Two small studies indicate mandarin oranges may lower risk of liver cancer

September 13, 2006

In two separate studies, Japanese scientists have shown that eating mandarin oranges may decrease the risks of various diseases, including liver cancer, arteriosclerosis, and insulin resistance. In one study, conducted at the Kyoto Prefectural University of Medicine, patients with chronic viral hepatitis were divided into two groups. The experimental group, consisting of 30 people, drank one cup a day of a specially prepared drink containing mandarin orange juice and added carotenoids. The control group, consisting of 45 people, did not. After one year, none of the patients in the experimental group had any signs of liver cancer. In the control group, four people, or about nine percent of the group, had developed liver cancer. The researchers plan to continue the study for five more years.

In a second study, performed by researchers from the National Institute of Fruit Tree Science and headed by Minoru Sugiura, 1,073 people from the town of Mikkabi, Shizuoka were monitored. The townspeople are known for their high consumption of mandarin oranges. An analysis of certain chemical markers in the blood of these people revealed a lower risk of liver disease, arteriosclerosis, and insulin resistance.

The studies are being presented during a four-day symposium called "Functional Foods and Health", which is part of the 232nd national meeting of the American Chemical Society from September 10 to September 13, 2006. "Functional foods" is the name given to foods that can fight various diseases, including cancer and heart disease. In all, more than 50 papers are being presented at the symposium.

Commenting on these studies, Cathy Ross, a cardiac nurse at the British Heart Foundation, said that the studies confirmed the beneficial effects of fruits. "The more types of fruit and vegetables you can include in your diet the better."

In light of these studies, mandarin orange is being called a "super food", according to the Belfast Telegraph.

Speaking for Cancer Research UK, spokesman Ed Yong stated "These studies are far too small to tell us anything conclusive about whether mandarin oranges protect against liver cancer." He also stated "Cancer Research UK recommends eating five daily portions of fruit and vegetables as part of a balanced diet to reduce the risk of cancer. But it is unclear if any specific fruits have particularly strong benefits."