Type of nut Nutrition Health effects

A nut is a fruit composed of an inedible hard shell and a seed, which is generally edible. In general usage, a wide variety of dried seeds are called nuts, but in a botanical context "nut" implies that the shell does not open to release the seed (indehiscent). The translation of "nut" in certain languages frequently requires paraphrases, as the word is ambiguous.


Nuts being sold in a market
Most seeds come from fruits that naturally free themselves from the shell, unlike nuts such as hazelnuts, chestnuts, and acorns, which have hard shell walls and originate from a compound ovary. The general and original usage of the term is less restrictive, and many nuts (in the culinary sense), such as almonds, pecans, pistachios, walnuts, and Brazil nuts,are not nuts in a botanical sense. Common usage of the term often refers to any hard-walled, edible kernel as a nut.

A nut in cuisine is a much less restrictive category than a nut in botany, as the term is applied to many seeds that have nuts that are not botanically correct. Any large, oily kernels found within a shell and used in food are commonly called nuts.

Nuts are an important source of nutrients for both humans and wildlife. Because nuts generally have a high oil content, they are a highly prized food and energy source. A large number of seeds are edible by humans and used in cooking, eaten raw, sprouted, or roasted as a snack food, or pressed for oil that is used in cookery and cosmetics. Nuts (or seeds generally) are also a significant source of nutrition for wildlife. This is particularly true in temperate climates where animals such as jays and squirrels store acorns and other nuts during the autumn to keep from starving during the late autumn, all of winter, and early spring.

Nuts are the source of energy and nutrients for the new plant. They contain a relatively large quantity of calories, essential unsaturated and monounsaturated fats including linoleic acid and linolenic acid, vitamins, and essential amino acids. Many nuts are good sources of vitamin E, vitamin B2, folate, fiber, and the essential minerals magnesium, phosphorus, potassium, copper, and selenium. Nuts are most healthy in their raw unroasted form,[6] because roasting can significantly damage and destroy fats during the process. Unroasted walnuts have twice as many antioxidants as other nuts or seeds. It is controversial whether increasing dietary antioxidants confers benefit or harm.