Suggest Natural Remedies For Diverticulitis, Fibroids And High BP

My dearest friend is African American, eats a high sugar and low fiber diet, and has diverticulities, fibroids, and high blood pressure. I am 20 years older than her, white, and have no health problems (vegan athlete). She tells me that I set the bar too high and she cannot even imagine eating the way I eat. Although I do no proselytize about vegetarianism, how can I support her to research ways to bring herself to a balanced healthy way of eating that can turn these health issues around? Are there natural cures to these things? She is talking surgery, colostomy bags, and is terrified.