13 Proven Health Benefits of Walnuts

Walnuts are a healthy nut chock-full of essential nutrients such as omega-3 fatty acids and antioxidants. They’re also easy to incorporate into your diet.

To say that walnuts are a nutritious food is a bit of an understatement.

Walnuts provide healthy fats, fiber, vitamins, and minerals — and that’s just the beginning of how they may support your health.

In fact, there’s so much interest in this one nut that scientists and industry experts have gathered annually for the past 50 years at the University of California, Davis, for a walnut conference to discuss the latest walnut health research.

The most common variety of walnut is the English walnut (Juglans regia), which is also the most studied type.

Here are 13 science-based health benefits of walnuts.

1. Rich in antioxidants

Walnuts have greater antioxidant activity than any other common nut.

This activity comes from vitamin E, melatonin, and plant compounds called polyphenols, which are found in particularly large amounts in the papery skin of walnuts.

A 2022 study in healthy adults over age 60 showed that eating a walnut-rich meal reduced the participants’ levels of LDL (bad) cholesterol.

If LDL cholesterol builds up in your arteries, it can cause atherosclerosis.

Summary

Walnuts are an excellent source of antioxidants that can help lower your LDL (bad) cholesterol level.

2. Super plant source of omega-3s

Walnuts are significantly higher in omega-3 fatty acids than any other nut, providing 2.5 grams (g) per 1-ounce (oz) serving.

Omega-3 fats from plants, including walnuts, is called alpha-linolenic acid (ALA). It’s an essential fat, which means you have to get it from your diet.

According to the Institute of Medicine, an adequate intake of ALA is 1.6 g per day for men and 1.1 g per day for women. A single serving of walnuts meets this guideline.

Studies suggest that increased dietary levels of ALA may lower the risk of cardiovascular conditions such as heart disease and arrhythmia.

Summary

Walnuts are a good source of the plant form of omega-3 fat, which may help reduce the risk of cardiovascular diseases and conditions.

3. May decrease inflammation

Inflammation, which can be caused by oxidative stress, is the root of many diseases, including:

The polyphenols in walnuts can help fight oxidative stress and inflammation.

A subgroup of polyphenols called ellagitannins may be especially involved.

Beneficial bacteria in your gut convert ellagitannins to compounds called urolithins, which have been found to protect against inflammation.

ALA, omega-3 fats, magnesium, and the amino acid arginine — all of which are found in walnuts — may also decrease inflammation.

Summary

Several plant compounds and nutrients in walnuts may help decrease inflammation, which is a key culprit in many chronic conditions.

4. Promote a healthy gut

Studies suggest that if your gut is rich in health-promoting bacteria and other microbes (your gut microbiota), you’re more likely to have a healthy gut and good overall health.

An unhealthy composition of gut microbiota can contribute to inflammation and disease in your gut and elsewhere in your body, increasing your risk of obesity, heart disease, and cancer.

What you eat can significantly influence the makeup of your microbiota. Eating walnuts may be one way to support the health of your microbiota and your gut.

In a 2018 study, 194 healthy adults ate 1.5 oz (43 g) of walnuts every day for 8 weeks. At the end, they showed an increase in beneficial bacteria compared to a period of not eating walnuts.

This included an increase in bacteria that produce butyrate, a fat that nourishes your gut and promotes gut health.

Summary

Eating walnuts nourishes both you and the beneficial bacteria that live in your gut. This promotes gut health and may help reduce the risk of obesity, heart disease, and cancer.

5. May reduce risk of some cancers

Animal and a few human studies suggest that eating walnuts may reduce your risk of certain cancers, including breast, prostate, and colorectal cancer.

As noted earlier, walnuts are rich in polyphenols called ellagitannins. Certain gut microbes can convert these to compounds called urolithins.

Urolithins can have anti-inflammatory properties in your gut, which may be one way that eating walnuts helps protect against colorectal cancer. These anti-inflammatory actions could also help protect against other cancers.

What’s more, urolithins have hormone-like properties that enable them to block hormone receptors in your body. This may help reduce your risk of hormone-related cancers, especially breast and prostate cancers.

But more human studies are needed to determine the effects of eating walnuts on the risk of these and other cancers.

Summary

The polyphenols in walnuts may reduce your risk of certain cancers, including breast, prostate, and colorectal cancers. However, more human studies are needed to learn more about this.

6. Support weight management

Walnuts are calorie-dense, but a small 2016 study suggests that your body absorbs 21% less energy from them than would be expected based on their nutrients.

What’s more, eating walnuts may help regulate your appetite.

A well-controlled study in 10 people with obesity found that drinking a smoothie made with about 1.75 oz (48 g) of walnuts once per day for 5 days decreased the participants’ appetite and hunger. This was in comparison to a placebo drink equal in calories and nutrients.

Additionally, after 5 days of consuming the walnut smoothies, brain scans showed that the participants had increased activation in a region of the brain that helped them resist highly tempting food cues, such as cake and french fries.

Even though larger and longer-term studies are needed, this provides some initial insight into how walnuts may help regulate appetite and weight.

Summary

Though walnuts are calorie-dense, you may not absorb all the calories they contain. Additionally, they may help regulate your appetite.

7. May help manage and lower your risk for type 2 diabetes

Observational studies suggest that one reason walnuts are linked to a lower risk of type 2 diabetes is that they help manage weight.

Excess weight increases your risk of high blood sugar and diabetes.

Eating walnuts may help regulate blood sugar by mechanisms beyond their influence on weight management.

In a small 2016 study, 100 people with type 2 diabetes consumed 1 tablespoon of cold-pressed walnut oil per day for 3 months while continuing their usual diabetes medication and balanced diet.

This resulted in an 8% decrease in fasting blood sugar.

Additionally, the walnut oil users had about an 8% decrease in hemoglobin A1C (3-month average blood sugar).

The control group showed no improvement in A1C or fasting blood sugar. Neither group had a change in their weight.

Some other research also suggests that supplementing your diet with walnuts could lead to a modest improvement in blood glucose levels.

However, it’s important to keep in mind that consuming walnut oil is not the same as eating whole walnuts.

Summary

Consuming walnut oil and walnuts may help manage type 2 diabetes and reduce your risk of the disease by helping to regulate your weight. Walnuts might have more direct effects on blood sugar regulation as well.

8. May help lower blood pressure

High blood pressure is a major risk factor for heart disease and stroke.

A small 2019 study suggests that eating walnuts may help lower blood pressure, including in people with high blood pressure.

Additionally, the authors of a 2019 research review examined the effects of a Mediterranean diet, which often involves consumption of walnuts and other nuts. They concluded that following the Mediterranean diet may help lower blood pressure in some people.

This suggests that nuts may slightly improve the blood pressure benefits of a heart-healthy diet. Even small differences in blood pressure are thought to have a big impact on your risk of heart disease.

Summary

Some studies suggest that eating nuts, including walnuts, daily as part of a heart-healthy diet may help improve blood pressure.

9. Support healthy aging

As you age, good physical functioning is essential for maintaining your mobility and independence.

One thing that may help you maintain your physical abilities is healthy eating habits.

In an observational study involving more than 50,000 women over 18 years, scientists found that those with the healthiest diets had a 13% lower risk of physical impairment.

Walnuts were among the foods that made the strongest contribution to a healthy diet.

Though relatively high in calories, walnuts are packed with essential vitamins, minerals, fiber, fats, and plant compounds that may help support good physical functioning as you age.

Summary

A healthy diet that includes walnuts may help preserve physical function, such as walking and self-care abilities, as you age.

10. Support good brain function

It may be just a coincidence that the shell of a walnut looks like a tiny brain, but research suggests that this nut may indeed be good for your mind.

Animal and human studies suggest that the nutrients and antioxidants in walnuts may help reduce oxidative stress and inflammation by reducing free radicals.

A 2016 study in mice suggests that walnut extract may improve symptoms of Parkinson’s disease (PD).

Additionally, a 2019 study in humans found that people with depression showed improvement in symptoms if nuts, including walnuts, were a part of their diet.

Studies in mice have linked eating walnuts to better brain function, including improvements in memory, learning skills, motor development, and anxiety-related behavior.

Though these results are encouraging, more studies on the effects of walnuts on brain function in humans are needed before researchers can draw firm conclusions.

Summary

Walnuts contain nutrients that may help protect your brain from damaging inflammation and support good brain function as you age.

11. Support reproductive health in people with sperm

Typical Western diets — high in processed foods, sugar, and refined grains — have been linked to reduced sperm function.

Eating walnuts may help support sperm health and male fertility.

In a 2012 study involving 117 healthy young men, participants who ate 2.5 oz (75 g) of walnuts per day for 3 months as part of a Western-style diet had improved sperm shape, vitality and motility compared to those who did not eat nuts.

Animal research suggests that eating walnuts may help protect sperm by reducing oxidative damage in their membranes.

Further studies are needed to learn more about these benefits. But if you have concerns about fertility and sperm function, eating walnuts is a simple thing to try.

Summary

Eating walnuts regularly may help counteract potentially harmful effects of less-than-ideal eating habits on sperm health.

12. Improve blood fat levels

Elevated levels of LDL (bad) cholesterol and triglycerides have long been linked to an increased heart disease risk.

Regularly eating walnuts has been consistently shown to decrease cholesterol levels.

In a small 2017 study in healthy adults, eating 1.5 oz (43 g) of walnuts daily for 8 weeks produced a 5% decrease in total cholesterol, LDL cholesterol, and triglycerides compared to not eating walnuts.

The walnut eaters also had nearly a 6% decrease in apolipoprotein B, which is an indicator of how many LDL particles are in your blood. Elevated apolipoprotein B is a major risk factor for heart disease.

Summary

A daily 1.5-oz (43-g) serving of walnuts may help lower cholesterol and triglyceride levels, which contribute to heart disease risk.

13. Widely available and easy to add to your diet

You can find walnuts in any grocery store. Check for raw walnuts in the baking aisle, roasted walnuts in the nut aisle, and cold-pressed walnut oil in the specialty oils section.

It’s helpful to understand how to convert the serving sizes used in studies so that you know how your portion sizes compare.

The following servings are essentially equivalent, providing about 190 calories each:

  • 1 oz shelled walnuts = 28 g = 1/4 cup = 12–14 halves = 1 small handful

Though it’s simplest to eat walnuts one by one as a snack, there are plenty of tasty ways to use them in dishes.

You can try walnuts:

  • sprinkled on leafy green or fruit salads.
  • finely ground in dips and sauces
  • chopped and used in whole grain breads and scones
  • crushed to use as a coating on fish or chicken
  • served atop oatmeal or yogurt
  • chopped and added to wraps or pita sandwiches
  • roasted and added to a homemade trail mix
  • lightly browned in your favorite stir-fry recipe
  • roasted or chopped on pasta or vegetables
  • as an oil in a vinaigrette dressing

You may also want to scour the internet for tasty recipe ideas.

If you’re cooking for guests, make sure no one is allergic to walnuts before adding them to your dishes.

Summary

Walnuts are easy to add to your diet since they’re widely available in stores and a great addition to countless dishes. Just be wary of any nut allergies.

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