Sweet Potato Leaves Kill 94% of Prostate Cancer Cells in Vitro: An extract of sweet potato leaves was discovered to be extremely toxic to prostate cancer cells in this study, killing 94% of them in vitro and slowing the growth of prostate tumors in mice by 75%. Other research has shown that these super-greens are also active against breast cancer, lung cancer, colon cancer, stomach cancer and leukemia. And the health benefits of these greens are not just for the lab. One study out of Taiwan showed that eating at least 100 grams per week of this super vegetable decreased lung cancer risk by up to 57%! In other studies, sweet potato leaves boosted immunity (T lymphocytes and natural killer cells) in humans and lowered blood sugar in mice with type II diabetes. And if you need an energy boost, sweet potato leaf could be just the vegetable for you: a recent study showed it significantly relieved fatigue in mice, increased exercise capacity and even boosted muscle glycogen levels! Why are these greens so powerful? They are an excellent source of potent antioxidants called polyphenols, including the unique and powerful caffeoylquinic acids, and anticancer peptides. And alkaline diet fans take note: these greens are one of the most alkalizing vegetables out there, delivering 400% the alkalizing power of pure lemon juice, ounce for ounce.