Thousands of women are seeking natural alternatives to hormone replacement therapy after the largest clinical study was abruptly ended this summer due to an increase in complications.
But, in the world of natural, or botanical, therapy, there is even less research about plants' efficacy. Connie Weaver, head and distinguished professor of foods and nutrition at Purdue University, said there is an ever-growing need for more botanical research, provided by places such as Purdue's Botanicals Center for Age Related Diseases.
"I think botanicals are tremendously understudied," said Weaver, director of the center. "With hormone replacement therapy, we are going from knowing there is a slight risk of complications, to knowing less about botanicals. This is why the National Institutes of Health acknowledges botanicals' importance by funding botanical centers."
Purdue's center, which was established in 2000, researches the efficacy and safety of natural products, which are often used as preventive medicine. Purdue is working in collaboration with the University of Alabama-Birmingham and investigators at Rutgers University, Indiana University School of Medicine, University of Illinois and Bioanalytical Systems Inc.
The center will study the effectiveness of polyphenolic compounds thought to reduce the risk of osteoporosis, cardiovascular disease, cognitive function and other age-related diseases.
The center also is planning a botanical conference for 2003 about postmenopausal health that will bring leading hormone replacement therapy experts to Purdue.
One of Weaver's research projects at the center will evaluate the effectiveness of a commonly consumed botanical -- soy -- that is marketed to reduce the risk of bone fractures.
Weaver is studying if isoflavones in soy products replace estrogen and suppress bone resorption in postmenopausal women. Results will be determined by measuring the rate of bone loss for postmenopausal women by the measuring calcium detected in urine. The study, which is beginning year three of a five-year grant, uses over-the-counter products that claim to be preventive for bone health.
"The participation of the women in this study means more than ever now because of the need to find safe and effective alternatives that have the same preventative benefits as hormone replacement therapy," Weaver said.
In the past, 20 percent of postmenopausal women used hormone replacement therapy as preventive medicine for postmenopausal symptoms such as hot flashes, mood swings and vaginal dryness. Hormone replacement therapy also was used to strengthen bone and reduce the risk for osteoporosis.
In July the Women Health Initiative study of estrogen plus progestin hormone replacement therapy, involving 16,000 women, was halted three years early. Investigators found a slight, but increased, risk of breast cancer, heart attacks, blood clots and stokes. At the same time, a decrease in the risk for fractures and colon cancer also was observed. Physicians have been advised to weigh the risks individually for each patient.
"The question is now what?" Weaver said. "There are a lot of unknowns about botanical products. When it comes to natural products we are lacking clinical data, and often people rely on anecdotal evidence. Our current information on the effectiveness of botanicals as substitutes for hormone replacement therapy is scanty."
Even if a botanical product may have medicinal properties, it is not required to be tested in clinical trials, as drugs are by the Food and Drug Administration. Dietary supplements containing vitamins, minerals, amino acids, herbs or other botanicals, fall under the Dietary Health and Supplement Education Act. The act also prevents distributors of botanical products from making unsubstantiated claims and provides guidance for their marketing.
Weaver said it will take time to determine the role natural alternatives play in postmenopausal health. Anecdotal evidence suggests there are benefits to botanical sources. Women in Asian countries have consumed soy with phytoestrogen all their lives and don't seem to have menopausal symptoms, Weaver said.
"Scientists need to determine: is that genetic or is that diet," Weaver said.