The green Mediterranean diet cuts non-alcoholic fatty liver disease in half

A green Mediterranean diet (MED) reduces intrahepatic fat more than other healthy diets and halves non-alcoholic fatty liver disease (NAFLD), according to a long-term clinical intervention trial conducted by researchers at Ben University -Gourion of the Negev and a team of international colleagues.

The results were published in Intestine, a leading international journal focusing on gastroenterology and hepatology.

“Our research team and other groups over the past 20 years have proven through rigorous long-term randomized trials that the Mediterranean diet is the healthiest,” says lead researcher Professor Iris Shai, epidemiologist at BGU School of Public Health, who is also a senior lecturer at Harvard TH Chan School of Public Health. “Now we have refined this diet and discovered things that can make dramatic changes in liver fat and other key health factors. Other Harvard investigators are Profs. Meir Stampfer and Frank Hu, chairman of the chan school nutrition department.

NAFLD affects 25% to 30% of people in the United States and Europe. Although some fats are normal in the liver, excess fat (5% or more) leads to insulin resistance, type 2 diabetes, cardiovascular risk, as well as a decrease in gut microbiological diversity and microbial imbalance. Since no drugs are currently available to treat fatty liver disease, the only intervention is weight loss and reducing alcohol consumption.

This nutritional MRI clinical trial (called Direct-Plus), conducted by an international research team led by Professor Shai is the first to develop and test a new Mediterranean green diet. This modified MED diet is high in vegetables, includes a daily intake of nuts (28 grams) and less processed and red meat. It is enriched with green components, rich in polyphenols, including three to four cups of green tea / day and 100 grams (frozen cubes / day) of a Mankai green shake. Mankai, an aquatic green plant also known as duckweed, is rich in bioavailable protein, iron, vitamin B12, vitamins, minerals, and polyphenols.

“Tackling this common liver disease with a targeted lifestyle intervention could promote a more effective nutritional strategy,” says Dr Anat Yaskolka-Meir, lead author and fellow of the BGU School of Public Health. “This clinical trial demonstrates an effective nutritional tool for NAFLD beyond weight loss.”

This 18-month DIRECT-PLUS trial began in 2017 at the Negev Nuclear Research Center in Dimona, Israel, when 294 workers in their 50s with abdominal obesity were randomly assigned to three groups: healthy diet, Mediterranean diet. and green Mediterranean diet. In addition to the diet, all participants received an exercise program with a free gym membership. Participants underwent MRI scans to quantify the exact proportion of excess intrahepatic fat before and after the trial.

The results showed that each diet resulted in a reduction in liver fat. However, the green MED diet resulted in the greatest reduction in liver fat (-39%), compared to the traditional Mediterranean diet (-20%) and healthy dietary recommendations (-12%). The results were significant after adjusting for weight loss.

Overall, the green MED diet produced dramatic reductions in fatty liver disease. The prevalence of NAFLD increased from 62% at baseline to 31.5% in the green Mediterranean group, to 47.9% in the Mediterranean group and to 54.8% in the healthy diet group.

Specifically, greater consumption of Mankai and nuts and less consumption of red / processed meat were significantly associated with the magnitude of the loss of IHF, after controlling for other variables. Both MED groups had significantly higher plasma total polyphenol levels. More specific polyphenols, found in walnuts and Mankai, were detected in the green MED group. Researchers hypothesize that the effect of polyphenols and the reduction of red meat play a role in reducing liver fat.