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Hazelnut Facts, Nutrients, Delicious Uses, and Allergies

Hazelnuts are delicious and nutritious.

Hazelnuts are delicious and nutritious.

Delicious and Versatile Nuts

Hazelnuts are nutritious and very versatile. I think they taste delicious, especially when they're roasted. They are rich in healthy monounsaturated oil and also contain minerals, vitamins, protein, fiber, and other nutrients. The nuts can be ground into a flour or used to make a milk, cream, butter, or oil. Adding cocoa and a sweetener to hazelnut butter makes a wonderful chocolate spread. The nuts can also be used to make a vegan cheese.

Hazelnuts are a great addition to desserts, including fruit dishes, breads, cakes, cookies, frozen desserts, and candies. They add an interesting flavor to coffee and liqueurs. They can also add a lovely taste to savory dishes, such as ones containing green vegetables, cheese, or meat. The nuts or products made from them are very useful ingredients to keep in a pantry or a refrigerator.

Hazelnut Production

Hazel trees are native to temperate areas of the northern hemisphere. They belong to the genus Corylus. Many species exist. Some species are cultivated for their nuts, while others are grown as ornamental plants.

The nuts of hazel trees are sometimes known as filberts or cobnuts, depending on the species. True nuts, including those produced by hazel trees, are hard fruits that contain a single seed. They develop from more than one carpel (the name of the female reproductive structure).

Turkey is the world’s biggest commercial producer of hazelnuts. The nuts are also grown commercially in Italy, in Oregon and Washington in the United States, and in British Columbia in Canada. They are prized by animals as well as humans. They are eaten by squirrels, mice, woodpeckers, and other birds.

Nutrient Content and Potential Health Benefits

Fat is a necessary substance in our bodies and in our diet. Most nutritionists say that fat should be eaten in moderation and that we should eat mainly monounsaturated and polyunsaturated fats instead of saturated and trans fats, however.

Monounsaturated Fatty Acids

Hazelnuts do contain a lot of oil, but this oil is rich in monounsaturated fatty acids. Monounsaturated fatty acids or MUFAs (which make up monounsaturated fats) can lower the level of LDL cholesterol in the blood. This is the so-called “bad” cholesterol that causes the buildup of fatty deposits in our arteries when its level is too high. MUFAs may also help people with type 2 diabetes control their blood sugar level.

Deposits of LDL cholesterol in blood vessels increase the risk of a heart attack or stroke. LDL cholesterol has important functions, so the term “bad” isn’t really appropriate, but researchers say that its level should be kept low so it doesn’t collect in blood vessels.

Minerals, Vitamins, Protein, and Fiber

Hazelnuts are an excellent source of manganese, a very good source of copper, and a good source of magnesium and iron. They contain smaller quantities of other minerals. In addition, they are a great source of vitamin E and a good source of vitamin B6, folate, and thiamine. They also contain a significant amount of protein and fiber.

Phytonutrients or Phytochemicals

Another nutritional bonus of eating hazelnuts is that they add important phytonutrients to our diet. Phytonutrients, which are sometimes called phytochemicals, are chemicals in plants that aren't essential for our survival but are believed to have important health benefits.

Hazelnuts contain phytonutrients in the phytosterol and flavonoid families. Phytosterols may lower our blood cholesterol. Flavonoids may act as antioxidants. Chemical reactions in our bodies produce free radicals, which antioxidants remove. A high concentration of free radicals has been linked to chronic inflammation and the aging process.

Roasting the Nuts

If possible, it's best to buy hazelnuts in the shell and to remove the shells just before eating the nuts. The nuts stay fresh for longer if they're stored intact instead of being shelled, chopped, or ground.

Hazelnuts are eaten both raw and roasted. Roasting intensifies the flavor and deepens the color. Dry roasting can be done in a home oven, but it’s important that the nuts aren't burned. Though I’ve never tried the process myself, the usual instructions are to place the hazelnuts on a cookie sheet in an oven at 350 degrees Fahrenheit and to cook them for five to seven minutes. The roasted nuts should then be rubbed between a towel to remove their skins.

Some people who like to eat raw foods claim that roasting nuts damages their fats. While this may be true, it’s hard to find reliable evidence to support the claim. It is known that roasting has advantages beyond improving the flavor. It can destroy fungi and microbes on the nuts.

Vegan Butter, Cream, and Milk

People who aren't allergic to hazelnuts can enjoy them in multiple ways. Like many other nuts, they can be very helpful as a dairy substitute for vegans. Vegans eat no food from animals, so milk, cheese, and other dairy foods are out of bounds for them. Products that resemble dairy foods can be made from nuts.

Hazelnut butter is usually (but not always) made from roasted nuts. The butter can be purchased or made at home. If you grind raw or roasted hazelnuts into a meal and then continue to grind, a paste will eventually form. If you use a home food processor instead of commercial equipment to grind the nuts, a small amount of oil will probably need to be added to the paste to get a buttery texture. It's a good idea to choose a healthy oil to complement the oil in the hazelnuts.

Cocoa and a sweetener can be added to hazelnut butter to make a delicious chocolate hazelnut spread. The nice thing about making this spread at home is that you can control the ingredients, using a healthier sweetener than the refined sugar that is used in commercial products.

Hazelnuts can also be used to produce a milk or cream. Hazelnuts and water are mixed in a blender to create a creamy liquid. Using less water produces a creamier milk, while using more water produces a skim milk consistency. Most people like to filter the nut skins out before they drink the milk.

A Flavorful Meal and Flour

A meal or flour is made from ground hazelnuts. The meal can be made at home in a food processor. It's aromatic, tasty, and nutritious and adds a rich flavor to foods. Since it contains oil, it should be stored in a refrigerator to stop it from going rancid. It should also be used up quickly. Some hazelnut flours are made from the material that's left over after the oil has been extracted. Hazelnut meal and flour add protein and fiber to baked goods, as well as healthy fat if they're made from whole nuts.

A Healthy Oil

Hazelnut oil is rich in monounsaturated fats (just like olive oil) and is very flavorful, so only small servings are needed. It makes an excellent addition to salads. It's also used to cook foods at medium-high heat. Some people like to add hazelnut oil to potatoes and other vegetables and to pasta, fish, meat, and bread. Like all fats—even healthy ones—hazelnut oil should be eaten in moderation.

The oil should be stored in a dark glass bottle and kept in a cool and dark place at home. A refrigerator would be a good storage place if the oil is used infrequently. Although the oil will turn cloudy in the refrigerator and even start to solidify, it will liquify when brought to room temperature again. Cooled oil will probably stay fresh for about three months.

It's good to know that when we are eat hazelnuts or a product made from the nuts, we are enjoying something that is not only delicious but also healthy and nutritious (assuming unhealthy ingredients haven't been added to a product).

A green hazelnut that is beginning to ripen near my home

A green hazelnut that is beginning to ripen near my home

Oral Allergy Syndrome

Unfortunately, allergies to hazelnuts seem to be quite common. The nuts can cause two disorders, one more serious than the other. Some people experience a condition called oral allergy syndrome (also known as pollen-food allergy syndrome) when they eat hazelnuts. This disorder may develop in people who experience hay fever or have a tree pollen allergy (especially an allergy to birch pollen). It's thought that a person's immune system reacts to proteins in the nuts that are similar to ones in the pollen.

When susceptible people eat hazelnuts, they experience a burning or itching sensation in the mouth and throat that may be accompanied by swelling. The symptoms generally disappear soon after the food is swallowed. Oral allergy syndrome is often not serious, but occasionally it is.

Some people who develop mild oral allergy symptoms when they eat raw hazelnuts can eat roasted ones with no problem. This is often the case for me. I can usually eat products made from roasted hazelnuts, but the raw nuts cause problems. It might be a good idea for people in a similar situation to avoid eating the raw nuts. Someone with a severe nut allergy must never eat any nuts, either raw or roasted.

A Major Hazelnut Allergy

A different type of allergy that is generally more serious than oral allergy syndrome develops in some people when they eat hazelnuts. In these people, swelling in the throat may be so severe that breathing is difficult. The lips and face may swell, hives may appear, and the person may experience vomiting and diarrhea. Ingestion of other tree nuts may cause similar symptoms.

In severe cases, a person may experience anaphylaxis after eating hazelnuts. This is a very dangerous condition and can be deadly. It's often described as a whole-body allergic response and can cause a major drop in blood pressure.

A doctor may prescribe an epinephrine auto-injector to people with a severe allergy to tree nuts. The injector should accompany the person at all times. The epinephrine relieves or reduces the symptoms of anaphylaxis if the patient comes into contact with the allergen. The person needs to get immediate medical attention after the injection, however.

Hazel Tree Leaves, Flowers, and Fruits

For me, part of the enjoyment linked to hazel nuts is seeing the trees that bear them. In some climates, hazel trees can be grown in gardens. They are beautiful plants. The trees tend to have several trunks instead of one main one. The leaves are broad with toothed edges and have a pointed tip.

The Male Catkins

A hazel tree is lovely to see in any season. It's deciduous, so in winter the branches are bare of leaves. The tree bears pale yellow, hanging catkins instead. These are the male flowers. In late winter—usually in February in my part of the world—the catkins open up and release their pollen. The mature catkins are often called "lambs' tails."

The Female Flowers

Hazel trees also have small female flowers, which are less obvious than the catkins. In the female flower, a red tuft of tassels emerges from a swollen, bud-like structure, as shown in the photo below. The exposed tassels are the stigmas. They catch the pollen that is blown by wind from the male flowers. Cross-pollination is needed to produce a nut.

The Fruits

The nuts form after pollination and fertilization. They are surrounded by papery leaves or a husk and usually form in groups. The nuts are often picked while they're still green, since they are a great attraction to squirrels when they're ripe.

Three hazelnut trees grow in a landscaped area near my home. I see the male and female flowers every year, but I rarely see the nuts. The one in my photo above was an exception. I think the local wildlife often gets to the fruits before I do, or else walkers along the trail beside the trees see them before I do.

Whether hazelnuts are grown at home, picked from trees growing in another area, or bought in a store, they can be an excellent and flavorful addition to the diet. Many nuts are both nutritious and tasty, but I think hazelnuts have a special flavor that is delicious, especially when they're roasted. They are my favorite type of nut based on the ones that I’ve tried so far.


This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

© 2011 Linda Crampton