On Thursdays, Dr. David Baker trades his stethoscope for a microscope -- leaving Stony Brook University's medical school for the day to study the biology of a widely consumed herbal plant.
Baker, a professor of obstetrics, gynecology and reproductive medicine, travels to The New York Botanical Garden in the Bronx where he's studying the herb black cohosh.
Pills and capsules of the plant have become increasingly popular among menopausal women who have shunned hormone replacement therapy in favor of the herbal alternative. Hormone therapy has been linked to blood clots, heart attacks and cancer.
But Baker has found that some brands of the over-the-counter remedy may contain very little, if any, of the active herb.
"We found some that had ornamental plant material from China," said Baker, who, along with colleagues at the botanical garden, has published research in a scientific journal that unmasks a problem that has become common in the supplement industry: discrepancies between labels and actual contents of supplement capsules.
"Patients were bringing me their supplements," Baker, said, noting that women were concerned the products were not helping them combat hot flashes, mood swings and other nagging menopausal symptoms. "So I tried to look into it and asked myself this question: Is what's on the bottle really what is in the bottle?"
Baker said he purchased 36 brands of black cohosh from retail outlets throughout Long Island and online. He and his collaborators -- Damon Little and Dennis Stevenson, both plant biologists -- subjected the specimens to rigorous genetic analysis. They searched in each sample for the equivalent of a fingerprint to produce a specific DNA bar code, the telltale marker revealing the genetic identity of black cohosh, or actaea racemosa, as the plant is formally known among botanists.
They found a quarter of the brands contained no black cohosh, not even a trace. The rest, however, passed the DNA test.
The team did not name the tested brands but is continuing the research, which has been ongoing for more than two years, examining a host of questions about black cohosh. The scientists hope to genetically analyze other herbs to determine whether label claims match the product in the bottle. They are interested in saw palmetto taken by many older men to prevent prostate problems.
Black cohosh, however, isn't the only supplement proven to have a discrepancy between label and capsule, studies have revealed
In a small analysis of vitamin C products this year, Dr. Tod Cooperman and colleagues at ConsumerLab.com found a few brands with label and pill differences. The lab is a private firm in White Plains that tests supplements for purity and efficacy.
Of 11 brands, three had a notable mismatch at the time of testing, according to the results: Douglas Laboratories' Ester C Plus had about 84 percent less vitamin C than claimed, while Rainbow Light Gummy Vitamin C Slices and ChildLife Vitamin C provided significantly more -- about 140 percent -- than claimed, the analysis found.
A 2013 study by researchers at Kaiser Permanente's Center for Health Research in Portland, Oregon, uncovered a similar mismatch involving vitamin D. Some brands had more active vitamin, others had less. Among those containing more than claimed, the product with the most had up to 400 times the listed amount. Both vitamins C and D can trigger physiological problems when doses are too high, experts say.
Baker worries more about herbal preparations because of the public's willingness to trust remedies billed as all natural.
"People trust these products," Baker said. "But they really need to know what they're buying, and they need to know what works and what doesn't work."