Proving health claims for foods

There are various ways of proving the quality of plant material for, for instance, health claims on labels. 

At the bottom of the hierarchy is anecdotal evidence or historical knowledge. To repeat existing knowledge is the cheapest alternative, but also the one most likely to be abused, according to experts. If an anecdote is used to make a claim, it should be clearly stated that the information is anecdotal or based on "general  knowledge'' only.

At the top of the ladder is the clinical trial, the ultimate way of eliminating subjective claims.

Clinical trials, however, are expensive and out of reach of even most large African companies. They cost easily in excess of $150,000, industry experts say. And even a clinical trial has its limitations – dependent on the standard of the trial, he says.

In Africa, very few indigenous plants have been subjected to clinical trials. The African potato, buchu and southerlandia are among the few which have.

Content analysis

Somewhere in the middle of the hierarchy of evidence and cost lies the content analysis.
Content analysis can be done by a number of South African laboratories, which should be internationally-accredited.
Once the contents are established, claims can be made on the proven qualities of, say, vitamins, zinc, selenium, etc.

Which market?
The objective of proving, or at least stating, health properties of a product is invariably to market it. The question then arises: what is adequate in order to achieve the marketing objectives related to the claimed health properties of an ingredient?
Sometimes an ingredient is so well known that the mere mention of it is sufficient.
For instance, a fruit juice whose label merely stated that it contains hoodia – with no claims as to the ingredient's form or efficacy – is being marketed by one juice company in South Africa.
Some ingredients from Africa – like hoodia – may be better known than initially thought. For instance, although the baobab tree does not grow in Japan, it is relatively well known there because of a Japanese children's story.
Another question which arises is to what extent proving of health claims is required for the target market. For instance, Germany and Australia are very strict on claims. However, in the US virtually any claim can be made and anything can be sold. US legislation (in the form of the Dietary Supplement Health and Education Act (DSHEA)) basically says that a supplement, if labelled with a statement that it is not a medicine, is not a medicine. So it may make health claims but may not claim to cure diseases and illnesses.
A new claim not previously part of the known labelling of a particular substance, or a new substance not previously marketed as a "nutraceutical" or recognised as a food, must be submitted to the US's FDA (Food and Drug Administration).
However, the onus is on the FDA to vet it within 75 days of submission. If the producer does not hear from the FDA in that time, it may assume that the FDA has no objection to it.
This avoids an onerous, complicated bureaucratic process but has largely offered good control in the US.