Yogurt improves insulin resistance, liver fat in obese women with NAFLD, MetS
Eating yogurt appears to be better than drinking milk at improving insulin resistance (IR) and liver fat in obese women with nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS), a China study has shown. Yogurt ameliorates IR by enhancing lipid metabolism, reducing inflammation, oxidative stress and lipopolysaccharides (LPS), and changing the gut microbiota composition.
The investigators randomized 100 obese women aged 36–66 years with both NAFLD and MetS to consume 220 g/d of either conventional yogurt or milk for 24 weeks. Anthropometric indices, serum glucose, insulin, lipids and cytokines in all participants, as well as liver fat and gut microbiota in 20 participants randomly selected from each group, were measured at baseline and week 24.
Of the participants, 48 from the yogurt group and 44 from the milk group completed the intervention. Those who consumed yogurt, compared with milk, had significantly reduced homeostasis model assessment of IR (–0.53, 95 percent CI, –1.03 to –0.02), fasting insulin (–2.77 mU/L, –4.91 to –0.63 mU/L), 2-h insulin (–25.5 mU/L, –33.0 to –17.9 mU/L), 2-h area under the curve for insulin (–29.4 mU/L · h, –44.0 to –14.8 mU/L · h), alanine aminotransferase (–4.65 U/L, –8.67 to –0.64 U/L), intrahepatic lipid (–3.44 percent, –6.19 to –0.68 percent) and hepatic fat fraction (–3.48, –6.34 to –0.63 percent).
The yogurt group also had decreased serum LPS (–0.31 EU/mL, –0.48 to –0.14 EU/mL), fibroblast growth factor 21 (–57.76 pg/mL, –86.32 to –29.19 pg/mL), lipids, and biomarkers of inflammation and oxidative stress, and altered gut microbiota composition. In mediation analysis, yogurt appeared to improve IR by reducing serum lipids, inflammation, oxidative stress and LPS.
“Because consumption of conventional yogurt has beneficial effects in a healthy population, and IR is the mutual pathogenesis in NAFLD and MetS, we hypothesized that yogurt would ameliorate IR in patients with NAFLD and MetS,” the investigators said.