title: Effects of Hazelnut Consumption on Blood Lipids and Body Weight: A Systematic Review and Bayesian Meta-Analysis.
abstract: Hazelnuts are rich in monounsaturated fatty acids and antioxidant bioactive substances: their consumption has been associated with a decreased risk of cardiovascular disease events. A systematic review and a meta-analysis was performed to combine the results from several trials and to estimate the pooled (overall) effect of hazelnuts on blood lipids and body weight outcomes. Specifically, a Bayesian random effect meta-analysis of mean differences of Δ-changes from baseline across treatment (MDΔ) (i.e., hazelnut-enriched diet vs. control diet) has been conducted. Nine studies representing 425 participants were included in the analysis. The intervention diet lasted 28-84 days with a dosage of hazelnuts ranging from 29 to 69 g/day. Out of nine studies, three randomized studies have been meta-analyzed showing a significant reduction in low-density lipoprotein (LDL) cholesterol (pooled MDΔ = -0.150 mmol/L; 95% highest posterior density interval (95%HPD) = -0.308; -0.003) in favor of a hazelnut-enriched diet. Total cholesterol showed a marked trend toward a decrease (pooled MDΔ = -0.127 mmol/L; 95%HPD = -0.284; 0.014) and high-density lipoprotein (HDL) cholesterol remained substantially stable (pooled MDΔ = 0.002 mmol/L; 95%HPD = -0.140; 0.147). No effects on triglycerides (pooled MDΔ = 0.045 mmol/L; 95%HPD = -0.195; 0.269) and body mass index (BMI) (pooled MDΔ = 0.062 kg/m²; 95%HPD = -0.293; 0.469) were found. Hazelnut-enriched diet is associated with a decrease of LDL and total cholesterol, while HDL cholesterol, triglycerides and BMI remain substantially unchanged.
authors.affiliation: Department of Public Health, Experimental and Forensic Medicine, Endocrinology and Nutrition Unit, University of Pavia, Azienda di Servizi alla Persona di Pavia, Pavia 27100, Italy. simoneperna@hotmail.it.
authors.forename: Simone
authors.initials: S
authors.lastname: Perna
authors.affiliation: Department of Gastroenterology, Policlinico di Monza, Monza 20097, Italy. attilio.giacosa@policlinicodimonza.it.
authors.forename: Attilio
authors.initials: A
authors.lastname: Giacosa
authors.affiliation: Department of Biomedical Sciences for Health, Division of General Surgery, IRCCS Policlinico San Donato, University of Milan, Milan 20097, Italy. bbonit@icloud.com.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Bonitta
authors.affiliation: Department of Public Health, Experimental and Forensic Medicine, Endocrinology and Nutrition Unit, University of Pavia, Azienda di Servizi alla Persona di Pavia, Pavia 27100, Italy. chiara.bologna02@universitadipavia.it.
authors.forename: Chiara
authors.initials: C
authors.lastname: Bologna
authors.affiliation: Department of Public Health, Experimental and Forensic Medicine, Endocrinology and Nutrition Unit, University of Pavia, Azienda di Servizi alla Persona di Pavia, Pavia 27100, Italy. antonio.isu@gmail.com.
authors.forename: Antonio
authors.initials: A
authors.lastname: Isu
authors.affiliation: Department of Public Health, Experimental and Forensic Medicine, Biostatistics and Clinical Epidemiology Unit, University of Pavia, Pavia 27100, Italy. davide.guido@unipv.it.
authors.forename: Davide
authors.initials: D
authors.lastname: Guido
authors.affiliation: Department of Public Health, Experimental and Forensic Medicine, Endocrinology and Nutrition Unit, University of Pavia, Azienda di Servizi alla Persona di Pavia, Pavia 27100, Italy. mariangela.rondanelli@unipv.it.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Rondanelli
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001499:Bayes Theorem; D001835:Body Weight / Q000187:drug effects*; D031211:Corylus / Q000737:chemistry*; D005227:Fatty Acids / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D008055:Lipids / Q000097:blood*
chemical_list: D000975:Antioxidants; D005227:Fatty Acids; D008055:Lipids
keywords: BMI; Corylus avellana; body weight; cholesterol; hazelnut; lipid; obesity; triglyceride