The EFSA opinion on yohimbe/yohimbine is extremely interesting, certainly surprising and may have significant implications.
The background is that Germany has sought to define a list of botanicals banned across the EU, using existing European legislation on substances that can and cannot be added to food and food supplements.
This initiative was partly thwarted when it was observed that only plants that have sometimes been used in food supplements could be added – and not poisonous plants nobody has ever used in food supplements.
Yohimbe and ephedra seemed good examples of botanicals used in food supplements at some point in time, and that most if not all EU member states regard as unsafe for use in food supplements. A scientific consensus that these two plants are bad apples would seem straightforward, at least in the EU.
EFSA seems to support this view, at least for yohimbe, but its opinion raises several questions.
First, for yohimbe, EFSA has used its own guidance for assessing the safety of botanicals dated 2009. With that methodology, EFSA concludes that there are insufficient data to assess the safety of yohimbine – that is level A in their system.
“…the chemical and toxicological characterisation of yohimbe bark and its preparations for use in food are not adequate to conclude on their safety as ingredients of food…” EFSA wrote.
This would seem all right.
But given past EFSA exercises, it is fair to wonder whether most botanicals, even those, unlike yohimbe, generally accepted as safe by member states, would be lumped, if assessed, in level A. The guidance for safety assessment is probably a good starting point, but it needs to be refined in order to better discriminate levels of risk.
Also, EFSA uses literature data for assessing population exposure but this is unlikely to reflect the actual range of exposures experienced by the population. It's an area where the authority could refine its approach.
Finally, it is remarkable that EFSA took into consideration medicinal uses of the plant, and the levels at which "pharmacological properties" are observed. While this helped with the specific safety assessment of yohimbe, the legal underpinnings of this part of the methodology should be clarified; EU law does not support this approach.
My view is that, if a negative list of botanicals is to be established in the EU, as is sought by Germany and others, EFSA should be enabled to refine its safety assessment approach for botanicals.
We need EFSA to be able to assess botanicals, but more discriminatory power is necessary. Exposure assessment can't be based on a few pieces in the literature, it may often not be reliable.
Also, the legal basis for the use of medicinal data needs explaining and sharpening; can EFSA consider medicinal uses of botanicals in its safety assessment? They have not done it for other substances, and I am not too sure they can do it for botanicals.
We need EFSA to assess the safety of botanicals; we also need even better methodology, from the scientific and regulatory standpoint.
[NB. Yohimbe bark (Pausinystalia yohimbe) contains the active compound yohimbine, which is said to have sexual stimulant and aphrodisiac effects and is often used as a weight loss aid. It is banned in the UK, Ireland, the Netherlands, Belgium, Denmark, the Czech Republic, Canada, Australia and New Zealand. Adverse effects have included headache, nausea, increased urinary urge, insomnia, anxiety, diarrhoea and genital pain.]
Luca Bucchini PhD, MPH, is the managing director of Italian-based Hylobates Consulting.