Nuts are nutrition powerhouses and are a staple of Mediterranean diet, which has been linked to longevity. One of their best qualities is that nuts can prevent cardiovascular diseases. Nuts and nut butters are a great source of unsaturated fats that help lower blood cholesterol.

When it comes to nut butters, choose all-natural with no added sodium or sugar.

Nuts are rich in vitamin E and potassium. Most are high in minerals, including calcium, iron, magnesium and zinc. Many are a good source of folate, niacin, and other B vitamins. They are a good source of protein, especially when combined with legumes.

However, there are some downsides to nuts. They are high in fat and calories. Oils quickly turn sour when exposed to oxygen. Nuts and seeds are also some of the common allergy triggers. These may also cause choking in children and people with swallowing problems. The molds in peanuts and other nuts may produce cancer-causing aflatoxins.

Nuts and seeds are packed with all the nutrients needed to grow an entire new plant and have been valued for their nutritional content since prehistoric times. Nut and seed bearing plants have been cultivated as early as 10000 BC.

Coconuts are the world’s leading nut crop, followed by peanuts, which are actually legumes but often classified and consumed as nuts.

Most nuts and seeds are a rich source of vitamins, especially folate, B vitamins, and vitamin E, minerals such as iron, calcium, selenium, magnesium, manganese, phosphorus, zinc and potassium, fibre, essential fatty acids, plant compounds such as flavonoids and plant sterols.

Certain nuts are higher in certain nutrients. A half-cup serving of almonds, peanuts, pine nuts, pistachios, or sunflower seeds, for example, provides more than 500 mg of potassium, more than is in a whole banana.

A 30-gram serving of almonds provides almost 50 per cent of the recommended dietary allowance (RDA) of vitamin E and a similar serving of hazelnuts, about 30 per cent.

Nuts and seeds are one of the best food sources of vitamin E, an important antioxidant that enhances the immune system, protects cell membranes, and helps make red blood cells.

A half-cup of almonds contains 3 mg of iron. Pistachios have 2 mg. Pumpkin, sesame seeds and flax are also good sources.

Brazil nuts are high in the antioxidant selenium. 7 gram serving provides more than twice the RDA for this mineral.

Walnuts are especially rich in ellagic acid, an antioxidant that may inhibit the growth of cancer cells. Walnuts are also rich in omega-3 fatty acids.

Hazelnuts are rich in vitamin E, fibre and copper and contain the same amount of potassium as half a banana.

One ounce of sunflower seeds contains about 75 per cent of RDA of vitamin E. Sunflower seeds are also rich in selenium, copper, fibre, iron, zinc, folate and vitamin B6.

Most nuts provide good amounts of protein. With the exception of peanuts, however, they lack lysine, an essential amino acid necessary to make a complete protein. This amino acid can easily be obtained by combining nut with legumes. Nut can provide a good source of protein in a vegetarian diet.

Most nuts and seeds are a good source of dietary fibre.

Nuts also contain plant sterols that can lower cholesterol and may offer some protection against cancer.

Nuts have two major drawbacks. They are high in calories and fats. But with the exception of coconuts and palm nuts, their fat is mostly mono or polyunsaturated. These are considered heart-friendly fats, especially when they replace saturated fats. Still, nuts should be consumed in moderation.

If you refrigerate or freeze nuts, their oil quickly turns sour. Never use nuts that are moldy or have an off taste. Molds especially on peanuts, create aflatoxins, substances that can cause liver cancer.

Some nuts, like peanuts (technically legumes), provoke allergic reactions in many people. Symptoms range from a tingling sensation in the mouth to hives and, in extreme cases, to anaphylaxis, a life-threatening emergency. But because the different varieties are not closely related, a person who is allergic to walnuts, for example, may be able to eat another type of nut or seed.

Other facts about nuts:

Ø  Gathered from trees in the Amazon basin, Brazil nuts are rarely cultivated.

Ø  There are two varieties of almond-the edible type is sweet. The inedible type is bitter and contains a form of cyanide.

Ø  All pistachios are tan, but imported ones are usually dyed red, and some domestic varieties are bleached white.

Ø  By weight, both pumpkin and sesame seeds have more iron than liver does.

Ø  Cashew shells contain urushiol, the same irritating oil that is in poison ivy. Heating inactivates urushiol, so toasted cashews are safe to eat. The raw nuts, however, should never be eaten.

Ø  Betel nuts are frequently chewed by many Asians despite the high probability that they contain a carcinogen and are likely responsible for numerous cases of oral cancer.