New cases of diabetes are down, but here’s why the U.S. is still in trouble

New data released by the Centers for Disease Control and Prevention show a bright spot in America's battle against diabetes: After more than a decade of skyrocketing new cases, the number appears to be on the decline.

CDC epidemiologists have noticed this trend for several years, but given the statistical margin for error for this kind of data, they weren't 100 percent confident it was a real drop until now.

"Whereas a couple of year ago when there was clearly no increase we called it a plateau and were perhaps nervous that things had not turned the corner. With the new data we feel quite comfortable that indeed there has been a decrease," Edward Gregg, an epidemiologist for the CDC who specializes in diabetes, said in a phone interview.

From 1980 to 2014, the number of U.S. adults ages 18-79 who were being newly diagnosed with diabetes tripled from 493,000 in 1980 to more than 1.4 million. The trend accelerated from 1991 to 2009, but appeared to decline from 2009 to 2014.

Gregg said he credits a "gradual change" in risk behaviors that include changes in diet and physical activity. He noted that the greatest reductions in cases was seen in men. For those with less than a high school education, women and minority groups, the decline wasn't statistically significant, but he said he is encouraged because the "trends are in the same direction."

Science into diabetes prevention hit an important point several decades ago when researchers theorized that if you can identify high-risk people and can educate them about the risk, you can reduce the number of people who get it. "Sometimes it takes a number of years for this to happen, for the chronic disease epidemic to change the tide," he explained.

Gregg cautioned that while there is good news in the new numbers, we are still in a crisis. In fact, about 1 out of 10 Americans has diabetes even with the decline in new cases.

"In terms of incidence, our rates are still 60 percent higher than in the '90s and prevalence is still two times as high," he said. "It is still a huge problem — we shouldn’t take this data as excuse to become complacent and not continue to try to change risk. This is still one of the largest public health problems we are facing."

Gregg also said he remains concerned that the data are so broad that some of what's happening in high-risk subgroups may be hidden. "Our greatest concern is in communities with high poverty and low education, and we don't have all the data to know whether some of the highest-risk parts of America are seeing this improvement as well," he said.

Meanwhile, diabetes continues to take a huge economic toll, with an annual cost of $245 billion — similar to the revenues of a number of countries, such as Mexico and Sweden.