Tree nut phytochemicals: composition, antioxidant capacity, bioactivity, impact factors. A systematic review of almonds, Brazils, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts. Nutr Res Rev. 2011;24:244-275. [PMID: 22153059 DOI: 10.1017/s095442241100014x]

Review of nut phytochemicals, fat-soluble bioactives, antioxidant components and health effects

The levels of phytochemicals (total phenols, proanthocyanidins, gallic acid + gallotannins, ellagic acid + ellagitannins, flavonoids, phenolic acids, stilbenes and phytates), fat-soluble bioactives (lipid, tocols, phytosterols, sphingolipids, carotenoids, chlorophylls and alkyl phenols) as well as natural antioxidants (nutrient and non-nutrient) present in commonly consumed twelve nuts (almond, Brazil nut, cashew, chestnut, hazelnut, heartnut, macadamia, peanut, pecan, pine nut, pistachio and walnut) are compared and reported. Recent studies adding new evidence for the health benefits of nuts are also discussed. Research findings from over 112 references, many of which have been published within last 10 years, have been compiled and reported.

Oral hepatoprotective ability evaluation of purple sweet potato anthocyanins on acute and chronic chemical liver injuries

In recent years, chemical liver injury cases increased significantly in Asian countries, and the imbalance in redox system was believed to be the main cause. Purple sweet potato anthocyanins (PSPA) have been shown to exert antioxidant activity and oxidative-stress-associated functional protein modulation through various signaling pathways, so it is considered to have the potential of liver injury preventive activity. In order to evaluate the hepatoprotective potency of PSPA according to its free radical scavenging and antioxidant effects, three acute chemical liver injury models were set up with ethanol, acetaminophen and carbon tetrachloride. PSPA at moderate and high doses obviously attenuated the tested serum biomarker levels and liver index in our experiments. Besides, one chronic liver injury model set up with carbon tetrachloride was also applied, in which PSPA was orally administrated after the liver damage had been formed. Both the serum biomarker levels and histopathological analysis showed that PSPA was able to attenuated chronic liver injury. Our experimental results demonstrated the potential of PSPA as an oral hepatoprotective agent against chemical liver injury from food plant.

Nutrition attributes and health effects of pistachio nuts

Epidemiological and/or clinical trials have suggested that nut consumption has a beneficial impact on health outcomes such as hypertension, diabetes, CVD, cancer, other inflammatory conditions and total mortality. Nuts are nutrient-dense foods with a healthy fatty acid profile, as well as provide other bioactive compounds with recognised health benefits. Among nuts, pistachios have a lower fat and energy content and the highest levels of K, γ-tocopherol, vitamin K, phytosterols, xanthophyll carotenoids, certain minerals (Cu, Fe and Mg), vitamin B6 and thiamin. Pistachios have a high antioxidant and anti-inflammatory potential. The aforementioned characteristics and nutrient mix probably contribute to the growing body of evidence that consumption of pistachios improves health. The present review examines the potential health effects of nutrients and phytochemicals in pistachios, as well as epidemiological and clinical evidence supporting these health benefits.

Effect of almond consumption on vascular function in patients with coronary artery disease: a randomized, controlled, cross-over trial

OBJECTIVE

Almonds reduce cardiovascular disease risk via cholesterol reduction, anti-inflammation, glucoregulation, and antioxidation. The objective of this randomized, controlled, cross-over trial was to determine whether the addition of 85 g almonds daily to a National Cholesterol Education Program (NCEP) Step 1 diet (ALM) for 6 weeks would improve vascular function and inflammation in patients with coronary artery disease (CAD).

RESEARCH DESIGN AND METHODS

A randomized, controlled, crossover trial was conducted in Boston, MA to test whether as compared to a control NCEP Step 1 diet absent nuts (CON), incorporation of almonds (85 g/day) into the CON diet (ALM) would improve vascular function and inflammation. The study duration was 22 weeks including a 6-weeks run-in period, two 6-weeks intervention phases, and a 4-weeks washout period between the intervention phases. A total of 45 CAD patients (27 F/18 M, 45-77 y, BMI = 20-41 kg/m(2)) completed the study. Drug therapies used by patients were stable throughout the duration of the trial.

RESULTS

The addition of almonds to the CON diet increased plasma α-tocopherol status by a mean of 5.8%, reflecting patient compliance (P ≤0.05). However, the ALM diet did not alter vascular function assessed by measures of flow-mediated dilation, peripheral arterial tonometry, and pulse wave velocity. Further, the ALM diet did not significantly modify the serum lipid profile, blood pressure, C-reactive protein, tumor necrosis factor-α or E-selectin. The ALM diet tended to decrease vascular cell adhesion molecule-1 by 5.3% (P = 0.064) and increase urinary nitric oxide by 17.5% (P = 0.112). The ALM intervention improved the overall quality of the diet by increasing calcium, magnesium, choline, and fiber intakes above the Estimated Average Requirement (EAR) or Recommended Dietary Allowance (RDA).

CONCLUSIONS

Thus, the addition of almonds to a NECP Step 1 diet did not significantly impact vascular function, lipid profile or systematic inflammation in CAD patients receiving good medical care and polypharmacy therapies but did improve diet quality without any untoward effect.

TRIAL REGISTRATION

The trial was registered with the ClinicalTrials.Gov with the identifier: NCT00782015.

Nut consumption on all-cause, cardiovascular, and cancer mortality risk: a systematic review and meta-analysis of epidemiologic studies

BACKGROUND

Recent pooled analyses supported a beneficial impact of nut consumption on health, but to our knowledge, whether nuts are associated with overall decreased mortality has not been previously reviewed.

OBJECTIVES

We aimed to systematically review prospective studies that explored the effects of nut consumption on all-cause, cardiovascular disease (CVD), and cancer mortality and quantify the size effect through a meta-analysis. We also reviewed confounding factors associated with nut consumption to assess potential clustering with other covariates.

DESIGN

We searched PubMed and EMBASE for studies published up to June 2014. Study characteristics, HRs, and 95% CIs were generated on the basis of quantitative analyses. A dose-response analysis was performed when data were available.

RESULTS

Seven studies for all-cause mortality, 6 studies for CVD mortality, and 2 studies for cancer mortality were included in the meta-analysis with a total of 354,933 participants, 44,636 cumulative incident deaths, and 3,746,534 cumulative person-years. Nut consumption was associated with some baseline characteristics such as lower body mass index and smoking status as well as increased intakes of fruit, vegetables, and alcohol. One-serving of nuts per week and per day resulted in 4% (RR: 0.96; 95% CI: 0.93, 0.98) and 27% (RR: 0.73; 95% CI: 0.60, 0.88) decreased risk of all-cause mortality, respectively, and decreased risk of CVD mortality [RR: 0.93 (95% CI: 0.88, 0.99) and 0.61 (95% CI: 0.42, 0.91), respectively]. Effects were primarily driven by decreased coronary artery disease deaths rather than stroke deaths. Nut consumption was also associated with decreased risk of cancer deaths when highest compared with lowest categories of intake were compared (RR: 0.86; 95% CI: 0.75, 0.98), but no dose-effect was shown.

CONCLUSION

Nut consumption is associated with lower risk of all-cause, CVD, and cancer mortality, but the presence of confounding factors should be taken into account when considering such findings.

Phenolic compounds in edible species of the Anacardiaceae family – a review

Members of the Anacardiaceae (cashew family) are of economic importance and contain a diverse range of phenolic compounds.

Patterns and predictors of nut consumption: results from the 2008/09 New Zealand Adult Nutrition Survey

Regular nut consumption is associated with reduced CVD risk. Insight into nut consumption patterns provides important information to help design strategies to encourage intake. The present study aimed to describe nut consumption in terms of the percentage of consumers, mean grams eaten among the population and nut consumers, and to identify the predictors of nut consumption. Data from the 24 h dietary recalls of the 2008/09 New Zealand Adult Nutrition Survey (n 4721) were used to measure nut consumption. On the recall day, the percentages of consumers of whole nuts, nut butters and nuts from hidden sources were 6.9% (n 240), 7.2% (n 346) and 19.2% (n 732), respectively (28.9% (n 1167) combined (total)). The mean grams consumed by the population were relatively low for whole nuts (2.8 g/d), nut butters (0.9 g/d), nuts from hidden sources (1.5 g/d) and total nuts (5.2 g/d). Among consumers, the mean daily grams of whole nuts, nut butters, nuts from hidden sources and total nuts eaten were 40.3, 12.9, 7.8 and 17.9 g/d, respectively. Those aged 15-18 years had the lowest whole nut consumption, but had the highest nut butter consumption. The consumption of total nuts was positively associated with education and socio-economic status, while whole nut consumption was inversely associated with BMI. In conclusion, the low percentage of nut consumers is of concern and new strategies to increase nut consumption are required. Future public health initiatives should be mindful of these patterns and predictors. In particular, different forms of nuts may appeal to different age and socio-economic groups.

Effect of almond consumption on the serum fatty acid profile: a dose-response study

Consumption of almonds has been shown to be associated with a decreased risk of CHD, which may be related to their fatty acid (FA) composition. However, the effect of almond consumption on the serum FA composition is not known. Therefore, in the present study, we investigated whether almond consumption would alter the serum FA profile and risk of CHD, as calculated using Framingham's 10-year risk score, in a dose-dependent manner in hyperlipidaemic individuals when compared with a higher-carbohydrate control group using dietary interventions incorporating almonds. A total of twenty-seven hyperlipidaemic individuals consumed three isoenergetic (mean 1770 kJ/d) supplements during three 1-month dietary phases: (1) full-dose almonds (50-100 g/d); (2) half-dose almonds with half-dose muffins; (3) full-dose muffins. Fasting blood samples were obtained at weeks 0 and 4 for the determination of FA concentrations. Almond intake (g/d) was found to be inversely associated with the estimated Framingham 10-year CHD risk score (P= 0·026). In both the half-dose and full-dose almond groups, the proportions of oleic acid (OA) and MUFA in the TAG fraction (half-almond: OA P= 0·003; MUFA P= 0·004; full-almond: OA P< 0·001; MUFA P< 0·001) and in the NEFA fraction (half-almond: OA P= 0·01; MUFA P= 0·04; full-almond: OA P= 0·12; MUFA P= 0·06) increased. The estimated Framingham 10-year CHD risk score was inversely associated with the percentage change of OA (P= 0·011) and MUFA (P= 0·016) content in the TAG fraction. The proportions of MUFA in the TAG and NEFA fractions were positively associated with changes in HDL-cholesterol concentrations. Similarly, the estimated Framingham 10-year CHD risk score was inversely associated with the percentage change of OA (P= 0·069) and MUFA content in the NEFA fraction (P= 0·009). In conclusion, the results of the present study indicate that almond consumption increases OA and MUFA content in serum TAG and NEFA fractions, which are inversely associated with CHD lipid risk factors and overall estimated 10-year CHD risk.

Cancer chemoprevention with nuts

It is well established that increased nut consumption is associated with a reduced risk of major chronic diseases, such as cardiovascular disease and type 2 diabetes mellitus. On the other hand, the association between nut consumption and cancer mortality is less clear. Recent studies have suggested that nut consumption is associated with reduced cancer mortality. This evidence reinforces the interest to investigate the chemopreventive properties of nuts, and it raises questions about the specific cancer type(s) and setting that can be more affected by nut consumption, as well as the cellular mechanisms involved in this protective effect. Here we discuss recent studies on the association of nut consumption and cancer, and we propose specific cellular mechanisms by which nut components can affect cancer progression.

Nut consumption, serum fatty acid profile and estimated coronary heart disease risk in type 2 diabetes

BACKGROUND AND AIMS

Nut consumption has been associated with decreased risk of coronary heart disease (CHD) and type 2 diabetes which has been largely attributed to their healthy fatty acid profile, yet this has not been ascertained. Therefore, we investigated the effect of nut consumption on serum fatty acid concentrations and how these relate to changes in markers of glycemic control and calculated CHD risk score in type 2 diabetes.

METHODS AND RESULTS

117 subjects with type 2 diabetes consumed one of three iso-energetic (mean 475 kcal/d) supplements for 12 weeks: 1. full-dose nuts (50-100 g/d); 2. half-dose nuts with half-dose muffins; and 3. full-dose muffins. In this secondary analysis, fatty acid concentrations in the phospholipid, triacylglycerol, free fatty acid, and cholesteryl ester fractions from fasting blood samples obtained at baseline and week 12 were analyzed using thin layer and gas chromatography. Full-dose nut supplementation significantly increased serum oleic acid (OA) and MUFAs compared to the control in the phospholipid fraction (OA: P = 0.036; MUFAs: P = 0.024). Inverse associations were found with changes in CHD risk versus changes in OA and MUFAs in the triacylglycerol (r = -0.256, P = 0.011; r = -0.228, P = 0.024, respectively) and phospholipid (r = -0.278, P = 0.006; r = -0.260, P = 0.010, respectively) fractions. In the cholesteryl ester fraction, change in MUFAs was inversely associated with markers of glycemic control (HbA1c: r = -0.250, P = 0.013; fasting blood glucose: r = -0.395, P < 0.0001).

CONCLUSION

Nut consumption increased OA and MUFA content of the serum phospholipid fraction, which was inversely associated with CHD risk factors and 10-year CHD risk.

CLINICAL TRIAL REG NO

NCT00410722, clinicaltrials.gov.

Prevention of renal dysfunction by nutraceuticals prepared from oil rich plant foods

OBJECTIVE

To investigate the protective effect of extracts prepared from avocado, walnut, flaxseed and Eruca sativa seeds in a rat model of kidney dysfunction induced by intraperitoneal cisplatin.

METHODS

Ethanol and petroleum ether extracts mixture was prepared from each plant. Six groups of rats were conducted; control healthy, cisplatin group and four test groups where rats were given daily oral dose of each extract mixture before cisplatin injection. Different biochemical and cytogenetic parameters and kidney histopathology were determined. Acute toxicity was tested for the nutraceuticals. Total phenolic contents, fatty acids (FA) and unsaponifiable matter were assessed in the extracts.

RESULTS

Walnut ethanol extract showed the highest content of total phenolic. FA analysis revealed that all the studied plants were rich in unsaturated FA. Gas-liquid chromatographic investigation of the unsaponifiable matter showed the presence of campesterol, stigmasterol and β-sitosterol in all the studied plants. Cisplatin treatment induced significant increase in plasma urea, creatinine and malondialdehyde along with significant reduction of plasma albumin, total protein, catalase and total antioxidant as well as reduction in creatinine clearance. Histopathological examination proved the induction of kidney dysfunction. Some sorts of chromosomal aberration and sperm-shape abnormalities were noticed after cisplatin treatment. Administration of extracts mixtures produced improvements in biochemical, histopathological and cytogenetic parameters.

CONCLUSIONS

Administration of the studied nutraceuticals proved to possess protective role against cisplatin-induced nephrotoxicity, chromosomal aberration and abnormal sperms. All studied nutraceuticals showed complete safety.

Nut consumption for vascular health and cognitive function

Nuts are rich in many nutrients that can benefit multiple cardiometabolic functions, including arterial compliance, blood pressure, inflammation, glucoregulation and endothelial vasodilatation. Impaired vasodilatation may contribute to impaired cognitive performance due to poor cerebral perfusion. The present narrative review examines associations between nut consumption, vascular health and cognitive function. It includes a systematic search which identified seventy-one epidemiological or intervention studies in which effects of chronic nut consumption on blood pressure, glucoregulation, endothelial vasodilator function, arterial compliance, inflammatory biomarkers and cognitive performance were evaluated. Weighted mean changes were estimated where data were available; they indicate that nut consumption reduces blood pressure and improves glucoregulation, endothelial vasodilator function and inflammation, whilst a limited number of studies suggest that nut consumption may also improve cognitive performance. Further clinical trials are warranted to explore relationships between nut consumption, endothelial function and cognitive function.

Oxidative & nitrosative stress in depression: why so much stress?

Many studies support a crucial role for oxidative & nitrosative stress (O&NS) in the pathophysiology of unipolar and bipolar depression. These disorders are characterized inter alia by lowered antioxidant defenses, including: lower levels of zinc, coenzyme Q10, vitamin E and glutathione; increased lipid peroxidation; damage to proteins, DNA and mitochondria; secondary autoimmune responses directed against redox modified nitrosylated proteins and oxidative specific epitopes. This review examines and details a model through which a complex series of environmental factors and biological pathways contribute to increased redox signaling and consequently increased O&NS in mood disorders. This multi-step process highlights the potential for future interventions that encompass a diverse range of environmental and molecular targets in the treatment of depression.

Separation and characterization of phenolic compounds from U.S. pecans by liquid chromatography-tandem mass spectrometry

The phenolic acids and proanthocyanidins (PACs) of pecans possess bioactive properties, which might be useful in retarding the onset of and ameliorating the status of certain chronic disease states. There is a general lack of information in the literature regarding such compounds, especially the PACs. Crude phenolic extracts pooled from eight commercially significant cultivars were selected based on their relatively high antioxidant capacities. The pooled extracts were separated via Sephadex LH-20 column chromatography into five ethanolic low-molecular-weight (LMW) fractions and one acetonic high-molecular-weight (HMW) fraction. The preparations were then characterized using RP-HPLC-ESI-MS/MS and diol-phase HPLC-ESI-MS/MS in order to determine the key constituents present in the LMW and HMW fractions, respectively. As previously observed in pecan nutmeat, ellagic acid and (+)-catechin were found to be the major phenolics in the LMW fractions. The last eluting LMW fraction did not contain phenolic acids; rather it possessed PAC monomers and dimers. The HMW fraction comprised a majority of its PACs as dimers; yet, monomers, trimers, tetramers, pentamers, and hexamers were also separated and characterized.

Effects of almond and pistachio consumption on gut microbiota composition in a randomised cross-over human feeding study

The modification of microbiota composition to a 'beneficial' one is a promising approach for improving intestinal as well as overall health. Natural fibres and phytochemicals that reach the proximal colon, such as those present in various nuts, provide substrates for the maintenance of healthy and diverse microbiota. The effects of increased consumption of specific nuts, which are rich in fibre as well as various phytonutrients, on human gut microbiota composition have not been investigated to date. The objective of the present study was to determine the effects of almond and pistachio consumption on human gut microbiota composition. We characterised microbiota in faecal samples collected from volunteers in two separate randomised, controlled, cross-over feeding studies (n 18 for the almond feeding study and n 16 for the pistachio feeding study) with 0, 1·5 or 3 servings/d of the respective nuts for 18 d. Gut microbiota composition was analysed using a 16S rRNA-based approach for bacteria and an internal transcribed spacer region sequencing approach for fungi. The 16S rRNA sequence analysis of 528 028 sequence reads, retained after removing low-quality and short-length reads, revealed various operational taxonomic units that appeared to be affected by nut consumption. The effect of pistachio consumption on gut microbiota composition was much stronger than that of almond consumption and included an increase in the number of potentially beneficial butyrate-producing bacteria. Although the numbers of bifidobacteria were not affected by the consumption of either nut, pistachio consumption appeared to decrease the number of lactic acid bacteria (P< 0·05). Increasing the consumption of almonds or pistachios appears to be an effective means of modifying gut microbiota composition.

Online LC-GC-based analysis of minor lipids in various tree nuts and peanuts

As information on free sterols/stanols and steryl/stanyl esters in nuts is lacking, the compositions and contents of these lipid constituents in ten different nut types were analyzed. The applied approach was based on online liquid chromatography-gas chromatography and enabled the simultaneous analysis of free sterols/stanols and individual steryl/stanyl fatty acid esters, and additionally of tocopherols and squalene. Total contents of free sterols/stanols ranged from 0.62 mg/g nut in hazelnuts to 1.61 mg/g nut in pistachios, with sitosterol as the predominant compound. Total contents of steryl/stanyl fatty acid esters were in the range of 0.11-1.26 mg/g nut, being lowest in Brazil nuts and highest in pistachios. There were considerable differences between the various nut types not only regarding the contents, but also the compositions of both classes. The levels of tocopherols were highest in pine nuts (0.33 mg/g nut); those of squalene were remarkably high in Brazil nuts (1.11 mg/g nut).

Characterisation of stilbenes in California almonds (Prunus dulcis) by UHPLC-MS

Stilbene polyphenols are present in some fruits and nuts, but their abundance in many foods, such as almonds, is unknown. Therefore, we characterised stilbenes from Nonpareil, Butte and Carmel almond (Prunus dulcis) varieties from California. UHPLC-MS conditions were optimised to resolve cis- and trans-resveratrol, d4-resveratrol, dienestrol, hexestrol, oxyresveratrol, piceatannol, pterostilbene, and resveratrol-3-β-glucoside (polydatin). Stilbenes were isolated from ethanolic almond extracts by solid-phase extraction and identified with UHPLC-MS by comparison of retention times, mass spectra, in-source CID spectra, and enzymatic hydrolysis to authentic standards. Polydatin was identified in almond extracts, with 7.19-8.52 μg/100 g almond. Piceatannol+oxyresveratrol was tentatively identified in almond blanch water, at 0.19-2.55 μg/100 g almond. Polydatin was concentrated in almond skins, which contained 95.6-97.5% of the total almond content. Therefore, almonds contain the stilbene class of polyphenols in addition to the previously identified proanthocyanidin, hydrolysable tannin, flavonoid, and phenolic acid classes.

Antioxidant and photoprotective effects of blanch water, a byproduct of the almond processing industry

The aim of the present work was to evaluate the antioxidant and photoprotective effect of blanch water (BW), a byproduct of the almond processing industry. The polyphenolic content of a BW extract, the level of proanthocyanidins and the vanillin index determination were determined. The antioxidant activity and the radical scavenging activity of the BW were evaluated by a range of in vitro tests. The in vivo photoprotective effect was investigated using a formulation containing 2% of the BW extract on skin erythema induced by acute UV-B exposure in twelve volunteers. Results confirmed the presence of added-value antioxidant compounds in the industrial BW extract, and the most representative compounds were naringenin-7-O-glucoside and kaempferol-7-O-rutinoside. The proanthocyanidin content was 71.84 ± 5.21 cyanidin equivalents/g of BW extract. The good antiradical activity of the BW extract was demonstrated in both the DPPH^• test and in the Reducing Power test. The percentage inhibition of erythema obtained using a formulation of BW was 50.48, value clearly demonstrating an effect against photooxidative damage in vivo.

Lipidomic fingerprint of almonds (Prunus dulcis L. cv Nonpareil) using TiO₂ nanoparticle based matrix solid-phase dispersion and MALDI-TOF/MS and its potential in geographical origin verification

A matrix solid-phase dispersion (MSPD) procedure with titanium dioxide (TiO2) nanoparticles (NP) as sorbent was developed for the selective extraction of phospholipids from almond samples, and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF/MS) was employed for analysis. A remarkable increase in the signals of phospholipid accompanied by a decrease in those of triacylglycerols and diacylglycerols was observed in the relevant mass spectra. The proposed method was applied to five batches of almonds originating from four geographical areas, whereas principal component analysis (PCA) was utilized to normalize the relative amounts of the identified phospholipid species. The results indicated that the lipidomic fingerprint of almonds was successfully established by the negative ion mode spectrum, and the ratio of m/z 833.6 to 835.6 as well as m/z 821.6 could be introduced as potential markers for the differentiation of the tested almonds with different geographical origins. The whole method is of great promise for selective separation of phospholipids from nonphospholipids, especially the glycerides, and superior in fast screening and characterization of phospholipids in almond samples.

Dietary (poly)phenolics in human health: structures, bioavailability, and evidence of protective effects against chronic diseases

Human intervention trials have provided evidence for protective effects of various (poly)phenol-rich foods against chronic disease, including cardiovascular disease, neurodegeneration, and cancer. While there are considerable data suggesting benefits of (poly)phenol intake, conclusions regarding their preventive potential remain unresolved due to several limitations in existing studies. Bioactivity investigations using cell lines have made an extensive use of both (poly)phenolic aglycones and sugar conjugates, these being the typical forms that exist in planta, at concentrations in the low-μM-to-mM range. However, after ingestion, dietary (poly)phenolics appear in the circulatory system not as the parent compounds, but as phase II metabolites, and their presence in plasma after dietary intake rarely exceeds nM concentrations. Substantial quantities of both the parent compounds and their metabolites pass to the colon where they are degraded by the action of the local microbiota, giving rise principally to small phenolic acid and aromatic catabolites that are absorbed into the circulatory system. This comprehensive review describes the different groups of compounds that have been reported to be involved in human nutrition, their fate in the body as they pass through the gastrointestinal tract and are absorbed into the circulatory system, the evidence of their impact on human chronic diseases, and the possible mechanisms of action through which (poly)phenol metabolites and catabolites may exert these protective actions. It is concluded that better performed in vivo intervention and in vitro mechanistic studies are needed to fully understand how these molecules interact with human physiological and pathological processes.

Extra virgin olive oil (EVOO) consumption and antioxidant status in healthy institutionalized elderly humans

Recent studies show that the elderly have increased oxidative stress and impaired antioxidant defense systems. Our study aims to evaluate the effects of daily consumption of EVOO in the healthy institutionalized elderly. We studied anthropometric, biochemical and antioxidant parameters in 62 subjects aged 65-96 years after a 6-week daily intake of polyphenol-rich EVOO with high oleuropein derivative contents. Subjects were divided into a control group (CG) who maintained their dietary habits (n=39) and an olive group (OG) who consumed EVOO as the only added fat, plus a daily dose of 50ml (n=23). We found a significant reduction of total cholesterol (TC), HDL, LDL and TGs in OG subjects and a significant increase of HDL levels. There was no significant variation in the CG parameters. In OG the total antioxidant capacity (TAC) in plasma increased with significant differences over CG. Plasma hydroxytyrosol (OH-Tyr) concentration showed a significant increase after EVOO intervention. Daily consumption of EVOO was found to have positive effects on lipid profiles, OH-Tyr levels and TAC. The results also show a significant increase of catalase (CAT) in erythrocytes and a decrease (p<0.05) in superoxide dismutase (SOD) and glutathione peroxidase (GH-PX) activity after EVOO intake. To our knowledge, no other study has examined the effects of EVOO consumption on biochemical parameters, antioxidant capacity and antioxidant enzyme activity in healthy elderly subjects. In conclusion, our results show that nutritional intervention with EVOO improves antioxidant status in healthy elderly people.

The Impact of Pistachio Consumption on Blood Lipid Profile

Studies showed that nut consumption is associated with a reduced risk in cardiovascular disease (CVD) mortality and morbidity and an improvement in the modifiable CVD risk factors. Our objective was to review studies that reported the effect of pistachios intake on blood lipid profile. A PUBMED and Loma Linda University Nut Library database search was conducted to identify relevant studies. Eight relevant studies were identified and included in the review. With a few exceptions, the results showed a consistent improvement in serum lipid profile, improving all cholesterol fractions. With one exception, all studies reported a large decrease in the mean LDL-cholesterol ranging from 7.6 to 9.7% of the baseline level. In four of the seven studies that reported a change in HDL-cholesterol level, the mean HDL-cholesterol increased after the intervention. In all but one studies that reported the change in TG, the post-test values were reduced. The majority of the studies reported statistically significant reduction in the mean TC and LDL-cholesterol fractions. Similarly, all studies that reported a change in TC/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol ratios reported a statistically significant improvement. Adding pistachios to a typical diet of normo and hypercholesterolemic individuals have a beneficial effect on blood lipid profile.

In vitro gastric and intestinal digestion of a walnut oil body dispersion

An oil body dispersion (11.3% fat) was prepared by wet disintegration of walnuts and was then subjected to a two-step model of in vitro digestion. In a gastric environment, proteolysis by pepsin led to the destabilization and coalescence of the oil bodies. Aggregation of the coalesced oil bodies was apparent under a confocal microscope, with aggregates up to 275 μm in size. Pepsin-resistant peptides and proteins remained at the surface of the oil bodies, and some were further resistant to intestinal proteases. Under intestinal conditions, the hydrolysis of walnut triglycerides led to the spontaneous formation of a new type of multiple emulsions, ranging from 2 to 45 μm in size and with protein material inside the inner water droplets. Transmission electron microscopy revealed the presence of a liquid-crystalline phase of bile salts and lipolytic products at the surface of the oil droplets and some bile salt crystals at the surface of the inner water droplets.

Flavonoid basics: chemistry, sources, mechanisms of action, and safety

In our efforts to understand how various dietary factors can influence the risk and progression of chronic disease, much recent research has focused on phytochemicals. Phytochemicals are defined as nonessential nutrients found in plant-based food, many of which have been established as bioactive and thus may affect human health. The largest group of phytochemicals is the polyphenols, comprised principally of the flavonoids, which are characterized chemically by two benzene rings joined by a linear carbon chain. Evidence from observational studies indicates that regular consumption of foods containing flavonoids may reduce the risk several chronic conditions, including neurodegenerative diseases, atherosclerosis, and certain forms of cancer. These results have generated considerable interest in flavonoids, although much basic information about their nutrient characteristics in humans remains limited, e.g., their bioavailability and metabolism, interactions with other dietary factors, mechanisms of action, and intakes associated with specific health outcomes. Although flavonoids are commonly defined as dietary antioxidants and their putative health benefits commonly attributed to this mechanism, it now appears their principal actions are mediated in vivo via other biochemical and molecular pathways.

Characterization of ellagitannins, gallotannins, and bound proanthocyanidins from California almond (Prunus dulcis) varieties

Extractable and bound proanthocyanidins and hydrolyzable tannins were characterized in Nonpareil, Carmel, and Butte almond varieties from California, with n = 3 samples/variety. Bound proanthocyanidins were recovered from extracted defatted almond residue by hydrolysis with 4 N sodium hydroxide and represented 3-21% of the total proanthocyanidin content among varieties. The bound proanthocyanidins were recovered primarily as monomers and dimers. In contrast, acid hydrolysis of extracted almond residue did not yield bound proanthocyanidins. Hydrolyzable tannins were characterized in aqueous acetone extracts of defatted almond using two-dimensional TLC and further quantitated by HPLC following acid hydrolysis. Almond hydrolyzable tannin content was 54.7 ± 2.3 mg ellagic acid and 27.4 ± 7.3 mg gallic acid per 100 g almond among varieties. The tannin contents of Nonpareil, Carmel, and Butte almond varieties were not significantly different. Thus, bound proanthocyanidins and hydrolyzable tannins significantly contribute to almond polyphenol content.

The role of nuts in the optimal diet: time for a critical appraisal?

During the last decades, nuts have attracted the attention of researchers for their potential benefits in cardiovascular prevention. We discuss here some aspects of the assumed beneficial effects of nuts, weighing them against potential harm. Epidemiological observations and controlled intervention trials consistently suggest that nuts consumption is associated with improved serum lipid profile, thus helping decrease cardiovascular risk. Being nuts an energy dense food, their impact on energy balance and body weight should be considered. In particular, the claim that adding nuts to the habitual diet, thus increasing calorie intake, does not cause body fat accumulation still needs evidence and biological plausibility. The potential risk associated with the relatively frequent occurrence of allergic reactions following the consumption of nuts is also discussed.