Monounsaturated Fat Linked to Fatty Liver Disease

New research out of the University of California, San Francisco has found that a monoun­sat­u­rated fat may be asso­ci­ated with fatty liver dis­ease.

The study observed groups of mice that were fed dif­fer­ent diets. Afterward, the liv­ers and adi­pose tis­sue, or fat, of the mice were exam­ined.

“We fed mice with four dif­fer­ent diets for up to six months,” lead author Caroline Duwaerts told Olive Oil Times. ​“The four dif­fer­ent diets were very spe­cific in their com­po­nents. They either had sim­ple sugar or sucrose, or they had a com­plex sugar or starch accom­pa­nied with either a sat­u­rated fat, palmi­tate, or an unsat­u­rated fat, oleate.”

The researchers found mice that ingested starch and the monoun­sat­u­rated fatty acid devel­oped fatty liver dis­ease.

“The mice who had been fed oleate and starch had much fat­tier and dis­eased liv­ers, and had also lost the most adi­pose weight due to cell death,” Duwaerts said.

“Something in the oleate is caus­ing extreme lypol­y­sis in the adi­pose, which is then shut­tling the fat to the liver. That’s why these liv­ers are much fat­tier and dis­eased.”

Monounsaturated fats are com­monly thought to help lower cho­les­terol lev­els when used in place of sat­u­rated fats. They can be found in oils such as olive oil, peanut oil and canola oil, along with avo­ca­dos and some nuts and seeds.

Some of these ingre­di­ents are sta­ples of the Mediterranean diet, but Duwaerts argues poten­tial health effects have more to do with the amount you con­sume. In a pre­vi­ous study where mice were fed diets with a lower con­cen­tra­tion of fat the results were not the same.

“It’s really a ques­tion of pro­por­tion of your fats and car­bo­hy­drates in your over­all diet,” she said. ​“If you were to eat pasta with olive oil, and that’s all you ate, it might be too much for your sys­tem to han­dle. If you sprin­kled a lit­tle bit of olive oil on a salad you’re prob­a­bly keep­ing your pro­teins much higher and your car­bo­hy­drates much lower. You’re also prob­a­bly not as much at risk than if you’re eat­ing a Western diet with a lot of car­bo­hy­drates and fats. In that sit­u­a­tion, oleate and starch are bad for you.”

She added: ​“The Mediterranean diet is also about includ­ing the good fats. That’s why they have a lot of fish. Those are for your omega‑3 and omega‑6 fatty acids. It’s more bal­anced than what the Western pop­u­la­tion is eat­ing.”

Duwaerts believes peo­ple need to keep bet­ter tabs on what they’re putting in their bod­ies.

“I think what the pub­lic truly needs to be aware of is their pro­por­tions of what they’re eat­ing and how much of each type of nutri­ent is being con­sumed and what type of each,” she said.

“The old say­ing doc­tors used that a lit­tle bit of every­thing is good for you, I think there’s some­thing to that.”

• Cellular and Molecular Gastroenterology and Hepatology


• American Gastroenterological Association