Benefits
Antioxidant pigments and vitamins in the fresh grass
Young wheat leaves contain chlorophyll, flavonoids, vitamins C and E and beta-carotene, and their extracts show antioxidant activity in laboratory assays. Content varies with growing conditions and processing: freeze drying kept the most chlorophyll and antioxidant activity, while oven drying lost vitamin C and beta-carotene. A test-tube reading does not show an effect inside the body.
Oxidative stress markers: thin human data
Direct human evidence is limited to a short letter, with no abstract to check its methods, reporting that wheatgrass lowered oxidative stress in healthy people in a comparison with spirulina, and a two-week study of 14 young women drinking wheat sprout juice with no control group. That makes the antioxidant idea plausible, not demonstrated.
Gut lining support: one small trial in ulcerative colitis
In a double-blind trial, 23 people with active distal ulcerative colitis drank 100 mL of wheatgrass juice or a matching placebo daily for a month. The juice group had a lower overall disease activity score and less rectal bleeding. Only 19 people had complete data, and we found no confirmatory trial since. It does not replace prescribed colitis care.
Studied alongside chemotherapy for blood counts
In a pilot study of 60 patients with breast cancer, those drinking 60 mL of juice daily through three chemotherapy cycles had fewer dose reductions, early stops or growth-factor starts than matched controls, 5 such events versus 15. There was no placebo, and six patients quit the juice because it worsened nausea. Any use during cancer treatment belongs with the oncology team.
Thalassemia transfusion studies point in different directions
An early pilot in beta thalassemia major, comparing time on home-grown juice with the year before, found transfusion needs fell by more than a quarter in 8 of 16 patients. Later uncontrolled series split, and the largest, 53 patients on wheatgrass tablets, saw no fall over a year. When 69 children were randomized to tablets or no wheatgrass for 18 months, transfusion numbers and blood needed did not differ between groups.
Mechanism of action
Chlorophyll does not become hemoglobin
Chlorophyll and the heme in hemoglobin share a ring-shaped porphyrin core, but chlorophyll holds magnesium where heme holds iron, and the body does not convert one into the other. The popular liquid-blood idea therefore has no mechanism behind it; any effect on blood counts would have to come through some other route.
Dietary antioxidants and processing losses
Flavonoids, phenolic compounds, vitamin C, vitamin E and carotenoids can neutralize reactive oxygen species in laboratory tests. Heat and drying degrade vitamin C and carotenoids, so freeze-dried powder keeps more than oven-dried material. Radical scavenging in a test tube does not predict what survives digestion and absorption.
Possible local action in the colon
In the colitis trial, electrochemical testing of the fresh juice gave a strong signal that the authors took to reflect four groups of compounds with antioxidant behavior. That suggests, but does not show, that these compounds could act locally on an irritated colon lining. The trial measured symptoms and endoscopic findings, not mechanism, so this remains a hypothesis.
Clinical trials
Randomized, double-blind, placebo-controlled trial of 100 mL wheatgrass juice daily for one month (Ben-Arye E, Goldin E, Wengrower D, Stamper A, Kohn R, Berry E 2002, Scand J Gastroenterol 37(4):444-9, PMID 11989836).
23 patients with clinically and sigmoidoscopically confirmed active distal ulcerative colitis, recruited through one hospital gastroenterology unit and three coordinating centers in Israel; 21 completed and 19 had full data.
Wheatgrass juice was associated with significant reductions in the overall disease activity index (P=0.031) and in the severity of rectal bleeding (P=0.025), with no serious side effects. The authors judged it effective and safe as single or add-on therapy, but with 19 analyzable patients and no replication, this is a signal rather than a proven treatment.
Self-controlled pilot study comparing the period on daily wheatgrass juice with the preceding year (Marawaha RK, Bansal D, Kaur S, Trehan A 2004, Indian Pediatr 41(7):716-20, PMID 15297687).
16 analyzed patients with transfusion-dependent beta thalassemia major whose families grew the grass at home; about 100 mL of juice daily.
Packed red cell requirement fell by more than 25% in 8 of 16 patients, and by more than 40% in 3 of them, with no perceptible adverse effects. Each patient served as his own control and there was no comparison group, so other changes over time cannot be ruled out.
Randomized, prospective, open-label study of wheatgrass tablets versus no wheatgrass for 18 months, with both groups receiving regular transfusions and folic acid (Mutha AS, Shah KU, Kinikar AA, Ghongane BB 2018, Cureus 10(3):e2306, PMID 29755902).
69 children with thalassemia on regular transfusion, 45 allocated to wheatgrass and 24 to control; 12 and 3 respectively did not complete the study.
The average number of transfusions and the blood transfusion requirement did not differ between groups, and serum ferritin did not differ between groups, though it rose from baseline only in the control group. Fetal hemoglobin rose and quality of life improved within the wheatgrass group. The groups differed in age, and one child stopped the tablets after a rash. The authors called wheatgrass promising while conceding it did not reduce transfusion needs.
Prospective matched-control pilot study of 60 mL wheatgrass juice daily during the first three cycles of FAC chemotherapy (Bar-Sela G, Tsalic M, Fried G, Goldberg H 2007, Nutr Cancer 58(1):43-8, PMID 17571966).
60 patients with breast carcinoma assigned to juice plus regular supportive care or regular supportive care alone.
Censoring events, defined as premature termination, dose reduction or starting G-CSF or epoetin, occurred 5 times in the juice arm and 15 times in the control arm (P=0.01); 11 of the 15 were hematological. No reduction in chemotherapy response was seen. Worsening nausea led six patients to stop the juice. The authors called for a phase III trial to confirm the result.
Two-week uncontrolled intervention with 100 mL/day of wheat sprout juice (Yi B, Kasai H, Lee HS, Kang Y, Park JY, Yang M 2011, Mutat Res 724(1-2):64-8, PMID 21736952).
14 young women, mean age 24.4 years.
Urinary bisphenol A fell steadily during the intervention (p=0.02), and BPA exposure tracked with the oxidative marker malondialdehyde (p=0.03). The abstract does not report that the juice itself lowered oxidative stress markers, and with no control group the fall in BPA cannot be attributed to the juice with confidence.