Case studies of quality control failures

Here are some examples of how lapses in the quality control and proper identification of natural products can lead to serious repercussions for human health.

A case of misidentification leading to Aristolochic acid nephropathy

In the early 1990s, over 100 patients of a slimming clinic in Belgium were diagnosed with kidney disease. Many of these patients required renal transplantation or dialysis and many subsequently developed cancer. The toxicity was associated with a herbal preparation prescribed in the clinic where the plant Stephania tetrandra was accidently substituted with Aristolochia fangchi. Acids from Aristolochia fangchi are Group 1 carcinogens.

A case of contamination – aflatoxicosis

Quality control is also important in the food supply chain.

Consumption of food contaminated with aflatoxins can cause poisoning. Aflatoxins are metabolites produced by certain species of Aspergillus fungi and exposure can cause acute and chronic health issues such as liver damage, cancer, immunosuppression and growth impairment in children. The fungi grow on cereal crops such as corn and proliferate in warm and humid conditions during growth or during post-harvest storage.

A combination of quality control measures are required to prevent aflatoxin contamination of food and animal feed including good agricultural practices and good post-harvest storage practice as well as food product monitoring and the setting of maximum allowable limits for aflatoxins in food.

A case of contamination – Amnesic shellfish poisoning

Amnesic shellfish poisoning is caused by the consumption of seafood contaminated with domoic acid. Domoic acid is a neurotoxin produced by certain species of microalgae that can accumulate in marine organisms, particularly filter-feeding shellfish such as mussels, clams, oysters and scallops. Domoic acid poisoning causes acute gastrointestinal and neurological symptoms. It can also cause long-term cognitive impairments including permanent short-term memory loss.

During harmful algal blooms, the risk of accumulation of this toxin is greater and environmental monitoring of algal bloom events and domoic acid levels is key. In addition, quality control tests ensure that any domoic acid detected in shellfish samples is below the maximum allowed limit for safety.

A case of adulteration – Tejocote root

Adulteration is the deliberate mixing or substitution of a material with another substance or inferior quality material.

Types of adulteration that can occur:

*Substitution of plant material with plant material of another species – unscrupulous suppliers may substitute plant material with material from another plant that is cheaper or more readily available. *Addition of filler materials – the use of bulking materials to increase weight or volume.
*Use of synthetic chemicals – the addition of chemicals to mimic the effects or the chemical fingerprint of the intended quality material.

Tejocote root is an example of a herbal supplement that has been subject to adulteration. Products on the US market have been found to be substituted with yellow oleander, a poisonous plant that can cause neurologic, gastrointestinal and cardiovascular adverse health effects that may be severe, or even fatal. Adulterated products can pose a serious threat to public health.