Hazelnuts (sometimes called filberts or filbert nuts) are nuts of any tree from the genus Corylus, especially Corylus avellana. Filberts was the name given to the hazelnut and the tree in England when it was first introduced by French settlers. It was named after St. Philibert, because his day (August 22) regularly coincided with the ripening dates of the nuts.

The English later changed the name to hazelnut and in 1981, the Oregon Filbert Commission decided to promote the name as the production in the US expanded. It is mostly cultivated in Turkey, Italy, Spain, and the United States. The hazelnut has always been the signature ingredient of Nutella, a brand of sweetened hazelnut cocoa spread.

They grow within protective husks, in clusters on trees and when they ripen, the nuts drop from the husks onto the ground, where they can be harvested. Like other nuts, they are rich in nutrients and have a high content of protein, fats, vitamins, and minerals. They are a rich source of nutrition as they contain unsaturated fatty acids, protein, fibres, and phytochemicals.

They also contain micronutrients such as calcium, magnesium, potassium, and selenium, along with polyphenols and B-complex vitamins. They contain alpha-tocopherol, a vitamin E type rich in antioxidants that reduces the risk of cancer by killing free radicals in the body responsible for damaging cell DNA.

Hazelnuts can be pressed to produce hazelnut oil, which is used as cooking oil in place of canola or olive oil. The nut can be ground up into flour which is used as a gluten-free alternative to wheat flour.

Some of the health benefits

Supporting healthy bowel movements: Hazelnuts are a good source of dietary fiber. Eating plenty of fiber encourages regular bowel movements and helps prevent constipation.

Loaded with antioxidants: Hazelnuts provide significant amounts of antioxidants. Antioxidants protect the body from oxidative stress which can damage cell structure and promote aging, cancer, and heart disease.

The most abundant antioxidants in hazelnuts are known as phenolic compounds. They are proven to help decrease blood cholesterol and inflammation. They could also be beneficial for heart health and protect against cancer.

An eight-week study showed that eating hazelnuts with or without the skin significantly decreased oxidative stress compared to not eating hazelnuts. However, the majority of the antioxidants present are concentrated in the skin of the nut.

Lowers cholesterol: Eating hazelnuts may help reduce cholesterol. A 2013 study found that a hazelnut-rich diet decreased participants’ levels of low-density lipoprotein cholesterol. This type of cholesterol can increase the risk of heart problems.

The researchers concluded that the best way to reap hazelnuts’ health benefits was to eat them every day. Results of a 2016 review likewise indicated that hazelnuts could reduce levels of harmful cholesterol. The researchers also noted no increase in participants’ body weight. This may alleviate some concerns that eating calorie-dense nuts could lead to weight gain.

Improves insulin sensitivity: Eating a nut mix that includes hazelnuts may help improve insulin sensitivity. A small 2011 trial found that eating a 30g nut mix that contained 7.5 g of hazelnuts every day improved participants’ insulin sensitivity over 12 weeks. Diminished insulin sensitivity plays a role in the development of type 2 diabetes.

Linked with lower rates of cancer: Among other nuts such as pecans and pistachios, hazelnuts have the highest concentration of a category of antioxidants known as proanthocyanidins. Some test-tube and animal studies have shown that proanthocyanidins may help prevent and treat some types of cancers. It is thought that they protect against oxidative stress.

Additionally, hazelnuts are rich in vitamin E, another powerful antioxidant that has exhibited possible protection against cell damage that could cause or promote cancer. Similarly, hazelnuts provide a whopping 87 per cent of the RDI (required daily intake) for manganese which has shown to help the functions of specific enzymes that could reduce oxidative damage and decrease the risk of cancer.

A couple of test-tube studies showed that hazelnut extract could be beneficial in the treatment of cervical, liver, breast, and colon cancer. Furthermore, an animal study using a product made from hazelnut skin extract resulted in a decreased risk of colon cancer after the eight-week study period.

Good for bone health: Magnesium and calcium are necessary for the health of your bones and joints. The extra magnesium which is being stored by your bones comes to the rescue when there is a deficiency of it. Furthermore, they contain manganese which is ideal for bone growth and strength.

Provides a surprising lift for the nervous system.

It is heat friendly

Great for the skin.

Enhanced muscle growth.

Scientific studies

In a study titled, “Hazelnut modulates neurobehaviour and ameliorates ageing-induced oxidative stress and Caspase-3-mediated apoptosis in mice,’’ by

Olofinnade et al, the conclusion is that hazelnut cultivars have beneficial effects on the brain in aged mice; suggesting a possible role in the prevention or management of age-related neurodegenerative changes.

In a study titled, “Effects of hazelnut consumption on blood lipids and body weight: A systematic review and Bayesian meta-analysis,’’ by Perna et al, the conclusion is that a hazelnut-enriched diet decreases low-density lipoprotein cholesterol (LDL-C) in a significant way and shows a trend toward reduction of total cholesterol, without decreasing high-density lipoprotein cholesterol (HDL-C); while triglycerides and body mass index (BMI) remain substantially unchanged. These data show a potentially favourable effect on cardiovascular disease (CVD) prevention.

In a study titled, “Hazelnut consumption improves testicular antioxidant function and semen quality in young and old male rats,’’ by Kara et al, the result showed that Hazelnut supplemented diet improved histopathological variables, sperm quality, seminal plasma, and plasma oxidative stress, seminal plasma vitamin E and plasma testosterone levels.

You can eat them raw, roasted, mixed with other nuts, chopped, and added to your cooking or baking.