The marketing of wheatgrass as one of nature's "superfoods" is all hype, a New Zealand food magazine has claimed.

In the latest Taste magazine, health writer Shiree Schumacher says claims made by some New Zealand juice bars that one 30ml shot of wheatgrass is nutritionally equivalent to 1kg to 2kg of vegetables are "simply not true" and based on outdated research.

"If you're relying on wheatgrass as your sole source of greens, it's not only costing you money, you're also selling yourself short in the nutrition department."

Schumacher said wheatgrass sellers' marketing of the plant as a cure-all superfood "astonished" her. She rubbished claims wheatgrass' 70 per cent chlorophyll content meant its nutritional value and antioxidant properties outweighed those of some vegetables.

"That's not to say wheatgrass doesn't contain some good things - the juice is known to have an array of vitamins, minerals, amino acids and antioxidants, for instance. But its nutritional profile is often lower than many common vegetables."

Two kilograms of peas provided 260 times the amount of vitamin C of a 30 ml shot of wheatgrass, Schumacher said.

Dr Chris Reynolds, medical director for Australasian distributor Dr Wheatgrass, agreed the plant suffered from false marketing.

He had spent 16 years researching its healing properties and said: "I have to say the myths regarding its nutritional content are just that - myths. But this doesn't mean to say that wheatgrass doesn't work in other ways and for other reasons."