Eat your vegetables, take your medicine

By Katie Weber

The next time you taste the tomatoes on your pizza, the onions on your hamburger or the garlic in your pasta sauce, thank your ancestors. Humans domesticated those and other plants thousands of years ago, when they may have been eaten to prevent or treat illness, as well as to fill empty stomachs. They may have used tomatoes to treat eye disease and certain skin conditions, and consumed onions and garlic to prevent blood clots.

However, one University of Wisconsin–Madison scientist feels that Americans today no longer recognize the ancient connection between plants, medicine and health. A plant geneticist and breeder who has long been interested in the link between human health and agriculture, Irwin Goldman is working to understand it and apply it to the modern diet.

“Plants were used as medicine for most of human history,” says Goldman, of the College of Agricultural and Life Sciences. “If people see the historic connection to plants, they might be more careful about consuming enough fruits and vegetables.”

Goldman, who is spending a semester doing research at Harvard University’s Arnold Arboretum, recently authored a historical look at how plants have many functions other than food. The article will appear in “New Crops, New Uses,” which Purdue University will publish later this year.

In addition to writing about the multiple functions of foods, Goldman also researches them. He and graduate student William Briggs, along with John Folts, a cardiologist from the School of Medicine, have found that the sulfur compounds in onions – the same ones that make you cry – help keep blood platelets from clotting and causing heart attacks and strokes. Even relatively small amounts of the sulfur compounds in blood are effective, says Goldman. And, since these sulfur compounds help protect onions from insects and diseases, “we’re eating and benefiting from natural pesticides,” he says.

The knowledge that onions act to thin the blood has been around for at least 4,000 years, explains Goldman. A document from the time of the ancient Egyptians explains how onions and garlic can be used to increase circulation. This is just one example of the historical link that interests Goldman, and it also illustrates another key point of his work: nutrients and vitamins aren’t the only beneficial compounds in plants. Sometimes plant compounds have health benefits, but we don’t fully understand all the possible effects of these compounds, he says.

In some parts of the world, such as Europe, plant-based remedies are routinely prescribed, even for serious diseases such as prostate cancer. In the United States, however, people now rely on science to chemically synthesize individual compounds that are purer and more concentrated than natural medicines, according to Goldman.

Recently, a renewed interest in natural and alternative medical therapies has made Americans curious about the medicinal qualities of natural substances. Curious health care consumers are finding that even commonly prescribed drugs have their origins in plants. For example, aspirin was initially isolated from a compound in the willow tree.

In the future, plant breeders may focus on specific health benefits and compounds associated with their crops. Meanwhile, Goldman believes that people should recognize the value of fruits and vegetables and increase their overall consumption of them to protect against chronic diseases. “Agriculture’s role in human health has not always been appreciated by the public,” he says.

Goldman is now developing a UW–Madison class about the many functions of foods. He plans to incorporate agriculture, medicine, history and public policy in the course.