Eating one avocado each day may help reduce levels of oxidized LDL cholesterol, according to Penn State University researchers.

In the randomized, controlled study, obese and overweight participants who added a single avocado to their daily diet had lower levels of LDL and most significantly, oxidized LDL cholesterol, said Penny Kris-Etherton, Ph.D., distinguished professor of nutrition.

Oxidation is thought to be linked to cancer and heart disease. It also appears to contribute to dangerous arterial plaque buildup, Kris-Etherton explained. “Oxidation is not good, so if you can help protect the body through the foods that you eat, that could be very beneficial.”

After a week on a prescribed typical American diet, the study’s 45 participants spent five weeks on a low-fat diet, a moderate-fat diet, and a moderate-fat diet that included one avocado a day. The no-avocado, moderate-fat diet included the same type and amount of fat as the avocado diet, but did not show the same benefits. That likely means that avocado contains other bioactive ingredients that are beneficial, Kris-Etherton concluded. 

“[Avocados] are such a nutrient-dense package, and I think we’re just beginning to learn about how they can improve health,” she said.

The study was published in The Journal of Nutrition.