Innocent, the smoothie maker, has been criticised for suggesting that a " superfood" drink removed bodily toxins and could supply more antioxidants than eating the recommended daily intake of five portions of fruit and vegetables.
The Advertising Standards Authority said that Innocent, whose sales more than doubled last year to £96m, was unable to back the claims with medical science and ordered them not to be repeated.
Innocent promoted the Superfoods Smoothie, made of crushed pomegranates, blueberries and acai berries, and packed with vitamins and minerals, as a "natural detox". In press advertising, it boasted that the drink offered "even more antioxidants than the average five a day", adding: "We think it's the world's superest smoothies recipe."
Innocent, founded in 1998 by Richard Reed, Adam Balon and Jon Wright, told the advertising watchdog the high level of antioxidants neutralised free radicals and therefore removed toxins from the body. The London-based firm added that the product had an oxygen radical absorption capacity value of 1,640 umol per 250g serving, compared with between 1,470 and 1,870 umol for an average five-a-day diet. But the ASA ruled that neutralising free radicals did not amount to removing toxins from the body, which could be done by drinking plenty of water and cutting out alcohol.
Dietary advice suggested that fruit juice and smoothies could make up no more than one of the Government's recommended five portions of fruit and vegetables a day, no matter how many were drunk, the watchdog concluded.
It added that even if Innocent's evidence had been correct, the Superfood Smoothie was in the middle of the antioxidant levels cited, so suggesting the drink could provide "even more" could not be justified.
The ASA said: "We welcomed Innocent's assurance that they had no plans to use the ad again or to use similar claims in the future. We told Innocent to delete the claims and to ensure they could provide suitable evidence to back up any future claims."
Today's ruling is a further skirmish in thebattle between Innocent and the authorities over the nutritional value of its drinks. Innocent insists that one of its smoothies provides "at least" the equivalent of two portions of fruit and vegetables, but the Food Standards Agency and the Department of Health disagree with the company.
They say that crushed, squeezed or pulped fruit drinks provide only one portion because the structure and fibre of the natural product is altered or lost.
Catherine Collins, spokeswoman for the British Dietetic Association, said raw fruit and vegetables were superior to commercial fruit drinks because fibre, phytochemicals and vitamins remained in their original forms. Even a home-made drink was superior to a shop-bought smoothie, she suggested. "An Innocent smoothie is pasteurised. It's not the same as having some orange juice and a handful of raspberries and blending them at home."
Innocent accepted the ASA's criticism but stuck to its guns on its two-a-day claim. spokeswoman Ailana Kamelmache suggested the Government had wrongly included smoothies with juice in its calculations. Smoothies provided one portion of vitamins and minerals and one portion of fibre, she said.
Ms Kamelmache apologised if people found claims for the Superfoods Smoothie confusing but she said the company had tried to make its packaging clear.