A study has found that eating one avocado a day for six months leads to a decrease in unhealthy cholesterol levels, but has no effect on belly fat, liver fat or waist circumference in people who are overweight or obese.

In the randomized trial, the team which included researchers at Penn State, also found that participants who ate avocados had better-quality diets during the study period, according to a report by Penn State University.

“While the avocados did not affect belly fat or weight gain, the study still provides evidence that avocados can be a beneficial addition to a well-balanced diet,” said Penny Kris-Etherton, Evan Pugh University Professor of Nutritional Sciences at Penn State. 

“Incorporating an avocado per day in this study did not cause weight gain and also caused a slight decrease in LDL cholesterol, which are all important findings for better health,” she added.

Kristina Petersen, assistant professor of nutritional sciences at Texas Tech University, said the study also found that eating avocados daily improved the overall quality of the participants’ diets by eight points on a 100-point scale.

“Our findings suggest that eating an avocado per day can substantially increase overall diet quality,” Petersen stated. “This is important because we know a higher diet quality is associated with lower risk of several diseases, including heart disease, type 2 diabetes and some cancers.”

For the study, the researchers conducted a six-month experiment involving more than 1,000 participants experiencing overweight or obesity, making it the most extensive study to date on the health effects of avocados. 

Half the participants were instructed to eat an avocado every day, while the other half continued their usual diet and were told to limit their avocado consumption to less than two a month. Fat in the abdomen and around other organs was measured precisely using MRI before and at the end of the study.

“While one avocado a day did not lead to clinically significant improvements in abdominal fat and other cardiometabolic risk factors, … [it] did not result in body weight gain,” said Joan Sabaté, professor at Loma Linda University School of Public Health. 

“This is positive because eating extra calories from avocados doesn’t impact body weight or abdominal fat, and it slightly decreases total and LDL-cholesterol,” she concluded.

The research, recently published in the Journal of the American Heart Association, was conducted in conjunction with Loma Linda University, Tufts University, and UCLA, with coordinating support from Wake Forest University.