Almonds may assist in cholesterol clean-up, claims industry study

14 Aug 2017 --- Regularly eating almonds may help to boost levels of high-density lipoprotein (HDL) cholesterol while also improving the way it removes cholesterol from the body, according to researchers at Penn State University in the US.

In the study, which was supported by the Almond Board of California, researchers compared the levels of function of 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.

Helping good cholesterol
Penny Kris-Etherton, Distinguished Professor of Nutrition at Penn State, says the study, which was published in the Journal of Nutrition, 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,” Kris-Etherton says. “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 only increase the levels of HDL cholesterol, but also improve its function. The “good” cholesterol 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 prebeta-1 to the larger, more mature alpha-1. The researchers hoped that eating almonds would result in more alpha-1 particles, which would be a signal of improved HDL function.

Larger particles increase
In the controlled-feeding study, 48 men and women with elevated low-density lipoprotein (LDL) cholesterol took part in two six-week diet periods. In both, their diets were identical except for the daily snack. On the almond diet, participants received 43g – 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.

The researchers found that compared to the control diet, the almond diet increased alpha-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.

“If people incorporate almonds into their diet, they should expect multiple benefits, including ones that can improve heart health,” Kris-Etherton concludes. “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.”