In food, and in supplements, ‘antioxidant’ is something of a catch-all, encompassing a mind-boggling number of phytochemicals, both phenolic compounds and flavonoids, as well as the more well-known vitamins C and E, and beta-carotene.
“Marketing surveys are showing that the word antioxidant resonates with the consumer,” said Alex Schauss, PhD, from AIBMR in an interview with NutraIngredients at last year’s SupplySide West in Las Vegas.
“The consumer is looking at certain claims that are being made and when they see the word antioxidant, the indications from very recent market surveys are that around 55 to 60 per cent of consumers may buy or stay with a product because it has an antioxidant claim to it,” said Dr Schauss.
“That means that the industry will definitely continue to use it,” he added.
Andrew Shao, PhD, vice president of scientific & regulatory affairs for the Council for Responsible Nutrition (CRN), a trade association, added that, since it is difficult to quantify the benefits of such products, in terms of a ‘hard’ endpoint like reduction of disease risk or modification of a risk factor or surrogate endpoint (like lipid levels), “manufacturers/marketers either choose not to or don't have the means to support research on hard end points. The default is to make ‘antioxidant’ claims,” he said.
Figures from Mintel’s Global New Products Database (GNPD) indicate that more and more products are emphasising a product’s antioxidant content on the label, with 135 launches in Europe of products labelled ‘antioxidants’ in 2008, compared to 111 in 2007, and only 37 in 2006.
Similar growth of the use of the term was observed across the Atlantic, with 106 launches in the US in 2006, 131 in 2007, and an impressive 262 in 2008. These figures, which do not take into account products that label specific antioxidants like vitamins A, C, and E, and are therefore a conservative indication of the use.
In addition to market surveys, reports in the scientific literature support the rise of antioxidant awareness amongst consumers. Researchers at the University of Scranton surveyed 251 male and 448 female patrons of a large grocery store chain in Dickson City, Pennsylvania about their perceptions of vitamins, and found that consumers considered vitamin C to be the single most important vitamin for health among all age groups, while the reputation of vitamin E increased with age (Food Quality and Preference, 2005, Vol. 16, pp. 151-155).
Another study by Greek researchers (Food Quality and Preference, 2008, Vol. 19, pp. 525-538) into the motivation behind buying functional foods found that 43 per cent of younger respondents (age 25-34), and 63 per cent of older participants (age 35-44) rated antioxidant ingredients as an important attribute in a functional food. (‘Added vitamins and minerals’ were considered important by 87 and 63 per cent of these age groups, respectively.)
In a study to understand consumers’ willingness to try functional milk desserts, both antioxidants and fibre were considered as the two functional ingredients of choice (Food Quality and Preference, 2009, Vol. 20, pp. 50-56). The study, limited to Uruguayans, found that emphasising the added ingredient had a significant influence on consumers’ evaluations. “The use of common names, such as fibre or antioxidants resulted in a marked increase of both healthiness and willingness to try when compared to the use of compound or scientific names,” wrote the researchers.
What these three studies show is the resonance of antioxidants as a word to enhance the overall healthiness of the product, despite a lack of a health claim on the label.
Time for a sea-change?
But sometimes it would seem the marketers go too far. In October 2007, the UK's Innocent was rapped on the knuckles by the Advertising Standards Authority (ASA) for making a health claim about its smoothie having a high antioxidant content and detoxifying effect.
The ASA said an advert by the firm, which claimed its fruit juice contained more antioxidants than the "five-a-day" portion, was not truthful or substantiated.
A week earlier, and the UK Tea Council was criticised for exaggerating the benefits of tea, and banned from making further claims about the drink’s antioxidant potential after running a series of adverts.
Daniel Fabricant, PhD, vice president of scientific & regulatory affairs for the Natural Products Association (NPA), a trade association, said that a shift will have to occur in the not too distant future “to ensure that terms like antioxidant have meaning is some type of biological activity/ standardization associated with the term.
“Now obviously there will be a multitude of endpoints but, if a product contains vitamin C as an antioxidant, how does that antioxidant level for vitamin C correlate with say an NK cell receptor activation assay” asked Dr Fabricant. “Do the other ingredients in that product potentiate the effect?
“There needs to be some sort of biological baseline to compare products. Obviously this won't provide all of the answers - good clinicals are still needed but it will definitely progress things in the right direction,” he added.
Gitte Jensen from NIS Labs, developer of the CAP-e antioxidant assay, a cell-based assay attracting much attention from the industry, told NutraIngredients.com that her company is working on a certification programme to differentiate products.
The Certified Bioavailable Antioxidants Program is a quality assurance program focusing on testing the bioavailability of antioxidants in humans. The programme, which uses the CAP-e assay, will “strengthen marketing claims regarding antioxidants and make it easy for consumers by using a ‘third party’ testing facility,” said NIS Labs.
The trade associations were not willing to comment on such an initiative, but it does mark a potential advance on the default antioxidant label.
Some companies and products are also starting to quote values from ORAC (oxygen radical absorbance capacity) testing – one of the, if not the, most common chemical assays to establish antioxidant activity.
However, with the list of assays longer than the proverbial arm, should one assay be singled out for consumers, and what do the results of such assays really mean?
“I am strongly of the opinion that claims related to antioxidant capacity of products must be backed by in vivo experimental research on the product in question, including biological fluids as markers,” said Dr Schauss.
“Just increasing the ORAC value provides no guarantee of greater benefit. It’s pure marketing and it is time the nutraceutical industry steps up to the plate and substantiates implicit and explicit claims of performance based on product antioxidant content.”
Tomorrow, NutraIngredients will navigate through the jungle of antioxidant testing.
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