Wheatgrass fans look away: we place the health tonic under the glare of scientific research.
The discoveries in the 1930s by US chemist Charles Schnabel, dubbed 'Mr Wheatgrass', have inspired a body of scientific research into wheatgrass that continues to this day.
If you believe the hype, wheatgrass has a higher nutritional content than any other vegetable, protects against inflammation, builds red blood cells and improves circulation.
Wheatgrass contains chlorophyll, vitamin A, vitamin C, vitamin E, iron, calcium and magnesium.
We've teamed up with the British Dietetic Association (BDA) to examine whether the host of health claims made about wheatgrass stand up to closer scrutiny.
The evidence on wheatgrass
Nutrition claims for wheatgrass
Despite claims that a 30ml (1oz) shot of wheatgrass contains as many nutrients as 1kg (2.2lbs) of your finest veggies, tests show that, pound for pound, the nutrient content of wheatgrass juice is roughly equivalent to that of common vegetables, such as spinach and broccoli.
Can drinking wheatgrass boost red blood cell production?
Fans of wheatgrass believe that because chlorophyll and haemoglobin (a protein that carries oxygen around your body) are similar in structure, taking wheatgrass juice enhances haemoglobin production. But as far as evidence goes, there is no scientific proof to support this claim.
Does wheatgrass salve inflammation of the colon?
A small study from 2002 found patients with ulcerative colitis (inflammation of the colon) saw their symptoms improve after they were given 100ml of wheatgrass juice daily for a month. However, the study involved only 21 people and the positive results could have been simply down to chance. As such, the evidence is inconclusive.
Can wheatgrass help people with blood disorders?
A small study from 2004 of 32 patients with a blood disorder called thalassaemia found half of the patients required fewer blood transfusions when 100ml (3.5oz) of wheatgrass juice was taken daily for three years. While interesting, the research has many weaknesses and further research is needed before these findings can be properly validated.
The dietitian's verdict on wheatgrass
Alison Hornby, a dietitian and BDA spokesperson, says: "There is no sound evidence to support the claim that wheatgrass is better than other fruits and vegetables in terms of nutrition. It cannot be recommended above any other choices in this food group.
"Although it contributes towards your recommended daily intake of fruit and veg, a single shot of wheatgrass doesn't count as one of your 5 A DAY. But if you're a big fan, you could combine a shot with a fruit or veg smoothie."
More on superfoods
Check out the evidence behind the health claims made about these other so-called superfoods: