The researchers, including senior author Penny M. Kris-Etherton, PhD, distinguished professor of nutrition at Pennsylvania State University, publish their findings in the Journal of the American Heart Association.
It is well known that avocados are high in fat, but the majority of an avocado's fat is monounsaturated, which is deemed a "good" type of fat. It is known that monounsaturated fats can help lower levels of bad cholesterol, reducing the risk of heart attack and stroke.
For their study, Kris-Etherton and colleagues set out to assess how avocado consumption - by replacing saturated fatty acids, or "bad" fats - affected risk factors associated with cardiovascular diseases.
The team recruited 45 healthy participants aged 21-70 years who were either obese or overweight.
Every participant was required to follow each of three cholesterol-lowering diets for 5 weeks. The diets consisted of a lower-fat diet without avocado, a moderate-fat diet without avocado or a moderate-fat diet with one Hass avocado a day.
Prior to starting each diet, subjects ate what the researchers deem an "average American diet," which was made up of 34% of calories from fat, 16% from protein, while around half of calories were from carbohydrates.
From both of the moderate-fat diets, participants gained 34% of calories from fat, of which 17% were from monounsaturated fatty acids (MUFAs). The lower-fat diet provided participants with 24% of calories from fat, of which 11% was from MUFAs.