A large-scale study showed that if women intake more than 800 mg of calcium per day, they can reduce the risk of colorectal cancer by 46%. Whether dietary or nutritional supplements can significantly reduce the risk of colorectal cancer in women. Previous studies have demonstrated that calcium intake is associated with the prevention of colorectal cancer.
In this new study, researchers at the University of Minnesota Cancer Center selected 45,354 women with an average age of 62 years. These women were selected from a breast cancer detection demonstration program and did not have a history of colorectal cancer. Researchers grouped according to their diet and living habits, and averaged 8.5 years of research.
About 150,000 people in the United States are diagnosed with colorectal cancer every year. This cancer mortality ranks second, and its incidence increases with age. However, researchers still do not know why calcium is protective for women. There are currently two main theories:
1. Calcium neutralizes secondary bile acids, reducing the irritation of the intestinal walls of secondary bile acids.
Secondary bile acids are secreted when digesting fat and are highly irritating to the inner wall of the colon. However, the current evidence supporting this argument is not very strong.
2. Calcium can directly affect a series of biochemical reactions in the cells of the colorectal wall.
These reactive pathways play an important role in the regulation of cell growth and maturation, and therefore may be an important factor in the development of cancer.
The researchers said that intake of calcium-rich diet should be at least 800 mg per day, which is less than the current recommended amount of 1200 mg, so intake of 800 mg is a safe and effective method to prevent women from developing colorectal cancer. The same benefits can be seen in men, but the researchers reminded that the main source of calcium in western diets is dairy products, and some studies have now found that ingesting dairy products is linked to the risk of prostate cancer.