More Americans are dying from colon cancer at younger ages, and researchers are not sure why. New statistics from the American Cancer Society show death rates from colon cancer have been increasing steadily among people under 54 since 2004. Katie Rich poses with husband Will and their three children, Quint, Madeline, and newborn, Brady in August 2012. She was diagnosed with colon cancer 8 weeks later. Courtesy of Katie Rich The effect is only seen in whites. Death rates are falling among blacks, another finding that confounds doctors. “This increase in incidence is real. And it's scary, because we don't know what's causing it,” said Rebecca Siegel of the American Cancer Society, who led the study team. "The increase was confined to white individuals, among whom mortality rates increased by 1.4 percent annually," the team wrote. Earlier this year, the American Cancer Society reported a puzzling rise in colon cancer rates among people born in 1990 or later. Now they’re showing an increase in death rates, too – which means that an increased emphasis on colonoscopy is not simply turning up more cases of cancer that otherwise people may not have even noticed. “It's not just more colonoscopy. We're having more disease for some reason that we don't understand,” Siegel said. Colorectal cancer is the third most commonly diagnosed cancer in Americans. Colon cancer will be diagnosed in more than 95,000 people this year and nearly 40,000 will be diagnosed with rectal cancer. The two cancers will kill more than 50,000 people this year, making colorectal cancer the second leading cause of cancer death in the U.S. “This increase in incidence is real. And it's scary, because we don't know what's causing it.” The look at data going back 40 years or more shows that death rates from colorectal cancer have fallen since 1970 in African-Americans aged 20 to 54, but that they’ve risen among whites aged 30 to 54. That’s puzzling, since obesity and diet are strongly linked to colon cancer risk and black Americans have higher rates of obesity and are less likely to eat recommended healthy diets than white Americans are. “Colorectal cancer incidence has been increasing in the United