Link Between Colorectal Cancer and Vegetarian Diet
Colorectal cancer is predicted to cause nearly 50,000 deaths in 2015 in the US, making it the 2nd major cause of cancer death in the nation. But in a new research, investigators say eating a vegetarian diet could considerably reduced the risk of developing the disease.
Research co-author Dr. Michael J. Orlich, of Lorna Linda University, CA, and co-workers publish their results in JAMA Internal Medicine.
Colorectal cancer is a cancer that starts in either the colon or the rectum. It is a combined term used for colon cancer and rectal cancer. With respect to the American Cancer Society, a person has a 1 in 20 possibility of developing the disease at some point in their life.
While the death rate from colorectal cancer continues to be high, it has dropped over the past 2 decades. This is mainly due to enhanced screening for the condition, enabling it to be recognized earlier and making it much easier to treat.
Treatment for colorectal cancer has also enhanced in current years, which has resulted in superior survival rates. There are now over 1 million colorectal cancer patients in the US.
While screening and therapy should remain an essential focus for colorectal cancer, Dr. Orlich and co-workers say determining risk aspects for the disease is essential for primary prevention. For their research, the team examined dietary risk factors for colorectal cancer.
22% reduced risk of colorectal cancer with veggie diet
Numerous research have recommended that a diet high in red and processed meats can increase the possibility of colorectal cancer, while a diet plan high in fruits, veggies and whole grains has been connected with a decreased risk. To develop on these results, the team set out to see how taking a veggie diet impacted the risk of developing colorectal cancer.
The investigators examined 77,659 men and women who were enrolled to the Adventist Health Study 2 (AHS-1) between 2002 and 2007.
All individuals were needed to complete a food frequency questionnaire and medical questionnaire at research baseline. Cancer occurrence among individuals was evaluated till 2014 via computer-assisted record linkage with state cancer registries, along with a follow-up medical questionnaire.
Over an average 7.3-year follow-up, 490 individuals were diagnosed with colorectal cancer, of which 380 conditions were colon cancer and 110 were rectal cancer.
The outcomes of the research exposed that people who ate a vegetarian diet were at a 22% reduced risk of colorectal cancer, with a 19% decreased risk of colon cancer and a 29% decreased risk of rectal cancer, in comparison with individuals who did not follow a veggie diet.
Looking at the outcomes by the type of veggie diet followed, the team identified pescovegetarians (who eat fish) had a 49% reduced risk of colorectal cancer, lacto-ovo vegetarians (who eat milk and eggs) had an 18% reduced risk, vegetarians had a 16% decreased risk, and semi-vegetarians were 8% less probably to develop the disease.
The scientists say their results appear reliable with previous studies associating intake of red and processed meats with enhanced risk of colorectal cancer.
Therefore, they say that if the association between a vegetarian diet and decreased risk of colorectal cancer is identified to be causal, following a vegetarian diet might be an essential prevention strategy for the disease. The team adds:
“The proof that veggie diets similar to those of our study individuals may be related with a decreased risk of colorectal cancer, combined with prior proof of the potential decreased risk of obesity, hypertension, diabetes and mortality, must be considered carefully in making dietary options and in giving dietary guidance.”