Walnuts – Wondernuts for Gut and Heart Health
- New research published in the Journal of Nutrition found that swapping out your usual salty or sweet afternoon snack for walnuts can boost gut health and help lower heart disease risk.
- The fiber and saturated fats in walnuts were found to have a positive impact on gut health and heart disease risk.
- Heart-healthy diets like the Mediterranean diet promote eating nuts as a source of healthy fats.
Walnuts appear to be quite good for you, it turns out. Reaching for a snack between mealtimes or postworkout is something we all do. And sometimes that snack is whatever is at the gas station or something packaged and tasty (but not always healthy) from the vending machine at work. But everything we eat can affect our gut health and risk for heart disease, so we can be more strategic about our snacking.
According to new research published in the Journal of Nutrition, swapping out your usual salty or sweet afternoon pick-me-up for walnuts can have some serious heart health benefits.
Researchers looked at 42 participants who were overweight or obese and were between the ages of 30 and 65. Before the study began, everyone was placed on a diet that mirrored an average American diet (where 12 percent of daily calories came from saturated fat) for two weeks. Then, participants switched to diets that were lower in saturated fat, where 7 percent of daily calories came from saturated fat, and incorporated walnuts. After munching on two handfuls of walnuts daily for six weeks in place of snacks like chips or crackers, all participants saw lower cholesterol levels and gut bacteria that improved their risk of heart disease. (It’s important to note that typically one serving of walnuts is about one handful.)
This is likely because eating whole walnuts daily lowers cholesterol levels and blood pressure, study authors Penny Kris-Etherton, Ph.D., distinguished professor of nutrition and Kristina Petersen, Ph.D., assistant research professor, both in the department of nutritional sciences at Penn State University explained to Bicycling. And while the researchers said that this study showed correlation, not causation, previous research published in the Journal of the American Heart Association also found that adding walnuts to a person’s diet can help lower blood pressure, especially when they are replacing foods high in saturated fat.
And, it’s not just people at risk for heart disease, the study authors explained. Nuts are recommended in many heart-healthy diets.
As for how gut health affects your risk of heart disease? That may be due in part to the fact that walnuts contain fibre, which can positively affect gut bacteria. Additionally, the unsaturated fats and omega-3s in walnuts can contribute to favorable gut microbiomes—which may aid in lowering blood pressure, leading to a lower risk for heart disease according to Kris-Etherton and Petersen.
Overall, swapping out unhealthy snacks for a serving of walnuts or other nuts is a relatively small change that will have major health benefits—and is easier than doing a radical diet or exercise overhaul, Kris-Etherton and Petersen said.
And, it’s not just people at risk for heart disease, the study authors explained. Nuts are recommended in many heart-healthy diets, such the Mediterranean diet. “It’s a great way to encourage people who are already healthy to stay healthy,” Petersen said.
In full disclosure, this one study was supported by grants from The California Walnut Commission. However, there have been ample amounts of independent research on all the heart-healthy components of nuts such as omega-3s, unsaturated fats, and fiber. Plus, adding nuts to your diet promotes healthy aging and can help prevent against risk of chronic disease, previous research published in the Journal of the American College of Cardiology found. So, even if you are healthy in your 20s or 30s, as you age, blood pressure and cholesterol levels increase, which is why eating a heart-healthy diet is important no matter your age or activity level, the study authors explained.
The bottom line: snacking on nuts is something people can do now to maintain health, rather than waiting until later in life. While this study looked at walnuts specifically, the researchers pointed out that adding a variety of nuts can help a person keep up this healthy habit, as eating walnuts daily may get boring. “It’s much harder to reverse disease once it comes about, so prevention is key,” Kris-Etherton said.