The Amazing Neem

BY AWAKE! CORRESPONDENT IN NIGERIA

“THE village pharmacy”—that is what people call the neem tree in India. For centuries people in that country have looked to the neem to provide relief from pain, fever, and infections. Believing that the neem can help purify their blood, many Hindus begin each year by eating a few neem leaves. People also clean their teeth with neem twigs, apply neem-leaf juice to skin disorders, and drink neem tea as a tonic.

In recent years scientists have shown a growing interest in the neem. However, a scientific report entitled Neem—A Tree for Solving Global Problems cautions: “Although the possibilities seem almost endless, nothing about neem is yet definite. The scientists who are most enthusiastic over the plant and its potential admit that at this stage the evidence to support their expectations is tentative.” Nevertheless, the report also states: “Two decades of research have revealed promising results in so many disciplines that this obscure species may be of enormous benefit to countries both poor and rich. Even some of the most cautious researchers are saying that ‘neem deserves to be called a wonder plant.’”

Its Role as a Tree

Found in tropical regions, the neem is a member of the mahogany family of trees. It grows up to 100 feet tall [30 m] and can achieve a girth of over 8 feet [2.5 m]. Since it is seldom leafless, it provides shade year-round. It grows quickly, requires little maintenance, and fares well in poor soil.

It was introduced to West Africa early in this century to provide shade and to halt the southward spread of the Sahara Desert. Foresters have also established the tree in Fiji, Mauritius, Saudi Arabia, Central and South America, and islands of the Caribbean. In the United States, there are experimental plots in southern areas of Arizona, California, and Florida.

In addition to providing year-round shade in hot climates, the neem can be used as firewood. Moreover, its termite-resistant wood is useful in construction and carpentry. So, judging solely on the basis of its usefulness as a tree, the neem does very well. But that is just the beginning.

Bugs Hate It

Because the people of India have long known that neem leaves repel troublesome insects, they place leaves in beds, books, bins, cupboards, and closets. In 1959 a German entomologist and his students became involved in neem research after witnessing a massive locust plague in the Sudan during which billions of locusts devoured the leaves of every tree except the neem.

Since then, scientists have learned that the neem’s complex chemical arsenal is effective against more than 200 insect species as well as various mites, nematodes, fungi, bacteria, and even several viruses. In one experiment, researchers placed soybean leaves in a container with Japanese beetles. Half of each leaf had been sprayed with neem extracts. The beetles devoured the untreated halves of each leaf but didn’t touch the treated portions. In fact, they died of starvation rather than eat even tiny portions of the treated leaves.

Such experiments suggest the possibility of developing an inexpensive, nontoxic, and easily prepared alternative to certain synthetic pesticides. In Nicaragua, for example, farmers mix pounded neem seed with water—80 grams of seed per liter of water. They soak the pounded seed for 12 hours, strain out the seeds, and then spray the water on the crops.

Neem products do not kill most insects outright. Neem sprays alter an insect’s life processes, so that eventually, it can no longer feed, breed, or metamorphose. But while neem products act against bugs, they do not appear to be harmful to birds, warm-blooded animals, or humans.

“The Village Pharmacy”

Then, there are other benefits to humans. The seeds and leaves contain compounds that demonstrate antiseptic, antiviral, and antifungal activity. There are suggestions that neem may be able to fight inflammation, hypertension, and ulcers. Medicines from neem extracts are said to battle diabetes and malaria. Other potential benefits include the following:

Insect repellents. One neem component, called salannin, powerfully repels certain biting insects. A fly and mosquito repellent made from neem oil is already on the market.

Dental hygiene. Millions of Indians break off a neem twig each morning, chew the end to soften it, and then use it to scrub their teeth and gums. Research has shown this to be beneficial, since compounds in the bark are strongly antiseptic.

Contraceptive properties. Neem oil is a strong spermicide and has proved effective in reducing the birth rate in laboratory animals. Experiments with monkeys hint that neem compounds might also make possible an oral birth-control pill for men.

Clearly, the neem is not the average tree. Although the evidence is not all in, the neem shows great promise—of improving pest control, promoting health, assisting reforestation, and, perhaps, checking overpopulation. Little wonder that people have called the amazing neem “God’s gift to mankind”!

[Pictures on page 23]

The neem, with inset of neem leaf