Wheatgrass is a nutrient-dense food that contains iron, calcium, amino acids, chlorophyll and magnesium, states Mayo Clinic. It also contains vitamins A, C and E. While many people tout the benefits of consuming wheatgrass juice and extract, there is little scientific research that supports this claim, states WebMD.
Consuming wheatgrass can have some negative side effects such as nausea, headaches, hives and swelling in the back of the throat, states Mayo Clinic. It can also be contaminated with bacteria and mold when consumed raw. Those with certain allergies to grass and those with celiac disease should avoid wheatgrass. Pregnant women should not consume wheatgrass because there is not enough information about its safety as of 2015, states WebMD.