Jerusalem, 12 November, 2026 (TPS-IL) — A diet rich in walnuts, green tea and an aquatic plant called Mankai can reduce fat accumulation in the pancreas, potentially offering new insights into how dietary changes may help regulate blood sugar, an international study led by Israeli researchers has found.
Previous research has shown that dietary changes can reduce fat in the liver and other internal organs. The new findings suggest that pancreatic fat may also respond to nutritional intervention, potentially offering a new avenue for improving metabolic health.
The 18-month study found that participants following a green Mediterranean diet experienced a 14% reduction in pancreatic fat, compared with 6.7% among those following a conventional Mediterranean diet and just 0.8% among those following standard healthy-eating guidelines.
The research, led by Ben-Gurion University of the Negev, was published in the peer-reviewed American Journal of Clinical Nutrition.
The pancreas plays a central role in regulating blood sugar by producing insulin, the hormone that helps the body’s cells absorb glucose from the bloodstream. Excess fat in the pancreas may impair insulin-producing cells, making it harder for the body to regulate blood sugar. Over time, this can contribute to insulin resistance and increase the risk of Type 2 diabetes.
Testing the Diet
The study involved 294 adults with abdominal obesity or unhealthy blood lipid levels who were assigned to one of three dietary programs: standard healthy-eating guidelines, a Mediterranean diet, or a green Mediterranean diet. All three groups also participated in regular physical activity.
Researchers used magnetic resonance imaging to measure pancreatic fat and overall pancreatic volume at the beginning of the study and again after 18 months.
The green Mediterranean diet combined walnuts, green tea and Mankai, a protein-rich aquatic plant also known as water lentils. Participants in both Mediterranean diet groups received 28 grams of walnuts daily, while those following the green version were additionally encouraged to drink three to four cups of green tea and consume 100 grams of Mankai daily.
The reduction in pancreatic fat was not accompanied by a significant decrease in pancreatic volume, suggesting that the intervention reduced fat accumulation without shrinking the organ.
Greater reductions in pancreatic fat were also associated with improvements in metabolic health, including reduced insulin resistance. The association persisted even after researchers adjusted for changes in abdominal fat. However, the relationship with long-term blood sugar levels, measured through hemoglobin A1c (HbA1c) — a blood test that reflects average glucose levels over the previous two to three months — was weaker and did not meet the study’s stricter statistical threshold.
Researchers also identified associations between individual foods and changes in pancreatic fat. Greater consumption of protein-rich Mankai and walnuts was associated with larger reductions in pancreatic fat, while higher consumption of refined carbohydrates, including bread, cereals and pasta, was associated with less favorable results.
“The clinical novelty of the findings is the proof that pancreatic fat is a completely dynamic and reversible reservoir,” said Prof. Iris Shai of Ben-Gurion University, who led the research. She added that the scientists found that fat could be reduced while preserving the volume of functional pancreatic tissue.
Lead author Liav Alufer, a doctoral researcher, said the findings demonstrate how specific nutrients can influence the body’s internal organs.
“The data showed that consumption of refined carbohydrates blocked the fat clearance process,” he said.
The findings could help inform future dietary strategies for people at risk of Type 2 diabetes. However, the study identified improvements in metabolic markers rather than demonstrating a reduction in diabetes cases. Further research is needed to determine whether reducing pancreatic fat can translate into better long-term blood sugar control and lower diabetes risk.
