At the 2014 Food and Nutrition Conference and Expo in Atlanta, Ga., given by the Academy of Nutrition and Dietetics (October 18–21), speakers discussed how fasting and a ketogenic diet may help treat and prevent certain cancers.
During the session "Fasting and the ketogenic diet: The next therapies for cancer treatment and revention?" Vincent Longo of the Univ. of Southern California Davis School of Gerontology said that although calorie restriction can be extreme, there is an optimal level of reduced calorie intake for improved health. In fact, 72 hrs of fasting is associated with reduced DNA damage. Cancer cells are very smart, Longo said, and adaptable until short-term starvation (i.e., fasting) occurs. Thus, short-term fasting can protect normal cells and organs while sensitizing cancer cells to chemotherapy.
Moreover, protein and sugars increase the risk of illness by activating genes that promote aging and diseases. Protein intake appears to affect levels of the hormone insulin-like growth factor-1 (IGF-1) and cancer growth. Studies have shown that men with highest levels of IGF-1 have more than four times the risk of prostate cancer and women with high IGF-1 levels have more than double the risk of breast and colorectal cancers. Consequently, low-carbohydrate diets—which usually involve consuming more protein—are associated with increased mortality from cancer, cardiovascular disease, and other diseases. Also discussed during the session was the positive effect of a ketogenic diet on ioblastomas (brain tumors). Leonora Renda of the Univ. of Arizona Cancer Center said that ketosis is a condition in which there are elevated levels of ketone bodies in the body's tissues and fluids. It occurs when there is not enough glucose in the body, so the body burns fat/fatty acids for energy. The increased prevalence of ketones in the body appears to have an effect on gene expression and tumor growth in patients with glioblastomas: Ketones are toxic to glioblastoma cells, she said.