Colorectal cancer is the third most common cause of cancer-related mortality in the U.S., with over 50,000 U.S. residents dying from the disease each year. While there are a number of well-known factors that may contribute to your risk of developing colorectal cancer, including a sedentary lifestyle, obesity, alcohol consumption, and smoking, new research suggests that there's one addition to your diet that could help lower your risk.
According to a recent study published in the journal Marine Drugs, researchers at Korea University, Kyungpook National University, and the University of Illinois at Urbana-Champaign found that red seaweed may have a protective effect against colorectal cancer. Working off previous research that demonstrated a notably low risk of colorectal cancer among people in Japan, researchers investigated specific components of the Japanese diet to find answers. In studying how red seaweed, a common component of Japanese diets, is digested, researchers discovered that, when broken down, red seaweed produces agarotriose and 3,6-anhydro-L-galactose (AHG), two types of sugar.
"After we produced these sugars, we tested their prebiotic activity using the bacteria Bifidobacterium longum ssp. infantis," explained Eun Ju Yun, the study's lead author and a former postdoctoral researcher at the Carl R. Woese Institute for Genomic Biology, in a statement. The study's authors also tested the sugars using B. kashiwanohense bacteria.
The researchers discovered that the bacteria only consumed the agarotriose, suggesting that the red seaweed-derived sugar may serve as a prebiotic, a type of food-derived compound that can support the growth of beneficial bacteria in the gut.
"These results show us that when we eat red seaweed, it gets broken down in the gut and releases these sugars which serve as food for the probiotic bacteria. It could help explain why Japanese populations are healthier compared to others," said Yong-Su Jin (CABBI/BSD/MME), a professor of food microbiology.
The study's researchers further examined the red seaweed-derived sugars for indications they might have cancer-fighting potential.
"We found that AHG specifically inhibits the growth of human colon cancer cells and does not affect the growth of normal cells," explained Yun.
While the study's researchers concluded that further research is needed to determine the exact applications of their findings, that's not the only benefit you may get from adding some red seaweed to your diet. According to a 2015 article published in Marine Drugs, there's also evidence to suggest that seaweed consumption may reduce your risk of cardiovascular disease.