Actually, I don't know much about wheatgrass (or wheatgrass juice), except that it's probably overpromoted (like a lot of supposed health benefits that people see as opportunities to allow them to cash in on a trend). Since wheatgrass plants are ordinary wheat plants, it's not a paleo food, obviously. Wheatgrass was originally promoted by Ann Wigmore, and the following quote, taken from the site of the American Cancer Society says it better than I can:
The wheatgrass diet was developed by Boston resident Ann Wigmore, who immigrated to the United States from Lithuania. Wigmore believed strongly in the healing power of nature. Wigmore's notion that fresh wheatgrass had value came from her interpretation of the Bible and observations that dogs and cats eat grass when they feel ill. Wigmore claimed that the wheatgrass diet could cure disease.
In 1982, the Massachusetts Attorney General sued Wigmore for claiming that her program could reduce or eliminate the need for insulin in diabetics. She later retracted her claims. In 1988, the Massachusetts Attorney General sued Wigmore again, this time for claiming that an "energy enzyme soup" she invented could cure AIDS. Wigmore was ordered to stop representing herself as a physician or person licensed to treat disease. Although Wigmore died in 1993, her Creative Health Institute is still active. Wheatgrass is readily available, and her diet is still in use.
What is the evidence?
Wheatgrass is a natural source of vitamins and minerals. However, available scientific evidence does not support the idea that wheatgrass or the wheatgrass diet can cure or prevent disease. One small early study found that wheatgrass juice, when used along with standard medical care, seemed to help control symptoms of chronic inflammation of the large intestine, a condition called ulcerative colitis. This 2002 study tested fresh wheatgrass juice against a sham drink in a group of people with ulcerative colitis. All of them received regular medical care, including their usual diet. Those who drank about 3 ounces of the juice every day for a month had less pain, diarrhea, and rectal bleeding than those in the group drinking the placebo.
http://www.cancer.org/Treatment/Treatme ... wheatgrass
Here's the problem with Wigmore's observation about dogs and cats eating grass: They don't eat it because they think it's healthy — they eat it because they know that they can't digest it and it will cause them to vomit. IOW, when they feel the need for an emetic, they eat grass so that they can purge their stomach contents. That has absolutely nothing to do with the benefits that Wigmore claimed for it.
That said, remember that the medical community as a group, has the rather unsavory habit of denying the efficacy of any treatment that has not been proven to be effective by a random, double-blind testing program. It doesn't matter that no researcher has ever done any research on any given topic, (because no one has come up the money to sponsor a study) — if a concept has never been proven (for whatever reason), then it must be a false claim (in their eyes). Here's an example of a study that actually was done (the one mentioned in the quote):
CONCLUSION: Wheat grass juice appeared effective and safe as a single or adjuvant treatment of active distal UC.
http://www.ncbi.nlm.nih.gov/pubmed/11989836
Remember, though, that MC seems to be much more closely related to Crohn's disease than to UC, in many aspects. Personally, I've never tried wheatgrass, or wheatgrass juice, and I have no plans to do so in the future, because I don't consider wheat to be my friend.
Love,
Tex