Natural History
Cashew nuts are the fruit of the cashew tree,  Anacardium occidentale,  which is in the same family as the mango and pistachio. The cashew is native to the coastal areas of north eastern Brazil. It was taken to other tropical countries in the 16th century by Portuguese explorers, but the nut itself didn’t gain popularity until early in the 20th century. Until then more interest was in its wood, the cashew balm and cashew apple.
The growth of the cashew nut on the tree is unusual and curious. The nut hangs below a juicy but inedible cashew ‘apple’ that itself hangs from the branches of the low tree. The nut itself is found within a double layer of skin. The inner shell contains a caustic resin called urushoil or cashew balm, which is toxic. It is used by industry to make varnishes and insecticides, and must be removed before the nut inside can be eaten. This is generally accomplished through steam treatment, which means that generally when you buy ‘raw’ cashews, they are not strictly raw because they have already been subjected to heat.
Conventionally farmed cashew nuts in developing countries are still treated with extremely toxic pesticides to deal with insects that eat the flowers before the fruits develop. These pesticides, like DDT, are generally banned in the developed countries which sell them, but are still sold elsewhere. There are horrific stories of deformities and even deaths, in both livestock and people, in the areas where intensive cashew farming happens. So it is even more important to ensure that you only buy certified organic cashew nuts.
Health Benefits
As with most nuts, cashews are high in calories but also in protein, mono-unsaturated fats and fibre, so you can eat less of them and still feel full and satisfied. Studies have found that people who eat nuts tend to be slimmer than those who don’t – possibly because their high calorific value means that you actually need to eat less overall.
Cashews have a lower fat content than most other nuts, and 75% of it is mono-unsaturated. About 75% again of the mono-unsaturated fat is oleic acid, which promotes good cardiovascular health, even in those with diabetes, since they help reduce high triglyceride levels. Cashews are also high in palmitoleic acid.
Copper: Just 35 g of cashews provide 37.5% of the daily recommended intake of Copper. Copper plays a key role in many processes including iron utilisation, elimination of free radcials, the development of bone and connective tissue, and the production of melanin.
Magnesium: A handful of cashews provides 25% of the RDV of magnesium. Magnesium is essential for healthy bone structure – 2/3 of the magnesium in our bodies is in our skeleton. Some helps to give physical structure to the bones and the rest stored on the surface where its stored for the body to draw upon as needed. Magnesium also helps to regulate nerve and muscle tone by balancing calcium, and thereby keeping muscles and nerves relaxed. Inadequate magnesium can mean that too much calcium gets into the nerve cells and they become overactivated, causing excessive contraction. Magnesium also helps maintain healthy blood pressure and reduces insulin resistance – so it is an important mineral for diabetics.
Anti-depressant: Cashews contain large amounts of the amino acid tryptophan, which is said to be ‘Nature’s antidepressant’. Just half a cup of cashews contains 470mg of tryptophan, which may qualify as a therapeutic dose. They have been said to offer a natural and healthy alternative to chemical and side-effect causing antidepressants like Prozac. Your body breaks down tryptophan into anxiety-reducing, snooze-inducing niacin, and more importantly, also serotonin. Serotonin provokes feelings of well-being and relaxed contentment, and many chemical antidepressants either mimic serotonin or artificially keep the body’s own serotonin levels high.
Other benefits:
Cashews are rich in:
- proanthocyanidins – a class of flavonols that starve tumours and stop cancer cells from dividing.
- selenium (but not as good as Brazil nuts!), which is an important co-factor for antioxidant enzymes such as Glutathione peroxidase – one of the most powerful antioxidants in the body.
- Zinc, which is a co-factor in many enzymes that regulate growth and development, sperm generation, digestion and nucleic acid synthesis.
- many essential vitamins including pantothenic acid (B5), pyridoxine (B6), riboflavin and thiamin (B1) – all of which the body needs to source from external sources.
- zea-xanthin, an important pigment flavonoid antioxidant which is absorbed into the retina in the eye and helps filter UV rays, and to prevent age-relvated macular degeneration.
