Effects of a 1-year dietary intervention with n-3 polyunsaturated fatty acid-enriched olive oil on non-alcoholic fatty liver disease patients: a preliminary study

Abstract

The results of this preliminary study showed that long-term consumption of olive oil enriched with n-3 PUFA in patients with NAFLD is able to decrease circulating liver enzymes and triglycerides, with a significant improvement of adiponectin levels.

Docosahexaenoic acid attenuates Western diet-induced hepatic fibrosis in Ldlr mice by targeting the TGFβ-Smad3 pathway

“…This is highly relevant because dietary 3 PUFAs are being evaluated as treatment strategies for NAFLD/NASH in children and adults (30)(31)(32)(33)(34)(35)63 ). Although these clinical studies show that dietary 3 PUFAs reduce liver fat (30)(31)(32)(33)(34)(35)(36)(37), some clinical trials have reported that 3 PUFAs, like fi sh oil ( 36 ) or EPA-ethyl esters ( 37 ), fail to improve fi brosis scores associated with NASH. Our previous report established that DHA was more effective than EPA at attenuating WD-induced hepatic fat, infl ammation, and fi brosis ( 17 ).…”

“…Omega-3 PUFAs have well-defi ned effects on hepatic lipid metabolism and infl ammation ( 29,73 ), and more recently their effects on hepatic fi brosis have been noted ( 17,28,69 ). Although several human studies have provided evidence in support of using supplemental 3 PUFAs to treat NAFLD (30)(31)(32)(33)(34)(35)(36)(37), other studies suggest there may be limitations for their use in NASH treatment ( 36,37 ). In trials using either fi sh oil or EPA-ethyl ester supplements, investigators report that 3 PUFA supplements failed to improve fi brosis scores.…”

Dietary approach in the treatment of nonalcoholic fatty liver disease

“…In contrast, no patient achieved complete regression in the group that received only the AHA diet, and only 27.7% of them presented some reduction in the steatosis [86] . Another study employing low dose of n-3 PUFA supplementation (0.83 g/d, of which 0.47 g of EPA and 0.24 g of DHA) in olive oil demonstrated improvement in the liver echotexture (evaluated by ultrasound) and in the hepatic Doppler perfusion index, after 12 mo of treatment of NAFLD patients, compared to a control group of individuals also with NAFLD [85] . Although the investigations based on imaging methods demonstrated a reduction in liver fat as commented above, the studies that investigated the role of n-3 PUFA in NAFLD treatment using liver histology to evaluate the results have shown controversial results [88,89] .…”

“…Pre-and post-intervention analysis demonstrated that the olive oil group presented increase in HDL-c levels; the canola oil group presented reduction in fasting blood glucose and TG; and both groups (olive and canola oils) presented improvement in the grade of fatty liver and liver span [82] . In several studies, the effects of the intake of n-3 PUFA supplements were investigated as a complementary treatment of NAFLD [83][84][85][86][87][88][89] . In general, these studies demonstrated a reduction in liver fat measured by different imaging methods, with the doses raging from 0.83 to 6 g/d, and duration therapy ranging from 8 wk to 18 mo [83][84][85][86][87] .…”

“…In several studies, the effects of the intake of n-3 PUFA supplements were investigated as a complementary treatment of NAFLD [83][84][85][86][87][88][89] . In general, these studies demonstrated a reduction in liver fat measured by different imaging methods, with the doses raging from 0.83 to 6 g/d, and duration therapy ranging from 8 wk to 18 mo [83][84][85][86][87] . A supplementation of 2 g of n-3 PUFA 3 times per day, for 24 wk, was associated with a complete fatty liver regression in almost 20% of the NAFLD patients and some reduction in 53% of them.…”