Colorectal cancer (CRC) is the third most commonTrusted Source cancer diagnosed in the United States. Studies have shown that the Western dietTrusted Source, high-sugar diets, and excessive consumption of animal protein — especially red meat — increase CRC risk.
Studies show that diets involving fasting and caloric restriction are protectiveTrusted Source against intestinal tumors in animal models. Whether they may translate over to humans remains unknown.
Understanding more about the mechanisms underlying the effects of various diets on tumor growth could help researchers develop treatments and preventative options for CRC.
Recently, researchers conducted a series of mouse studies investigating the underlying protective mechanisms behind a low-carb diet for CRC.
They found that beta-hydroxybutyrateTrusted Source (BHB) — an alternative-energy molecule produced in response to low carb diets — suppresses intestinal tumor growth.
“BHB is a small molecule produced in the liver in response to starvation or a ketogenic diet,” Dr. Anton Bilchik, surgical oncologist and chief of medicine at Saint John’s Cancer Institute at Providence Saint John’s Health Center in Santa Monica, CA, told Medical News Today.
“This [new study] demonstrates in a mice model that it prevents colorectal cancer by activating a growth slowing receptor Hcar2 which is found in the lining of the bowel. This receptor may play an important role in preventing cell growth within the intestine,” Dr. Bilchik added. He was not involved in the study.
The new study was published in NatureTrusted Source.
LIMITED EMAIL SERIES
Going through chemotherapy? Get a helping hand
Learn essential facts about chemo, including what to eat, how to manage side effects, and habits to avoid.
Your privacy is important to us
The researchers first sought to identify dietary interventions that affect intestinal tumor growth. To do so, they designed six diets with varying fat-to-carbohydrate ratios, including two ketogenic diets with 90% fat-to-carbohydrate ratios from plant or animal sources.
After beginning the diets, the researchers induced CRC in the mice via standard chemical procedures. In doing so, they noted tumor numbers and sizes reduced when fat-to-carbohydrate ratios increased.
They also found that mice on keto diets survived for longer, and keto diets inhibited tumor development in a genetic model of CRC.
The keto diet also suppressed tumor growth when started after triggering CRC.
Meanwhile, cessation of the keto diet led to tumor regrowth, even if the diet had previously reduced tumor size.
The researchers wrote that their findings indicate that keto diets potently suppress colorectal tumor growth in both prevention and treatment models of CRC.