are sparse. Objective: The objective was to determine the relation between nut consumption and long-term weight change. Design: The participants were 51,188 women in the Nurses’ Health Study II aged 20-45 y, who had no cardiovascular disease, diabetes, or cancer. We prospectively evaluated the dietary intake of nuts and subsequent weight changes from 1991 to 1999. Results: Women who reported eating nuts _2 times/wk had a slightly less mean (6 SE) weight gain (5.04 6 0.12 kg) than did women who rarely ate nuts (5.55 6 0.04 kg) (P for trend , 0.001). For the same comparison, when total nut consumption was subdivided into peanuts and tree nuts, the results were similar (i.e., less weight gain in women eating either peanuts or tree nuts _2 times/wk). The results were similar in normal-weight, overweight, and obese participants. In multivariate analyses in which lifestyle and other dietary factors were controlled for, we found that greater nut consumption (_2 times/wk compared with never/almost never) was associated with a slightly lower risk of obesity (hazard ratio: 0.77; 95% CI: 0.57, 1.02; P for trend ¼ 0.003). Conclusions: Higher nut consumption was not associated with greater body weight gain during 8 y of follow-up in healthy middle aged women. Instead, it was associated with a slightly lower risk of weight gain and obesity. The results of this study suggest that incorporating nuts into diets does not lead to greater weight gain and may help weight control.
Alasalvar, C., F. Shahidi, 2009. Natural antioxidants in tree nuts. Eur. J. Lipid Sci. Technol. 111:1056-1062
The levels of natural antioxidants and phytochemicals present in tree nuts are reported. Where possible, the health claims by Food and Drug Administration and European Food Safety Authority and health effects of tree nuts are provided. The content and recommended dietary allowances of nutrient antioxidants (such as vitamins A, C, E, and the mineral selenium) present in various tree nuts are compared. Antioxidant activity and phytochemicals present among tree nuts have been thoroughly reviewed. Research findings from over 65 references, many of which have been published within the last 10 years, have been compiled and reported.
Sabate’, J., Y. Ang, 2009. Nuts and health outcomes: new epidemiologic evidence. Am J Clin Nutr89(suppl):1643S-8S.
This article reviews recent epidemiologic evidence on nut intake and health outcomes. It focuses on studies in which nut consumption is directly assessed or when nuts are included in a dietary score or pattern. Epidemiologic studies have been remarkably consistent in showing an association between nut consumption and a reduced risk of coronary heart disease (CHD). Some evidence has emerged recently to suggest health-protective benefits of nuts other than CHD. Frequent nut intake probably reduces risk of diabetes mellitus among women, but its effects on men are unknown. Evidence on the anticarcinogenic effects of nuts is somewhat limited because studies in the past 2 decades have examined only 3 tumor sites, and the benefits appear to be manifested only in women. However, the protective benefits of frequent nut consumption on gallstone diseases are observed in both sexes. Long-term nut consumption is linked with lower body weight and lower risk of obesity and weight gain. A dietary pattern or score that includes nuts is consistently related with beneficial health outcomes, and this provides an indirect evidence of the salutary benefits of nut consumption. More longitudinal studies are needed to clarify the possible effects of nuts on diseases other than CHD.
Raw, D., B. Lockwood, 2009. The health benefits of nuts. NUTRAfoods. 8(3)7-14.
Overall, nuts can belp reduce the certain risk factors associated with CVD and other chronic diseases, helping to prevent disease and promote health.
