Adding almonds to your diet may boost levels of HDL cholesterol, so-called “good cholesterol,” while also helping your body to remove cholesterol, a small study suggests.
In the study, 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.
Penny Kris-Etherton, professor of nutrition at Penn State, says the study builds on previous research on the effects of almonds on cholesterol-lowering diets.
“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,”
HDL Cholesterol Function
The researchers wanted to find out 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.
“HDL is very small when it gets released into circulation,” Kris-Etherton says. “It’s like a garbage bag that slowly gets bigger and more spherical as it gathers cholesterol from cells and tissues before depositing them in the liver to be broken down.”
Depending on how much cholesterol it has collected, HDL cholesterol is categorized into five “subpopulations,” which range from the very small preβ-1 to the larger, more mature α-1. The researchers hoped that eating almonds would result in more α-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 the participants’ baseline measurements taken at the beginning of the study.
Pulling Out Cholesterol
The researchers found that compared to the control diet, the almond diet increased α-1 HDL — when the particles are at their largest size and most mature stage — by 19 percent. Additionally, the almond diet improved HDL function by 6.4 percent, in participants of normal weight.
“We were able to show that there were more larger particles in response to consuming the almonds compared to not consuming almonds,” Kris-Etherton says. “That would translate to the smaller particles doing what they’re supposed to be doing. They’re going to tissues and pulling out cholesterol, getting bigger, and taking that cholesterol to the liver for removal from the body.”
An increase in this particular HDL subpopulation is meaningful, Kris-Etherton explains, because the particles have been shown to decrease overall risk of cardiovascular disease.
Kris-Etherton says that while almonds will not eliminate the risk of heart disease, they may be a smart choice for a healthy snack. She adds that in addition to their heart-healthy benefits, almonds also provide a dose of good fats, vitamin E, and fiber.
“They’re not a cure-all, but when eaten in moderation—and especially when eaten instead of a food of lower nutritional value—they’re a great addition to an already healthy diet,” Kris-Etherton says.
The study was funded by the Almond Board of California.
Claire E Berryman, Jennifer A Fleming, and Penny M Kris-Etherton
Inclusion of Almonds in a Cholesterol-Lowering Diet Improves Plasma HDL Subspecies and Cholesterol Efflux to Serum in Normal-Weight Individuals with Elevated LDL Cholesterol
J. Nutr. August 1, 2017 vol. 147 no. 8 1517-1523