Polyphenol Intervention Ameliorates Non-Alcoholic Fatty Liver Disease: An Updated Comprehensive Systematic Review.

2024-11-29
Nutrients 16(23)
- Yazan Ranneh
- Alaa S Bedir
- Abdelghafar M Abu-Elsaoud
- Seham Al Raish

PubMed: 39683546
DOI: 10.3390/nu16234150

Study Design

Type: Systematic Review
Population: 1840 NAFLD patients
Methods: PRISMA systematic search appraisal in PubMed, Scopus, Web of Science Core Collection; included 29 randomized clinical trials

Rigorous Journal

Non-alcoholic fatty liver disease (NAFLD) has recently emerged as a challenging metabolic disorder with a strong emphasis on its prevention and management. Polyphenols, a group of naturally occurring plant compounds, have been associated with a decreased risk of various metabolic disorders related to NAFLD. The current systematic review aims to critically assess evidence about the ameliorative effect of polyphenol supplementation on NAFLD patients. A PRISMA systematic search appraisal was conducted in PubMed, Scopus, Web of Science Core Collection, and all relevant studies published prior to April 2024 and met the inclusion criteria were included. Twenty-nine randomized clinical trials (RCTs) comprised 1840 NAFLD patients. The studies primarily examined eleven phenolic compounds, including turmeric, curcumin, resveratrol, genistein, catechin, green tea extract, hesperidin, and silymarin. Turmeric and curcumin decreased liver enzymes, inflammatory cytokines, lipid profile, insulin resistance, and NAFLD score, while resveratrol did not present consistent results across all the studies. Most studies on silymarin showed a reduction in liver enzymes and lipid profile; however, no changes were observed in inflammatory cytokine levels. The dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine, while genistein supplementation did not modulate blood lipid profile. In conclusion, dietary supplementation of polyphenols could potentially prevent and ameliorate NAFLD. Still, the inconsistent results across the included RCTs require further clinical research to establish optimal dosage and duration.

Research Insights

Camellia→Decreased Liver Enzyme Level
no information on liver enzymes for genistein, but abstract suggests no effect on lipid profile; other outcomes not specified for genistein. However, the abstract groups genistein with others and states it did not modulate blood lipid profile. For other outcomes (liver enzymes, inflammatory cytokines), no explicit statement is made. I will assume genistein did not affect those either based on the lack of mention. But to be precise, I only have explicit null for lipid profile. I will include only that null.
Effect
Neutral
Effect size
Small
Camellia→Improved Blood Lipid Profile
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Camellia→Improved Liver Enzyme Level
dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine
Effect
Beneficial
Effect size
Moderate
Camellia→Reduced Pro-Inflammatory Cytokines
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Camellia→Reduced Pro-inflammatory Cytokine Levels
dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine
Effect
Beneficial
Effect size
Moderate
Hesperidin→Decreased Liver Enzyme Level
no information on liver enzymes for genistein, but abstract suggests no effect on lipid profile; other outcomes not specified for genistein. However, the abstract groups genistein with others and states it did not modulate blood lipid profile. For other outcomes (liver enzymes, inflammatory cytokines), no explicit statement is made. I will assume genistein did not affect those either based on the lack of mention. But to be precise, I only have explicit null for lipid profile. I will include only that null.
Effect
Neutral
Effect size
Small
Hesperidin→Improved Blood Lipid Profile
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Hesperidin→Improved Liver Enzyme Level
dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine
Effect
Beneficial
Effect size
Moderate
Hesperidin→Reduced Pro-Inflammatory Cytokines
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Hesperidin→Reduced Pro-inflammatory Cytokine Levels
dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine
Effect
Beneficial
Effect size
Moderate
Pueraria→Decreased Liver Enzyme Level
no information on liver enzymes for genistein, but abstract suggests no effect on lipid profile; other outcomes not specified for genistein. However, the abstract groups genistein with others and states it did not modulate blood lipid profile. For other outcomes (liver enzymes, inflammatory cytokines), no explicit statement is made. I will assume genistein did not affect those either based on the lack of mention. But to be precise, I only have explicit null for lipid profile. I will include only that null.
Effect
Neutral
Effect size
Small
Pueraria→Improved Blood Lipid Profile
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Pueraria→Reduced Pro-Inflammatory Cytokines
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Resveratrol→Decreased Liver Enzyme Level
no information on liver enzymes for genistein, but abstract suggests no effect on lipid profile; other outcomes not specified for genistein. However, the abstract groups genistein with others and states it did not modulate blood lipid profile. For other outcomes (liver enzymes, inflammatory cytokines), no explicit statement is made. I will assume genistein did not affect those either based on the lack of mention. But to be precise, I only have explicit null for lipid profile. I will include only that null.
Effect
Neutral
Effect size
Small
Resveratrol→Improved Blood Lipid Profile
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Resveratrol→Improved Insulin Resistance
resveratrol did not present consistent results across all the studies
Effect
Neutral
Effect size
Small
Resveratrol→Improved Insulin Sensitivity
resveratrol did not present consistent results across all the studies
Effect
Neutral
Effect size
Small
Resveratrol→Reduced NAFLD Activity Score
resveratrol did not present consistent results across all the studies
Effect
Neutral
Effect size
Small
Resveratrol→Reduced Pro-Inflammatory Cytokines
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Resveratrol→Reduced Pro-inflammatory Cytokine Levels
dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine
Effect
Beneficial
Effect size
Moderate
Sweet Orange→Decreased Liver Enzyme Level
no information on liver enzymes for genistein, but abstract suggests no effect on lipid profile; other outcomes not specified for genistein. However, the abstract groups genistein with others and states it did not modulate blood lipid profile. For other outcomes (liver enzymes, inflammatory cytokines), no explicit statement is made. I will assume genistein did not affect those either based on the lack of mention. But to be precise, I only have explicit null for lipid profile. I will include only that null.
Effect
Neutral
Effect size
Small
Sweet Orange→Improved Blood Lipid Profile
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Sweet Orange→Improved Liver Enzyme Level
dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine
Effect
Beneficial
Effect size
Moderate
Sweet Orange→Reduced Pro-Inflammatory Cytokines
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Sweet Orange→Reduced Pro-inflammatory Cytokine Levels
dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine
Effect
Beneficial
Effect size
Moderate
Thistle→Decreased Liver Enzyme Level
no information on liver enzymes for genistein, but abstract suggests no effect on lipid profile; other outcomes not specified for genistein. However, the abstract groups genistein with others and states it did not modulate blood lipid profile. For other outcomes (liver enzymes, inflammatory cytokines), no explicit statement is made. I will assume genistein did not affect those either based on the lack of mention. But to be precise, I only have explicit null for lipid profile. I will include only that null.
Effect
Neutral
Effect size
Small
Thistle→Improved Blood Lipid Profile
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Thistle→Reduced Pro-Inflammatory Cytokines
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Thistle→Reduced Pro-inflammatory Cytokine Levels
dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine
Effect
Beneficial
Effect size
Moderate
Turmeric→Decreased Liver Enzyme Level
no information on liver enzymes for genistein, but abstract suggests no effect on lipid profile; other outcomes not specified for genistein. However, the abstract groups genistein with others and states it did not modulate blood lipid profile. For other outcomes (liver enzymes, inflammatory cytokines), no explicit statement is made. I will assume genistein did not affect those either based on the lack of mention. But to be precise, I only have explicit null for lipid profile. I will include only that null.
Effect
Neutral
Effect size
Small
Turmeric→Decreased Liver Enzyme Level
no information on liver enzymes for genistein, but abstract suggests no effect on lipid profile; other outcomes not specified for genistein. However, the abstract groups genistein with others and states it did not modulate blood lipid profile. For other outcomes (liver enzymes, inflammatory cytokines), no explicit statement is made. I will assume genistein did not affect those either based on the lack of mention. But to be precise, I only have explicit null for lipid profile. I will include only that null.
Effect
Neutral
Effect size
Small
Turmeric→Improved Blood Lipid Profile
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Turmeric→Improved Blood Lipid Profile
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Turmeric→Improved Insulin Resistance
resveratrol did not present consistent results across all the studies
Effect
Neutral
Effect size
Small
Turmeric→Improved Insulin Resistance
resveratrol did not present consistent results across all the studies
Effect
Neutral
Effect size
Small
Turmeric→Improved Insulin Sensitivity
resveratrol did not present consistent results across all the studies
Effect
Neutral
Effect size
Small
Turmeric→Improved Insulin Sensitivity
resveratrol did not present consistent results across all the studies
Effect
Neutral
Effect size
Small
Turmeric→Reduced NAFLD Activity Score
resveratrol did not present consistent results across all the studies
Effect
Neutral
Effect size
Small
Turmeric→Reduced NAFLD Activity Score
resveratrol did not present consistent results across all the studies
Effect
Neutral
Effect size
Small
Turmeric→Reduced Pro-Inflammatory Cytokines
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Turmeric→Reduced Pro-Inflammatory Cytokines
genistein supplementation did not modulate blood lipid profile
Effect
Neutral
Effect size
Small
Turmeric→Reduced Pro-inflammatory Cytokine Levels
dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine
Effect
Beneficial
Effect size
Moderate
Turmeric→Reduced Pro-inflammatory Cytokine Levels
dietary supplementation of hesperidin and naringenin or green tea extract caused improvements in liver enzyme, lipid profile, and inflammatory cytokine
Effect
Beneficial
Effect size
Moderate