We were recently asked to withdraw a batch of our FibrePlan product from the shelves due to non compliance.
There was no danger to the health of the consumer but the particular batch of the product technically breached the legal limit of pyrrolizidine alkaloids (PAs) set per kilogram of botanical preparations including extracts in food and food supplements.
When I was a child, my grandmother made what I still consider the finest apricot jam I have ever tasted. During apricot season, the kitchen would be filled with the aroma of simmering fruit, and once the apricots had been processed, there remained a treasure that fascinated me even more than the jam itself: the kernels hidden inside the hard pits.
I spent countless hours cracking the dried apricot stones and eating the kernels within. At the time, I had no idea that these kernels contained amygdalin, a naturally occurring compound that can release cyanide when digested. Today, we know that consuming large quantities of apricot kernels can be dangerous and that a kilogram of kernels could potentially provide a lethal dose of cyanide, specially to a child.
The reason I am here telling the story is simple: I never consumed a kilogram of apricot kernels in a single sitting. The fundamental principle of toxicology applied then, just as it does today: the dose makes the poison.
This principle, first articulated by the sixteenth-century physician Paracelsus, remains the foundation of modern toxicology. Virtually every substance can be harmful if consumed in sufficient quantity, while many substances that are toxic at high doses can be harmless at low levels. Risk is determined not merely by the presence of a substance, but by the amount consumed.
Even today, there are no restrictions preventing someone from purchasing large quantities of apricots, extracting the kernels, and consuming them. Nor are there warning labels on. bags of apricots informing consumers that the kernels contain compounds capable of releasing cyanide. The risk is recognised, yet society implicitly assumes that people will consume these products in realistic quantities.
Apricot kernels are far from unique in this regard.
Consider nutmeg. Nutmeg contains myristicin and related psychoactive compounds capable of causing serious toxic effects. Symptoms of nutmeg poisoning have been reported after consuming as little as 20–50 grams. A kilogram would constitute a medical emergency. Yet packets of nutmeg sitting on supermarket spice shelves rarely if ever carry prominent warnings about hallucinations, delirium, cardiovascular effects, or hospitalisation. Even on packs of nutmeg of 50 grams!
Black liquorice provides another example. Its active constituent, glycyrrhizin, can disrupt potassium balance and elevate blood pressure when consumed in large quantities. Excessive intake, like a kilogram, can lead to muscle weakness, hypertension, and abnormal heart rhythms, including potentially dangerous effects on the heart muscle itself. Nevertheless, black liquorice remains widely available without restrictions.
Brazil nuts offer perhaps an even more striking illustration. They are exceptionally rich in selenium, an essential mineral that becomes toxic when consumed in excess. One kilogram of Brazil nuts may contain between 15,000 and 20,000 micrograms of selenium, while the adult upper safe intake level is approximately 400 micrograms per day. Excessive selenium intake can cause nausea, vomiting, hair loss, brittle nails, neurological symptoms, and nerve damage. Yet consumers are free to eat Brazil nuts in whatever quantity they choose
Indeed, when considering common foods capable of causing toxicity when consumed in one kilogram amounts, the list includes:
- Apricot kernels (cyanide)
- Nutmeg (myristicin poisoning)
- Brazil nuts (selenium toxicity)
- Liver (vitamin A toxicity)
- Improperly prepared bitter cassava (cyanide)
- Black liquorice (glycyrrhizin toxicity)
What all these examples demonstrate is that food safety assessments generally recognise the importance of realistic consumption patterns. Regulators understand that people do not typically consume a kilogram of nutmeg, liver, liquorice, or Brazil nuts in a single day. Let alone, day after day.
Yet this principle appears to become less clear when examining certain areas of food supplement regulation.
A notable example is Commission Regulation (EU) 2023/915, as amended, which establishes maximum levels for various contaminants in foods, including pyrrolizidine alkaloids (PAs). Among other provisions, the regulation sets a maximum level of 400 micrograms of PAs per kilogram for certain food supplements and products containing botanical ingredients such as psyllium and other plant-derived materials.
The objective of limiting exposure to potentially harmful compounds is understandable and appropriate. However, questions arise when the regulation is interpreted in a manner that focuses on theoretical consumption levels that bear little resemblance to real-world use.
Unlike conventional foods, food supplements in unit dose form, such as tablets and capsules are not consumed by the kilogram. A typical psyllium or green tea capsule may weigh approximately 500 mg and contain only a fraction of a microgram of PAs. For example, a capsule containing 0.21 micrograms of PAs, taken at a recommended dosage of two capsules per day, would result in a daily intake of approximately 0.42 micrograms. Which is a little over 1% of the daily maximum set for PA .
Yet such a product is considered non-compliant if the concentration exceeds the regulatory limit when extrapolated to a kilogram of product. In practical terms, this means that the assessment is based on a hypothetical scenario in which an individual consumes 2,000 capsules—equivalent to one kilogram—in a single day. Under that scenario, the person would consume 420 micrograms of PAs, marginally exceeding the regulatory threshold. And thus be classified as ‘non compliant’.
The contrast with ordinary foods is difficult to ignore. Society accepts that consuming a kilogram of Brazil nuts, apricot kernels, or nutmeg is unrealistic and therefore assesses risk based on expected consumption patterns. Yet in the case of food supplements, products may be judged on the basis of equally unrealistic consumption scenarios involving thousands of capsules in a single day.
This raises an important question about consistency in regulatory philosophy. Should risk assessments be based primarily on concentration per kilogram, regardless of how a product is actually consumed? Or should they place greater emphasis on realistic daily intake and actual consumer exposure?
Food safety regulation exists to protect public health, and that objective should never be compromised. However, the cornerstone of toxicology remains unchanged: exposure matters. The presence of a substance alone does not determine risk; the quantity consumed determines risk.
The lesson I unknowingly learned as a child eating apricot kernels from my grandmother's kitchen remains as relevant today as it was then. Toxicity is not simply about what is present in a food. It is about how much is consumed. In other words, as Paracelsus observed nearly five hundred years ago, it is the dose that makes the poison.