Last December, Loretta McClintock, the wife of Representative Tom McClintock from California, died unexpectedly in her home in California. The cause of death was not released at the time. This week, an investigation by Kaiser Health News revealed that the coroner who performed her autopsy linked her death to white mulberry leaf, a centuries-old herbal remedy which, in recent years, has been marketed as a supplement for weight loss and diabetes management.
According to the Sacramento County Coroner’s report, which the Times has since obtained, Ms. McClintock died from dehydration caused by stomach inflammation as a result of “adverse effects of white mulberry leaf ingestion.” It is unclear what form of white mulberry leaf Ms. McClintock was taking, or why. The cause of death was classified as an accident. She was 61.
The news has raised questions about white mulberry’s health risks. While supplements derived from the herb are not strictly regulated, as supplements typically are not, doctors generally consider white mulberry leaf to be safe, and there is no clear evidence that it can cause severe adverse reactions.
What is white mulberry leaf?
White mulberry leaves grow on trees and shrubs native to Asia. They have been used as an herbal remedy for centuries to treat myriad health concerns, said Dr. Melinda Ring, director of the Osher Center for Integrative Health at Northwestern University.
Small studies have shown that mulberry leaf extract, which is typically taken in pill form, can reduce blood glucose levels. There is some evidence that the herb can suppress appetite and aid in weight loss in mice, but that is less robust, said Dr. Brent Bauer, director of the Mayo Clinic Complementary and Integrative Medicine Program. Some researchers have investigated other uses of the plant.
Kaiser Health News reported that a “partially intact” white mulberry leaf was found in Ms. McClintock’s stomach. People sometimes brew white mulberry leaves into a tea, a practice that dates back “many, many years, if not centuries,” Dr. Bauer added. The coroner’s report does not list what form of mulberry leaf Ms. McClintock ingested, or her motivations for taking the herb, but the news provides a reminder that supplements can sometimes pose risks, experts said.
“There are studies looking at it for everything from alopecia to high blood pressure to joint pain to osteoporosis,” said Dr. Ring. But, as with appetite and weight loss, there is limited evidence that the herb is an effective treatment for these conditions, she said.
Is white mulberry leaf safe?
According to the coroner’s report, Ms. McClintock complained that she had an upset stomach the day before her death. According to Dr. Bauer, people who consume more than one gram per day may experience stomach cramps or pain, Dr. Bauer said.
Dr. Pieter Cohen, an associate professor of medicine at the Cambridge Health Alliance, who studies supplements, said supplements can vary in the amount of an ingredient they contain. Just because a supplement says it contains a certain amount of an herb doesn’t mean a regulatory body is double-checking that measurement, he explained.
The CFSAN Adverse Event Reporting System, a database of adverse event and product complaints submitted to the F.D.A. for food, dietary supplements and cosmetics from January 2004 to March 2022, lists only four complaints that mention mulberry, and one complaint involving mulberry leaf.
Participants in studies involving mulberry extract have reported nausea, bloating and gas, but no more serious or lasting problems. “There’s really been very few, if any, serious effects seen with this,” Dr. Ring said.
Anyone who experiences an upset stomach, which can lead to diarrhea and vomiting, is theoretically at risk for dehydration, Dr. Ring added. But, she also said, it would be rare for white mulberry to cause such dehydration in normal doses — and many drugs and supplements can cause these symptoms.
A representative from the Sacramento County Coroner’s Office said they were unable to comment or release any additional information about the cause of Ms. McClintock’s death.
How can consumers find out if supplements are safe?
Under the Dietary Supplement Health and Education Act of 1994, known as the SHEA Act, dietary supplements are not considered medications, leaving them in a gray area in terms of regulation. “There’s no guarantee that a supplement is effective or safe,” Dr. Ring said.
You should talk to your primary care doctor before starting any supplement, Dr. Bauer stressed, particularly to ensure they will not interact with medications you may already be taking.
Dr. Cohen said people should be especially wary of weight loss products, which are among the most high-risk supplements on the market. The F.D.A. maintains a list of more than 200 “tainted weight loss products” the agency has notified the public about, with hidden ingredients found in pills and “detoxes.”
If you are seeking out safe supplements, aim for ones that only contain a single ingredient, he said. You especially want to avoid pills or gummies that make claims on their labels, saying they will transform aspects of your health. Try to find supplements that a third party has certified — Dr. Cohen recommends looking for U.S.T. or N.S.F. certification. “You really have to do your homework,” he said.
