TY - JOUR
T1 - Dietary Interventions in Patients With Non-alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis
AU - Houttu, Veera
AU - Csader, Susanne
AU - Nieuwdorp, Max
AU - Holleboom, Adriaan G.
AU - Schwab, Ursula
N1 - Funding Information: This work has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 813781 ITN BestTreat (on which SC and VH are appointed). AH was supported by the Amsterdam UMC Fellowship grant, Health–Holland TKI-PPP grants, and by the research grants from Gilead and Novo Nordisk. MN was supported by a personal ZONMW VICI grant 2020 [09150182010020]. Funding Information: We thank Heikki Laitinen from the University of Eastern Finland, Kuopio for his great help with the search-term combinations. Funding. This work has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sk?odowska-Curie grant agreement No. 813781 ITN BestTreat (on which SC and VH are appointed). AH was supported by the Amsterdam UMC Fellowship grant, Health?Holland TKI-PPP grants, and by the research grants from Gilead and Novo Nordisk. MN was supported by a personal ZONMW VICI grant 2020 [09150182010020]. Publisher Copyright: © Copyright © 2021 Houttu, Csader, Nieuwdorp, Holleboom and Schwab. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/7/22
Y1 - 2021/7/22
N2 - Background: With no approved pharmacotherapy to date, the present therapeutic cornerstone for non-alcoholic fatty liver diseases (NAFLD) is a lifestyle intervention. Guidelines endorse weight loss through dietary modifications, physical exercise, or both. However, no consensus exists on the optimal dietary treatment. Objectives: The aim of our systematic review and meta-analysis was to summarize and assess the evidence for applied types of dietary interventions on the liver and metabolic outcomes in patients with NAFLD, aside from any effects of exercise intervention. Methods: This systematic review was conducted according to the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) statement guidelines. The search was conducted in PubMed, Scopus, and Cochrane databases in February 2020. Included were only dietary interventions without exercise. This study was registered at PROSPERO: CRD42020203573. Results: Eight randomized controlled trials, seven with endpoint reduction of hepatic steatosis, one with an assessment of endpoint fibrosis, were included in this systematic review, five of which were included in the meta-analysis. Mediterranean dietary interventions without energy restriction (n = 3) showed significant reduction of intrahepatic lipid content (IHL) (SDM: −0.57, 95% CI: −1.04, −0.10), but there was no significant change in alanine transaminase (ALT) (SDM: 0.59, 95% CI: −0.5, −1.68). Hypocaloric dietary interventions with foods high in unsaturated fatty acids (n = 2) led to a significant decrease in ALT (SDM: −1.09, 95% CI: −1.49, −0.69) and aspartate aminotransferase (AST) (SDM: −0.75, 95% CI: −1.27, 0.23); yet effects on steatosis could not be aggregated due to different assessment techniques. Mediterranean diet did not lead to significant changes in concentrations of gamma-glutamyl transpeptidase (γGT), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), fasting glucose or insulin, or homeostatic assessment for insulin resistance. Conclusions: In patients with NAFLD, Mediterranean and hypocaloric dietary interventions favoring unsaturated fatty acids result in improvements in IHL and transaminases. Since many dietary intervention studies are combined with exercise interventions and there is a paucity of ample-sized studies examining dietary interventions on the more advanced and clinically relevant stages of NAFLD, that is active and fibrotic NASH, with multiparametric imaging and liver histology as outcome measures, the optimal dietary invention in NAFLD remains to be defined.
AB - Background: With no approved pharmacotherapy to date, the present therapeutic cornerstone for non-alcoholic fatty liver diseases (NAFLD) is a lifestyle intervention. Guidelines endorse weight loss through dietary modifications, physical exercise, or both. However, no consensus exists on the optimal dietary treatment. Objectives: The aim of our systematic review and meta-analysis was to summarize and assess the evidence for applied types of dietary interventions on the liver and metabolic outcomes in patients with NAFLD, aside from any effects of exercise intervention. Methods: This systematic review was conducted according to the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) statement guidelines. The search was conducted in PubMed, Scopus, and Cochrane databases in February 2020. Included were only dietary interventions without exercise. This study was registered at PROSPERO: CRD42020203573. Results: Eight randomized controlled trials, seven with endpoint reduction of hepatic steatosis, one with an assessment of endpoint fibrosis, were included in this systematic review, five of which were included in the meta-analysis. Mediterranean dietary interventions without energy restriction (n = 3) showed significant reduction of intrahepatic lipid content (IHL) (SDM: −0.57, 95% CI: −1.04, −0.10), but there was no significant change in alanine transaminase (ALT) (SDM: 0.59, 95% CI: −0.5, −1.68). Hypocaloric dietary interventions with foods high in unsaturated fatty acids (n = 2) led to a significant decrease in ALT (SDM: −1.09, 95% CI: −1.49, −0.69) and aspartate aminotransferase (AST) (SDM: −0.75, 95% CI: −1.27, 0.23); yet effects on steatosis could not be aggregated due to different assessment techniques. Mediterranean diet did not lead to significant changes in concentrations of gamma-glutamyl transpeptidase (γGT), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), fasting glucose or insulin, or homeostatic assessment for insulin resistance. Conclusions: In patients with NAFLD, Mediterranean and hypocaloric dietary interventions favoring unsaturated fatty acids result in improvements in IHL and transaminases. Since many dietary intervention studies are combined with exercise interventions and there is a paucity of ample-sized studies examining dietary interventions on the more advanced and clinically relevant stages of NAFLD, that is active and fibrotic NASH, with multiparametric imaging and liver histology as outcome measures, the optimal dietary invention in NAFLD remains to be defined.
KW - diet intervention
KW - glucose metabolism
KW - lipid metabolism
KW - liver fat
KW - liver transaminases
KW - meta-analysis
KW - non-alcoholic fatty liver disease
KW - systematic review
UR - http://www.scopus.com/inward/record.url?scp=85112098322&partnerID=8YFLogxK
U2 - https://doi.org/10.3389/fnut.2021.716783
DO - https://doi.org/10.3389/fnut.2021.716783
M3 - Review article
C2 - 34368214
SN - 2296-861X
VL - 8
JO - Frontiers in Nutrition
JF - Frontiers in Nutrition
M1 - 716783
ER -