TUESDAY, Sept. 11, 2018 (HealthDay News) -- There's no disputing the fact that regular colonoscopies, now suggested to start at age 45 for those with an average risk of colorectal cancer, can help prevent the disease by finding -- and removing -- precancerous growths.
And a study of 77,000 adults published in JAMA Internal Medicine found that you can also lower your risk of this cancer by making changes in your diet right now, whatever your age.
Doctors know that eating red and processed meats raises the risk of colorectal cancer, while eating fiber-rich foods lowers it. The JAMA findings got more specific about different types of diets.
On average, eating vegetarian may lower colon cancer risk by 19 percent and rectal cancer by 29 percent compared to non-vegetarians -- people who eat meat at least once a week. Besides eating less meat, the vegetarians in the study ate fewer sweets, snacks, refined grains and high-calorie beverages and more fruits, vegetables, whole grains, beans and nuts.
However, the protective effects vary with the type of vegetarian diet, the researchers said.
By the study's numbers:
- Pesco-vegetarians: Eating fish and seafood, but avoiding other meats lowers colorectal cancer risk by 43 percent.
- Lacto-ovo vegetarians: Avoiding meat, but eating eggs and/or dairy products lowers colorectal cancer risk by 18 percent.
- Vegans: Avoiding all meat, eggs and dairy lowers colorectal cancer risk by 16 percent.
- Semi-vegetarians: Eating meat less than once a week lowers colorectal cancer risk by 8 percent.
Research can't yet explain exactly how eating vegetarian helps. But one theory says it could be because vegetarians often follow other healthy behaviors, such as exercising and not smoking, which also reduce cancer risk.
The Vegetarian Resource Group has many ideas on how to go vegetarian.