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Walnuts Improve Semen Quality In Men Consuming A Western-Style Diet: Randomized Control Dietary Intervention Trial

Walnuts Improve Semen Quality In Men Consuming A Western-Style Diet: Randomized Control Dietary Intervention Trial

BACKGROUND
Center for Occupational and Environmental Health, Fielding School of Public Health, University of California Los Angeles, Los Angeles, CA 90095-1772
School of Nursing, University of California Los Angeles, Los Angeles, CA 90095-6919
David Geffen School of Medicine, Center for Human Nutrition, University of California Los Angeles, Los Angeles, CA 90095-1742
OBJECTIVE
We tested the hypothesis that 75 gm of whole-shelled walnuts/day added to a Western-style diet of healthy young men would beneficially affect semen quality.

METHOD
A randomized, parallel two-group, dietary intervention trial with single-blind masking of outcome assessors, was conducted with 117 healthy men, age 21 – 35 years, who routinely consumed a Western-style diet. Primary outcome evaluated was improvement from baseline to 12 weeks in conventional semen parameters and sperm aneuploidy. Secondary endpoints included blood serum and sperm fatty acid (FA) profiles, sex hormones, and serum folate.

RESULT
The group consuming walnuts (n=59) experienced improvement in sperm vitality, motility, and morphology and the group continuing their usual diet but avoiding tree nuts (n=58) saw no change. Comparing differences from baseline between the groups, significance was found for vitality p=0.003, motility p=0.009, and morphology (normal forms) p=0.04. Serum FA profiles improved in the walnut group with increases in omega-6 (p=0.0004) and omega-3 (p=0.0007) but not the control group. Only the plant source of omega-3, alpha-linolenic acid (ALA), increased (p=0.0001). Sperm aneuploidy was inversely correlated with sperm ALA, particularly sex chromosome nullisomy (-0.41, p=0.002). Findings demonstrated that walnuts added to a Western-style diet improved sperm vitality, motility and morphology.

CONCLUSION
*More research is needed to determine if adding walnuts to the diet will improve birth outcomes for men within fertility clinic populations or in the general population.

PUBLISHED : OCTOBER 25, 2012
STUDY TYPE : RANDOMIZED CONTROLLED CLINICAL TRIAL
TOPICS : FERTILITY, RANDOMIZED CONTROLLED CLINICAL TRIAL
SOURCE : http://www.biolreprod.org/content/early/2012/08/07/biolreprod.112.101634.full.pdf+html?sid=fbd66b4a-a368-443f-9431-e379680f8933

An Increase In Dietary N-3 Fatty Acids Decreases A Marker Of Bone Resorption In Humans

By Griel AE, Kris-Etherton PM, Hilpert KF, Zhao G, West SG, Corwin RL. An increase in dietary n-3 fatty acids decreases a marker of bone resorption in humans. Nutr J. 2007 Jan 16;6:2.

BACKGROUND
Human, animal, and in vitro research indicates a beneficial effect of appropriate amounts of omega-3 (n-3) polyunsaturated fatty acids (PUFA) on bone health. This is the first controlled feeding study in humans to evaluate the effect of dietary plant-derived n-3 PUFA on bone turnover, assessed by serum concentrations of N-telopeptides (NTx) and bone-specific alkaline phosphatase (BSAP). Subjects (n = 23) consumed each diet for 6 weeks in a randomized, 3-period crossover design: 1) Average American Diet (AAD; [34% total fat, 13% saturated fatty acids (SFA), 13% monounsaturated fatty acids (MUFA), 9% PUFA (7.7% LA, 0.8% ALA)]), 2) Linoleic Acid Diet (LA; [37% total fat, 9% SFA, 12% MUFA, 16% PUFA (12.6% LA, 3.6% ALA)]), and 3) alpha-Linolenic Acid Diet (ALA; [38% total fat, 8% SFA, 12% MUFA, 17% PUFA (10.5% LA, 6.5% ALA)]). Walnuts and flaxseed oil were the predominant sources of ALA. NTx levels were significantly lower following the ALA diet (13.20 +/- 1.21 nM BCE), relative to the AAD (15.59 +/- 1.21 nM BCE) (p < 0.05). Mean NTx level following the LA diet was 13.80 +/- 1.21 nM BCE. There was no change in levels of BSAP across the three diets. Concentrations of NTx were positively correlated with the pro-inflammatory cytokine TNFalpha for all three diets. The results indicate that plant sources of dietary n-3 PUFA may have a protective effect on bone metabolism via a decrease in bone resorption in the presence of consistent levels of bone formation.

PUBLISHED : JANUARY 16, 2007
STUDY TYPE : RANDOMIZED CONTROLLED CLINICAL TRIAL
TOPIC : COGNITIVE AND AGING, HEALTH, NUTRITION, RANDOMIZED CONTROLLED CLINICAL TRIAL
SOURCE : http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1784104/?tool=pubmed

Acute Effects Of Three High-Fat Meals With Different Fat Saturations On Energy Expenditure, Substrate Oxidation And Satiety

By Casas-Agustench P, López-Uriarte P, Bulló M, Ros E, Gómez-Flores A, Salas-Salvadó J. Acute effects of three high-fat meals with different fat saturations on energy expenditure, substrate oxidation and satiety. Clin Nutr. 2009 Feb;28(1):39-45. Epub 2008 Nov 17.

BACKGROUND
To compare the acute effects of three fatty meals with different fat quality on postprandial thermogenesis, substrate oxidation and satiety.

METHOD
Twenty-nine healthy men aged between 18 and 30 years participated in a randomised crossover trial comparing the thermogenic effects of three isocaloric meals: high in polyunsaturated fatty acids from walnuts, high in monounsaturated fatty acids from olive oil, and high in saturated fatty acids from fat-rich dairy products. Indirect calorimetry was used to determine resting metabolic rate, respiratory quotient, 5-h postprandial energy expenditure and substrate oxidation. Satiety was estimated by using visual analogue scales and measuring caloric intake in a subsequent ad libitum meal.

RESULT
Five-h postprandial thermogenesis was higher by 28% after the high-polyunsaturated meal (p=0.039) and by 23% higher after the high-monounsaturated meal (p=0.035) compared with the high-saturated meal. Fat oxidation rates increased nonsignificantly after the two meals rich in unsaturated fatty acids and decreased nonsignificantly after the high-saturated fatty acid meal. Postprandial respiratory quotient, protein and carbohydrate oxidation, and satiety measures were similar among meals.

CONCLUSION
Fat quality determined the thermogenic response to a fatty meal but had no clear effects on substrate oxidation or satiety.

PUBLISHED : NOVEMBER 17, 2008
STUDY TYPE : RANDOMIZED CONTROLLED CLINICAL TRIAL
TOPIC : HEALTH, NUTRITION, WEIGHT MANAGEMENT, RANDOMIZED CONTROLLED CLINICAL TRIAL
SOURCE : http://www.clinicalnutritionjournal.com/article/S0261-5614(08)00198-2/fulltext

Acute Effect Of Nut Consumption On Plasma Total Polyphenols, Antioxidant Capacity And Lipid Peroxidation

By Torabian S, Haddad E, Rajaram S, Banta J, Sabaté J. Acute effect of nut consumption on plasma total polyphenols, antioxidant capacity and lipid peroxidation. J Hum Nutr Diet, 22, pp. 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.

METHOD
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.

RESULT
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 post-consumption 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.

CONCLUSION
Consumption of both nuts increased plasma polyphenol concentrations, increased the total antioxidant capacity and reduced plasma lipid peroxidation.

PUBLISHED : FEBRUARY 1, 2009
STUDY TYPE : RANDOMIZED CONTROLLED CLINICAL TRIAL
TOPIC : HEALTH, NUTRITION, RANDOMIZED CONTROLLED CLINICAL TRIAL
SOURCE : http://onlinelibrary.wiley.com/doi/10.1111/j.1365-277X.2008.00923.x/full

Recruitment Of Lactating Women Into A Randomized Dietary Intervention: Successful Strategies And Factors Promoting Enrollment And Retention

By Stendell-Hollis NR, Laudermilk MJ, West JL, Thompson PA, Thomson CA. Recruitment of lactating women into a randomized dietary intervention: Successful strategies and factors promoting enrollment and retention. Contemp Clin Trials. 2011 Mar 5.

BACKGROUND
Recruitment and retention of lactating women require unique strategies to prevent high attrition. The purpose of this report is to identify successful recruitment strategies and evaluate demographic and lifestyle characteristics associated with study completion.

METHOD
A randomized, controlled trial was initiated to test the hypothesis that lactating women adhering to a Mediterranean diet will show a significant reduction in anthropometric measurements as compared to lactating women randomized to the USDA’s MyPyramid diet for Pregnancy and Breastfeeding (control diet). Measurements were collected at baseline, 2months, and 4months. Recruitment methods and baseline characteristics of completers and non-completers are described.

RESULT
The largest percentage of women, 24.8%, were recruited from a local parenting magazine, 20.9% from Craig’s List, 20.2% from local hospitals, and 34.1% from various other sources. At baseline, women (n=129) were mostly Non-Hispanic (75.2%), average age 29.7years, BMI averaged 27.2kg/m(2), waist:hip ratio 0.84cm (SD: 0.07), and body fat averaged 30.8%. Approximately 72% were exclusively breastfeeding, a mean 17.5weeks postpartum, and 69.0% had a college degree. Non-completers were more likely to have supplemented with formula at baseline as compared to completers (P < 0.001). No other characteristics were significantly associated with attrition.

CONCLUSION
Researchers conducting studies with lactating women may consider “exclusive breastfeeding” as a study inclusion criterion to prevent high attrition rates or include additional breastfeeding support to study participants.

PUBLISHED : MARCH 5, 2011
STUDY TYPE : RANDOMIZED CONTROLLED CLINICAL TRIAL
TOPIC : HEALTH, NUTRITION, RANDOMIZED CONTROLLED CLINICAL TRIAL
SOURCE : http://www.sciencedirect.com/science?_ob=ShoppingCartURL&_method=add&_udi=B7P72-529V1BP-7&_acct=C000228598&_version=1&_userid=10&_ts=1314040562&md5=c1d61fecf378d637d747274cff869bb6

Novel Multimetabolite Prediction Of Walnut Consumption By A Urinary Biomarker Model In A Free-Living Population: The PREDIMED Study

By Mar Garcia-Aloy, Rafael Llorach, Mireia Urpi-Sarda, Sara Tulipani, Ramon Estruch, Miguel A. Martínez-Gonzalez, Dolores Corella, Montserrat Fito, Emilio Ros, Jordi Salas-Salvado and Cristina Andres-Lacueva

BACKGROUND
The beneficial impact of walnuts on human health has been attributed to their unique chemical composition.

DESIGN
In order to characterize the dietary walnut fingerprinting, spot urine samples from two sets of 195 (training) and 186 (validation) individuals were analyzed by an HPLC-q-ToF-MS untargeted metabolomics approach, selecting the most discriminating metabolites by multivariate data analysis (VIP ≥ 1.5). Stepwise logistic regression analysis was used to design a multimetabolite prediction biomarker model. The global performance of the model and each included metabolite in it was evaluated by receiver operating characteristic curves, using the area under the curve (AUC) values. Dietary exposure to walnuts was characterized by 18 metabolites, including markers of fatty acid metabolism, ellagitannin-derived microbial compounds, and intermediate metabolites of the tryptophan/serotonin pathway. The predictive model of walnut exposure included at least one compound of each class. The AUC (95% CI) for the combined biomarker model was 93.4% (90.1–96.8%) in the training set and 90.2% (85.9–94.6%) in the validation set. The AUCs for individual metabolites were ≤ 85%. As far as we know, this is the first study proposing a combination of biomarkers of walnut exposure in a population under free-living conditions, as considered in epidemiological studies examining associations between diet and health outcomes.

PUBLISHED : JUNE 2, 2014
STUDY TYPE : IN VITRO STUDY
TOPIC : NUTRITION
SOURCE : http://pubs.acs.org/doi/abs/10.1021/pr500425

Effect Of A Mediterranean Diet Intervention On Dietary Glycemic Load And Dietary Glycemic Index: The PREDIMED Study

By Rodríguez-Rejón A.I., Castro-Quezada I., Ruano-Rodríguez C., Ruiz-López M.D., Sánchez-Villegas A., Toledo E., Artacho R., Estruch R., Salas-Salvadó J., Covas M.I., Corella D., Gómez-Gracia E., Lapetra J., Pintó X., Arós F., Fiol M., Lamuela-Raventós R.M., Ruiz-Gutierrez V., Schröder H., Ros E., Martínez-González M.Á., Serra-Majem L.

OBJECTIVE
To compare the one year effect of two dietary interventions with MeDiet on GL and GI in the PREDIMED trial.

METHOD
Participants were older subjects at high risk for cardiovascular disease. This analysis included 2866 nondiabetic subjects. Diet was assessed with a validated 137-item food frequency questionnaire (FFQ). The GI of each FFQ item was assigned by a 5-step methodology using the International Tables of GI and GL Values. Generalized linear models were fitted to assess the relationship between the intervention group and dietary GL and GI at one year of follow-up, using control group as reference.

RESULT
Multivariate-adjusted models showed an inverse association between GL and MeDiet + extra virgin olive oil (EVOO) group: β = -8.52 (95% CI: -10.83 to -6.20) and MeDiet + Nuts group: β = -10.34 (95% CI: -12.69 to -8.00), when comparing with control group. Regarding GI, β = -0.93 (95% CI: -1.38 to -0.49) for MeDiet + EVOO, β = -1.06 (95% CI: -1.51 to -0.62) for MeDiet + Nuts when comparing with control group.

CONCLUSION
Dietary intervention with MeDiet supplemented with EVOO or nuts lowers dietary GL and GI.

PUBLISHED : SEPTEMBER 11, 2014
STUDY TYPE : ANIMAL FEEDING STUDY
TOPIC : MEDITERRANEAN DIET, NUTRITION, PREDIMED
SOURCE : http://www.hindawi.com/journals/jnme/2014/985373/

Influence Of Roasting Conditions On Health-Related Compounds In Different Nuts

By W. Schlörmann, M. Birringer, V. Böhm, K. Löber, G. Jahreis, S. Lorkowski, A.K. Müller, F. Schöne, M. Glei

BACKGROUND
Due to their health-beneficial ingredients the consumption of nuts can contribute to a healthy diet.

METHOD
The composition of hazelnuts, almonds, macadamia nuts, pistachios and walnuts regarding health-promoting and potentially harmful compounds was examined before and after roasting under different time and temperature conditions.

RESULT
Fatty acid compositions were not affected by roasting. Malondialdehyde increased with higher roasting temperatures (17-fold in walnuts). Levels of tocopherol isomers were reduced after roasting (a-T: 38%, b-T: 40%, c-T: 70%) and hydrophilic antioxidant capacity decreased significantly in hazelnuts (1.4-fold), macadamia nuts (1.7-fold) and walnuts (3.7-fold).

CONCLUSION
Increasing roasting temperatures supported the formation of significant amounts of acrylamide only in almonds (1220 lg kg_1). In general, nuts roasted at low/middle temperatures (120–160 _C) exhibited best sensory properties. Therefore, desired sensory quality along with a favourable healthy nut composition may be achieved by roasting over a low to medium temperature range.

PUBLISHED : FEBRUARY 11, 2015
STUDY TYPE : IN VITRO STUDY
TOPIC : NUTRITION
SOURCE : http://www.sciencedirect.com/science/article/pii/S0308814615001867