A green Mediterranean diet reduces non-alcoholic fatty liver disease by half

A green Mediterranean (MED) diet reduces intrahepatic fat more than other healthy diets and cuts non-alcoholic fatty liver disease (NAFLD) in half, according to a long-term clinical intervention trial led by researchers from Ben-Gurion University of the Negev and ‘ a team of international colleagues.

The findings 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 randomized long-term trials that the Mediterranean diet is the healthiest,” says lead researcher Prof. Iris Shai, an epidemiologist at the BGU School of Public Health, who is also an adjunct lecturer at the Harvard TH Chan School of Public Health. “Now we have refined that diet and discovered elements that can make dramatic changes to liver fat and other important health factors.” Other Harvard researchers are prof. Meir Stampfer and Frank Hu, chair of the Department of Nutrition at Chan School.

NAFLD affects 25% to 30% of the people in the United States and Europe. Although fat in the liver is normal, excess fat (5% or higher) leads to insulin resistance, type 2 diabetes, cardiovascular risk, as well as reduced intestinal microbiome diversity and microbial imbalance. Since there is currently no medicine available for the treatment of fatty liver, the only weight loss and restriction of alcohol use.

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

“Addressing this common liver disease through targeted lifestyle intervention can promote a more effective nutritional strategy,” says Dr. Anat Yaskolka-Meir, first author and member of the BGU School of Public Health. “This clinical trial demonstrates an effective nutritional tool for NAFLD outside of weight loss.”

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

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

Overall, the green MED diet reduced dramatically in fatty liver. NAFLD prevalence decreased from 62% at baseline to 31.5% in the green Mediterranean group, to 47.9% in the Mediterranean group and 54.8% in the healthy diet group.

Specifically, greater intake of Mankai and walnut and less red / processed meat intake were significantly associated with the extent of IHF loss, after being checked for other variables. Both MED groups had significantly higher total plasma foil levels. More specific polyphenols, found in walnuts and Mankai, were found in the green MED group. The researchers believe the effect of polyphenols and the reduction of red meat play a role in reducing liver fat.