With today's lifestyle, nuts are a convenient, tasty and easy-to-carry snack that contributes positively to a healthy lifestyle (Brufau et al., 2006). 

The healthy fats presented in nuts contribute to beneficial effects observed in epidemiological studies (prevention of coronary heart disease, diabetes and sudden death) and short-term intervention studies (cholesterol reduction) (Ros, 2007).

In addition to their flavour, nuts are cholesterol free and rich in important nutrients, including vegetable proteins, fibres and unsaturated fat acids. They also contain relevant micronutrients, such as folic acid, niacin and vitamins E and B6, and minerals such as magnesium, copper, zinc, selenium, phosphorus and potassium. Experts recommend eating a variety of foods every day to get the nutrients you need. The recommended number of portions of this group is up to 2 to 3 per day (Brufau et al., 2006).

Evidence suggests that, regardless of the type of nut, its consumption has a neutral or moderately beneficial effect on the oxidative state of the organism (Ros, 2007).

Effects of nuts consumption 

Effects on appetite

Ingestion of nuts suppresses hunger and the desire to eat and promotes the sensation of satiety (Tan, Dhillon, & Mattes, 2014).

Effects on metabolism

Due to the peculiar composition of its lipid and non-lipid components, nuts may have a beneficial effect on vascular activity. There is growing evidence that usual ingestion of nuts favourably influences cardiovascular risk in addition to cholesterol reduction (Ros, 2007).

In several tests, a reduction in the cardiovascular disease risk indexes was observed in the nuts-consuming groups (Tan et al., 2014). 

There is evidence in studies showing that frequent consumption of nuts is associated with a reduction in cardiovascular risk factors, including dyslipidemia, type 2 diabetes and metabolic syndrome, as well as a lower risk of coronary heart disease. Increasing intake of a variety of nuts as part of a healthy diet may help reduce the risk of cardiovascular disease in the population in general (INC, 2018).

A recently published study in the Journal of Nutrition concludes that eating nuts is a way of improving intestinal flora (INC, 2016b).

Nuts are also a good source of nutrients, which are considered beneficial for bone health, namely calcium, magnesium, vitamin K and boron. It is estimated that boron plays a role in preventing osteoporosis (INC, 2016b).

There is scientific evidence that eating 2 or 3 servings (57-84 g) of nuts a week may reduce the risk of several types of cancer, such as: breast, colon, and pancreas. That is due to its content in vitamin E, folic acid, magnesium, arginine, plant sterols and phytochemical compounds (INC, 2016a).

At the symposium of the International Council of Nuts, Dr. Fran Grodstein presented his study, explaining that there is a relationship between increased nuts consumption and improved cognitive function in older men, namely processing speed, memory, attention and learning (INC, 2015).

Effects on body weight

Epidemiological studies indicate that the incorporation of nuts in diets does not compromise the defined goal, and may help maintain weight. Current data indicate that the inclusion of nuts in a weight maintenance program does not lead to weight gain and may assist in weight loss (Tan et al., 2014).

Peanut, unlike other nuts (which grow on trees or shrubs), is produced by a herbaceous, creeping plant and grows buried in the ground (Ljezur, 2008). Originating in South America, its earliest archaeological records of cultivation date from the period between 3800 and 2900 years BC (Veras et al., 2016).

The first Spanish and Portuguese explorers found the Indians growing peanuts in several of the West Indies Islands, in Mexico, and on the northeast and east coasts of Brazil. From these regions, peanuts were spread to Europe, to the coasts of Africa, Asia and the Pacific Islands (Hammons & Herman, 2016).

This legume crop is the fourth largest production in the world (Agronomia, Florestal, & Florestal, 2017).

From the pea and bean families, the peanut pod contains two to five seeds rich in proteins, carbohydrates, fibers, vitamins (Vitamin E, vitamin A) and minerals (potassium, magnesium and phosphorus) (Veras et al., 2016).

It is one of the most nutritious and, at the same time, easily digestible food products. These properties allowed this plant to be used by the prehistoric man, before knowing pottery or even dominating fire (Inácio, Rodrigues, & Quast, 2003).

Curious curiosities...

• Peanut was placed in pots in the Inca tombs so that the dead would feed during the passage to another life, according to beliefs (Veras et al., 2016).
• In the ruins of an ancient pyramid of Sipán, the archaeologist Walter Alva found the tomb of an important priest, dating back to the 3rd century, with its rich and abundant ornamentation still preserved. The most interesting thing is that among the hundreds of ornamental objects of gold, silver, feathers, pottery, richly carved stones and paintings, which portray the life, customs, ceremonial instruments, masks and scenes of the everyday life of this people, the only object representing food is a rich necklace, with a series of peanut fruits, molded in gold and silver, which adorned the priest's neck. This shows the great importance, culinary and religious, of peanut in people's lives (Inácio et al., 2003).

The hazelnut tree is one of the oldest species of the plant kingdom. Proof of this is the existence of numerous fossils of its leaves from the Tertiary age. It appears as a tree that sometimes takes the appearance of a bush, 4 to 5 m tall. The shrub can live up to 100 years, but only produces fruit between 4-6 and 40-50 years old. The species of this genus are all indigenous to the Northern Hemisphere and their habitat is situated from the high Himalayas to northern Canada (AP Silva, 2003).

Currently, the main hazelnut producers worldwide are Turkey, Italy, Spain and the United States. Portugal, although with a modest production in Europe, also appears as a potential hazelnut producer, especially in the areas of Beira Interior, Trás-os-Montes and Minho Interior.

Since the Neolithic period, in Europe, hazelnut has been used in human food. This is the seed of the hazelnut tree (Corylus avellana), belonging to the Betulaceae family, which comes from the Black Sea area and can currently be found in Europe, Asia and North America (AP Silva, 2003).

This fruit is an excellent food given its richness in lipids, proteins, minerals and vitamins. Potassium, phosphorus, magnesium and calcium are its most important minerals. They are also rich in fiber, calcium and vitamin E, presenting low amounts of sodium and sugars (Ed, Peixe, Energ, & Macroconstituintes, n.d.).

"DID YOU KNOW..."

• Dioscorides, in the first century BC, had already recommended hazelnut to calm the cough and to treat respiratory diseases.
• Saint Hildegard advised hazelnut as a remedy for impotence.
• Mattioli, a 16th-century Italian physician, advised a lotion composed of ground hazelnut and bear fat for hair growth.
• There are ancient Chinese references that regard hazelnut as one of the five sacred foods.
• In Central European countries, hazelnuts were offered to young couples on the day of marriage because they were considered the symbol of fertility. Also, because they were considered a symbol of fruitfulness, in many regions blessed hazelnuts were placed on the bridal bed, because the fruit was enclosed in a double "envelope", like a child in its mother's womb.
• According to a British belief, if a woman gets married in a year in which hazelnut production is high, she will have many children.
• A very ancient legend assures that the hazelnut tree is immune to lightning bolts, since during a storm it provided shelter to the Virgin Mary.
• In German tradition, hazelnuts are considered a symbol of immortality, and are placed in tombs with the purpose of favoring regeneration.
• According to the "Horoscope of the Trees", humans born between 22 and 31 March and between 24 September and 3 October belong to the sign of the hazelnut. This sign is designated as the "extraordinary" and has the following characteristics: Charming person. Not demanding, very understanding, knows how to make a good impression, activist for social causes. Popular, honest and tolerant companion.

There are several applications that have been given over the years to hazelnuts, among which the soothing of nerves. However, many of these applications have not been definitively demonstrated (AP Silva, 2003).

The cashew tree is a tree native to Brazil, found mainly in the North and Northeast regions. Its cultivation has spread since the 16th century to other countries such as: Mozambique, India, Angola and Kenya (Moraes, Da, Prateleira, & Produto, 2014).

The cashew (Anacardium occidentale L.) is composed of the peduncle, called pseudofruit, and the chestnut, which constitutes the true fruit. The cashew stands out nutritionally for presenting high levels of ascorbic acid, minerals, organic acids, carotenoids, phenolic compounds and carbohydrates. Among the main vitamins present are vitamin E, K, B6 and vitamin C (Santos, 2012).

With a brittle surface, the cashew is more susceptible to physical damage. This characteristic increases its perishability, which makes essential special care during transportation (Moraes et al., 2014).

It's a high protein food (average 25%) and, despite having a lot of fat, it's healthy, since its lipids are mainly monounsaturated fatty acids, namely oleic acid, which contributes to the reduction of cholesterol levels (LDL).

"DID YOU KNOW..."

• Cashews are used in traditional medicine, mainly in the Brazilian Northeast with therapeutic effects such as: relieving toothache, anti-inflammatory for gums and throat, bronchitis, arthritis, intestinal cramps, against diabetes, asthma and even used as an aphrodisiac (J. G. da Silva et al., 2007);
• The English name cashew is derived from the Portuguese word of similar pronunciation "caju", which in turn comes from the indigenous word "acaju" (Moraes et al., 2014);
• Although the cashew is definitely from Brazil, it wasn't Brazil that first spread its consumption, but rather India. While still under British rule, the fruit won over the palate of consumers in cold-weather regions and has established itself as one of the most commonly accepted tropical agricultural products by Americans, Canadians and Europeans in general. It is around them that the world's cashew agro-industry is turning today. (Bacharelado & Biologia, 2013).

The common almond tree, Amygdalus communis L., is a tree from the Rosaceae family and the Prunus genus. The almond is the nut that offers the best properties in view of its conservation, which is why shepherds and sailors included it in their diet (Ladra, 2011).

Almonds are a nutrient-rich food, and several studies have been conducted over the past decade on its potential health benefits. Almond consumption has been linked to reduced risk of chronic diseases, such as coronary artery disease (CHD), type 2 diabetes, and also for weight control and maintenance (Ros, 2010). 

Almonds are also a source of vitamin E, riboflavin, manganese, magnesium, calcium, phosphorus, potassium, copper, iron and zinc, as well as protein and fiber (Chen et al. 2006). In addition, the polyphenolic constituents of whole almonds were characterized and demonstrated to possess antioxidant action (Amarowicz et al. 2005; Chen et al. 2005, 2007; Chen and Blumberg 2008). Almonds are considered an important component of an healthy diet, and increased consumption has the potential to improve public health, especially if they replace foods high in saturated fatty acids, sugar and salt. Of all nuts, almonds contain the least amount of saturated lipids (Ros, 2010).

"DID YOU KNOW..."

• The almond is a biblical symbol of hope (Rebelo, 2017);
• Nowadays, North Americans give wedding guests a sack of sugary almonds representing: children, happiness, romance, health and fortune (Nuts, 2017);
• In China the almond is a symbol of enduring sadness and feminine beauty (Nuts, 2017);
• The almond tree is one of the few trees that can still flower with the fruit of the previous year still in their branches (Ladra, 2011).