Yellow oleander has been appearing as an adulterant in botanical formulations marketed for weight loss, according to two unrelated studies of consumer products conducted by the U.S. Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC).
 
Tejocote Root
 
In a report appearing in the CDC’s Morbidity and Mortality Weekly Report, a team of researchers from the New Jersey Poison Information and Education System (NJPIES) found that nine of 10 products labeled as containing Crataegus mexicana root, also known as tejocote or Mexican hawthorn, actually contained 100% yellow oleander.
 
“Yellow oleander contains the cardenolide thevetin B, which has the same clinical effects as other cardenolides, such as digoxin, and can be highly toxic,” the authors wrote.
 
The investigation into the purported tejocote root products was spurred by a phone call from an emergency physician to NJPIES regarding a 23-month-old child who had consumed a supplement called Eva Nutrition Mexican Tejocote Root and developed nausea and poisoning. The patient had bradycardia and was hypotensive, along with other tests that were consistent with cardenolide toxicity.
 
As a result, NJPIES purchased 10 products online which were labeled as tejocote and marketed for weight loss benefits, and shipped them to Flora Research Laboratories, which specializes in identity testing. 
 
“These readily available dietary supplements, upon testing, appeared to be mislabeled. Instead, they contained a toxic substance of concern to both clinicians and public health officials,” the authors reported. “For public health officials, this is concerning because these supplements contain a highly toxic substance and are readily available from multiple retailers. Future prevention efforts need to include reporting products such as these to FDA and alerting retailers who might be unknowingly selling these hazardous products.”
 
Nuez de la India
 
Just one week prior to the publication by NJPIES, FDA and the Maryland Department of Health (MDH) conducted research on weight loss products labeled as Nuez de la India after someone in the state of Maryland was hospitalized following consumption of a product labeled as such, which is generally understood to be nuts from the candlenut (Aleurites moluccanus) tree.
 
Additional analyses by the MDH and FDA found that purported Nuez de la India products marketed by the brands Nut Diet Max and Todorganic Natural were actually yellow oleander seeds, which have similar physical appearance as nuts from the candlenut tree, and contain cardiotoxic glycosides.
 
“Ingestion of yellow oleander can cause neurologic, gastrointestinal, and cardiovascular adverse health effects that may be severe, or even fatal. Symptoms may include nausea, vomiting, dizziness, diarrhea, abdominal pain, cardiac changes, dysrhythmia, and more,” FDA reported.
 
The products contaminated with yellow oleander which were tested by FDA and MDH were purchased online. Since the investigation, both Nut Diet Max and Todorganic brands issued press releases that their products were being recalled voluntarily. The brands were being sold on Amazon, eBay, and Walmart’s online platforms.
 
FDA reported that its investigation is ongoing, and products may be added to the advisory as the agency works with federal and state partners to address potentially-related adverse events, product complaints, and other issues.
 
Under the Radar, Until Now
 
According to Stefan Gafner, PhD, technical director of the ABC-AHP-NCNPR Botanical Adulterants Prevention Program (BAPP) and chief science officer of the American Botanical Council (ABC), yellow oleander as an adulterant hadn’t been on BAPP’s radar until recently.
 
However, a 2021 publication found that both tejocote and Nuez de la India products were adulterated with yellow oleander after these products caused digoxin-like toxicity symptoms in two 16-year-old patients.
 
“The adulterant, yellow oleander [Cascabela thevetia] contains constituents known as cardiac glycosides. Their name is due to their pronounced effects on the heart. Cardiac glycosides are therapeutically used in patients with irregular heartbeat or heart failure, but they are also known for their toxicity, hence dosage has to be closely monitored,” said Gafner.
 
Because it defies common sense to use a toxic adulterant in a dietary supplement, Gafner said that manufacturers most likely either lacked knowledge about oleander’s toxicity or mistook the identity of the raw material.
 
“One can only speculate that the manufacturers of these dietary supplements were unaware of the potential toxicity of yellow oleander, and used it because of reports in the scientific literature that cardiac glycosides can lead to weight loss, therefore hoping to provide the consumers with some weight loss benefits,” said Gafner.
 
“In the case of Nuez de la India seeds, accidental misidentification might be a possible explanation since the yellow oleander seeds are morphologically similar to the Aleurites moluccana seeds,” Gafner added. “Although it cannot be excluded that these were purposefully adulterated as well since most of these products appear to be marketed for weight loss.”
 
Through industry-standard testing methodologies, such as high-performance thin layer chromatography (HPTLC) or high-performance liquid chromatography with ultraviolet and visible detection (HPLC-UV/Vis), the fact that the products were adulterated would have been obvious, Gafner said. “It is much more of a challenge to figure out the identity of the adulterant, but regular testing should have been able to detect the adulteration.”
 
The yellow oleander situation underscores the need to have trustworthy suppliers, and a verification system in place for those suppliers, Gafner said, along with robust identity testing for all ingredients.
 
“This is one of the messages we have emphasized for a long time via the ABC-AHP-NCNPR Botanical Adulterants Prevention Program. This type of adulteration is also a good example why manufacturers should consider adopting the BAPP Best Practices SOP for the Disposal/Destruction of Irreparably Defective Articles, as no one wants to see yellow oleander being rejected by a manufacturer just to be returned to the supplier, leaving the door open that it shows up in a different product.”