The Penn State researchers compared the levels and function of high-density lipoprotein (HDL cholesterol) in people who ate almonds every day, to the HDL levels and function of the same group of people when they ate a muffin instead. The researchers found that while participants were on the almond diet, their HDL levels and functionality improved.
Researcher Penny Kris-Etherton said, “There’s a lot of research out there that shows a diet that includes almonds lowers low-density lipoprotein, or LDL cholesterol, which is a major risk factor for heart disease. But not as much was known about how almonds affect HDL cholesterol, which is considered good cholesterol and helps lower your risk of heart disease.”
The researchers wanted to see if almonds could not just increase the levels but also improve the function of HDL cholesterol, which works by gathering cholesterol from tissues, like the arteries, and helping to transport it out of the body.
Depending on how much cholesterol it has collected, HDL cholesterol is categorized into five “subpopulations,” which range from the very small prebeta-1 to the larger, more mature alpha-1. The researchers hoped that eating almonds would result in more alpha-1 particles, which would signal improved HDL function.
In the controlled-feeding study, 48 men and women with elevated LDL cholesterol participated in two six-week diet periods. In both, their diets were identical except for the daily snack. On the almond diet, participants received 43 grams, about a handful, of almonds a day. During the control period, they received a banana muffin instead.
At the end of each diet period, the researchers measured the levels and function of each participant’s HDL cholesterol. The researchers then compared the results to…