Written by Dr. Patrick Massey, MD, PH.D. Dr. Massey discusses NEEM oil as an effective substitute for DEET.

If someone were to ask what is the most dangerous animal on the planet, it wouldn’t be the lion or sharks — it would be the mosquito. Throughout history it has been estimated that mosquito-borne diseases have killed more humans than all the wars combined. Every year tens of millions of people die from mosquito-borne illnesses.

Well, summer is here, it’s been raining several times a week and mosquito season is in full force.

Most people enjoy being outside during the summer and as a result are bitten by mosquitoes.

The best way to reduce the risk of being bitten by a mosquito is to destroy all of the ponds and water in which mosquito eggs grow. However, not only is this impossible, but it would be ecologically disastrous.

The next best approach is to use some form of mosquito repellent.

At a time when we are beginning to realize the toxicities associated with many of the chemicals we use, is there a safe and effective, natural mosquito repellent? The answer is yes.

In Illinois, mosquito-borne illnesses include viruses that can cause life-threatening encephalopathy and meningitis. These illnesses include West Nile virus and viruses responsible for St. Louis encephalitis, Eastern equine encephalitis and Western equine encephalitis (highest mortality rate), and the Lacrosse virus resulting in California encephalitis.

The mosquitoes that carry these diseases do not only stay with the local area. Some species, especially after heavy rains, will travel up to 10 miles to find a blood meal.

Local spraying of your yard with insecticides and mosquito repellents may be insufficient to prevent mosquito bites. The most commonly used mosquito repellent is a chemical known as DEET (N,N-Diethyl-meta-toluamide). It is a very effective mosquito repellent, in some studies yielding up to 100 percent protection for hours.

However, there have been documented neurologic toxicities when using DEET inappropriately, especially in young children.

So, people have searched for an alternative that is natural and effective. There is some reasonable medical research to indicate that the oil from the seeds of an evergreen tree from India, the neem tree, could be a safe solution.

One recent medical study published in the Malaria Journal compared neem oil to DEET in an area of the world where malaria mosquitoes are endemic. DEET was definitely superior; however, neem oil was also quite effective in reducing the chance of mosquito bite by almost 70 percent over four hours.

Other medical studies have demonstrated that neem oil mixed with coconut oil can reduce the risk of mosquito bites by almost 100 percent over the same time frame.

Neem oil has a long history of use in India for a variety of medicinal and industrial purposes. It has been used against parasites and insects as well as topical treatment for various skin conditions.

There are potential drawbacks to the use of neem oil. Extended consumption of neem oil (not recommended) could potentially result in sterility in men and liver damage in children. But, no toxicities have been noted with use of neem oil on the skin.

• Patrick B. Massey, MD, PH.D., is medical director for complementary and alternative medicine at Alexian Brothers Hospital Network and president of ALT-MED Medical and Physical Therapy, 1544 Nerge Road, Elk Grove Village. His website is www.alt-med.org.