Rong Wang

Ph.D.

Zhongshan City People's Hospital

Dr.

PLCO (Learn more about this study)

PLCO-1420

Dec 18, 2023

Adherence to a Low-carbohydrate Dietary Pattern Increases the Risk of Breast Cancer: A Prospective Cohort Study

Breast cancer (BC) is a malignant tumor that begins in the cells of the breast and spreads to other parts of the body. Among all cancer types, BC is the fifth leading cause of cancer, comprising 11.7% of all cancer incidences worldwide. With the highest incidence among women, BC contributes to 31% of all cancer instances. According to the American Cancer Society, the number of new cases and deaths from BC in United States women in 2020 is estimated to be 2.3 million and 685,000, respectively. Projections for 2023 indicate an estimated 297,790 new cases, resulting in 43,170 deaths among females.
The rate of BC occurrence is on a steady rise in both advanced and developing nations and the incidence of it increases with age. Several studies have demonstrated that diet may be related to an increased risk of BC. Many studies have pointed out that red meat consumption and alcohol abuse is attributed to the development of BC. High antioxidant content such as fruits, vegetables, olive oil, fish, and red wine, and polyphenols, flavonoids, carotenoids, fibers, a beneficial profile of fatty acids, could potentially lower the risk of BC. The ketogenic diet characterized by high-fat content and extremely-low-carbohydrate content and low-protein content, shows potential effect to impede the development of BC. However, the evidence for a correlation between dietary patterns and BC risk is very limited and more exploration is still needed.
Low-carbohydrate diets (LCD) have received much attention in recent years as people emphasize the relationship between diet and health. The concept of LCD is compared with a regular diet, which is a diet pattern that is low in carbohydrates and generally focuses on consuming foods rich in unsaturated fat-based fats and proteins, such as meats, and reduces the intake of grain-based carbohydrates. Some fundamental experiments showed that LCD was indeed effective in both slowing the growth of subcutaneously implanted tumors in mice and in preventing the appearance of tumors in mice genetically predisposed to develop various cancers, and it inhibited the development and progression of neuroendocrine tumors. A large prospective cohort study in China revealed that adherence to LCD might be beneficial for pancreatic cancer prevention. A RCT in United States showed that LCD suggestively slowed the progression of prostate cancer. While a prospective cohort study in Japan showed that LCD could increase the risk of colorectal cancer and lung cancer, but decreased the risk of gastric cancer. A prospective cohort study in Singapore also confirmed that was associated with a moderate increase in the risk of colon cancer. However, a case-control study in Iran showed that there was no correlation between adhering to LCD and the risk of gastric cancer.
So far, the long-term safety of LCD is still controversial, and there is still little evidence about how LCD affects the incidence of cancer. Therefore, the purpose of this study is to evaluate the association between LCD and the risk of BC based on a large prospective cohort study.