Nut (food)

Botanically, a nut is a fruit with a woody pericarp developing from a syncarpous gynoecium. True nuts include, for example, chestnut, hazelnut and filbert. Culinarily, the term 'nut' is used much more widely, and includes examples of drupes (such as pecans and almonds) or seeds (such as pine nuts and peanuts). Also widely known as nuts are dry drupes, which include pecans, almonds, macadamia (Macadamia integrifolia), candlenut (Aleurites moluccanus) and the water caltrop (Trapa bicornis). A drupe is an indehiscent fruit that has an outer fleshy part consisting of the exocarp, or skin, and mesocarp, or flesh, which surround a single pit or stone, the endocarp with a seed (kernel) inside. In a dry drupe, the outer parts dry up and the remaining husk is part of the ovary wall or pericarp, and the hard inner wall surrounding the seed represents the inner part of the pericarp. Walnuts and hickories (Juglandaceae) have fruits that are difficult to classify. They are considered to be nuts under some definitions but are also referred to as drupaceous nuts. In common use, a "tree nut" is, as the name implies, any nut coming from a tree. This most often comes up regarding food allergies; a person may be allergic specifically to peanuts (which are not tree nuts but legumes), whereas others may be allergic to the wider range of nuts that grow on trees. ==Production==

In the 21st century, about a dozen species constitute most of the worldwide production of nuts, shown in the table below for major commercial nuts. == Toxicity ==

Nuts used for food are a common source of food allergens. Many experts suggest that a person with an allergy to peanuts should avoid eating tree nuts, and vice versa. In the European Union, foods containing nuts must be labelled. The EU regulation requires labelling of foods containing peanuts or nuts, specified as: • almonds (Amygdalus communis L.), • hazelnuts (Corylus avellana), • walnuts (Juglans regia), • cashews (Anacardium occidentale), • pecan nuts (Carya illinoinensis (Wangenh.) K. Koch), • Brazil nuts (Bertholletia excelsa), • pistachio nuts (Pistacia vera), • macadamia or Queensland nuts (Macadamia ternifolia) and products thereof, except for nuts used for making alcoholic distillates including ethyl alcohol of agricultural origin. == Nutrition ==

, sold as a snack food Nuts contain the diverse nutrients that are needed for the growth of a new plant. The fats are largely unsaturated and nuts are a source of essential omega-3 fatty acids. As part of a healthy human diet, long-term consumption of diverse nutrients in nuts may contribute to a lower risk of cardiovascular diseases, reduced levels of blood cholesterol, and lower all-cause mortality. This table lists the percentage of various nutrients in four unroasted seeds. Units are presumably grams, and out of 100 g. Research Nuts are under preliminary research to assess whether their consumption is associated with lower risk for some diseases, such as cardiovascular diseases and cancer. A 2014 review indicated that consuming one or more servings of nuts or peanut butter per day was associated with lower risk of ischemic heart disease, overall cardiovascular disease, stroke in women, and all-cause mortality. A 2022 umbrella review confirmed these findings and found a 22% reduction in all-cause mortality. ==See also==