It increases the production of T and B-lymphocytes and enhances the ability of macrophage, cycotoxic cells and natural killer cells to reverse tumor and cancer cell growth. All of this is without any damaging side effects. If you eat too much beta-carotene, which is practically impossible, there is a recipe in the cell for getting rid of the excess without any cell, tissue or organ damage. Young children with chronic ear infections always showed improvement with increased intake of dietary carotene. It will be interesting to see if we, in America, will ever be privileged to have our doctors acknowledge that nutrition is the foundation of both of these.
Authorities differ in their answers, of course.
Since powdered barley leaves have generous amounts of beta-carotene, it is one more reason to take one to two teaspoons daily. While I don't doubt that many have experienced immediate beneficial results, one needs to be careful not to go overboard in order to avoid side effects. Even vitamins, especially isolated vitamins, can throw off the body's balance. Hypervitaminosis, caused by excessive vitamin ingestion, is almost always associated with synthetic vitamin preparations, hardly ever with natural vitamins. Since green barley contains vitamins in their natural state, its use will not result in an excessive intake of any particular vitamin.