Botanists and herbal medicine experts are challenging the Sacramento County coroner’s conclusion that white mulberry (Morus alba)—an herb with a long record of safe use—caused the death of Loretta McClintock, wife of Congressman Tom McClintock (R-CA4).
Mrs. McClintock, died unexpectedly on December 15, 2021, at the age of 61 years. Her husband had returned home for the holiday recess, and found his wife unresponsive.
Initially, the death certificate, dated December 20, said the immediate cause of death was “pending,” and mentioned an “accident pending investigation.” A December 16 autopsy report suggested that Mrs. McClintock’s death could be due to severe dehydration, secondary to gastroenteritis, likely caused by “ingested white mulberry leaf.”
In a subsequent report dated March 10, 2022, the coroner’s office declared that McClintock’s death was due to “adverse effects of white mulberry leaf ingestion.” This report—and an updated death certificate–were not released to the public until July. The story made national headlines following an August 24 report by Samantha Young in Kaiser Health News.
“A Partial Plant Leaf”
During the autopsy, investigators found a 1 1/8 inch by 1 7/8 inch fragment of a leaf in McClintock’s stomach, which—for reasons that have not been clearly disclosed–the coroner’s office claimed was white mulberry (Morus alba).
Widely used as fodder for cattle, goats and other livestock, white mulberry leaves are rich in polyphenols and anthocyanidins. They are also the primary food for silkworms. Though seldom used as a human food, the leaves are a common remedy in traditional Chinese medicine. Known as Sang Shèn Zǐ or Sang Ye, mulberry leaves are typically ingested as teas or ground powder form, and prescribed to treat lung and liver conditions.
The coroner’s line of evidence implicating white mulberry leaf is shaky at best. And even if the plant identification is correct—which many experts have challenged–1,800 years of traditional use and several good quality modern trials suggest that it is highly unlikely this herb would trigger a lethal reaction.
More recently, supplement makers and some functional medicine practitioners have promoted the herb, or extracts from it, for glucose regulation, lipid reduction, and weight management, based on clinical studies suggesting it has promise for these indications.
The coroners gave no reason for the initial suspicion that the leaf fragment they found was mulberry. They make no mention of, for example, a family member stating that Lori McClintock was using this herb, or that a package containing mulberry leaves was found in her home. The Kaiser story and other media reports noted that McClintock had recently begun dieting and exercising in the months before her death, but none mentioned that she was using mulberry or any other herbs.
Predictably, the Kaiser article sparked a barrage of poorly researched media reports blaming Mrs. McClintock’s untimely death on the “behemoth,” “poorly regulated,” and “highly-influential” dietary supplements industry.
Egregious headlines, like this one from Newsweek—How Did Herbal Remedy Kill Lori McClintock?—peppered newsfeeds in the weeks after the Kaiser report.
But the coroner’s line of evidence implicating white mulberry leaf is shaky at best. And even if the plant identification is correct—which many experts have challenged–1,800 years of traditional use and several good quality modern trials suggest that it is highly unlikely this herb would trigger a lethal reaction.
Further, the size and condition of the leaf fragment found in the deceased woman’s stomach suggests it did not come from a tea, and could not have come from dietary supplements, which are typically in liquid, tablet, powder, or capsule form. The nature of the plant fragment suggests McClintock had eaten uncooked, unprocessed leaf.
Roy Upton, President of the American Herbal Pharmacopoeia, notes that while human ingestion of raw mulberry leaves is not unheard of, particularly in Asia, it is highly unusual especially in the US. The leaves are bitter and generally unpleasant to the taste.
Upton also points out that in TCM herbal practice, the dose range for white mulberry leaves is 3.5 to 9 grams, and “there’s no history of human toxicity with this.” He added that animal studies show the plant to be safe at levels as high as 4 g per Kg.
A subsequent Kaiser Health News article, also by Samantha Young and released on September 14, more or less admitted that the case against mulberry is weak.
“Sacramento County Coroner Kimberly Gin has not explained — nor provided records that explain — why she determined white mulberry leaf led to the dehydration that killed McClintock at age 61, fueling skepticism among a variety of experts,” writes Young.
“There is no other reference to her use of white mulberry leaves, supplements, extracts, powders — or any other method of ingesting the plant — in the documents the coroner’s office has released relating to the case.”
In describing the contents of Mrs. McClintock’s gastrointestinal tract, the coroner’s report states: “The esophagus is intact throughout. The stomach is not distended. It contains 50 cc of tan fluid. The mucosa is smooth and glistening. Portions of tablets and capsules cannot be discerned in the stomach. A partial plant leaf is present within the contents. The external and in situ appearance of the small intestine and colon are unremarkable. The small intestine and colon are opened along the anti-mesenteric border and are unremarkable. The appendix is present.”
The size and condition of the leaf fragment found in the deceased woman’s stomach suggests it did not come from a tea, and could not have come from dietary supplements, which are typically in liquid, tablet, powder, or capsule form.
There is no detailed description of the contents of the intestines. It would be logical to think that if a leaf fragment was found in the stomach, more of this leaf material might be present in the small or large intestines. Yet the coroners did not indicate such a finding.
Likewise, there is no information on morphologic changes indicative of gastroenteritis, which is usually caused by microbial pathogens, not by herbs. Neither is there any listing of other prescription, OTC, or supplement products that the deceased may have been using.
The conclusion that the congressman’s wife died from dehydration seems based largely on lab work done by NMS Labs, a forensic toxicology lab in Horsham, PA. NMS’s tests showed elevated vitreous sodium, creatinine, and urea nitrogen. But the Sacramento coroners fail to describe how the leaf fragment in question would have caused the dehydration.
Chief Pathologist Jason Tovar, MD, who signed the autopsy report, declined Holistic Primary Care’s request for an interview. Head coroner Kimberly Gin has categorically refused to comment on the case in the media.
The coroner’s report gives no information about analytical methods employed to identify the “partial plant leaf” they found inside Mrs. McClintock.
Presumably, they based their conclusions on a December 29, 2021 report from botanist Alison Colwell, PhD, Curator or the UC Davis Center for Plant Diversity. In her letter to the supervising deputy coroner, Colwell states:
“I picked up a leaf fragment from your office yesterday for identification…This leaf fragment was taken from the stomach of a deceased person. It measures 1 1/8” by 1 7/8” and includes a portion of the center of one leaf with a portion of one major vein and two adjacent secondary veins joined by a single bronchiodromous loop. The leaf tissue retains flexibility and some green color, so the leaf was likely ingested when fresh.
In comparing this leaf fragment to fresh leaves and to our extensive library of pressed specimens, we determine that this leaf fragment is a match to Morus alba, the white mulberry. The sample matches white mulberry specimens in all traits examined: upper and lower leaf surface texture, hairiness, venation pattern, intercostal tissue patterning, the frequency, size and shape of the stomata and the embeddedness of the veins relative to the plane of the leaf.”
“The characteristics used to identify the leaf are not unique to this genus and species. They are shared by many plants.”–Elan Sudberg, Alkemist Labs
Dr. Colwell concludes her report by stating definitively, “White mulberry is not toxic. I compared the specimen to lethally toxic species that are known to be planted or are native in the Sacramento area and found no matches.”
But this statement did not deter the coroner’s office from citing the white mulberry leaf fragment as the cause of Lori McClintock’s lethal gastroenteritis and dehydration.
UC Davis’ Dr. Colwell declined to comment on the case.
According to Elan Sudberg, who heads Alkemist Labs—one of the nation’s leading analytical testing labs for botanical identity and quality—the morphologic features described in the UC Davis report are overly general and not specific to white mulberry.
“The characteristics used to identify the leaf are not unique to this genus and species. They are shared by many plants,” said Sudberg, who has 26 years of experience as a botanical microscopist.
“There are things called cystoliths, which are found only in maybe 10 types of plants. I can think of only one other medicinal herb, besides mulberry leaf, that has cystoliths and that is nettle leaf.”
Cystoliths are distinctive, specialized cells within certain plants that contain calcium carbonate or other ergastic crystalline substances, and serve as plant defense mechanisms. Another distinctive feature of Morus alba is the presence of oxalate crystals within parenchymal cells.
“These two features are unique to this genus and species. They’re not found in spinach, or watercress, or lettuce, or cilantro, or other common plants that people ingest. They are unique and describable features (of mulberry leaf). Yet they were not described in the findings, which makes me question said findings,” Sudberg told Holistic Primary Care.
“You remark on the remarkable, not on the common features.”
Advanced chromatograpy or genomic fingerprinting techniques could potentially provide a more definitive identification of the leaf fragment, at least in theory. But Sudberg, whose lab specializes in high-performance liquid, and thin-layer chromatography (HPLC, HPTLC), says it is questionable whether a leaf sample subjected to gastric juices for an unknown period of time would yield reliable results.
Further, one cannot simply do chromatography or genetic testing, de novo, on an unknown plant fragment and expect to come up with a definitive identification. The sample’s phytochemical or genetic profile would need to be compared against known reference standards, meaning that the test would be done with a specific target in mind, explained Sudberg.
Again, the coroner’s report does not give any reason for the a priori suspicion that the leaf was from Morus alba. Further, if chromatography or genome tests were part of the coroner’s analysis, those data were not included in the report.
Swift Industry Response
Supplement industry trade organizations responded swiftly and forcefully to the conclusion put forward by the Sacramento coroners, and to the trial-by-media judgment that a dietary supplement was responsible Mrs. McClintock’s death—a presumption that was not even stated in the coroner’s report.
Daniel Fabricant, a former director of the Food and Drug Administration’s Division of Dietary Supplement Programs, and currently president of the Natural Products Association (NPA) called the coroner’s conclusion about mulberry “completely speculative.”
A formal statement issued by the American Herbal Products Association (AHPA) holds the media to task for using the occasion of a tragic death to, “challenge the robust regulation of dietary supplements by the federal government, despite the fact that there is no information in the report showing that Mrs. McClintock’s assumed consumption of white mulberry leaf was in the form of a dietary supplement.”
“There is no weight of evidence with multiple streams of data implicating white mulberry.”–Rick Kingston, Pharm D, clinical toxicologist, SafetyCall International
AHPA notes that, “The majority of clinical trials studying white mulberry leaf report no adverse events, but some studies did report minor gastrointestinal issues – such as upset stomach – in both mulberry leaf and placebo control groups. A pooled analysis of these studies found that there was no statistically significant difference in adverse events between the two groups.”
Further, AHPA stresses that, “No causality can be inferred from the facts reported in the coroner’s report.”
Rick Kingston, PharmD, a clinical toxicologist and adverse event expert at SafetyCall International is quoted in the AHPA position paper stating, “There is no weight of evidence with multiple streams of data implicating white mulberry.” He adds that the Sacramento autopsy findings raise more questions than answers.
The Wrong Herb to Bully
“They picked the wrong herb to try to bully,” says Stefan Wypyszyk, managing director of the North American division of Phynova, a global botanical ingredient supplier.
Phynova’s flagship ingredient is called Reducose ®, a patented water extract of white mulberry leaves. The company is, understandably, concerned about the negative light that the McClintock case—and the careless media coverage–has cast on this beneficial herb.
In response to the McClintock tragedy, he and colleagues compiled a summary of all the safety, toxicology, and efficacy data for Phynova’s mulberry leaf extract. The report states that, “One study specifically explored gastrointestinal tolerability of Reducose® over 24-hours post-consumption. The study was a dose-ranging study that explored half-dose, recommended dose and double the recommended dose, and reported that there was no difference in the frequency or severity of any GI symptoms compared with placebo, at any dose.”
The conclusion that white mulberry triggered a fatal reaction is inconclusive at best, and based on circumstantial evidence. But that did not stop monkey-see, monkey-do media outlets from mindlessly echoing the coroner’s baseless claim, and vilifying the entire dietary supplement industry.
Beyond Phynova’s branded mulberry extract, a 2016 meta-analysis of 13 clinical trials looking at various forms of supplemental mulberry leaf showed no significant differences in relative risk of adverse events in the two trials in which events were reported.
These minor effects included headache, nausea, unusual sense of fullness, and diarrhea. There were no serious, let alone life-threatening, adverse events. In the three studies reporting lab findings, there were no changes in liver enzymes, blood urea nitrogen, or any other indicators of toxicity between patients taking mulberry and those on placebo.
We may never know what actually caused the death of Loretta McClintock. Congressman McClintock and other family members have said little in public about it. There is no police report on record, and scant public information about the setting or circumstances prior to her passing. The Sacramento coroner’s office is refusing to discuss the matter.
The conclusion that white mulberry triggered a fatal reaction is inconclusive at best, and based on circumstantial evidence. But that did not stop monkey-see, monkey-do media outlets from mindlessly echoing the coroner’s baseless claim, and even going a step further to vilify the entire dietary supplement industry.
Critics of holistic medicine and natural products often accuse its advocates of playing loose and fast with facts in order to promote non-conventional modalities. Those critics are notably silent when a county coroner uses the thinnest of evidence to blame an unfortunate death on a generally safe herb.