NIH Awards $6 Million to ISU and UI to Study Echinacea and St. John's Wort

July 23rd, 2002

AMES, Iowa — Two of the nation's top-selling herbal dietary supplement ingredients will undergo scientific scrutiny in a new National Institutes of Health (NIH) research program on dietary botanical supplements at Iowa State University.

A $6 million, five-year grant from NIH's National Institute for Environmental Health Sciences and Office of Dietary Supplements links Iowa State and University of Iowa scientists in multidisciplinary research on Echinacea and St. John's wort (Hypericum).

Echinacea is an herb used to treat infection and inflammation and to help wounds heal. St. John's wort has long been used for ailments ranging from headache to depression. Currently, there is much interest in the anti-viral properties of St. John's wort.

Echinacea and St. John's wort were selected for study because they are popular with consumers and there is substantial evidence of their potential health benefits. Both are grown in Iowa.

"More and more people use botanical supplements, a trend that reflects awareness of the potential health benefits of plants. Yet, we know very little about the activity of these supplements — the nature of their active components and the factors in the plants that interact to optimize a health benefit or cause toxicity," said Diane Birt, who will direct the new research program. Birt is professor and chair of Iowa State's food science and human nutrition department and director of the Center for Designing Foods to Improve Nutrition.

The grant was announced by Sen. Tom Harkin, who is the chair of the Senate panel that funds NIH research.

"On one of my recent visits to Iowa State, we discussed the contributions their great faculty could bring to improving research on dietary supplements. I'm proud that this important new research program will be at Iowa State and be linked to the medical scientists at the University of Iowa. Consumers want and need improved information on dietary supplements and this center will help make sure they get it," Harkin said

The research program will include plant scientists, epidemiologists, chemists, molecular biologists, nutritionists and statisticians. More than 20 scientists will conduct studies to uncover the scientific workings of Echinacea and St. John's wort.

Researchers will identify the bioactive constituents in the two plants. Bioactive constituents are the chemical components that cause an effect on humans or other living organisms. State-of-the-art instrumentation at Iowa State's Metabolomics Research Laboratory will enable researchers to identify these constituents.

The researchers will pinpoint genetic, growth, environmental and harvest conditions that influence the quantity and quality of the bioactive ingredients in Echinacea and St. John's wort. By identifying the chemicals responsible for specific health and medicinal effects, it will be possible to standardize and label supplements based on their actual chemical content, Birt said.

The research on the herbs' growth conditions and the developmental and genetic factors that influence bioactivity will allow producers to grow appropriate varieties under conditions that promote bioactivity. In addition, Birt said, a better understanding of the relationship between plant genetics and bioactivity could point to related herbs that may have useful medicinal and nutritive bioactivities.

"Supplement manufacturers can use our findings to develop the best procedures for herb processing, storage and product delivery," Birt said.

Medical researchers at the University of Iowa will conduct epidemiological studies to determine the characteristics of human populations most likely to have either clinical improvements or adverse effects from using botanicals as dietary supplements. These studies will improve the understanding of potential risks and benefits and provide critical, science-based information for health practitioners and consumers.

In addition to the University of Iowa and Iowa State University, researchers at Louisiana State University, Baton Rouge, will be involved in the research program.

Iowa State is home to the U. S. Department of Agriculture's North Central Regional Plant Introduction Station, which maintains the nation's germplasm repository for Echinacea, conserving all known species in the genus.

In 1999, Congress appropriated funds for the NIH Office of Dietary Supplements to develop a botanical research center initiative. The new program at Iowa State is the sixth national botanical research program. The others are at the University of Arizona, Tucson; the University of California, Los Angeles; the University of Illinois, Chicago; the University of Missouri, Columbia; and Purdue University, West Lafayette, Ind.

The research program on dietary botanical supplements at ISU will be administered through the Center for Designing Foods to Improve Nutrition, which is a center of Iowa State's Plant Sciences Institute, College of Agriculture and College of Family and Consumer Sciences.


Note to editors: A downloadable, print-quality photo of Birt is at

Fact sheet


Species are popularly known as echinacea, purple coneflower or Kansas snakeroot
Perennial herbs
Native to eastern half of North America
There are nine species; three are commonly used for medicinal purposes, especially for infection, inflammation and to heal wounds
Widely used as medicine by Native Americans
Both oral and topical preparations are used

St. John's wort (Hypericum perforatum)

Flowering perennial
Grows wild in Europe and as an escaped weed in North America
There are more than 370 species in nature
Folk medicine with a long history of use to treat a wide range of ailments, including bed wetting, headache, rheumatism and depression


Diane Birt, Food Science and Human Nutrition, (515) 294-3011

Robert Wallace, Epidemiology, (319) 384-5005

Teddi Barron, News Service, (515) 294-4778