Eating a handful of walnuts every day can have many potential health benefits. Walnuts are packed with nutrients like healthy fats, protein, fiber, and antioxidants that may boost heart health, improve blood sugar control, enhance brain function, and even support weight loss.
Walnuts are nutritious and calorie-dense
Walnuts are jam-packed with nutrients. Just one ounce (28 grams) of walnuts contains:
- Calories: 182
- Protein: 4 grams
- Carbs: 4 grams
- Fiber: 2 grams
- Fat: 18 grams
Around 65% of the calories in walnuts come from fat. However, it’s mostly polyunsaturated and monounsaturated fats, which are considered heart-healthy fats. Walnuts also provide a good amount of fiber and high-quality plant-based protein.
Vitamins and minerals
Walnuts contain many important micronutrients as well:
- Manganese: 60% of the Daily Value (DV)
- Copper: 50% of the DV
- Magnesium: 25% of the DV
- Phosphorus: 13% of the DV
- Vitamin B6: 12% of the DV
- Iron: 6% of the DV
- Potassium: 5% of the DV
- Zinc: 5% of the DV
- Thiamine: 5% of the DV
- Folate: 7% of the DV
- Vitamin E: 5% of the DV
Walnuts are especially high in manganese and copper. Both minerals are essential for many aspects of health, including bone formation, energy production, metabolism, and the formation of connective tissue.
Plant compounds
Walnuts are rich in many plant compounds that act as antioxidants to help protect your cells against damage from unstable molecules called free radicals. The most prominent antioxidants in walnuts include:
- Ellagic acid. This polyphenol has antioxidant, anti-inflammatory, and anticancer properties.
- Gallic acid. This is found in the brown skin of the walnut kernel. It has been shown to have antiviral, anticancer, and anti-inflammatory effects.
Walnuts are particularly high in ellagic acid, containing more than other nuts like almonds, pecans, and peanuts.
May benefit heart health in many ways
Eating walnuts regularly has been linked to a reduced risk of heart disease:
- Lower LDL (bad) cholesterol. Walnuts may decrease LDL cholesterol levels, total cholesterol, and apolipoprotein B, which carries LDL throughout the bloodstream.
- Higher HDL (good) cholesterol. They may also increase levels of HDL cholesterol, which helps remove cholesterol from arteries and transport it back to the liver for elimination.
- Improved artery function. Eating walnuts may improve the function of your arteries by increasing blood flow and reducing inflammation.
- Lower blood pressure. The omega-3s, minerals, and antioxidants in walnuts may help lower blood pressure levels.
This effect on heart health is likely due to the unique blend of nutrients, antioxidants, and anti-inflammatory compounds in walnuts.
May reduce inflammation
Chronic, low-level inflammation contributes to many common illnesses, including heart disease and diabetes. Eating five walnuts a day may help lower levels of inflammation.
In one study, people with obesity and type 2 diabetes who ate 1 ounce (30 grams) of walnuts per day had significant reductions in inflammatory markers, compared with those who did not eat walnuts.
Animal studies suggest walnuts may reduce some of the underlying causes of chronic inflammation, including reducing inflammatory cytokine levels and preventing the activation of pro-inflammatory genes.
May enhance blood sugar control
Walnuts may also help improve blood sugar control, which is important for preventing and managing type 2 diabetes.
In one study in over 24,000 adults, those who ate a 1-ounce (28-gram) serving of walnuts 3 times per week or more had a 19% lower risk of developing type 2 diabetes.
Additionally, several studies indicate that eating walnuts alongside foods high in carbs may help reduce high blood sugar levels after meals.
This blood-sugar-lowering effect is likely due to the fiber, magnesium, and healthy fats provided by walnuts.
May promote brain health
As you get older, your risk of neurodegenerative disorders like Alzheimer’s disease or dementia increases. Eating walnuts may help keep your brain healthy.
Test-tube and animal studies suggest that antioxidants in walnuts, like vitamin E, and plant compounds like polyphenols, may help reduce oxidative stress and inflammation in your brain.
In humans, eating walnuts was linked to improved inferential reasoning skills, memory, and focus compared to not eating walnuts.
Additionally, one review of 15 studies found that replacing saturated fats with polyunsaturated fats like the omega-3 alpha-linolenic acid (ALA) found in walnuts resulted in modest improvements in memory and brain function.
Provide essential nutrients for brain function
Your brain needs a variety of nutrients like vitamin E, B vitamins, zinc, copper, and magnesium to function properly. Walnuts provide many of these essential nutrients:
- Vitamin E. This antioxidant plays a vital role in protecting your brain from oxidative stress and inflammation.
- B vitamins. These support the health of nerves in your brain and assist in making neurotransmitters like serotonin.
- Zinc and copper. These minerals are crucial for nerve signaling in your brain.
- Magnesium. This mineral is involved in over 600 cellular reactions, including energy production.
While many foods contain these nutrients, walnuts provide them all in one easy-to-eat package.
High in healthy fats
Additionally, the fats in walnuts are uniquely brain-healthy:
- Omega-3s. ALA omega-3s make up nearly 7% of the fats in walnuts. Your body can convert ALA to the active omega-3s EPA and DHA.
- Omega-6s. Linoleic acid makes up around 52% of the fat in walnuts. Consuming linoleic acid alongside omega-3s may have brain-protective effects.
The omega-3s in walnuts provide anti-inflammatory benefits for your brain while their Vitamin E works as an antioxidant to help protect your brain cells.
May aid weight loss when combined with a healthy diet
Several components of walnuts may encourage weight loss when eaten in combination with an overall healthy diet:
- Filling fiber and protein. Walnuts are more filling than other snacks, providing 4 grams of protein and 2 grams of fiber per 1-ounce (28-gram) serving.
- Satiating fats. The polyunsaturated fats in walnuts may encourage the production of the fullness hormone leptin.
- Increased calorie burn. The fatty acids in walnuts may slightly increase the number of calories you burn at rest.
In one study, people eating a diet rich in walnuts lost significantly more weight than those not eating walnuts. However, this effect appears strongest when combined with an overall healthy diet.
May regulate hunger hormones
The protein, fiber, and polyunsaturated fat content of walnuts may help regulate ghrelin and leptin, two hormones involved in appetite control.
Ghrelin stimulates hunger, while leptin increases feelings of fullness and discourages overeating.
In one study, overweight adults given 20% of their daily calorie needs from walnuts experienced greater reductions in leptin and ghrelin, compared to those not eating walnuts.
May increase fat burn
The fats in walnuts are mostly polyunsaturated. Some research indicates polyunsaturated fatty acids may slightly increase fat burning and the number of calories you burn at rest, compared with saturated fats.
In a controlled study, people eating diets rich in polyunsaturated fats burned up to 4% more calories per day than those consuming diets high in saturated fats.
While the effect is small, it could contribute to meaningful weight loss over the long term when combined with other lifestyle changes.
May reduce inflammation to improve gut health
Eating walnuts every day may improve gut health by reducing inflammation in your gastrointestinal tract.
In one 10-week study, people who ate 3/4 cup (117 grams) of walnuts per day experienced reduced inflammation and improved gut barrier integrity, compared to a control group.
Walnuts’ anti-inflammatory plant compounds and polyunsaturated fats may alleviate inflammation in the gut, reducing discomfort and improving symptoms like bloating, diarrhea, and constipation.
May support growth of healthy gut bacteria
Walnuts contain insoluble fiber, a type of fiber that acts as a prebiotic. This means it provides food for your healthy gut bacteria.
Eating walnuts daily provides up to 7 grams of insoluble fiber, depending on the amount consumed.
Insoluble fiber is fermented by bacteria in your colon and produces short-chain fatty acids, which help nourish the beneficial bacteria in your gut.
Rich in anti-inflammatory nutrients
Walnuts also provide nutrients shown to reduce markers of inflammation in your gut, including omega-3s, magnesium, and antioxidants like ellagic acid.
Chronic inflammation in your gut can cause discomfort and intensify symptoms like bloating and cramps. Eating walnuts may help relieve this inflammation.
Potential downsides of eating walnuts
While walnuts offer many benefits, there are a few potential downsides to keep in mind:
- Allergies. Tree nuts like walnuts are among the most common food allergens. If you have a tree nut allergy, you should avoid walnuts.
- Weight gain. Walnuts are high in calories. Eating more than a handful per day could lead to weight gain if you do not account for the extra calories.
- Phytic acid content. Walnuts contain phytic acid, an antinutrient that may reduce your absorption of minerals like iron and zinc.
- Oxidation. Walnut oil is prone to oxidation, which can produce free radicals and harmful compounds when exposed to heat and light. Purchase walnut oil in small bottles and store it in the fridge.
For most people, eating a handful of walnuts per day should provide health benefits without significant risks. However, you may want to limit walnut intake if you’re allergic or need to watch your weight.
How to incorporate walnuts into your diet
Here are some easy ways to add a handful of walnuts to your daily diet:
- Sprinkle chopped walnuts onto oatmeal, yogurt, or cereal in the morning.
- Mix walnuts into muffin, cookie, pancake, or waffle batters.
- Top salads with chopped or whole walnut pieces.
- Add walnuts to pasta, pesto, or pesto sauce.
- Blend walnuts into smoothies.
- Use walnut pieces as a topping on fish, meats, and roasted veggies.
- Make homemade snack bars or energy balls using walnuts, oats, seeds, and dried fruit.
- Stir walnut pieces into homemade granola or trail mixes.
- Sprinkle chopped walnuts onto bananas or apples.
Aim to consume 1–2 ounces (28–56 grams) of walnuts per day to take advantage of their many health benefits without excess calories and fat.
The fatty acids in walnuts can become rancid if exposed to heat, light, or oxygen for too long. Store walnuts in an airtight container in the fridge or freezer to maximize freshness.
The bottom line
Eating a handful of walnuts every day may improve several aspects of health, including:
- Heart health
- Brain function
- Blood sugar control
- Weight control
- Gut health
Their rich array of antioxidants, vitamins, minerals, and plant compounds provides anti-inflammatory, antioxidant, and anti-aging effects.
Aim to eat a 1-ounce (28-gram) handful of walnuts per day to maximize the potential health benefits while avoiding excess calorie intake.
Walnuts can be easily incorporated into many dishes, including oatmeal, yogurt, salads, pasta, pesto, granola, snack bars, smoothies, and more.
Including a daily handful of walnuts alongside an overall healthy diet can provide impressive benefits for your heart and many other aspects of health.
