Hazelnuts:16 Health Benefits, Side Effects & How to Eat Them

Imagine a small, golden-brown nut with a distinctive sweet flavor that not only satisfies your taste buds but also works silently to boost your overall health. That’s the humble hazelnut! These delightful, subtly sweet nuts, also known as filberts, are more than just a tasty snack or a delightful addition to your favorite chocolate spread. Hazelnuts are nutritional superstars, brimming with essential vitamins and minerals.

From supporting heart health to enhancing brain function and even offering anti-cancer properties, the benefits of incorporating hazelnuts into your diet are truly remarkable. In this article, we’ll explore 16 remarkable health benefits of hazelnuts and potential side effects. Plus, we will also share creative ways to incorporate these nutritional gems into your daily diet.

What Are Hazelnuts?

Hazelnuts, scientifically known as Corylus avellana, are the nuts of the hazel tree, which belongs to the birch family. They’re also commonly called filberts or cobnuts, depending on the region. These nuts grow inside a protective husk that opens as the nut matures, revealing the hard shell that encases the edible kernel.

Native to parts of Europe and Asia, hazelnut cultivation dates back thousands of years. Today, Turkey leads global hazelnut production, accounting for approximately 70% of the worldwide supply, followed by Italy, Spain, the United States (primarily Oregon), and Azerbaijan.

When harvested, hazelnuts have a rounded shape with a pointed end, typically measuring about 1-2 cm in diameter. Their thin, hard brown shell protects the cream-colored kernel inside, which is covered with a bitter brown skin that’s often removed during processing.

The flavor profile of hazelnuts is distinctive – sweet, rich, and buttery with subtle earthy notes that intensify when roasted. This unique taste has made hazelnuts a prized ingredient in both sweet and savory culinary applications worldwide.

16 Science-Backed Health Benefits of Hazelnuts

1. A Treasure Trove of Nutrients

Hazelnuts are incredibly nutrient-dense, meaning they pack a lot of goodness into a small serving. Just a handful provides a significant amount of your daily recommended intake for various vitamins and minerals.

Nutritional Snapshot of Hazelnuts (per 1-ounce serving, approx. 28g or 20 whole kernels):

2. Power-Packed with Antioxidants

Hazelnuts are brimming with powerful antioxidants, which are crucial for fighting off harmful free radicals in your body. Free radicals can damage cells, leading to chronic diseases and premature aging.

The dominant antioxidants in hazelnuts include:

• Vitamin E: A fat-soluble antioxidant that protects cell membranes from oxidative damage.
• Phenolic Compounds: Such as gallic acid, caffeic acid, and proanthocyanidins (the same compounds found in grapes and cocoa). These are exceptionally potent.
• Flavonoids: These compounds have anti-inflammatory effects and can support heart health.

The high concentration of these protective compounds means that by simply enjoying hazelnuts, you’re giving your body an excellent defense mechanism against cellular damage and inflammation.

3. Boost Heart Health

This is one of the most well-researched benefits of hazelnuts. Their unique combination of healthy fats, fiber, antioxidants, and minerals like magnesium and potassium makes them incredibly beneficial for cardiovascular health.

How Hazelnuts Help Your Heart:

• Lowers LDL (Bad) Cholesterol: The high monounsaturated fat content, particularly oleic acid, helps reduce levels of “bad” LDL cholesterol while maintaining or even increasing “good” HDL cholesterol (Alshahrani et al., 2018).
• Reduces Triglycerides: Studies show that regular hazelnut consumption can significantly lower triglyceride levels, another important marker for heart disease risk.
• Improves Blood Pressure: Magnesium and potassium found in hazelnuts play a role in regulating blood pressure. Magnesium helps relax blood vessels, while potassium counteracts the effects of sodium.
• Decreases Inflammation: The antioxidants and anti-inflammatory compounds in hazelnuts help protect blood vessels from damage and reduce overall systemic inflammation, a key contributor to heart disease.

Adding hazelnuts to your diet is a delicious way to give your heart the love it deserves!

4. May Help Prevent Cancer

While no single food can cure or prevent cancer, a diet rich in antioxidants and anti-inflammatory compounds, like those found in hazelnuts, can play a significant role in reducing cancer risk.

Potential Anti-Cancer Mechanisms:

• Antioxidant Power: The abundant antioxidants, especially proanthocyanidins, vitamin E, and manganese, help protect cells from DNA damage that can lead to cancer.
• Anti-inflammatory Effects: Chronic inflammation is a known risk factor for various cancers. Hazelnuts’ anti-inflammatory properties can help mitigate this risk.
• Specific Compounds: Test-tube and animal studies suggest that compounds in hazelnuts may slow the growth of certain cancer cells, including those of the colon, liver, and breast . More human research is needed, but the preliminary findings are promising.

5. Aids in Blood Sugar Control

For those managing blood sugar levels or looking to prevent type 2 diabetes, hazelnuts can be a valuable dietary addition.

How Hazelnuts Support Blood Sugar Regulation:

• Healthy Fats: Monounsaturated fats have been shown to improve insulin sensitivity, meaning your cells are more responsive to insulin, which helps regulate blood sugar more effectively.
• Fiber: The dietary fiber in hazelnuts slows down the absorption of sugar into the bloodstream, preventing rapid spikes and crashes.
• Low Glycemic Index: Hazelnuts have a low glycemic index, meaning they cause a gradual, rather than sharp, rise in blood glucose levels.
• Magnesium: Magnesium plays a crucial role in carbohydrate metabolism and insulin secretion. Many people with type 2 diabetes are deficient in magnesium.

Including hazelnuts as part of a balanced diet can be a smart strategy for maintaining healthy blood sugar levels.

6. Reduces Inflammation

Inflammation is the body’s natural response to injury or infection. However, chronic inflammation can contribute to numerous diseases, including heart disease, diabetes, and certain cancers.

Hazelnuts contain several compounds that possess powerful anti-inflammatory properties:

• Proanthocyanidins: These unique flavonoids found in hazelnuts are excellent at reducing inflammation.
• Monounsaturated Fats: These healthy fats can also help lower inflammatory markers in the body.
• Antioxidants: By neutralizing free radicals, antioxidants reduce the oxidative stress that often triggers inflammatory responses.

Regular consumption of hazelnuts can help keep inflammation in check, contributing to overall well-being.

7. Boosts Brain Function

Who doesn’t want a sharper mind? Hazelnuts are often touted as a “brain food,” and for good reason!

Brain-Boosting Benefits of Hazelnuts:

• High Vitamin E Content: Vitamin E is a powerful antioxidant that protects brain cells from oxidative stress, which is linked to cognitive decline and neurodegenerative diseases like Alzheimer’s and Parkinson’s.
• B Vitamins (Thiamin, B6, Folate): These vitamins are essential for nerve function and neurotransmitter synthesis. Thiamin is crucial for energy metabolism in the brain.
• Monounsaturated Fats: These fats are vital for brain health and can help improve memory and cognitive processing.
• Manganese: This trace mineral is involved in various enzymatic reactions, including those important for brain function.

Snacking on hazelnuts could be a delicious way to keep your brain agile and focused throughout 2026.

8. Supports Bone Health

While dairy often gets all the credit for bone health, hazelnuts offer valuable contributions as well.

How Hazelnuts Strengthen Bones:

• Manganese: Hazelnuts are an excellent source of manganese, a mineral critical for bone formation and density. It helps activate enzymes involved in creating cartilage and bone.
• Magnesium: This mineral works with calcium to maintain bone structure. Adequate magnesium intake is essential for preventing osteoporosis.
• Copper: Copper plays a role in collagen production, a structural component of bones.

Including hazelnuts in a diverse diet contributes to strong, healthy bones.

9. Improves Digestion

A healthy gut is fundamental to overall health, and hazelnuts can give your digestive system a helping hand.

Digestive Benefits of Hazelnuts:

• Dietary Fiber: Hazelnuts are a good source of fiber, which is crucial for digestive health. Fiber adds bulk to stool, promoting regular bowel movements and preventing constipation.
• Prebiotic Effects (Potential): Some research suggests that the fiber and other compounds in nuts may act as prebiotics, feeding beneficial gut bacteria. A healthy gut microbiome is linked to improved digestion, nutrient absorption, and even mood.

10. Enhances Skin and Hair Health

The benefits of hazelnuts aren’t just internal; they can manifest externally too!

For Radiant Skin and Hair:

• Vitamin E: This powerful antioxidant protects skin cells from damage caused by UV radiation and environmental pollutants, reducing signs of aging like wrinkles and fine lines. It also promotes healthy blood circulation to the scalp, which is essential for hair growth.
• Healthy Fats: The monounsaturated and polyunsaturated fats in hazelnuts help keep skin hydrated and supple, giving it a natural glow. These fats also nourish hair follicles, leading to stronger, shinier hair.
• Flavonoids: These compounds have anti-inflammatory effects that can help soothe skin conditions and reduce redness.

Consider a handful of hazelnuts your secret beauty weapon!

11. May Reduce Risk of Metabolic Syndrome

Metabolic syndrome is a cluster of conditions – increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels – that occur together, increasing your risk of heart disease, stroke, and type 2 diabetes.

Hazelnuts can help address several components of metabolic syndrome:

• Improved Cholesterol and Triglycerides: As discussed, hazelnuts effectively lower “bad” cholesterol and triglycerides.
• Blood Sugar Control: They help stabilize blood sugar levels.
• Blood Pressure Regulation: Magnesium and potassium contribute to healthier blood pressure.
• Weight Management (indirectly): The fiber and protein provide satiety, which can help with weight management.

12. Supports Immune System Function

A strong immune system is your body’s best defense against illness and infection. Hazelnuts contribute to this defense in several ways.

Immune-Boosting Properties:

• Vitamin E: This antioxidant is vital for immune function, helping to protect immune cells from damage and supporting their proper operation.
• Copper: This mineral is crucial for immune system development and function. It helps in the production of white blood cells.
• Zinc: While not as high as some other nuts, hazelnuts still provide some zinc, a mineral essential for immune cell development and communication.
• Antioxidants: By reducing oxidative stress and inflammation, hazelnuts create a more favorable environment for a robust immune response.

13. Excellent Source of Dietary Fiber

Fiber is a superstar nutrient, and hazelnuts deliver a healthy dose of it.

Why Fiber Matters:

• Digestive Health: Promotes regularity and prevents constipation.
• Satiety: Helps you feel fuller for longer, which can aid in weight management by reducing overall calorie intake.
• Blood Sugar Control: Slows sugar absorption, preventing spikes.
• Cholesterol Reduction: Soluble fiber can help lower LDL cholesterol.
• Gut Microbiome: Feeds beneficial gut bacteria, contributing to overall gut health.

14. Rich in Healthy Unsaturated Fats

Roughly 80% of the fat in hazelnuts is monounsaturated, primarily oleic acid, which is the same healthy fat found in olive oil. The remaining fat is a mix of polyunsaturated and a small amount of saturated fat.

Benefits of Healthy Fats:

• Heart Health: Lowers LDL cholesterol, reduces inflammation.
• Brain Health: Essential for brain structure and function.
• Vitamin Absorption: Helps the body absorb fat-soluble vitamins (A, D, E, K).
• Hormone Production: Important for various bodily functions.

It’s crucial to remember that “fat” isn’t a dirty word when it comes to healthy, unsaturated fats like those in hazelnuts!

15. Good for Muscle and Nerve Function

Hazelnuts provide key minerals that are vital for the proper functioning of your muscles and nervous system.

Key Minerals and Their Roles:

• Magnesium: Essential for muscle contraction and relaxation, nerve impulse transmission, and maintaining electrolyte balance. A deficiency can lead to muscle cramps and fatigue.
• Potassium: Works with sodium to maintain fluid balance and is crucial for nerve signals and muscle contractions, including the heart muscle.
• Thiamin (Vitamin B1): Crucial for nerve function, as it helps convert carbohydrates into energy that nerve cells use.

16. May Help Combat Anemia

Anemia, often caused by iron deficiency, results in reduced oxygen transport in the blood, leading to fatigue and weakness. Hazelnuts can play a supportive role.

How Hazelnuts Help with Anemia:

• Iron Source: Hazelnuts provide a decent amount of non-heme iron (plant-based iron). While not as easily absorbed as heme iron from animal sources, combining them with vitamin C can significantly boost absorption.
• Copper: Hazelnuts are an excellent source of copper, which is vital for iron absorption and utilization. Copper helps the body form hemoglobin, the protein in red blood cells that carries oxygen.

Therefore, including hazelnuts in a diet rich in iron and vitamin C can contribute to maintaining healthy iron levels.

Potential Side Effects and Precautions

While hazelnuts offer a wealth of health benefits, it’s important to be aware of potential side effects and precautions, especially for certain individuals. Generally, hazelnuts are safe for most people when consumed in moderation.

1. Nut Allergies

The most significant and serious side effect associated with hazelnuts is an allergic reaction. Hazelnuts are a common tree nut allergen. Symptoms can range from mild to severe and may include:

• Mild Symptoms:
  • Hives, skin rash, or eczema
  • Itching or tingling in the mouth
  • Nausea, stomach cramps, or diarrhea
  • Runny nose or nasal congestion
• Severe Symptoms (Anaphylaxis):
  • Swelling of the throat and airways
  • Difficulty breathing
  • Sudden drop in blood pressure (dizziness, fainting)
  • Rapid pulse
  • Loss of consciousness

If you have a known tree nut allergy, you must avoid hazelnuts and products containing them. Always check food labels carefully. If you suspect you have a nut allergy, consult a doctor for diagnosis and management.

2. Digestive Issues

Due to their high fiber content, consuming very large quantities of hazelnuts, particularly for individuals not accustomed to a high-fiber diet, can lead to:

• Bloating
• Gas
• Stomach cramps
• Diarrhea

To avoid these issues, increase your intake of fiber-rich foods gradually and ensure adequate fluid intake.

3. Calorie Density

Hazelnuts are calorie-dense due to their high fat content. While these are healthy fats, consuming excessive amounts can lead to weight gain. A typical serving size is about 1 ounce (28 grams) or roughly 20 whole kernels. Enjoy them in moderation as part of a balanced diet.

4. Interactions with Medications (Rare)

While rare, some sources suggest that very high consumption of specific plant compounds found in nuts could theoretically interact with certain medications, such as blood thinners. If you are on specific medications and have concerns, it’s always best to discuss your diet with your healthcare provider.

5. Contamination Risks (Aflatoxins)

Like other nuts, hazelnuts can occasionally be susceptible to fungal contamination (specifically Aspergillus flavus), which can produce toxins called aflatoxins. However, strict quality controls in commercial production, proper storage, and responsible harvesting greatly minimize this risk.

How to Eat Hazelnuts: Delicious & Versatile Ways to Enjoy Them

Hazelnuts are incredibly versatile and can be incorporated into your diet in numerous delicious ways. Whether you prefer them raw, roasted, or as a spread, there’s a method for everyone.

1. Raw Hazelnuts

Simply enjoy a handful of raw, shelled hazelnuts as a quick and nutritious snack. They have a slightly sweet, buttery flavor that is satisfying on its own.

2. Roasted Hazelnuts

Roasting enhances the hazelnut’s flavor, making it richer and nuttier.
How to Roast:

• Preheat oven to 300°F (150°C).
• Spread raw, shelled hazelnuts in a single layer on a baking sheet.
• Roast for 10-15 minutes, shaking the pan occasionally, until fragrant and lightly golden.
• Optional: For easier skin removal, immediately after roasting, transfer the hot hazelnuts to a clean kitchen towel. Fold the towel over them and rub vigorously for a few minutes. The skins should largely come off.

3. Hazelnut Butter

Homemade hazelnut butter is a creamy, delicious, and healthier alternative to store-bought spreads, often loaded with sugar.
How to Make:

• Roast hazelnuts as described above and remove most of the skins.
• Place warm hazelnuts in a high-speed blender or food processor.
• Process for 5-15 minutes, scraping down the sides occasionally. The hazelnuts will go from crumbs to a thick paste, then a creamy butter as their natural oils release.
• Add a pinch of salt, and optionally, a touch of honey or maple syrup for sweetness.

4. Culinary Uses in Sweet Dishes

• Baking: Add chopped roasted hazelnuts to cookies, brownies, cakes, muffins, and bread. They pair exceptionally well with chocolate.
• Desserts: Sprinkle over ice cream, yogurt, or fruit salads. Use them to make homemade nougat, pralines, or a delicious hazelnut torte.
• Breakfast: Stir into oatmeal, sprinkle over cereal, or add to pancake or waffle batter.
• Nutella-style Spreads: Use homemade hazelnut butter as a base for a healthier chocolate-hazelnut spread.

5. Culinary Uses in Savory Dishes

• Salads: Add a delightful crunch to green salads or grain salads (like quinoa or farro) by tossing in some chopped roasted hazelnuts.
• Pasta: Use as a topping for pasta dishes, especially those with pesto or creamy sauces.
• Vegetable Dishes: Sprinkle over roasted vegetables (like Brussels sprouts, green beans, or asparagus) for added texture and flavor.
• Crusts and Coatings: Grind hazelnuts and use them as a gluten-free coating for fish or chicken.
• Cheese Boards: Pair whole roasted hazelnuts with cheeses and fruits on a charcuterie board.

6. Hazelnut Milk

A dairy-free alternative, hazelnut milk can be made at home and used in smoothies, coffee, or cereals.
How to Make:

• Soak 1 cup of raw hazelnuts in water overnight.
• Drain and rinse the hazelnuts.
• Blend with 3-4 cups of fresh water, a pinch of salt, and an optional sweetener (dates, maple syrup).
• Strain the mixture through a nut milk bag or fine-mesh sieve.

7. Hazelnut Oil

Cold-pressed hazelnut oil is a gourmet ingredient, perfect for salad dressings, finishing dishes, or dipping bread. It has a delicate, nutty flavor but a low smoke point, so it’s not ideal for high-heat cooking.

How Many Hazelnuts Can You Eat in a Day?

The appropriate amount varies based on individual health needs and overall diet:

• General Recommendation: About 1 ounce (28 grams or approximately 20 whole hazelnuts) daily is considered a heart-healthy serving according to most dietary guidelines.
• For Weight Management: Stick to 1 ounce daily, ensuring it fits within your overall calorie goals.
• Maximum Safe Amount: While there’s no strict upper limit for healthy individuals, consuming more than 2-3 ounces daily may displace other foods from your diet and provide excess calories.

Sourcing and Quality: Ensuring the Best Hazelnuts

The nutritional benefits of hazelnuts can vary based on quality and processing methods:

• Organic Certification: Choose organically grown hazelnuts when possible to minimize exposure to pesticides and herbicides.
• Storage Conditions: Due to their high fat content, hazelnuts can go rancid if improperly stored. Look for hazelnuts kept in cool, dark environments, and store yours in airtight containers in the refrigerator or freezer for maximum freshness.
• Appearance: Quality hazelnuts should have a uniform color without mold, discoloration, or shriveling. The shell should be intact without cracks if buying unshelled nuts.
• Processing: Minimally processed hazelnuts retain more nutrients. Raw or simply roasted varieties are preferable to heavily processed, flavored, or sugared options.

FAQs

1. Are hazelnut skins edible?

Yes, hazelnut skins are completely edible and contain high concentrations of antioxidants. While they have a slightly bitter taste, they provide significant health benefits. Many people remove them for textural preference, but keeping them maximizes nutritional value.

2. How long do hazelnuts last?

In-shell hazelnuts can last 6-12 months in a cool, dry place. Shelled hazelnuts are best stored in the refrigerator (up to 6 months) or freezer (up to 1 year) in airtight containers to prevent rancidity.

3. Is hazelnut oil as healthy as whole hazelnuts?

Hazelnut oil contains many of the beneficial fats found in whole hazelnuts but lacks the fiber, protein, and some vitamins and minerals. It’s excellent for culinary uses and skin care, but doesn’t provide the complete nutritional profile of whole nuts.

4. Are hazelnuts keto-friendly?

Yes, hazelnuts are excellent for ketogenic diets due to their high fat content, moderate protein, and low net carbs (approximately 2g net carbs per ounce after subtracting fiber).

5. Can hazelnuts help with diabetes management?

Research suggests that hazelnuts may help improve insulin sensitivity and glycemic control. Their combination of healthy fats, fiber, and magnesium makes them a smart choice for those managing diabetes, when consumed in appropriate portions.

6. What’s the difference between hazelnuts and filberts?

While often used interchangeably, filberts technically refer to nuts from cultivated European hazel trees (Corylus maxima), while hazelnuts generally refer to nuts from the wild hazel (Corylus avellana). In practice, most people use “hazelnuts” for all varieties in North America.