Hazelnut Drug Interactions, Uses, Effectiveness, Safety & More

Hazelnuts come from trees and shrubs in the genus Corylus, most commonly Corylus avellana. The plant grows in temperate parts of Europe, Asia, and North America, and Turkey is one of the largest producers in the world.

People mostly use hazelnuts as a food. The nuts are eaten whole, roasted, ground into flour, made into nut butter, or pressed into oil. Hazelnut is also a popular flavoring in chocolate spreads, coffee drinks, and baked goods.

Beyond food, some people take hazelnuts or hazelnut products hoping for health benefits such as supporting heart health, providing antioxidants, and adding healthy fats to the diet.

Hazelnuts are rich in monounsaturated fats (the same kind found in olive oil), which may help with cholesterol levels. They also provide fiber, plant protein, vitamin E, and minerals such as magnesium and copper.

The skins and kernels contain antioxidant compounds like polyphenols and tocopherols. In laboratory studies, these compounds can neutralize free radicals and reduce markers of inflammation.

It is important to know that much of this is based on lab and animal research or on studies of overall diet. The exact way hazelnuts affect the human body, and how much you would need to eat for a benefit, is not fully established.

For most people, hazelnuts are safe to eat as a normal food. The biggest concern is tree nut allergy. Hazelnut is one of the most common causes of nut allergy, and reactions can be severe and life-threatening. People with a known tree nut allergy should avoid hazelnuts entirely.

Some people who are allergic to birch pollen may also react to hazelnuts (a type of cross-reaction), often with itching or swelling in the mouth.

Hazelnuts are high in calories and fat, so large amounts may add up if you are watching your weight. Whole nuts can also be a choking hazard for young children.

Pregnancy and breastfeeding: Eating hazelnuts as a normal part of the diet is generally fine if you are not allergic and tolerate them well. Concentrated hazelnut extracts or supplements have not been well studied in pregnancy or breastfeeding, so it is best to avoid those unless your doctor or pharmacist approves.

If you are unsure whether hazelnut is right for you, check with a pharmacist or doctor, especially if you have allergies.

When eaten as food by people who are not allergic, hazelnuts usually cause few side effects. Eating a lot at once may cause bloating, gas, or stomach upset because of the fat and fiber.

The most serious risk is an allergic reaction. Symptoms can include itching, hives, swelling of the lips, mouth, or throat, trouble breathing, and in severe cases a life-threatening reaction called anaphylaxis. Anyone with these symptoms needs emergency medical care right away.

Mold contamination of poorly stored nuts can sometimes be a concern, so store hazelnuts in a cool, dry place and discard any that smell off or taste bitter or rancid.

There is no official medical dose for hazelnuts. As a food, a small handful (about an ounce) is a common serving size in studies of nuts and heart health.

For any hazelnut supplement, oil, or extract, there is no standardized dose. Follow the directions on the product label and do not assume more is better.

Talk with a pharmacist or doctor before using concentrated hazelnut products, especially if you have allergies, are pregnant or breastfeeding, or take other medications.