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.
Research Nut: Pine Nuts
Nuts and novel biomarkers of cardiovascular disease
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.
Nuts and oxidation: a systematic review
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.
Almonds lead increase in tree nut consumption
USDA, ERS, June 2008. Almonds Lead Increase in Tree Nut Consumption. Amber Waves.http://www.ers.usda.gov/AmberWaves/June08/Findings/Almonds.htm
Americans increased their consumption of tree nuts by 45 percent between the mid-1990s and mid-2000s, with almonds being among the favorites. Promotional programs that advertise the nutritional value of nuts, including beneficial levels of vitamin E and omega fatty acids, have likely contributed to the upswing in per capita nut consumption. The trend toward healthier eating has also played a role, along with the increasing popularity of Mediterranean and Middle Eastern foods that contain nuts. Strong domestic and international demand for U.S.-grown tree nuts has helped keep prices up despite increased production.
Tree nuts and peanuts as components of a healthy diet
King, J.C., J. Blumberg, L. Ingwersen, M. Jenab, K.L. Tucker, 2008. Tree nuts and peanuts as components of a healthy diet. J. Nutr. 138: 1736S-1740S.
Nuts have been part of the diet for thousands of years. In 2003, a Qualified Health Claim was approved, stating that eating 1.5 oz (42 g) of nuts per day may reduce the risk of heart disease. Usual intakes fall short of this recommendation. About one-third of Americans report consuming nuts (tree nuts or peanuts) on any one day. Seven percent of Europeans report eating nuts, but the amount eaten by European nut consumers (31 g/d) is larger than that of Americans (21 g/d). Nuts are an excellent source of vitamin E and magnesium. Individuals consuming nuts also have higher intakes of folate, β-carotene, vitamin K, lutein+zeaxanthin, phosphorus, copper, selenium, potassium, and zinc per 1000 kcal. Regular nut consumption increases total energy intake by 250 kcal/d (1.05 MJ/d), but the body weight of nut consumers is not greater than that of nonconsumers. Nuts are an excellent source of phytochemicals (phytosterols, phenolic acids, flavonoids, stilbenes, and carotenoids). The total phenolic constituents probably contribute to the total antioxidant capacity of nuts, which is comparable to broccoli and tomatoes. To improve guidance on the use of nuts in the diet, the position of nuts in typical food patterns needs to be addressed. The 2005 MyPyramid includes nuts in the meat and beans group. Yet, nuts are rarely consumed as meat substitutes. Because 60% of the nuts consumed in the U.S. are eaten as snacks, emphasizing their use as a healthy snack may be more effective than inclusion within a food group.
Tree nut and peanut consumption in relation to chronic and metabolic diseases including allergy
Davis, P.A., M. Jenab, J.P. Vanden Heuvel, T. Furlong, S. Taylor, 2008. Tree nut and peanut consumption in relation to chronic and metabolic diseases including allergy. J. Nutr. 138: 1757S-1762S.
The New and Emerging Research session highlighted the emerging understanding of both the positive and negative effects of nuts consumption on health. The limited nature of both experimental and epidemiological evidence for positive relationship(s) between nut intake and health were noted. Study inconsistency and limitations, particularly survey methodology, were explored. Recent results from epidemiologic studies indicating a potential negative association between nut and seed intake and cancer risk were reviewed. The ability of walnuts to reduce endothelin suggests an interesting biochemical mechanism of nut action that may affect other endothelin-associated diseases, which should be further explored. The effects of nuts and their constituents on a nuclear receptor screen (PPAR, β/, , LXR, β, RXR, β, , PXR, and FXR) have been explored. Nut allergenicity and approaches necessary to minimize this effect were also described. In contrast to the positive effects, nut allergies present tree nut-allergic consumers with health challenges. The Food Allergy and Anaphylaxis Network stressed the importance of ensuring that consumers with food allergies have legible, accurate food labels. The Food Allergen Labeling and Consumer Protection Act has engendered precautionary, worst-case allergen scenario labeling statements with unknown benefits to consumer health. Issues of cross-contamination due to shared equipment and shared facilities highlighted the need to rely on allergen control programs that use ELISA technology and have increased understanding of nut allergens. Ultimately, to maximize the positive benefits of nuts, the consumer must be provided with all the information required to make an informed choice.
Nut consumption in Spain and other countries
Aranceta, J., C.P. Rodrigo, A. Naska, V.R. Vadillo, A. Trichopoulou, 2006. Nut consumption in Spain and other countries. British Journal of Nutrition. 96, Suppl. 2, S3-S11
In countries of the Mediterranean region, nuts have been consumed in moderate quantities since ancient times. Epidemiological studies show lower risk of cardiovascular diseases in populations with frequent nut consumption, independent from other dietary components. This article assesses nut consumption in Spain and other countries using different sources of data collected at the country, household or individual levels. The per capita consumption of nuts in Spain in 2001 was 7.9 g/person/d. The varieties most widely consumed are walnuts, almonds, hazelnuts and peanuts. Results of the eVe study estimate an average nut consumption in the Spanish population aged 25-60 years of 3.3 g/person/d. No significant statistical differences were observed between men and women. Consumption is higher in men aged between 35 and 44 years (4.5 g/d) and in women aged between 45 and 54 years (3.5 g/d). In the population of 2-24 years, according to the enKid study, nut consumption is estimated at 4.9±18.5 g/person per d. The age group with the highest consumption is teenagers between 14 and 17 years. The northeastern, northern and eastern regions of Spain show the highest consumption. According to FAO balance sheets, in 2001, Lebanon (16.5 kg/person per year) and Greece (11.9 kg/person per year) were the countries in the Mediterranean region with the highest consumption of nuts, followed by Spain (7.3 kg/person per year), Israel and Italy.
The role of tree nuts and peanuts in the prevention of coronary heart disease: multiple potential mechanisms
Kris-Etherton, P.M., F.B. Hu, E. Ros, J. Sabaté, 2008. The role of tree nuts and peanuts in the prevention of coronary heart disease: multiple potential mechanisms. J Nutr. 138, 1746S-1751.
Epidemiologic and clinical trial evidence has demonstrated consistent benefits of nut and peanut consumption on coronary heart disease (CHD) risk and associated risk factors. The epidemiologic studies have reported various endpoints, including fatal CHD, total CHD death, total CHD, and nonfatal myocardial infarct. A pooled analysis of 4 U.S. epidemiologic studies showed that subjects in the highest intake group for nut consumption had a 35% reduced risk of CHD incidence. The reduction in total CHD death was due primarily to a decrease in sudden cardiac death. Clinical studies have evaluated the effects of many different nuts and peanuts on lipids, lipoproteins, and various CHD risk factors, including oxidation, inflammation, and vascular reactivity. Evidence from these studies consistently shows a beneficial effect on these CHD risk factors. The LDL cholesterol-lowering response of nut and peanut studies is greater than expected on the basis of blood cholesterol-lowering equations that are derived from changes in the fatty acid profile of the diet. Thus, in addition to a favorable fatty acid profile, nuts and peanuts contain other bioactive compounds that explain their multiple cardiovascular benefits. Other macronutrients include plant protein and fiber; micronutrients including potassium, calcium, magnesium, and tocopherols; and phytochemicals such as phytosterols, phenolic compounds, resveratrol, and arginine. Nuts and peanuts are food sources that are a composite of numerous cardioprotective nutrients and if routinely incorporated in a healthy diet, population risk of CHD would therefore be expected to decrease markedly.
The natural history of peanut and tree nut allergy.
Fleischer, D.M., 2007. The natural history of peanut and tree nut allergy. Current Allergy and Asthma Reports. 7:175–181.
Peanut and tree nut allergies were once thought to be permanent. Recent studies have shown that about 20% and 10%, respectively, of young patients may outgrow peanut and tree nut allergies. For the majority of patients, however, the natural history is not favorable. In addition, approximately 8% of patients who outgrow peanut allergy may suffer a recurrence. The rising prevalence of these allergies, coupled with the knowledge that allergic reactions to these foods have the potential to be severe or fatal and that accidental exposures are common, makes developing effective treatments to alter the natural history of peanut and tree nut allergies even more crucial for those who will not outgrow them. At this time, avoidance of the offending foods and being prepared to treat a potential reaction after accidental ingestion is the only treatment, but many promising therapeutic interventions are being investigated.
Soluble and insoluble oxalate content of nuts
Ritter, M.M.C., G.P. Savage, 2007. Soluble and insoluble oxalate content of nuts. Journal of Food Composition and Analysis. 20:169-174.
This study was conducted to determine the oxalate contents in common nuts either locally grown or imported into New Zealand. Samples of imported nuts were purchased from supermarkets in Christchurch while locally grown nuts were obtained directly from the growers. In this experiment gastric soluble and intestinal soluble oxalates were extracted from the nuts using an in vitro assay, which involved incubations of the food samples for 2 h at 37 1C in gastric and intestinal juice. The extracted oxalates were then determined by HPLC chromatography. Roasted pistachio nuts and chestnuts contained very low levels (<85 mg/100 g fresh weight (FW)) of gastric soluble oxalate. Peanuts, Spanish peanuts, peanut butter, ginkgo, cashew nuts and pecan nuts all contained relatively low levels of gastric soluble oxalate (147–250 mg gastric soluble oxalate/100 g FW). Almonds, Brazil, pine and candle nuts contained high levels of gastric soluble oxalate (492.0–556.8 mg/100 g FW). The intestinal soluble oxalate is the fraction that will be absorbed in the small intestine. Peanuts, Spanish peanuts, peanut butter, ginkgo and pecan nuts all contained relatively low levels of intestinal soluble oxalate (129–173 mg intestinal soluble oxalate/100 g FW). Almonds, Brazil, cashew and candle nuts contained higher levels of intestinal soluble oxalate (216–305 mg/100 g FW). Pine nuts contained the highest levels of intestinal soluble oxalate (581 mg/100 g FW), while chestnuts and roasted pistachio nuts were low (72 and 77 mg /100 g FW). Overall the mean soluble oxalate content of nuts was 78% of the gastric soluble oxalate content (41–100%). The results obtained in this study confirm that the intestinal soluble oxalate contents of nuts range widely and people who have a tendency to form kidney stones would be wise to moderate their consumption of certain nuts.