STUDY: Japanese Americans are Predisposed to Excess Body Fat

According to a University of Hawai‘i Cancer Center study, Japanese Americans have a greater predisposition to accumulate fat inside the abdomen (visceral fat) and liver (liver fat), compared to other races/ethnicities.

“This new discovery is important because excess visceral fat and liver fat found in Japanese Americans pose a much greater risk of metabolic disorders than fat stored in other body areas,” said Unhee Lim, UH Cancer Center epidemiologist and the study’s lead author. “These metabolic disorders, if left untreated, may lead to heart disease, diabetes and more than a dozen types of common cancers.”

Different amounts of visceral fat (left) vs. fat under the skin (right) in the abdomen. Courtesy photo.

Researchers for the study published in Gastroenterology collected data from almost 2,000 participants in the Multiethnic Cohort Study (Hawai‘i and Los Angeles residents, 60–77 years old; of African, European (white), Japanese, Latino, or Native Hawaiian ancestry) from 2013 to 2016. The study is the most ethnically diverse study conducted to date measuring body fat distribution accurately with whole-body composition imaging and abdominal MRI.

Distribution of fat as visceral, and liver fat varied significantly with ethnicity—they were highest in Japanese Americans, lowest in African Americans, and intermediate in the other ethnic groups. For the same amount of total body fat and compared with African Americans, visceral fat area was 45 and 73 percent greater in Japanese American men and women, respectively, and liver fat was 61 and 122 percent greater in Japanese American men and women.

“Our goal is to develop blood markers of visceral and liver fat in order to identify high-risk individuals for prevention of metabolic diseases,” said Loïc Le Marchand, UH Cancer Center epidemiologist and study’s principal investigator. “We are also testing dietary and lifestyle changes that would specifically reduce visceral fat and liver fat. Physicians in Hawai‘i and elsewhere should be aware that race/ethnicity is an important risk factor for metabolic diseases and obesity-related cancers.”

The University of Hawai’i Cancer Center through its various activities, cancer trial patients and their guests, and other visitors adds more than $54 million to the O’ahu economy. It is one of only 70 research institutions designated by the National Cancer Institute. Affiliated with the University of Hawai’i at Mānoa, the Center is dedicated to eliminating cancer through research, education, patient care and community outreach with an emphasis on the unique ethnic, cultural, and environmental characteristics of Hawai’i and the Pacific. Learn more online.