But did you know? Eating whole grains may be more effective in preventing colorectal cancer than eating fruits or vegetables.
There are 2 types of fiber, both of which can help prevent colorectal cancer
Compared to other cancers, colorectal cancer is very common. In 2020, colorectal cancer was the third leading cause of new cancer cases and the second leading cause of cancer deaths.
Diet is one of the main factors that cause cancer. For example, eating too few fruits or vegetables, foods high in oil and/or calories, red and processed meat, and alcoholic beverages may contribute to the cause of cancer. Bad eating habits have an impact of 30 to 50% on the incidence of colorectal cancer worldwide. Among them, too little dietary fiber intake, such as less than 10 grams per day, can increase the risk of colorectal cancer by 18 percent.
Dietary fiber is divided into insoluble fiber and water-soluble fiber, which have different functions. Insoluble fiber can increase the bulk of the stool, combine with carcinogens and toxins that are eaten or produced after digestion, shorten the time that the stool remains in the intestines, and reduce the contact between the carcinogens and the intestinal wall.
Water-soluble fiber can be fermented and broken down by gut bacteria into short-chain fatty acids (SCFAs) such as butyrate, propionate, and acetate. Short-chain fatty acids promote immunity, prevent inflammatory diseases and improve intestinal barrier function. Among them, butyrate has anti-tumor and anti-inflammatory properties and can be used as an energy source for intestinal epithelial (lining) cells.
So which type of fiber is most effective in preventing colorectal cancer? A 2021 meta-analysis found that both types of fiber are beneficial for colorectal cancer prevention and provide nearly equal protection.
In fact, most whole foods contain both types of dietary fiber, just in varying proportions. Therefore, consumption of vegetables, fruits, whole grains, legumes, and nuts can provide these two gut-protective nutrients.
Cereal fiber and colon cancer prevention
There are so many foods that contain fiber, so which one is most effective in preventing colon cancer? A large National Cancer Institute study found that whole grains and grain fiber are more effective at preventing colorectal cancer, especially cancer in the last section of the colon, the rectum.
The study, published in 2020 in The American Journal of Clinical Nutrition, showed that people with the highest intake of whole grains had a 16% lower risk of colorectal cancer compared to those who ate the least amount of whole grains .
In addition, whole grain intake was associated with prevention of colorectal cancer at all cancer sites (eg, proximal colon, distal colon, and rectum). In particular, the risk of rectal cancer was reduced by 24 percent. The fiber in the beans also helps reduce the risk of colorectal cancer by 11 percent and is effective in preventing distal colon and rectal cancers.
The British Medical Journal published a meta-analysis of dietary fiber from vegetables, fruits, legumes and other foods. The study found that among all foods, whole grain intake had the clearest association with colorectal cancer risk. In particular, consuming three servings of whole grains (90 g) a day can reduce the risk of colorectal cancer by about 20 percent. In addition, a daily intake of 10 grams of total dietary fiber and grain fiber is also beneficial in the prevention of colorectal cancer.
Why does eating whole grains have significant colon cancer prevention benefits? Researchers at the National Cancer Institute believe that whole grains contain bran, germ, and endosperm, which preserve soluble and insoluble complete fiber. In addition, they contain a large number of other nutrients, including vitamin B, minerals, phenols, antioxidants and phytoestrogens, all of which may help prevent colon cancer.
Whole grains include brown rice, millet, corn, oats, buckwheat, barley, wheat, quinoa, rye, and sorghum.
The proportion of vegetables
In fact, in the traditional oriental diet there is the concept of maintaining health with cereals as basics and vegetables as supplements. However, people today eat a lot of vegetables and fruits, which are beneficial, and pay less and less attention to grains.
Based on his many years of clinical experience, Dr. Ting-Ming Huang, an assistant physician at the Division of Colorectal Surgery at Hanming Christian Hospital in Taiwan, said that a diet of grains with vegetables is very beneficial for prevention of colorectal cancer.
His patients always ask him, “I ate a lot of vegetables, but how come I still have colon cancer?”
In fact, there are two other problems with eating too many vegetables and fruits.
1. Eat ugly vegetables
Huang noted that people often enjoy selecting attractive fruits and vegetables when grocery shopping. However, the better the agricultural products, the more pesticides they contain. And if they have not been thoroughly cleaned, people will ingest these toxins.
2. Don’t eat so many vegetables that you load your intestines
Eating too many vegetables, that is, excessive intake of insoluble fiber, will also increase the load on the intestines, so the intestines will be overloaded. Consuming too much insoluble fiber will increase the amount of stool in the intestines, which can easily cause constipation, one of the risk factors for colon cancer.
Type of rice
When eating rice as a staple, most people eat white rice with the gluten and germ removed because it tastes better. This ends up reducing its nutritional benefit.
Brown rice, which retains these parts, is harder. But you can compromise and mix your brain rice with white rice.
However, for people with poor gastrointestinal digestion, it is recommended to use white rice as a staple food. White rice is easy to digest and also contains a certain amount of micronutrients and fiber.
According to Huang, in addition to starch, rice also contains soluble fiber, which can help with bowel movements. “Eating rice can lead to smooth bowel movements and the intestines will become even healthier.”
Eating grains with vegetables is also in line with the principles of the health preservation regimen of traditional Chinese medicine. As the Yellow Emperor’s Inner Canon says: “The five grains act as food; the five fruits serve to increase; all five pets provide additional benefits; and the five vegetables complement the diet”.
Eating grains and cereals can nourish the body, help strengthen the spleen and stomach, enhance yang energy, and allow food to be completely converted into energy. According to Dr. Jonathan Liu, a professor of traditional Chinese medicine at a Canadian public university, traditional Chinese medicine believes that the fundamental problem of colon cancer is a lack of yang energy.
Liu explained that 93 percent of colorectal cancer patients are over 45, at the turning point in life when the body’s yang energy shifts from prosperity to decline. Poor nutrition will cause internal disturbances in the body and will also harm the yang energy. Conversely, a balanced diet, including a normal intake of grains, can better protect yang energy and give the body stronger immunity against cancers.