8 Health Benefits of Walnuts, According to a Nutritionist
All the ways this nut can help your body, plus how to add more of it to your meals and snacks.
You may think of walnuts as a dessert ingredient in cookies, muffins, brownies, and baklava. But walnuts are also perfect for snacking, or as a topping for salads, cooked veggies, whole grains, and hummus. In addition to their crunch, walnuts deliver important nutrients and offer science-backed health benefits. Here are some of the top perks of this healthful tree nut.
Walnuts are nutrient-rich
One ounce (about a quarter cup, or 14 walnut halves) provides 18 grams of good fat, 4 grams of protein, 2 grams of fiber, nearly 50% of the daily target for manganese, and smaller amounts of magnesium, iron, calcium, and B vitamins. Manganese is a mineral that supports healthy bones and is needed for collagen production and wound healing. Walnuts are also packed with antioxidants known to possess anti-inflammatory effects, which help protect against the initiation and progression of cancer, heart disease, and neurodegenerative diseases.
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They deliver healthy fats
Alpha linolenic acid, or ALA, is a type of omega-3 fatty acid known to reduce inflammation. Walnuts contain more ALA than any other type of nut. A 2020 study, published in the journal Nutrients, assessed the effects of walnut consumption on the omega-3 fatty acid profile of healthy adults over a four-week period. Researchers found that after a month of consuming a few ounces of walnuts daily, the subjects' omega-3 status improved. They also experienced reductions in body weight and body fat, plus gains in lean body mass and body water.
Walnuts can help gut and heart health
The bioactive compounds in walnuts may play an important role in altering the gut environment in ways that impact disease outcomes, say researchers. In a six-week Penn State study of overweight adults with cardiovascular risk, the addition of walnuts to their diet enhanced beneficial gut bacteria linked to health benefits, including reduced blood pressure and total cholesterol.
They help reduce blood pressure
In a 2019 study, published in Journal of the American Heart Association, researchers found that when study subjects ate whole walnuts, they experienced greater benefits than when they consumed a diet with a similar fatty acid profile without walnuts. Outcomes included a reduction in central diastolic blood pressure (the pressure that moves towards the heart), and positive changes to cholesterol profiles. Scientists say the study is an example of how a relatively small eating change can result in significant cardiovascular benefits.
They can benefit brain health
Eating walnuts may help slow cognitive decline in at-risk groups of older adults, according to a 2020 study published in The American Journal of Clinical Nutrition. Researchers randomly assigned over 600 elder adults to either a diet with 15% of calories from walnuts or a control diet without walnuts. While the walnuts had no effect on the cognitive function of healthy subjects, brain MRIs showed that the nuts had a greater effect on higher-risk people, including heavier smokers, and those with lower baseline neuropsychological test scores.
Walnuts offer breast cancer protection
Building on previous studies in animals, researchers assessed the effects of breast cancer growth in women, in a study published in Nutrition Research. In the trial, women with breast lumps were randomly assigned to consume either two ounces of walnuts per day or no walnuts for two to three weeks prior to surgery. Initial biopsy samples were compared to those obtained when the lumps were removed. Scientists found that walnut consumption altered the expression of over 450 genes in the tumors in ways that could suppress cancer growth and improve survival outcomes.
They play a role in weight regulation
In a small trail published in the journal Diabetes Obesity and Metabolism, subjects were given smoothies that either contained walnuts or no walnuts for five days, while living in a controlled clinical research center. The addition of walnuts decreased feelings of hunger and improved appetite regulation. Researchers say the impact of walnuts on satiety could be due to changes to the central nervous system that affect food cues. The shift could help curb obesity risk.
Walnuts can improve male fertility
The largest clinical trial to date to analyzing the effects of nut consumption on sexual function in healthy men was published in the journal Nutrients in 2019. Researchers found that over 14 weeks, men who ate about two servings (two ounces) of a nut mixture daily as part of a Western-style diet experienced a significant increase in orgasmic function and sexual desire. The mixture was made up of 50% walnuts, 25% almonds, and 25% hazelnuts.
More ways to enjoy walnuts
For a healthy snack, pair walnuts with fresh fruit, dip them into melted dark chocolate, or incorporate them into energy balls. Add walnuts to smoothies or overnight oats at breakfast, sprinkle them onto black bean or lentil soup at lunch, and include them in recipes like veggie tacos and stir fries at dinner.
You can also whip up a simple walnut pesto made from walnuts, pureed with extra virgin olive oil, basil, garlic, salt, and pepper. Drizzle it over roasted veggies, toss it with zucchini spirals, or use it as a creamy, flavorful salad dressing.
Cynthia Sass, MPH, RD, is Health's contributing nutrition editor, a New York Times best-selling author, and a private practice performance nutritionist who has consulted for five professional sports teams.
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