Usually on the train back from a trip to Devon I spend my time reading and immersing myself in the view. Yesterday was pleasantly different as I was sat next to Adal, a charming doctor. We got chatting about all kinds of topics including medicine, nutrition and faddy diet foods. As I got back to London I was greeted by a juice bar advertising ‘shots’ of bright green wheat grass juice and this got me thinking – is it a hyped up fad food or is there some science behind the wheat grass phenomenon?
Wheat grass is also known as wheat sprouts and can be widely bought as a juice or a powder that is mixed into a drink. The bright green colour comes from chlorophyll, a pigment fundamental in the conversion of sunlight into carbohydrate in plants via the process of photosynthesis. Regular consumers of the grass juice say that it improves their feelings of wellbeing, aids digestion and gives them an instant energy boost. Wheat grass contains fibre, vitamin B, vitamin C, beta carotene, minerals (calcium, magnesium, potassium), amino acids and more. So it seems that this grass does pack a nutrient filled punch. However, I wanted to know if there was any science behind the anecdotal health claims. After some investigation I managed to unearth a few studies.
A small study last year(1) found that 500mg of wheat grass taken daily increased blood plasma antioxidant status, vitamin C, beta carotene, vitamin E and the blood activity of an antioxidant enzyme and reduced oxidative stress in individuals when compared to placebo. In addition to this trial a cell study in 2004(2) found that wheat grass contains a powerful cocktail of antioxidant molecules and biologically active substances (such as flavonoids) that can be absorbed during the digestion process.
An antioxidant is a substance that protects our cells from the damaging effects of highly reactive molecules called free radicals (which cause oxidative stress in the body). These destructive molecules are associated with ageing, cancer, heart disease, stroke, cataracts, arthritis and more. The body does produce its own antioxidants but also relies on vitamins, mineral and phytochemicals (bioactive plant compounds) from the diet, especially from colourful vegetables and fruits, for additional valuable supplies. A shot of wheat grass may be one way to give the body an antioxidant boost!
In addition to the antioxidant potential of wheat grass, which may be beneficial in the prevention against cancer via protection of our DNA from free-radical damage, studies suggest that wheat grass may additionally be cancer protective via blocking the metabolic activation of many carcinogens (cancer causing substances)(3).
There is also preliminary emerging evidence to suggest that wheat grass may have beneficial effects on the health of our blood cells and blood cell production. So far these studies have only been carried out in individuals with serious conditions such as cancer(4) and the blood disorder thalassaemia(5). As yet there is no definitive literature to confirm if these benefits occur in healthy individuals but these trials certainly point the way. Scientists believe that the positive benefits to the blood may come from the antioxidants in the wheatgrass(6) or perhaps from the chlorophyll in wheat grass which has a similar structure to haem, the iron containing pigment in our red blood cells that binds oxygen in order to carry it to all of the cells in our body(7).
Finally, the use of wheat grass juice for treatment of various gastrointestinal/digestive conditions has been suggested by its proponents for more than 30 years, but until recently had never been clinically assessed in a controlled trial. In 2002 a small randomized, double-blind, placebo-controlled study(8) took place to assess the use of wheat grass in ulcerative colitis sufferers. Ulcerative colitis is characterized by chronic inflammation and ulceration of the lining of the colon and rectum. The study patients received either 100 ml of wheat grass juice, or a matching placebo, daily for 1 month. Treatment with wheat grass juice was associated with significant reductions in the overall disease activity and in the severity of rectal bleeding. The authors think the beneficial effects were probably due to the antioxidant capacity of the wheat grass.
The above mentioned studies have been small and mainly based on serious conditions that thankfully are not common. However, the evidence is interesting and it seems as though there is some benefit to the green shot. It will be interesting to see if any further evidence emerges over the next few years. Please note that wheat grass is not a miracle food and cannot make up for a poor diet. Including a colourful variety of vegetables and fruits in the daily diet will provide a huge host of antioxidant vitamins, minerals and phytochemicals. If you decide to try wheat grass juice try to view it as an added nutrient bonus for your body!
(1)Shyam R et al. 2007. Wheat grass supplementation decreases oxidative stress in healthy subjects: a comparative study with spirulina [letter to the editor]. J Altern Complement Med. 13(8):789-791.
(2) Marsili V, Calzuola I, Gianfranceschi GL. 2004. Nutritional relevance of wheat sprouts containing high levels of organic phosphates and antioxidant compounds. J Clin Gastroenterol. 2004 Jul;38(6 Suppl):S123-6.
(3)Peryt B et al. 1992. Mechanism of antimutagenicity of wheat sprout extracts. Mutat Res. 269(2):201-215.
(4) Bar-Sela G, Tsalic M, Fried G, Goldberg H. 2007. Wheat grass juice may improve hematological toxicity related to chemotherapy in breast cancer patients: a pilot study. Nutr Cancer. 58(1):43-8.
(5) Marawaha RK et al. 2004. Wheat grass juice reduces transfusion requirement in patients with thalassemia major: a pilot study. Indian Pediatr.41(7):716-20
(6) Fernandes CJ & O’Donovan DJ. 2005. Natural antioxidant therapy for patients with hemolyticanemia. Indian Pediatr. 42: 618-619. Letter to the editor
(7) Pole SN. 2006. Wheat grass juice in thalassemia. Indian Pediatr. 43(1):79-80; author reply 80.
(8) Ben-Arye E et al. 2002. Wheat grass juice in the treatment of active distal ulcerative colitis: a randomized double-blind placebo-controlled trial. Scand J Gastroenterol. 37(4):444-449.
Written by Ani Kowal