New evidence from a study reveals that eating an avocado a day for six months can improve diet quality while also decreasing unhealthy cholesterol levels.

However, it has no effect on belly fat, liver fat, or waist circumference in overweight people.

Previous smaller studies already found a link between consuming avocados and lower body weight, BMI, and waist circumferences. But this randomized trial is the largest and most extensive study to date on the health effects of avocados, especially in terms of participant number and study period length.

The study – recently published in the Journal of the American Heart Association – was conducted by Penn State researchers in conjunction with Loma Linda University, Tufts University, and the University of California, Los Angeles, with coordinating support from Wake Forest 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. 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,” said Penny Kris-Etherton, Evan Pugh University professor of Nutritional Sciences.

Kristina Petersen, assistant professor of nutritional sciences at Texas Tech University, said that aside from decreasing bad cholesterol levels, the study also found that regular avocado consumption improved diet quality by eight points on a 100-point scale.

"Adherence to the Dietary Guidelines for Americans is generally poor in the U.S., and our findings suggest that eating an avocado per day can substantially increase overall diet quality," Petersen added.

Since a higher diet quality is associated with a lower risk of several deadly conditions like heart disease, cancer, and type 2 diabetes, the researchers believe this is important knowledge.

The study also revealed no significant improvement in abdominal fat and other cardiometabolic risk factors. Still, the researchers are optimistic.

"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,” said Joan Sabaté, professor at Loma Linda University School of Public Health.

The researchers plan to continue analyzing data from the study in the future.