Li, T.Y., A.M. Brennan, N.M. Wedick, C. Mantzoros, N. Rifai, F.B. Hu, 2009. Regular Consumption of Nuts Is Associated with a Lower Risk of Cardiovascular Disease in Women with Type 2 Diabetes. J. Nutr.139:1333-1338.
Higher nut consumption has been associated with lower risk of coronary heart disease (CHD) events in several epidemiologic studies. The study examined the association between intake of nuts and incident cardiovascular disease (CVD) in a cohort of women with type 2 diabetes. For the primary analysis, there were 6309 women with type 2 diabetes who completed a validated FFQ every 2-4 y between 1980 and 2002 and were without CVD or cancer at study entry. Major CVD events included incident myocardial infarction (MI), revascularization, and stroke. During 54,656 person-years of follow-up, there were 452 CHD events (including MI and revascularization) and 182 incident stroke cases. Frequent nut and peanut butter consumption was inversely associated with total CVD risk in age-adjusted analyses. After adjustment for conventional CVD risk factors, consumption of at least 5 servings/wk of nuts or peanut butter [serving size, 28 g (1 ounce) for nuts and 16 g (1 tablespoon) for peanut butter] was significantly associated with a lower risk of CVD (relative risk = 0.56; 95% CI: 0.36-0.89). Furthermore, when we evaluated plasma lipid and inflammatory biomarkers, we observed that increasing nut consumption was significantly associated with a more favorable plasma lipid profile, including lower LDL cholesterol, non-HDL cholesterol, total cholesterol, and apolipoprotein-B-100 concentrations. However, we did not observe significant associations for HDL cholesterol or inflammatory markers. These data suggest that frequent nut and peanut butter consumption is associated with a significantly lower CVD risk in women with type 2 diabetes.
Ros, E., 2009. Nuts and novel biomarkers of cardiovascular disease. Am J Clin Nutr. 89(suppl):1649S-56S.
Nuts are energy-dense foods, rich in total fat and unsaturated fatty acids. The favorable fatty acid profile probably contributes to the beneficial effects of nut consumption observed in epidemiologic studies (prevention of coronary heart disease and diabetes) and feeding trials (cholesterol lowering). Besides fat, the complex matrices of nuts contain many bioactive compounds: vegetable protein, fiber, minerals, tocopherols, and phenolic compounds. By virtue of their unique composition, nuts are likely to benefit newer cardiovascular risk biomarkers, such as LDL oxidizability, soluble inflammatory molecules, and endothelial dysfunction. Protection of LDL oxidation by nut intake has been documented in some, but not all, clinical studies. In one study, feeding one daily serving of mixed nuts was associated with lower oxidized LDL concentrations. Regarding inflammation, cross-sectional studies have shown that nut consumption is associated with lower concentrations of circulating inflammatory molecules and higher plasma adiponectin, a potent anti-inflammatory adipokine. Clinical studies with nuts have documented reduced inflammatory cytokine concentrations but no consistent changes of C-reactive protein. Only walnuts have been formally tested for effects on endothelial function. After both walnut diets and single walnut meals, favorable vasoreactivity changes have been observed. Walnut consumption also reduced expression of endothelin 1, a potent endothelial activator, in an animal model of accelerated atherosclerosis. Beneficial effects on vascular reactivity may be ascribed to several constituents of walnuts: L-arginine, the precursor of nitricoxide, a-linolenic acid, and phenolic antioxidants. Although more studies are warranted, the emerging picture is that nut consumption beneficially influences cardiovascular risk beyond cholesterol lowering.
Lopez-Uriarte. P., M. Bullo, P. Casas-Agustench, N. Babio, J. Salas-Salvado, 2009. Nuts and oxidation: a systematic review. Nutrition Reviews. 67(9):497-508.
In recent years, nuts have received special attention because of their potential role in preventing cardiovascular disease. Because nuts are very rich in total fat that can potentially be oxidized and their skins contain several antioxidants, studies have been conducted to evaluate the potential effect of nut consumption on oxidative stress. This review evaluates the in vitro and in vivo studies conducted in animals or humans to analyze the effect of nuts on oxidation.
Escurriol, V., Cofán, M., M. Serra, M. Bullo’, J. Basora, J. Salas-Salvado’, D. Corella, I. Zazpe, M.A. Martínez-González, V. Ruiz-Gutiérrez , R. Estruch, E. Ros, 2009. Serum sterol responses to increasing plant sterol intake from natural foods in the Mediterranean diet. Eur J Nutr. 48(6):373-382.
Background: Phytosterols in natural foods are thought to inhibit cholesterol absorption. The Mediterranean diet is rich in phytosterol-containing plant foods. Aim of the study: To assess whether increasing phytosterols intake from natural foods was associated with a cholesterol-lowering effect in a substudy of a randomized trial of nutritional intervention with Mediterranean diets for primary cardiovascular prevention (PREDIMED study). Methods: One hundred and six high cardiovascular risk subjects assigned to two Mediterranean diets supplemented with virgin olive oil (VOO) or nuts, which are phytosterols-rich foods, or advice on a low-fat diet. Outcomes were 1-year changes in nutrient intake and serum levels of lipids and non-cholesterol sterols. Results: Average phytosterol intake increased by 76, 158 and 15 mg/day in participants assigned VOO, nuts and low-fat diets, respectively. Compared to participants in the low-fat diet group, changes in outcome variables were observed only in those in the Mediterranean diet with nuts group, with increases in intake of fiber, polyunsaturated fatty acids and phytosterols (P<0.020, all) and significant (P<0.05) reductions of LDL-cholesterol (0.27 mmol/l or 8.3%) and the LDL/HDL-cholesterol ratio (0.29 mmol/l or 11.5%). Variations in saturated fat, cholesterol or fiber intake were unrelated to LDL-cholesterol changes. In the whole group, changes in serum sitosterol-to-cholesterol, which reflect those of dietary phytosterol intake and absorption, correlated inversely to LDL-cholesterol changes (r = -0.256; P = 0.008). In multivariate analyses, baseline LDL-cholesterol, increases in serum sitosterol ratios and statin use were independently associated with LDL-cholesterol reductions. Conclusions: Small amounts of phytosterols in natural foods appear to be bioactive in cholesterol lowering.
Torabian, S., E. Haddad, S. Rajaram, J. Banta, J. Sabate’, 2009. Acute effect of nut consumption on plasma total polyphenols, antioxidant capacity and lipid peroxidation. J Hum Nutr Diet. 22:64-71.
Background: Nuts have been shown to have beneficial effects on human health due to the healthy fat content; however, the effect of antioxidants (i.e. polyphenols) in nuts have not been fully investigated. The present study aimed to assess the immediate effect of a polyphenol-rich meal (75% of energy from nuts: walnuts or almonds) and a polyphenol-free meal on plasma polyphenol content, antioxidant capacity and lipid peroxidation in healthy volunteers. Methods: Thirteen subjects participated in a randomized, crossover, intervention study. After an overnight fast, walnuts, almonds or a control meal in the form of smoothies were consumed by study subjects. Each subject participated on three occasions, 1 week apart, consuming one of the smoothies each time. Blood samples were obtained at fasting and then at intervals up to 3.5 h after consumption of the smoothies. Results: There was a significant increase in plasma polyphenol concentration following both nut meals, with peak concentrations being achieved at 90 min, and with a walnut meal having a more sustained higher concentration than an almond meal. The plasma total antioxidant capacity reached its highest point at 150 min postconsumption of the nut meals, and was higher after the almond compared to walnut meal. A gradual significant (P < 0.05) reduction in the susceptibility of plasma to lipid peroxidation was observed 90 min after ingestion of the nut meals. No changes were observed following consumption of control meal. Conclusions: Consumption of both nuts increased plasma polyphenol concentrations, increased the total antioxidant capacity and reduced plasma lipid peroxidation.
Skripak, J.M., R.A. Wood, 2008. Peanut and tree nut allergy in childhood. Pediatr Allergy Immunol. 19:368–373.
Peanut and tree nut allergies present multiple challenges in their presentation and management. These challenges have become increasingly relevant in recent years, as these allergies appear to have become more common. An estimated 1–2% of the population in the USA is allergic to peanut or tree nuts. Peanut allergy typically presents with symptoms in one of the first few exposures to peanut. Diagnosis is based on clinical history along with skin prick test, or quantitation of allergen-specific immunoglobulin E (IgE), and oral food challenges when indicated. Once the diagnosis is confirmed, the only current management approach is strict avoidance of the food. This is clearly an imperfect option as it can be difficult to avoid completely peanut and tree nuts and accidental exposures are not uncommon. Only about 20% of those with peanut allergy, and <10% of those with tree nut allergy, are reported to acquire tolerance. Additionally, peanut allergy can recur, with one study finding a recurrence rate of 8%. Peanut and tree nuts are the foods most frequently associated with fatal episodes of anaphylaxis. This is of particular concern in adolescents and young adults, among whom life-threatening and fatal food allergy-related reactions are most common.
Gideon Lack, 2008. Epidemiologic risks for food allergy. J Allergy Clin Immunol. 121:1331-6.
This article reviews possible risk factors and theories for the development of food allergy. It is noted that previous strategies to prevent food allergy through allergen avoidance during pregnancy, breast-feeding, and infancy have more recently been called into question. Alternative hypotheses are examined with respect to food allergy, namely the hygiene hypothesis, the dietary fat hypothesis, the antioxidant hypothesis, and the vitamin D hypotheses. An alternative hypothesis is proposed, suggesting that sensitization to allergen occurs through environmental exposure to allergen through the skin and that consumption of food allergen induces oral tolerance. This hypothesis provides a possible explanation for the close link between eczema and the development of food allergies. It also suggests novel interventional strategies to prevent the development of food allergies.
Ross, M.P., M. Ferguson, D. Street, K. Klontz, T. Schroeder, S. Luccioli, 2008. Analysis of food-allergic and anaphylactic events in the National Electronic Injury Surveillance System. J Allergy Clin Immunol. 121:166-71.
Background: The National Electronic Injury Surveillance System (NEISS) captures a nationally representative probability sample from hospital emergency departments (EDs) in the United States. Objective: Emergency department data from NEISS were analyzed to assess the magnitude and severity of adverse events attributable to food allergies. Methods: Emergency department events describing food-related allergic symptomatology were identified from 34 participating EDs from August 1 to September 30, 2003. Results: Extrapolation of NEISS event data predicts a total of 20,821 hospital ED visits, 2333 visits for anaphylaxis, and 520 hospitalizations caused by food allergy in the United States during the 2-month study period. The median age was 26 years; 24% of visits involved children ≤5 years old. Shellfish was the most frequently implicated food in persons ≥6 years old, whereas children ≤5 years old experienced more events from eggs, fruit, peanuts, and tree nuts. There were no reported deaths. Review of medical records found that only 19% of patients received epinephrine, and, using criteria established by a 2005 anaphylaxis symposium, 57% of likely anaphylactic events did not have an ED diagnosis of anaphylaxis. Conclusion: Analysis of NEISS data may be a useful tool for assessing the magnitude and severity of food-allergic events. A criteria-based review of medical records suggests underdiagnosis of anaphylactic events in EDs.
Zazpe, I.A. Sanchez-Tainta, R. Estruch, R.M. Lamuela-Raventos, H. Schröder, J. Salas-Salvado, D. Corella, M. Fiol, E. Gomez-Gracia, F. Aros, E. Ros, V. Ruíz-Gutierrez, P. Iglesias, M. Conde-Herrera, M.A. Martinez-Gonzalez, 2008. A large randomized individual and group intervention conducted by registered dietitians increased adherence to Mediterranean-type diets: the PREDIMED study. J Am Diet Assoc. 108:7 1134-1143.
Objective: To assess the effectiveness of an intervention aimed to increase adherence to a Mediterranean diet. Design: A 12-month assessment of a randomized primary prevention trial. Subjects/settings: One thousand five hundred fifty-one asymptomatic persons aged 55 to 80 years, with diabetes or ≥3 cardiovascular risk factors. Intervention: Participants were randomly assigned to a control group or two Mediterranean diet groups. Those allocated to the two Mediterranean diet groups received individual motivational interviews every 3 months to negotiate nutrition goals, and group educational sessions on a quarterly basis. One Mediterranean diet group received free virgin olive oil (1L/week), the other received free mixed nuts (30 g/day). Participants in the control group received verbal instructions and a leaflet recommending the National Cholesterol Education Program Adult Treatment Panel III dietary guidelines. Main outcome measures: Changes in food and nutrient intake after 12 months. Statistical analyses: Paired t tests (for within-group changes) and analysis of variance (for between-group changes) were conducted. Results: Participants allocated to both Mediterranean diets increased their intake of virgin olive oil, nuts, vegetables, legumes, and fruits (P<0.05 for all within- and between-group differences). Participants in all three groups decreased their intake of meat and pastries, cakes, and sweets (P<0.05 for all). Fiber, monounsaturated fatty acid, and polyunsaturated fatty acid intake increased in the Mediterranean diet groups (P<0.005 for all). Favorable, although nonsignificant, changes in intake of other nutrients occurred only in the Mediterranean diet groups. Conclusions: A 12-month behavioral intervention promoting the Mediterranean diet can favorably modify an individual’s overall food pattern. The individual motivational interventions together with the group sessions and the free provision of high-fat and palatable key foods customary to the Mediterranean diet were effective in improving the dietary habits of participants in this trial.
Salas-Salvadó, J., A. Garcia-Arellano , R. Estruch, F. Marquez-Sandoval , D. Corella, M. Fiol , E. Gómez-Gracia, E. Viñoles , F. Arós, C. Herrera, C. Lahoz, J. Lapetra, J.S. Perona, D. Muñoz-Aguado, M.A. Martínez-González, E. Ros; for the PREDIMED Investigators, 2008. Components of the Mediterranean-type food pattern and serum inflammatory markers among patients at high risk for cardiovascular disease. European Journal of Clinical Nutrition. 62, 651-659.
Objective: To evaluate associations between components of the Mediterranean diet and circulating markers of inflammation in a large cohort of asymptomatic subjects at high risk for cardiovascular disease. Subjects/Methods: A total of 339 men and 433 women aged between 55 and 80 years at high cardiovascular risk because of presence of diabetes or at least three classical cardiovascular risk factors, food consumption was determined by a semi-quantitative food frequency questionnaire. Serum concentrations of high-sensitivity C-reactive protein (CRP) were measured by immunonephelometry and those of interleukin-6 (IL-6), intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) by enzyme-linked immunosorbent assay. Results: After adjusting for age, gender, body mass index, diabetes, smoking, use of statins, non-steroidal anti-inflammatory drugs and aspirin, a higher consumption of fruits and cereals was associated with lower concentrations of IL-6 (P for trend 0.005;both). Subjects with the highest consumption of nuts and virgin olive oil showed the lowest concentrations of VCAM-1, ICAM-1, IL-6 and CRP; albeit only for ICAM-1 was this difference statistically significant in the case of nuts (for trend 0.003) and for VCAM-1 in the case of virgin olive oil (P for trend 0.02). Participants with higher adherence to the Mediterranean-type diet did not show significantly lower concentrations of inflammatory markers (P<0.1 for VCAM-1 and ICAM-1).
