Rong Wang

Ph.D.

Zhongshan City People's Hospital

Dr.

PLCO (Learn more about this study)

PLCO-1357

Oct 17, 2023

Adherence to a Low-carbohydrate Dietary Pattern Reduces Biliary Cancer Risk: Evidence from the PLCO Trial

Biliary cancer refers to a group of invasive glandular cancers including intrahepatic, perihilar, distal bile duct and gallbladder cancers, which are relatively rare but detrimental digestive system tumors. The incidence of biliary cancer has shown a slow rising trend globally. Despite improved understanding of biliary cancer pathogenesis, about 50% of cases in Western countries still have no identifiable risk factors at diagnosis. Thus, it is conceivable that other undetermined etiological factors account for the recent rise in global incidence of biliary cancer. As dietary patterns are changing, the incidence of many diseases is also shifting. Therefore, the association between dietary patterns and risk of biliary cancer warrants further clarification. Evidence on the correlation between dietary patterns and risk of biliary cancer is very limited and more investigations are needed.
With increasing awareness of diet-health relationship, low-carbohydrate diets have gained considerable popularity in recent years. Low-carbohydrate diets refer to restriction of sugar and starch intake and higher proportions of protein and fat. This dietary pattern is commonly used for weight loss. A small number of studies have examined the association between low-carbohydrate diet and cancer risk. A prospective cohort study in Japan showed that low-carbohydrate diet increased the risk of colorectal and lung cancers but lowered the risk of gastric cancer. Another prospective cohort study in Chinese Singaporeans also confirmed the increased risk of colon cancer with low carbohydrate diet. However, a case-control study from Iran found no association between adherence to low carbohydrate diet and gastric cancer risk. Another case-control study from Iran showed that adherence to low carbohydrate diet may increase the risk of postmenopausal breast cancer in women.
The long-term safety of low-carbohydrate diet remains controversial and evidence regarding how low-carbohydrate diet may influence cancer incidence is still scarce. Low-carbohydrate diets lead to increased fat intake, which promotes bile secretion and subsequently higher incidence of gallstones and cholangitis, thus possibly increasing the risk of biliary cancer. However, these speculations lack evidentiary support. Therefore, this study aimed to examine the association between low-carbohydrate diet and risk of biliary cancer based on a large US cohort, using low-carbohydrate diet score for assessment.