Pecan nuts and pecan polyphenols in mice fed a high-fat diet
What it found
In mice fed a high-fat diet, whole pecan nuts or a pecan polyphenol extract reduced fat gain, cholesterol, insulin and blood sugar problems, and increased energy use.
The work was done in mice, not people.
What they found
Animal and lab studies
Weight and body fat
Mice on the high-fat diet gained more weight than control mice. Mice given whole pecans or the 6 mg/g polyphenol extract gained the same weight as control mice and had about 44% less fat mass than the high-fat group, despite eating similar amounts of food and energy.
Cholesterol and blood sugar
The high-fat diet raised circulating cholesterol and glucose. Whole pecans lowered cholesterol slightly, while the polyphenol extract kept cholesterol similar to control levels. Only the 6 mg/g polyphenol dose lowered glucose compared with the high-fat diet.
Insulin and glucose tolerance
Mice on the high-fat diet had much higher insulin and worse glucose tolerance than controls. Whole pecans and the 6 mg/g polyphenol extract brought insulin back to control levels and improved glucose tolerance by 26% and 37%, respectively. The polyphenol extract also improved insulin sensitivity.
Pancreas and energy use
The high-fat diet enlarged the pancreatic islets by about 71%. Whole pecans and the polyphenol extract kept islet size similar to controls. The polyphenol groups also used 24% to 27% more oxygen than the high-fat group, suggesting higher energy expenditure.
Liver and muscle
Livers of high-fat mice showed clear fat accumulation, which was reduced by whole pecans and the polyphenol extract. In skeletal muscle, the polyphenol extract increased mitochondrial content and reduced fat buildup compared with the high-fat diet.
Gut bacteria and inflammation
Mice given whole pecans or the polyphenol extract had greater gut bacterial diversity than high-fat mice. Their blood levels of lipopolysaccharide, a bacterial endotoxin, were 83% to 95% lower than in the high-fat group, and their TNF-alpha levels were similar to controls.
What the authors conclude
“The present study demonstrates that WP or a PP extract prevented obesity, liver steatosis and diabetes by reducing dysbiosis, inflammation, and increasing mitochondrial content and energy expenditure.”
Also in their conclusions
- They conclude that whole pecans or a pecan polyphenol extract prevented obesity, liver steatosis and diabetes in mice by reducing dysbiosis and inflammation and by increasing mitochondrial content and energy expenditure.
- They propose a model of early and late events in high-fat diet metabolic disorder and suggest possible molecular targets for pecan compounds.
- They say this work lays the groundwork for future clinical studies.
How it was done
Pecans contain unsaturated fats, fibre and polyphenols, and earlier human studies used only about 42 to 90 g of pecans a day. The authors thought the benefits of pecan phenolics had been underestimated at those doses.
They fed 42 male C57BL/6 mice either a control diet, a high-fat diet, a high-fat diet with 30% whole pecans, or a high-fat diet with 3.6 or 6 mg/g of a pecan polyphenol extract for 18 weeks. A second group of mice ate the high-fat diet for 18 weeks and then switched to the high-fat diet with 6 mg/g polyphenols for 4 weeks.
What it can’t tell you
- This was a study in mice, so it cannot show what happens in people.
- The doses used in mice were converted to an equivalent human intake of 110 to 183 g of pecan kernels a day, but that dose has not been tested in people.
- The authors call for clinical studies to confirm whether the same effects occur in humans.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ), Mexico; Instituto Nacional de Medicina Genómica (INMEGEN), Mexico; Texas A&M University, USA
The paper
- Title
- Pecans and Its Polyphenols Prevent Obesity, Hepatic Steatosis and Diabetes by Reducing Dysbiosis, Inflammation, and Increasing Energy Expenditure in Mice Fed a High-Fat Diet
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Delgadillo-Puga C, Torre-Villalvazo I, Noriega LG, et al (2023). Pecans and Its Polyphenols Prevent Obesity, Hepatic Steatosis and Diabetes by Reducing Dysbiosis, Inflammation, and Increasing Energy Expenditure in Mice Fed a High-Fat Diet. Nutrients. doi:10.3390/nu15112591Free full textPubMed 37299553DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error