title: An Umbrella Review of Nuts Intake and Risk of Cardiovascular Disease.
abstract: Nuts have been an indispensable component of the human diet for hundreds because of their unique nutrient composition and are thought to play a beneficial part in the prevention of cardiovascular diseases.
  
  
  
  To evaluate the extent, validity and presence of evidence for studies investigating the impact of nuts intake on biomarkers of cardiovascular disease and cardiovascular events, we performed an umbrella review of all published meta-analyses synthesizing data from both observational studies and randomized controlled trials.
  
  
  
  PubMed (between 1966 and April 2016) was searched for systematic reviews and meta-analyses. Methodological quality was assessed by applying the AMSTAR score (0-11 points), and the meta-evidence by applying NutriGrade, our recently developed scoring system (0-10 points).
  
  
  
  In total, 14 meta-analyses were included in the umbrella review. Only 4 out of 14 reported an AMSTAR score ≥8 (high methodological quality), whereas NutriGrade meta-evidence score varied between 2 (very low meta-evidence) and 7.9 (moderate meta-evidence). There is consistent evidence from intervention trials, reporting significant reductions for total cholesterol, and from observational studies that higher intakes of nuts were associated with reduced risk of cardiovascular disease and hypertension. On the other side no effect could be observed for stroke, HDL-cholesterol, and blood pressure in the normal range.
  
  
  
  In summary, the present umbrella review showed that nuts intake was associated with reduced risk of cardiovascular disease and hypertension, and lower levels of total cholesterol. The observed evidence is limited by the moderate methodological quality and very low to moderate quality of evidence.
authors.affiliation: Arthur-Scheunert-Allee 114- 116; 14558 Nuthetal. Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Schwingshackl
authors.affiliation: Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Althanstraße 14 (UZAII). Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Hoffmann
authors.affiliation: Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Althanstraße 14 (UZAII). Austria.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Missbach
authors.affiliation: Department of Pediatric Gastroenterology and Metabolic Diseases, Poznan University of Medical Sciences, Szpitalna 27/33, 60-537 Poznan. Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Stelmach-Mardas
authors.affiliation: Department of Epidemiology, German Institute of Human Nutrition, Arthur-Scheunert-Allee 114-116 14558 Nuthetal. Germany.
authors.forename: Heiner
authors.initials: H
authors.lastname: Boeing
mesh_terms: D000818:Animals; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D004435:Eating; D006801:Humans; D006973:Hypertension / Q000517:prevention & control*; D009754:Nuts / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D012307:Risk Factors
chemical_list: D010936:Plant Extracts
keywords: Nuts intake; blood lipids; blood pressure; cardiovascular disease; meta-evidence; umbrella review