Archive

Research Area: Nutrient and Bioactive Composition

A dietary model of partial meat replacement with walnuts demonstrates changes in the nutrient profile and quality of the United States Population’s Diet.

Spence, L.A., B. Henschel, R. Li, C.D. Tekwe, K. Thiagarajah, 2023. A dietary model of partial meat replacement with walnuts demonstrates changes in the nutrient profile and quality of the United States population’s diet. Nutrients. 15(21):4518. https://doi.org/10.3390/nu15214518

The purpose of the study is to assess the impact of partial meat replacement with walnuts using a dose–escalation approach on nutrient intake and diet quality in the usual US diet. Food modeling was implemented using the nationally representative 2015–2018 National Health and Examination Survey (NHANES), with a focus on non-nut consumers, which included 2707 children and adolescents and 5190 adults. Walnuts replaced meat in a dose-escalating manner (0.5, 1, 1.5, and 2 oz walnuts per day replaced 1, 2, 3, and 4 oz meat, respectively). Diet quality was estimated using the population ratio method of the 2015 Healthy Eating Index. The usual intake of nutrients was estimated using the National Cancer Institute method. Significant differences were determined using non-overlapping 95% confidence intervals. The partial replacement of meat with walnuts demonstrated significant increases in the mean intake of fiber, magnesium, and omega-3 fatty acids and significant decreases in cholesterol and vitamin B12 in the modeled diets for children, adolescents, and adults. Additionally, the partial replacement of meat with walnuts improved overall diet quality. Walnut consumption at 1–2 oz as a replacement for some meat may improve nutrient intake and diet quality across age groups.

Effect of walnut supplementation on dietary polyphenol intake and urinary polyphenol excretion in the Walnuts and Healthy Aging Study.

Amen, R.I., R. Sirirat, K. Oda, S. Rajaram, I. Nwachukwu, M. Cofan, E. Ros, J. Sabate, E.H. Haddad, 2023. Effect of walnut supplementation on dietary polyphenol intake and urinary polyphenol excretion in the Walnuts and Healthy Aging Study. Nutrients.15(5):1253. https://doi.org/10.3390/nu15051253.

Among all tree nuts, walnuts contain the highest total polyphenols by weight. This secondary data analysis examined the effect of daily walnut supplementation on the total dietary polyphenols and subclasses and the urinary excretion of total polyphenols in a free-living elderly population. In this 2-year prospective, randomized intervention trial (ID NCT01634841), the dietary polyphenol intake of participants who added walnuts daily to their diets at 15% of daily energy were compared to those in the control group that consumed a walnut-free diet. Dietary polyphenols and subclasses were estimated from 24 h dietary recalls. Phenolic estimates were derived from Phenol-Explorer database version 3.6. Participants in the walnut group compared to the control group had a higher intake of total polyphenols, flavonoids, flavanols, and phenolic acids in mg/d (IQR): 2480 (1955, 3145) vs. 1897 (1369, 2496); 56 (42,84) vs. 29 (15, 54); 174 (90, 298) vs. 140 (61, 277); and 368 (246, 569) vs. 242 (89, 398), respectively. There was a significant inverse association between dietary flavonoid intake and urine polyphenol excretion; less urinary excretion may imply that some of the polyphenols were eliminated via the gut. Nuts had a significant contribution to the total polyphenols in the diet, suggesting that a single food like walnuts added to habitual diet can increase the polyphenol intake in a Western population.

Walnut protein: A rising source of high-quality protein and its updated comprehensive review.

Wen, C., Z. Zhang, L. Cao, G. Liu, L. Liang, X. Liu, J. Zhang, Y. Li, X. Yang, S. Li, J. Ren, X. Xu, 2023. Walnut protein: A rising source of high-quality protein and its updated comprehensive review. J Agric Food Chem. 71(28):10525-10542.

Recently, plant protein as a necessary nutrient source for human beings, a common ingredient of traditional processed food, and an important element of new functional food has gained prominence due to the increasing demand for healthy food. Walnut protein (WP) is obtained from walnut kernels and walnut oil-pressing waste and has better nutritional, functional, and essential amino acids in comparison with other vegetable and grain proteins. WP can be conveniently obtained by various extraction techniques, including alkali-soluble acid precipitation, salting-out, and ultrasonic-assisted extraction, among others. The functional properties of WP can be modified for desired purposes by using some novel methods, including free radical oxidation, enzymatic modification, high hydrostatic pressure, etc. Moreover, walnut peptides play an important biological role both in vitro and in vivo. The main activities of the walnut peptides are antihypertensive, antioxidant, learning improvement, and anticancer, among others. Furthermore, WP could be applied in the development of functional foods or dietary supplements, such as delivery systems and food additives, among others. This review summarizes recent knowledge on the nutritional, functional, and bioactive peptide aspects of WP and possible future products, providing a theoretical reference for the utilization and development of oil crop waste.

The effect of high-polyphenol Mediterranean diet on visceral adiposity: the DIRECT PLUS randomized controlled trial.

Zelicha, H., N. Kloting, A. Kaplan, A. Yaskolka Meir, E. Rinott, G. Tsaban, Y. Chassidim,  M. Bluher, U. Ceglarek, B. Isermann, M. Stumvoll, R.N. Quayson, M. von Bergen, B. Engelmann, U.E. Rolle-Kampczyk, S.B. Haange, K.M. Tuohy, C. Diotallevi, I. Shelef, F.B. Hu, M.J. Stampfer, I. Shai, 2022. The effect of high-polyphenol Mediterranean diet on visceral adiposity: the DIRECT PLUS randomized controlled trial. BMC Medicine. 20(1):327. https://doi.org/10.1186/s12916-022-02525-8

Background: Mediterranean (MED) diet is a rich source of polyphenols, which benefit adiposity by several mechanisms. We explored the effect of the green-MED diet, twice fortified in dietary polyphenols and lower in red/processed meat, on visceral adipose tissue (VAT). Methods: In the 18-month Dietary Intervention Randomized Controlled Trial PoLyphenols UnproceSsed (DIRECT-PLUS) weight-loss trial, 294 participants were randomized to (A) healthy dietary guidelines (HDG), (B) MED, or (C) green-MED diets, all combined with physical activity. Both isocaloric MED groups consumed 28 g/day of walnuts (+ 440 mg/day polyphenols). The green-MED group further consumed green tea (3–4 cups/day) and Wolffia globosa (duckweed strain) plant green shake (100 g frozen cubes/day) (+ 800mg/day polyphenols) and reduced red meat intake. We used magnetic resonance imaging (MRI) to quantify the abdominal adipose tissues. Results: Participants (age = 51 years; 88% men; body mass index = 31.2 kg/m2; 29% VAT) had an 89.8% retention rate and 79.3% completed eligible MRIs. While both MED diets reached similar moderate weight (MED: − 2.7%, green-MED: − 3.9%) and waist circumference (MED: − 4.7%, green-MED: − 5.7%) loss, the green-MED dieters doubled the VAT loss (HDG: − 4.2%, MED: − 6.0%, green-MED: − 14.1%; p < 0.05, independent of age, sex, waist circumference, or weight loss). Higher dietary consumption of green tea, walnuts, and Wolffia globosa; lower red meat intake; higher total plasma polyphenols (mainly hippuric acid), and elevated urine urolithin A polyphenol were significantly related to greater VAT loss (p < 0.05, multivariate models). Conclusions: A green-MED diet, enriched with plant-based polyphenols and lower in red/processed meat, may be a potent intervention to promote visceral adiposity regression.

Diet-induced fasting ghrelin elevation reflects the recovery of insulin sensitivity and visceral adiposity regression.

Tsaban, G., A. Yaskolka Meir, H. Zelicha, E. Rinott, A. Kaplan, A. Shalev, A. Katz, D. Brikner, M. Blüher, U. Ceglarek, M. Stumvoll, M.J. Stampfer, I. Shai, 2022. Diet-induced fasting ghrelin elevation reflects the recovery of insulin sensitivity and visceral adiposity regression. JCEM. 107(2):336–345. https://doi.org/10.1210/clinem/dgab681

Aims: Lower fasting-ghrelin-levels (FGL) are associated with obesity and metabolic syndrome. We aimed to explore the dynamics of FGL during weight-loss and its metabolic and adiposity-related manifestations beyond weight-loss. Methods: A secondary analysis of a clinical trial where we randomized participants with abdominal-obesity/dyslipidemia to one of three diets: healthy-dietary-guidelines (HDG), Mediterranean diet (MED), or green-MED diet, all combined with physical activity (PA). Both MED diets were similarly hypocaloric and included 28g/day walnuts. The green-MED group further consumed green tea (3-4 cups/day) and a Wolffia-globosa (Mankai) plant green-shake. We measured FGL and quantified body fat depots by Magnetic-Resonance-Imaging at baseline and after 18-months. Results: Among 294 participants [body-mass-index=31.3kg/m 2;FGL=504±208pg/mL; retention rate=89.8%], lower FGL were associated with unfavorable cardiometabolic parameters as higher visceral-adipose-tissue (VAT), intra-hepatic fat, leptin, and blood pressure (p<0.05 for all; multivariate models). ΔFGL18-month differed between men (+7.3+26.6%) and women (-9.2+21.3%,p=0.001). After 18-months of moderate and similar weight loss among the MED-groups, FGL increased by 1.3%, 5.4%, and 10.5% in HDG, MED, and green-MED groups, respectively (p=0.03 for green-MED vs. HDG), sex-stratified analysis revealed similar changes in men only. Among men, FGL18-month elevation was associated with favorable changes in insulin resistance profile and VAT regression, after adjusting for relative weight-loss (HbA1c:r=-0.216; homeostatic-model-of insulin-resistance:r=-0.154; HDL-c:r=0.147;VAT:r=-0.221;p<0.05 for all). , Insulin resistance and VAT remained inversely related with FGL elevation, beyond which was explained by weight-loss (residual regression analyses;p<0.05). Conclusions: Diet-induced FGL elevation may reflect insulin sensitivity recovery and VAT regression beyond weight-loss, specifically among men. Green-MED diet is associated with greater FGL elevation.

Why Should Pistachio Be a Regular Food in Our Diet?

Mateos, R., M.D. Salvador, G. Fregapane, L. Goya, 2022. Why Should Pistachio Be a Regular Food in Our Diet? Nutrients. 14(15):3207. https://doi.org/10.3390/nu14153207

The pistachio is regarded as a relevant source of biologically active components that, compared to other nuts, possess a healthier nutritional profile with low-fat content composed mainly of monounsaturated fatty acids, a high source of vegetable protein and dietary fibre, remarkable content of minerals, especially potassium, and an excellent source of vitamins, such as vitamins C and E. A rich composition in terms of phytochemicals, such as tocopherols, carotenoids, and, importantly, phenolic compounds, makes pistachio a powerful food to explore its involvement in the prevention of prevalent pathologies. Although pistachio has been less explored than other nuts (walnut, almonds, hazelnut, etc.), many studies provide evidence of its beneficial effects on CVD risk factors beyond the lipid-lowering effect. The present review gathers recent data regarding the most beneficial effects of pistachio on lipid and glucose homeostasis, endothelial function, oxidative stress, and inflammation that essentially convey a protective/preventive effect on the onset of pathological conditions, such as obesity, type 2 diabetes, CVD, and cancer. Likewise, the influence of pistachio consumption on gut microbiota is reviewed with promising results. However, population nut consumption does not meet current intake recommendations due to the extended belief that they are fattening products, their high cost, or teething problems, among the most critical barriers, which would be solved with more research and information.

Exploration of walnut components and their association with health effects.

Ni, Z.J., Y.G. Zhang, S.X. Chen, K. Thakur, S. Wang, J.G. Zhang, Y.F. Shang, Z.J. Wei, 2022. Exploration of walnut components and their association with health effects. Crit Rev Food Sci Nutr. 62(19):5113-5129.

Traditionally, walnuts have occupied an imperative position in the functional food market with consistently recognized nutritious and functional properties. In the past years, the lipid profile of walnuts has brought much scientific attention via linking a cascade of biological attributes and health-promoting effects. Over time, researchers have focused on diversified composition (polyphenols and vitamins) of different parts of walnut (flower, pellicle, and kernel) and emphasized their physiological significance. Consequently, a plethora of reports has emerged on the potential role of walnut consumption against a series of diseases including cancer, gut dysbiosis, cardiovascular, and neurodegenerative diseases. Therefore, we accumulated the updated data on composition and classification, extraction methods, and utilization of different parts of walnuts as well as associated beneficial effects under in vivo and clinical studies. Altogether, this review summarized the ameliorative effects of a walnut-enriched diet in chronic diseases which can be designated to the synergistic or individual effects of walnut components mainly through anti-oxidative and anti-inflammatory role.

The effects of almond consumption on inflammatory biomarkers in adults: A systematic review and meta-analysis of randomized clinical trials.

Fatahi, S., E. Daneshzad. K. Lotfi, L. Azadbakht, 2021. The effects of almond consumption on inflammatory biomarkers in adults: A systematic review and meta-analysis of randomized clinical trials. Adv. Nutr. doi:10.1093/advances/nmab158.

Conflicting findings have been reported regarding the effects of almond consumption on inflammatory markers. This study aimed to summarize the current literature to determine whether almond can affect inflammatory markers. A systematic search was carried out in PubMed, Scopus, and ISI Web of Science up to March 2021. Randomized clinical trials (RCTs) that compared almond with no almond consumption were included. The outcomes of interest were changes in circulating C-reactive protein (CRP), Interleukin-6 (IL-6), Tumor Necrosis Factor Alpha (TNF-α), Intercellular Adhesion Molecule-1 (ICAM-1) and Vascular Cell Adhesion Molecule-1 (VCAM-1) concentrations. The random-effects model was used to find the mean differences. Totally, 18 trials with 847 participants were eligible for the current analysis. Participant age ranged from 26.3 to 69.6 y. Combining 16 studies, almond consumption significantly reduced serum levels of CRP (WMD: -0.25 mg/L; 95% CI: -0.43, -0.06; I2 = 0.0% P-heterogeneity = 0.633). However, the beneficial effect of almond intake only occurred at doses <60 g/d. Pooling 11 effect sizes, almond interventions significantly decreased circulating IL-6 concentrations (WMD: -0.11 pg/mL; 95% CI: -0.21, -0.01; I2 = 19.9% P-heterogeneity = 0.254). In subgroup analyses, effects on CRP and IL-6 were not significant in unhealthy participants or those with obesity. In addition, almond consumption had no significant effect on TNF-α (WMD: -0.05 pg/mL; 95% CI: -0.11, 0.01; I2 = 0.0% P-heterogeneity = 0.893; n = 6), ICAM-1 (WMD: 6.39 ng/mL; 95% CI: -9.44, 22.22; I2 = 66.6% P-heterogeneity = 0.006; n = 7) or VCAM-1 (WMD: -8.31 ng/mL; 95% CI: -35.32, 18.71; I2 = 58.8% P-heterogeneity = 0.033; n = 6). In conclusion, almond consumption beneficially affects CRP and IL-6 concentrations in adults. However, it has no beneficial effect on TNF-α, ICAM-1, or VCAM-1. More trials are needed to determine the effects of almond on inflammation.

Prospective randomized controlled trial on the effects of almonds on facial wrinkles and pigmentation. 

Rybak, I., A.E. Carrington, S. Dhaliwal, A. Hasan, H. Wu, W. Burney, J. Maloh, R.K. Sivamani, 2021. Prospective randomized controlled trial on the effects of almonds on facial wrinkles and pigmentation. Nutrients. 13(3):785. https://doi.org/10.3390/nu13030785

Background: Almonds have long been studied as a rich source of fatty acids, phytochemical polyphenols and antioxidants such as vitamin E. A recent study compared almond supplementations to a calorie-matched intervention for 16 weeks, yielding statistically significant improvement in wrinkle severity in postmenopausal women with Fitzpatrick skin types I and II that received almonds. This study furthers that assessment with a larger population and duration of 24 weeks to assess the influence of almond consumption on wrinkle severity, skin pigmentation and other skin biophysical profiles. Objective: To investigate the effects of almond consumption on photoaging such as wrinkles and pigment intensity as well as facial biophysical parameters such as sebum production, skin hydration and water loss. Design and interventions: A prospective, randomized controlled study assessed postmenopausal women with Fitzpatrick skin types I or II who consumed 20% of their daily energy consumption in either almonds or a calorie-matched snack for 24 weeks. A facial photograph and image analysis system was used to obtain standardized high-resolution photographs and information on wrinkle width and severity at 0, 8, 16 and 24 weeks. Measurements of transepidermal water loss (TEWL), skin pigmentation, skin hydration and sebum production were also completed at each visit. Results: The average wrinkle severity was significantly decreased in the almond intervention group at week 16 and week 24 compared to baseline by 15% and 16%, respectively. Facial pigment intensity was decreased 20% in the almond group at week 16 and this was maintained by week 24. There were no significant differences in skin hydration or TEWL in the almond group compared to the control, although sebum excretion was increased in the control group. Conclusion: The daily consumption of almonds may improve several aspects of photoaging such as facial wrinkles and pigment intensity in postmenopausal women. In conclusion, the daily consumption of almonds may contribute to the improvement of facial wrinkles and reduction of skin pigmentation among postmenopausal women with Fitzpatrick skin types I and II.

The metabolomic-gut-clinical axis of Mankai plant-derived dietary polyphenols.

Yaskolka, M.A., K. Tuohy K, M. von Bergen, R. Krajmalnik-Brown, U. Heinig, H. Zelicha, G. Tsaban, E. Rinott, A. Kaplan, A. Aharoni, L. Zeibich, D. Chang, B. Dirks, C. Diotallevi, P. Arapitsas, U. Vrhovsek, U. Ceglarek, S.-B. Haange, U. Rolle-Kampczyk, B. Engelmann, M. Lapidot, M. Colt, Q. Sun, I., 2021. The metabolomic-gut-clinical axis of Mankai plant-derived dietary polyphenols. Nutrients. 13(6):1866. https://doi.org/10.3390/nu13061866.

Background: Polyphenols are secondary metabolites produced by plants to defend themselves from environmental stressors. We explored the effect of Wolffia globosa ‘Mankai’, a novel cultivated strain of a polyphenol-rich aquatic plant, on the metabolomic-gut clinical axis in vitro, in-vivo and in a clinical trial. Methods: We used mass-spectrometry-based metabolomics methods from three laboratories to detect Mankai phenolic metabolites and examined predicted functional pathways in a Mankai artificial-gut bioreactor. Plasma and urine polyphenols were assessed among the 294 DIRECT-PLUS 18-month trial participants, comparing the effect of a polyphenol-rich green-Mediterranean diet (+1240 mg/polyphenols/day, provided by Mankai, green tea and walnuts) to a walnuts-enriched (+440 mg/polyphenols/day) Mediterranean diet and a healthy controlled diet. Results: Approximately 200 different phenolic compounds were specifically detected in the Mankai plant. The Mankai-supplemented bioreactor artificial gut displayed a significantly higher relative-abundance of 16S-rRNA bacterial gene sequences encoding for enzymes involved in phenolic compound degradation. In humans, several Mankai-related plasma and urine polyphenols were differentially elevated in the green Mediterranean group compared with the other groups (p < 0.05) after six and 18 months of intervention (e.g., urine hydroxy-phenyl-acetic-acid and urolithin-A; plasma Naringenin and 2,5-diOH-benzoic-acid). Specific polyphenols, such as urolithin-A and 4-ethylphenol, were directly involved with clinical weight-related changes. Conclusions: The Mankai new plant is rich in various unique potent polyphenols, potentially affecting the metabolomic-gut-clinical axis.