Muralidharan J, S. Galiè, P. Hernández-Alonso, M. Bulló, J. Salas-Salvadó, 2019. Plant-based fat, dietary patterns rich in vegetable fat and gut microbiota modulation. Front. Nutr. 6:157. doi: 10.3389/fnut.2019.00157.
Diet is advocated as a key factor influencing gut microbiota. Several studies have focused on the effect of different carbohydrates, mainly fiber, on gut microbiota. However, what remains to be elucidated is the impact of a key component of diet that is widely debated upon: dietary fats. This review highlights the importance of understanding the source, quality, and type of fats that could differentially modify the intestinal microbiome. Fats from plant-based sources such as nuts, or vegetable oils have shown positive alterations in gut microbiota biodiversity both in in vivo and in vitro studies. Nuts and other plant-based
fat sources, dietary patterns (e.g., Mediterranean diet) rich in polyunsaturated and monounsaturated fats and, in some cases, polyphenols, and other phytochemicals, have been associated with increased bacterial diversity, as well beneficial butyrate-producing bacteria imparting a positive metabolic influence. It is with this interest, this narrative review brings together evidences on different plant-based fat sources, dietary patterns rich in vegetable fats, and associated changes in gut microbiota.
Keywords: gut microbiota, plant-based fats, nuts, vegetable oils, Mediterranean diet
House, J.D., K. Hill, J. Neufeld, A. Franczyk, M.G. Nosworthy, 2019. Determination of the protein quality of almonds (Prunus dulcis L.) as assessed by in vitro and in vivo methodologies. Food Sci Nutr. 7:2932–2938.
Almonds (Prunus dulcis), such as all nuts, are positioned within the protein foods grouping within the current U.S. Dietary Guidelines. The ability to make claims related to the protein content of almonds, within the United States, requires substantiation via the use of the Protein Digestibility‐Corrected Amino Acid Score (PDCAAS). The present study was designed to provide current estimates of PDCAAS, using both in vivo and in vitro assays, of key almond varietals from the 2017 California harvest. Additionally, historical protein and amino acid composition data on 73 separate analyses, performed from 2000 to 2014, were analyzed. Amino acid analysis confirmed lysine as the first‐limiting amino acid, generating amino acid scores of 0.53, 0.52, 0.49, and 0.56 for Butte, Independence, Monterey, and Nonpareil varietals, respectively. True fecal protein digestibility coefficients ranged from 85.7% to 89.9% yielding PDCAAS values of 44.3–47.8, being highest for Nonpareil. Similar, albeit lower, results were obtained from the in vitro assessment protocol. Analysis of the historical data again positioned lysine as the limiting amino acid and yielded information on the natural variability present within the protein and amino acid profiles of almonds. Comparison of the 2017 AA profile, averaged across almond varietals, to the historical data provided strong evidence of persistence of amino acid composition and indices of protein quality over time.
Foolad, N., A.R. Vaughn, I. Rybak, W.A. Burney, G.M. Chodur, J.W. Newman, F.M. Steinberg, R.K. Sivamani, 2019. Prospective randomized controlled pilot study on the effects of almond consumption on skin lipids and wrinkles. Phytotherapy Research. 1–6. https://doi.org/10.1002/ptr.6495.
Objective: Almonds are a rich source of fatty acids and antioxidants, and their supplementation is known to significantly modulate serum lipids. The effects of almond on the skin’s lipid barrier and the appearance of wrinkles have not yet been elucidated. The aim of this study was to investigate the effects of almond consumption on facial sebum production and wrinkles. Methods: This was a prospective, investigator‐blinded, randomized controlled trial in which subjects consumed 20% of their daily energy consumption in either almonds or a calorie‐matched snack for 16 weeks. This study was completed at the UC Davis Dermatology clinic. Participants were a volunteer sample of generally healthy postmenopausal females with Fitzpatrick skin types 1 and 2. A facial photograph and image analysis system was used to obtain standardized photographs and information on wrinkle width and severity at 0, 8, and 16 weeks. Measurements of transepidermal water loss and sebum production were also completed at 0, 8, and 16 weeks. Results: Fifty healthy postmenopausal females were recruited, 31 participants were enrolled, and 28 completed the study. Under photographic analysis, the almond group had significantly decreased wrinkle severity and width compared with the control group at 16 weeks (p < .02). Changes in skin barrier function were nonsignificant, measured by the transepidermal water loss (p = .65) between the almond and control groups relative to baseline after 16 weeks. No adverse effects were reported. Conclusion: Our study demonstrates that daily almond consumption may reduce wrinkle severity in postmenopausal females to potentially have natural antiaging benefits.
Tuccinardi, D., O.M. Farr, J. Upadhyay, S.M. Oussaada, M.I. Klapa, M. Candela, S. Rampelli, S. Lehoux, I. Lázaro, A. Sala‐Vila, P. Brigidi, R.D. Cummings, C.S. Mantzoros, 2019. Mechanisms underlying the cardiometabolic protective effect of walnut consumption in obese subjects: a cross‐over, randomized, double‐blinded, controlled inpatient physiology study. Diabetes Obes Metab. 21(9):2086-2095.
Aims: To assess the effects of walnuts on cardiometabolic outcomes in obese subjects and to explore underlying mechanisms using novel methods including metabolomic, lipidomic, glycomic, and microbiome analysis integrated with lipid particle fractionation, appetite-regulating hormones and hemodynamic measurements. Materials and Methods: 10 obese subjects were enrolled in this cross-over, randomized, double-blind, placebo-controlled clinical trial. Patients participated in two 5-day inpatient stays during which they consumed a smoothie containing 48g walnuts or a macronutrient-matched placebo smoothie without nuts, with a one-month washout period between the two visits. Results: Walnut consumption improved aspects of the lipid profile, i.e. reduced fasting small and dense LDL particles (p<.02) and increased postprandial large HDL particles (p<.01). Lipoprotein Insulin Resistance Score, glucose and insulin AUC decreased significantly after walnut consumption (p<.01, p<.02, p<.04, respectively). Consuming walnuts significantly increased 10 N-glycans, with 8 of them carrying a fucose core. Lipidomic analysis showed a robust reduction in harmful ceramides, hexosylceramides and sphingomyelins, which have been shown to mediate effects on cardiometabolic risk. Peptide YY AUC significantly increased after walnut consumption (p<.03). No major significant changes in hemodynamic, metabolomic analysis or in host health-promoting bacteria such as Faecalibacterium were found. Conclusions: These data provide a more comprehensive mechanistic perspective of the effect of dietary walnut consumption on cardiometabolic parameters. Lipidomic and lipid nuclear magnetic resonance spectroscopy analysis showed an early but significant reduction in ceramides and other atherogenic lipids with walnut consumption that may explain the longer-term benefits of walnuts on insulin resistance, cardiovascular risk and mortality.
