Index

2007-07-31

Antibacterial properties of spices and condiments

Ever since life emerged on Earth, organisms have been waging chemical warfare against each other. One of the earliest examples was the poisoning of anaerobes by oxygen-producing cyanobacteria 2500 million years ago. The oxygen produced by photosynthetic organisms on the surface of the earth makes life possible for us today, and anaerobes seek refuge in the deep and dark recesses of the biosphere.

For millennia, humans have used salt, alcohol, and vinegar as preservatives for food. Alcohol is the product of fermentation by yeast, whereas vinegar is the result of fungal fermentation. In 1676 Antoni van Leeuwenhoek, the inventor of the microscope, published his first observations of single-celled organisms which now we characterize as bacteria, yeasts, and protozoa. It was only in the nineteenth century that Louis Pasteur's experiments determined that food fermentation was caused by microorganisms that could be killed by heat. In 1945, bacteriologist Alexander Fleming succeeded in isolating the antibiotic substance penicillin from a mold that had contaminated and suppressed growth of his bacterial cultures.

Plants have evolved to defend themselves chemically from insects, yeasts, and fungi. Since ancient times, garlic has been claimed to cure a variety of conditions. Although many claims about garlic remain unconfirmed by modern research, its antibiotic properties can be clearly demonstrated. The Petri dish, above, shows the powerful inhibition of bacterial growth by garlic.[1] A study conducted at the University of California Irvine Medical Center showed that garlic juice, even when diluted significantly, has antibacterial activity against many pathogenic bacteria including antibiotic-resistant staphylococci (MRSA), enterococci, and Pseudomonas.[2]

Eating raw garlic can sometimes provide relief for an upset stomach caused by spoiled food. This remedy can be a tasty treat: Make a sauce by grating half a tomato, add 2 cloves of crushed raw garlic, one teaspoon of olive oil, and a dash of salt and pepper. Spoon the sauce onto a slice of toasted bread, and eat to your health!

[1] Inquiry Lab: Spices as Antibiotics (http://www.woodrow.org/teachers/bi/1999/projects/group5/photos_spice.html)
[2] Lee YL, Cesario T, Wang Y, Shanbrom E, Thrupp L, Antibacterial activity of vegetables and juices, Nutrition, 2003 Nov-Dec; 19(11-12): 994-6, PMID: 14624951

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