South African herbal extracts specialist Green Cell Technologies (GCT) has defended the antioxidant measures that showed its green and rooibos tea extracts could deliver ORAC values of around 1,700,000 per 100g.
The company said the measure using its patented cell disruption technology method was the highest in the world and had been attained at the Cape Peninsular University of Technology in Capetown in assays that have been seen by NutraIngredients.
In an article here on Wednesday, Dr Jörg Grünwald, president of the German contract research organisation and natural products consultancy, analyze&realize, said the results should be verified at another lab, as they seemed very high.
Responding GCT said it was willing to send, “a sample of GCT's Rooibos extract to any establishment they choose for verification.”
ORAC or not ORAC?
Dr Grünwald said Massachusetts-based Brunswick Laboratories is the only lab in the world that was qualified to accurately measure ORAC (Oxygen Radical Absorbance Capacity) at that concentration.
Levels aside, Dr Grünwald questioned the dietary need for antioxidants at such levels, noting a lack of data, and the fact that ORAC measures are, “only one of several in vitro methods and does not show the situation in humans.”
“Human clinical trials are needed as the European Food Safety Authority accepts only those as proof of evidence,” he reflected.
“The pure run after the highest ORAC value may help to sell some product – mainly in the US – but does not prove the real situation in man.”
GCT CEO Roy Henderson said the absence of such clinical data didn’t detract from the spectacular ORAC numbers.
“Green Cell Technologies process is merely more efficient than others and as a result more bio-actives are patently available for the consumer, the clinical evidence of this is relevant,” Henderson said.
“The clinical evidence that the plant cell destabalising process has benefit to the consumer comes in the form of the Assays … now a stabilised product can be produced which is consistently at a clinically significant level of Aspalatin in every batch.”
He also pointed to studies that showed the dietary need for antioxidants.
Brunswick Labs got in touch and said companies should be wary about how they used ORAC values in the marketplace.
“It is misleading to present ORAC values for extracts using 100 gram samples. Extracts are typically used for human consumption in doses of between 100mg and 1g,” said external relations manager, David N. Bell.
“Most suppliers of high-performance botanical extracts express their ORAC results per gram. Doing so in this case would result in an ORAC value of 17,000 per gram, which is in line with other high-ORAC extracts.”
Bell added: “ORAC is a starting spot for antioxidant investigation, not an end point. Like any chemical in vitro assay - such as those used to quantify items on nutrition or supplement facts panels - ORAC is not meant to describe in vivo outcomes. That is the domain of clinical investigation. We urge companies to use the ORAC method responsibly and with a recognition of its limitations.”
The GCT extraction technology involves a, “mechanical intervention that forms part of the process destabilises the plant cell structures and releases all of the actives and not just part of them, as is common in other extraction methods. Because of the high number of extracted actives, we are able to achieve the high H-ORACs in these products.”