Whole grains decrease colorectal cancer risk, processed meats increase the riskBy cwan | November 6th, 2017
Colorectal cancer is one of the most common cancers. In the US, colorectal cancer is the third most common cancer among both men and women, with an estimated 371 cases diagnosed each day. The World Cancer Research Fund estimates that 47% of US colorectal cancer cases could be prevented each year through healthy lifestyle changes.
To understand the correlation between diet/lifestyle and incidence of colorectal cancer, scientists from the Harvard TH Chan School of Public Health evaluated the scientific research worldwide on how diet, weight and physical activity affect colorectal cancer risk. They analyzed 99 studies, including data on 29 million people, of whom over a quarter of a million were diagnosed with colorectal cancer.
The Harvard scientists found that eating whole grains daily, such as brown rice or whole-wheat bread, reduces colorectal cancer risk, with the more you eat the lower the risk. The report concluded that eating approximately three servings (90 grams) of whole grains daily reduces the risk of colorectal cancer by 17%. This adds to previous evidence showing that foods containing fiber decreases the risk of this cancer.
The report also found links between the consumption of fish and foods containing vitamin C with the lowered risk of colorectal cancer. Oranges, strawberries and spinach are all foods high in vitamin C. There is limited evidence correlating higher intake of non-starchy vegetables and fruit with lower risk of the cancer.
On the other hand, the study found that hot dogs, bacon and other processed meats consumed regularly increase the risk of the cancer. Other factors found to increase colorectal cancer include:
- Eating high amounts of red meat (above 500 grams cooked weight a week), such as beef or pork
- Being overweight or obese
- Consuming two or more daily alcoholic drinks (30 grams of alcohol), such as wine or beer
For physical activity, people who are more physically active have a lower risk of colon cancer compared to those who do very little physical activity. Here, the decreased risk was apparent for colon and not rectal cancer.
This report demonstrates there is a lot people can do to dramatically lower their risk of colorectal cancer. Factors such as maintaining a lean body weight, proper exercise, limiting red and processed meat and eating more whole grains and fiber would lower risk substantially. Moreover, limiting alcohol to at most two drinks per day and avoidance or cessation of smoking also lower risk.
When it comes to cancer there are no guarantees, but it’s clear now there are choices you can make and steps you can take to lower your risk of colorectal and other cancers.
Thanks for reading.
Dr. Connie Wan
Journal reference: American Institute for Cancer Research. “Whole grains decrease colorectal cancer risk, processed meats increase the risk: Report analyzing the global research finds hot dogs and other processed meats increase risk of colorectal cancer, eating more whole grains and being physically active lowers risk.” ScienceDaily, 7 September 2017. <www.sciencedaily.com/releases/2017/09/170907093623.htm>.