The missive from the Medicines and Healthcare Products Regulatory Agency (MHRA) warned consumers about the liver damage link whilst promoting those products registered under the EU Traditional Herbal Medicinal Products Directive (THMPD) that became active in 2011.
"It's easy to use the odd isolated and unfortunate case of poisoning that is supposedly related to back cohosh to tarnish the very good safety record of the herb, especially around its use among menopausal women,” ANH chief and scientific director, Rob Verkerk, PhD, told us.
“That's not to say that there isn't a problem with inferior quality products containing misidentified species that can pose a risk to consumers. It's this cowboy sector that needs to be the focus of government enforcement action.”
In its warning, the MHRA said it had received 53 complaints it linked to black cohosh, 36 of which referenced, “liver problems including abnormal liver function, jaundice and hepatitis.”
“The MHRA always recommends that registered herbal products are used. Registered products can be identified by the Traditional Herbal Registration (THR) registration number or logo on their packaging,” the agency said.
The British Herbal Medicine Association (BHMA) backed the MHRA’s stance, noting nine black cohosh products had been registered in the UK under the THMPD, but said the problem was more likely down to adulteration.
“There are a number of non-registered products that have remained on the market in spite of attempts by the MHRA to restrict them,” the BHMA said.
“The particular problem with black cohosh is that adulteration with the wrong species is rife, with a number of published academic papers citing a rate of around 30% in purchased samples.”
“The adulterants are usually related species, often from China - black cohosh only grows in North America - and usually with uncertain safety profiles. Only the quality assurance of medicine production and the regulatory enforcement of these standards can prevent this adulteration.”
In 2010 Health Canada said its AERs, “demonstrate that products not containing authentic black cohosh may be associated with liver adverse reactions”.
The BHMA called for a tightening of supply channels to tackle the authenticity issue, along with more robust enforcement of the THMPD.
Two routes to market
Dr Verkerk said the warning, which was provoked by the liver failure and subsequent transplant of a black cohosh user, should not be used as a tool to denigrate the perfectly legal status of black cohosh products on the market as food supplements.
“You can't help feeling that the BHMA is exploiting an isolated case of misfortune to tarnish responsible food supplement companies that have long sold carefully selected and manufactured black cohosh food supplements with no history of significant adverse events,” he observed.
“It's also noteworthy that these companies have voluntarily withdrawn black cohosh from the market since the EU herbal directive has been fully implemented. But BHMA wants all food supplements containing herbs that have now been registered under the EU herbal directive off the market – and this is legal nonsense and will greatly limit consumer choice."
BHMA director Dick Middleton noted the 53 adverse event reports (AERs) dated back to September, 1998.
Since 1964, Paracetamol has had 4555 AERs and 331 fatalities linked to it. Ibuprofen has 4845 AERs and 213 deaths since 1969.
The MHRA rapped supplements manufacturer Bee Health in late 2011 for selling a product with 50 times the recommended dose of black cohosh.