JAMA Netw Open: High dietary fiber, calcium and yogurt can reduce the incidence of colorectal cancer

Worldwide, colorectal cancer (CRC) is the third most commonly diagnosed cancer among men and the second most commonly diagnosed cancer in women.
CRC is multi-factor, in which genetic factors and environmental factors play a major role.
studies have shown that lifestyle plays an important role in the occurrence and development of CRC, including obesity, unhealthy diet and lack of physical activity.
, a recent study published in JAMA Netw Open showed that higher dietary fiber, calcium and yogurt, as well as lower alcohol and red meat intake, reduced the risk of CRC.
the study, researchers searched the MEDLINE, Embase and Cochrane databases to evaluate 222 related studies, including 45 meta-studies.
the median number of studies per meta-analysis was 6, with a median follow-up time of 10.2 years.
sample size is 598744.
number of cases (i.e. the occurrence rate of CRC) was 5076.
in these five published meta-research analyses, a risk assessment was conducted on the relationship between 109 dietary factors and CRC rates through the Systematic Evaluation Methodology Quality Evaluation Tool (AMSTAR-2).
showed a negative correlation between healthy eating habits, the Mediterranean diet, an all-vegetarian and semi-vegetarian diet, and whole grains, total dairy products and calcium supplementation.
intake of red meat and alcohol was positively associated with the occurrence of CRC, while dietary fiber, calcium and yogurt intake was negatively associated with the occurrence of CRC.
The relationship between diet and increased incidence of colorectal cancer was specifically associated with higher red meat intake and lower red meat intake (AMSTAR-2, high quality) and severe alcohol intake (AMSTAR-2, medium quality) associated with an increased risk of CRC morbidity.
in contrast, higher or lower intakes of total dietary fiber (AMSTAR-2, high quality), calcium (AMSTAR-2, medium quality) and yogurt (AMSTAR-2, medium quality) were associated with a reduced risk of CRC.
higher total dairy intake (e.g., milk, cheese, yogurt) (AMSTAR-2, high quality) significantly reduces CRC risk compared to lower intakes.
, moderate alcohol consumption (defined as 1-3 glasses per day but not more than 4 cups) was associated with an increase in CRC rates compared to 0 glasses of alcohol or occasional drinking.
diet was also associated with a reduced incidence of colorectal cancer, and diet or diet was associated with a reduced risk of CRC, such as the Mediterranean diet, vegetarian/semi-vegetarian diet, whole grains, non-fermented milk and calcium supplementation.
, however, studies have shown that adherence to Western-style diets and the intake of processed meats are associated with an increased risk of CRC.
, a healthy diet is characterized by higher intakes of vegetables, fruits, whole grains and low-fat dairy products, and lower intakes of alcohol and meat products.
healthy eating habits, Mediterranean diet, all-vegetarian, semi-vegetarian diet and semi-vegetarian diet to prevent CRC, while Western dietary patterns increase CRC risk.