Caffeine is a natural pesticide that protects plants by paralyzing and killing the insects that feed upon them. According to one study a known pesticide combined with a small amount of a synthetic caffeine compound was 10 times more potent than the pesticide itself, and raised the possibility of developing caffeine-based insecticides that would be harmless to animals and humans for spraying on food crops.

Coffee Nature’s Own Pesticide

There are mixed opinions on whether caffeine is good for humans or not. It can do many things, including sharpening your attention, stave off Alzheimer’s disease, and decrease your risk of cancer. It also cranks up your blood sugar, interacts adversely with your prescription medication, and can cause Stomach problems like Gastric Reflux and Gastritis.

According to one of the first articles on the subject, appearing in the New York Times October 1984,  reported that Caffeine and related compounds were potent, natural insecticides that helped plants to ward off damaging pests and the findings could lead to a new way to fight insects.

In a report published


in the journal Science, Dr. James A. Nathanson said the natural function of caffeine in plants has been a mystery, even though it has been used for centuries as a stimulant by millions of people.

Arabica Tree     Click to Enlarge

Dr. Nathanson, a neurologist at Harvard Medical School and Massachusetts General Hospital, said that despite all of the research that has been done on caffeine in mammals, no one to my knowledge has ever determined why it is present in plants”

”Over time, plants have developed certain defenses to protect themselves against insects, and we suspected that caffeine might have been present for that purpose – as a natural insecticide”.

Disturbed Insect Behavior Tests with powdered tea and coffee, as well as with pure caffeine and related compounds, found that they disturbed the behavior and growth of numerous insects and their larvae. The mosquito larvae, for instance, became so uncoordinated with exposure to these compounds that they could not swim to the water’s surface for air and drowned.

At concentrated doses, the test substances killed the insects within hours or a few days, the report said. In tests, caffeine distorted behavior, depressed food consumption or inhibited reproduction of tobacco hornworms, mealworms, milkweed bugs, butterfly larvae and mosquito larvae.

The scientist also found that when caffeine compounds were mixed with certain other natural insecticides, an increase in their killing power occurred. The potency of the combination, the researchers found, was far greater than that of the sum of the parts..

But he cautioned that it might take at least five years for large-scale testing to determine if caffeine-related insecticides were practical and economical.

Dr. Nathansan said caffeine appeared to suppress certain enzymes in insect nervous systems. ”The side effects of caffeine-like compounds appear to be relatively minor in humans and animals”.

The miracle substance, as it turns out, does a lot for animal bodies as well. Specifically, it creates piles and piles of animal bodies. Caffeine is a potent pesticide. Although there are insects who have adapted to caffeine, most lie down and die when they get a dose of it.

After spraying lots of produce with caffeine solution, and watching snails and other bugs stop feeding to curl up and die, scientists believe they understand the mechanism. Caffeine inhibits the workings of a certain enzyme. This enzyme is meant to break down adenosine monophosphate. It works as a messenger in cells — in particular the messenger that drives up the bodies use of sugars and of a little hormone called adrenaline. But adenosine monophosphate isn’t all good. It’s also a waste product. It forms part of RNA, and when RNA breaks down, the adenosine monophosphate is meant to be further broken down by enzymes and excreted from the body. If the adenosine monophosphate isn’t broken down, it just circulates in the body, throwing off the metabolism, overstimulating the production of hormones, and poisoning the system until the entire body breaks down. This is easier to do in a snail than in a full-sized human, so we escape the deadly effect of coffee with little more than a spring in our step. But maybe not if you consume higher doses than 400 mg, four or five cups per day, as recommended by our Doctors. 


  1. Gavin says:

    My wife had chronic gastritis and insomnia with a difficulty in keeping food down which was ruining her quality of life. I lost count of the number of pills she had tried without any relief until she changed doctors. It turned out it was the caffeine in the dozen cups of tea/coffee she was drinking that was causing her problems. It took three months before her symptoms disappeared. We now drink more water and use Roo Tea as a substitute for tea and Caro (made from barley) instead of coffee.

  2. Ruby says:

    Caffeine is like any other stimulant…..it gives you a buzz to start with, after which your body builds up a tolerance, then you need higher doses to get the same effect, which in turn starts to affect your health and the only thing you notice after that is when you decide to stop.

  3. Catherine West says:

    Withdrawal symptoms after moderate use of caffeine can be so severe that it can act as a deterrent from giving it up. The longer the period of suffering the symptoms the greater the effect just one cuppa has in removing these symptoms. What I have done is to set a limit on my intake of just two cups per day and stick to it.


  4. charles says:

    They did not go any further with the trialling of caffeine in pesticides to spray our food crops. Imagine if it were successful what it would do to the coffee and tea industry had that idea gone any further. That is why it went no further.

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