Tree Nuts and Your Health: What to Know About the Super Snack

5 min read

Feb. 26, 2024 – For anyone who's nutty about nuts, there's good news: it turns out that certain types – tree nuts to be exact – might hold an important key to reversing several risk factors for something known as metabolic syndrome. 

These risk factors for metabolic syndrome include high blood sugar levels, unhealthy levels of bad fats (triglycerides), low bloodstream levels of "good cholesterol" (HDL), and a large waist circumference. In combination, they can lead to heart disease, stroke, and diabetes.

The link between what we eat and disease risk is not exactly new news: Researchers and doctors have long known that diet and lifestyle are essential for disease prevention, especially when it comes to conditions affecting heart health. But it appears that replacing fatty, salty, and sugary snacks with raw or dry-roasted tree nuts (hazelnuts, cashews, pecans, pistachios, pecans, walnuts, macadamia, and almonds) can alter metabolic syndrome risk factors. What’s more, these changes occur in a relatively short period of time, especially in young adults between the ages of 22 and 39, according to a recent study.

“Compared to adults who only ate carbohydrate snacks (unsalted pretzels, graham crackers, animal crackers, and grain/granola-type bars), the women who ate tree nuts had a decrease in their waist circumference without changing physical activity or calorie intake. The men had more of a change in their blood insulin levels,” said Heidi Silver, RD, PhD, co-author of the study and a professor of medicine at Vanderbilt University Medical Center in Nashville. 

“Overall, both men and women had decreases in their overall metabolic syndrome score and reduced risk,” she noted, explaining that the results in both groups were mostly due to an increase in intake of unsaturated fats compared to saturated fats.

 “We have the ability to oxidize unsaturated fat more rapidly and more completely than saturated fat, meaning that if we oxidize it, we don’t store it," Silver said. 

Life Changes, Dietary Exchanges

Metabolic syndrome risk factors have long been considered to be an issue in older, not younger, adults. But today’s statistics paint a stark reality: Metabolic syndrome now affects slightly more than 1 in 5 people between the ages of 20 and 39. 

“Oftentimes we see patients once they develop heart disease,” said Sadiya Khan MD, a preventive cardiologist at Northwestern Memorial Hospital in Chicago. “But we really want to emphasize the importance of prevention when lifelong habits are being formed and cemented, and when a lot of life changes are happening." 

Khan pointed to many things during the young adult years that increase this risk, including diabetes during pregnancy (gestational diabetes). She explained that although gestational diabetes was once considered to be an isolated event, more people are getting sick with it: Not only does it affect 10% of pregnant women, but it also increases the risk of full-blown diabetes by ten times within a decade. The risk often extends to partners who, in addition to parenthood, are also dealing with the variety of life changes that come with early adulthood. 

“It’s the really important life transitions – attending college, leaving the nest, having children – when heart-healthy habits are formed,” Khan said.

“Intervention needs to start young,” agreed Julia Zumpano, a registered dietitian at the Center for Human Nutrition at the Cleveland Clinic in Ohio. Zumpano, who specializes in heart disease, explained that though young adults have not been traditionally targeted, “no matter how young you are, I think that you should eat nuts and monounsaturated fats; there’s an impact at age 20, and it’s notable in such a short time." 

Dan Cummins, a 36-year-old former Army combat veteran, saidthat he gained almost 200 pounds after leaving the military. 

“It was stress and reactive eating from life situations,” he recalled. A self-professed "non-cook," Cummins explained that it became easier to “order a pizza, or grab some fast food or a bag of chips.” Today, Cummins is down almost 80 pounds, but more importantly, he said that his type 2 diabetes is under control and blood sugar numbers reduced by more than half. He said several things led him to make these changes: addressing mental health issues, enlisting the help of Zumpano, and nuts. 

“I’ve got a bag of pistachios and almonds in my house, and I keep two bags of walnuts at work,” he said. “Having it on hand is easy; I don’t have to do anything, and there’s no prep work involved, so there are no excuses." 

Nuts “satiate the stomach fullness,” he said. 

Fortunately for Kelsey Lovik, a 30-year-old master of social work student at Western Washington University in Bellingham, her love affair with nuts started when she was a child. 

“I spent a lot of time with my grandparents, and they always had happy hour. I couldn’t have cocktails (they’d make her a Shirley Temple), so I’d sit and eat the bowl of nuts that were on the table.”

Today, that healthy habit has stuck. 

“It’s a matter of convenience,” said Lovik, who also encourages her children to eat nuts. “They’re pretty easy to procure, and it's the easiest snack to have." 

"They don’t have to be heated or kept cold. If I’m in between meals or the 3 o’clock slump hits at work, I reach for a tiny bag of cashews,” she said. 

Count Nuts, Not Calories

Nuts have long gotten a bad rap because they are calorie-rich. But they are also filled with nutrients.

“There’s this myth about eating nuts and potential weight gain,” said Silver. “When we compare them to typical snacks, not only do we get a better fat profile with more unsaturated fats, but we also get a rich source of protein, fiber, certain vitamins, minerals, and antioxidants. So, another potential benefit is that eating nuts might improve overall diet quality." 

Ready to make the switch from chips to nuts? There are a few things to keep in mind. Reach for a variety of raw or dry-roasted tree nuts, and read the label to be sure that they don’t contain added oils or sugar. Unsalted nuts are preferable. Nut butters are OK, so long as they don’t contain other oils that might change their fatty acid profile. 

Finally, “the most important thing is making sure that you are not trying to get full on nuts, but instead, have a small handful to help keep the diet balanced,” advised Khan.

Corrections: An earlier version of this story mistakenly said Kelsey Lovik is a Ph.D student at Western Washington University. She is a master of social work student. Also, Vanderbilt University Medical Center is in Nashville, not Chattanooga, TN.