The spread of Western eating habits across Asian diets, including in Korea, is raising the risk of colorectal cancer, according to a new study.
A research team led by Prof. Kang Dae-hee of Seoul National University College of Medicine and Prof. Shin Sang-ah of Chung-Ang University’s Department of Food and Nutrition said Thursday that they had confirmed a clear association between Westernized diets and colorectal cancer after analyzing 82 cohort studies conducted in Korea, Japan, China, Taiwan and Singapore.
Colorectal cancer has traditionally been considered a “Western cancer,” most common in the United States and Europe. But in recent years, incidence has surged across Asia, including in Korea.
The incidence of colorectal cancer in East Asia has increased by a factor of two to four in the past 30 years, according to the World Health Organization. Korea now records one of the highest rates in the world. The researchers attributed this to the shift in Asian diets toward those of the West, which are high in fat, calories and meat.
Meat, processed foods and alcohol raise risk
The analysis found that higher total meat consumption raised colorectal cancer risk by 18 percent. Processed meats, such as sausages and ham, also independently increased the risk by 18 percent. While white meat such as chicken and turkey, showed no significant link to colorectal cancer overall, it was associated with a 40 percent increase in rectal cancer risk.
Alcohol was identified as the strongest risk factor. People who consumed more than 30 grams (2.05 ounces) of alcohol daily ? equivalent to two cans of beer (750 milliliters), two to three glasses of wine or half a bottle of soju ? had a 64 percent higher risk of developing colorectal cancer. The risk was consistent across both colon and rectal cancers.
Calcium intake, on the other hand, reduced the risk by 7 percent. Dairy products and small fish eaten whole, such as anchovies, were the main sources. “Calcium binds with fatty acids and bile acids in the gut, reducing the effects of carcinogens,” the researchers explained.
Diets rich in vegetables, fruits, whole grains and lean proteins also had a preventive effect. Those in the “healthy diet” group had a 15 percent lower risk of colon cancer thanks to the combined benefits of dietary fiber, antioxidants and plant-based bioactive compounds.
This marks the first large-scale meta-analysis focused on Asian populations. Most previous research on diet and colorectal cancer risk has been based on Western populations.
“It has been difficult to directly apply results from Western studies to Asians due to differences in dietary patterns and cooking methods,” Kang said. “This analysis shows that reducing alcohol and processed meat consumption could be a key strategy for preventing colorectal cancer in Asia.”
Although colorectal cancer is rising rapidly in the region, experts stress that it is largely preventable through lifestyle changes. They recommend limiting processed and red meat, avoiding excessive drinking, exercising regularly and increasing the intake of vegetables, fruits and whole grains.