Lifestyle changes often follow a cancer diagnosis, both during treatment and after. Eating well is often the first step. And there is good reason for it.A healthy diet can help prolong life for cancer patients and cancer survivors, says University of Michigan Rogel Cancer Center member Suzanna Zick, N.D., MPH.Surveys show as many as 48 percent of cancer patients, or those at increased risk of cancer, turn to special diets often promoted in pop culture, including the alkaline, Paleolithic, ketogenic, vegan/vegetarian and macrobiotic diets."People with cancer often learn about diets from their friends, their family and what's trendy in pop culture. Then they say, 'Could this diet help me to cure my cancer or to have a better quality of life on my cancer journey?'" says Zick, a research associate professor of family medicine and nutritional sciences at the University of Michigan.