Asian-adapted Mediterranean diet works well against fatty liver

In the TANGO* trial, a Mediterranean-like, culturally contextualized Asian diet rich in fibre and unsaturated fatty acids, induced multiple health benefits in Chinese women with nonalcoholic fatty liver disease (NAFLD), including weight loss.

“NAFLD is strongly associated with obesity, type 2 diabetes, hypertension, and dyslipidaemia and is expected to pose an important public health challenge in tandem with the pandemics of obesity and diabetes,” the researchers noted.

In this study, all groups (including control) achieved body weight and liver fat reductions after the 12-week interventions. The magnitude of improvement was greater in the two Mediterranean-like diet groups (with [group 1] and without [group 2] supplementation of pentadecanoic acid or C15:0) vs the control group (habitual hypocaloric diet without C15:0; group 3).

Body weight reductions in groups 1 and 2 were 4.0 and 3.4 kg, respectively; in group 3, the reduction was 1.5 kg (p for interaction<0.001). These reductions corresponded to relative weight changes of 5.3, 4.5, and 2.1 percent for groups 1, 2, and 3, respectively.

Concurrently, liver proton density fat fraction – the study’s primary outcome – dropped by 33, 30, and 10 percent, respectively (p for interaction=0.001). [Am J Clin Nutr 2024;119:788-799]

“These findings confirm observations from previous studies indicating that even small decreases in body weight (3–5 percent) result in considerable reductions in liver fat (30–50 percent), and that liver fat decreases dose-dependently with the amount of weight loss,” the researchers explained.

Along with the weight loss, there were notable reductions in fat mass (p for interaction=0.004), visceral adipose tissue (p for interaction =0.039), subcutaneous abdominal adipose tissue (SAT; p for interaction=0.006), and superficial SAT (p for interaction =0.002).

C15:0 also helps cut bad cholesterol

“Both diet groups achieved significantly greater reductions in total cholesterol, gamma-glutamyl transferase, and triglyceride concentrations compared with the control group,” the researchers added. C15:0 supplementation further cut LDL-cholesterol and increased the abundance of Bifidobacterium adolescentis (β=0.22 [vs group 3] and β=0.35 [vs group 1]).

“Bifidobacteria abundance is lower in older people and NASH patients … [As such,] these findings suggest potential gut health benefits from C15:0 supplementation,” they explained.

No approved therapy yet

In Asia, the estimated prevalence of NAFLD is ~30 percent and is expected to increase over the next decade. [Lancet Gastroenterol Hepatol 2020;5;167-228] In Singapore, a small observational study reported a prevalence of about 40 percent. [Gastroenterol Rep 2016;4:131-135]

There is no currently approved pharmacotherapy for the treatment of NAFLD or nonalcoholic steatohepatitis, and the only clinical recommendations are diet and lifestyle modifications that can help facilitate weight loss. [Obes Facts 2016;9:65-90; Hepatology 2018;67:328-357]

To evaluate the effects of a calorie-restricted (1,000–1,500 kcal/day) Asian-adapted Mediterranean diet with or without C15:0 in Chinese females with NAFLD, researchers randomized 88 participants to one of the three groups for 12 weeks. At baseline, study participants had a mean age of 35.7 years, mean BMI of 28.4 kg/m², and mean liver CAP** score of 310.5 dB/m.

Group 1 and 2 participants received nutrition education on the Mediterranean diet and food components on top of general dietetic advice. They were required to consume 12 frozen meals/week (prepared in line with Asian cuisine), and soymilk once daily (with or without C15:0 300 mg) throughout the 12-week intervention period.

“The diet was high in fibre, MUFA/PUFA***, whole-grain products, legumes, vegetables, salmon, plant-based protein, nuts, fruits, and high-polyphenol extra virgin olive oil. The calorie content of the soymilk supplement, both with or without C15:0, was 108 kcal,” the researchers shared.

Cornerstones of NAFLD management

Taken together, the findings suggest that Chinese females with NAFLD may lose weight after cutting calories for 12 weeks, with no concomitant changes in physical activity, said the researchers.

“Our results support the notion that dietary energy deficit and weight loss are the cornerstones for the management of NAFLD, although there is some evidence to suggest that macronutrient composition or diet quality also affects liver fat content and metabolic profile,” they continued.

The researchers called for future trials to establish which diet would be more effective for NAFLD management in clinical practice and to develop ways to motivate people to make healthier food choices and stick to these habits in the long term.