CHICAGO — New research suggests that half of all U.S. adults have diabetes or pre-diabetes.

The study of government health surveys echoes previous research and shows numbers increased substantially between 1988 and 2012 although they mostly leveled off after 2008. Overall, 12 percent to 14 percent of adults had diagnosed diabetes in 2012, the latest data available. Most of that is Type 2 diabetes, the kind linked with obesity and inactivity.

Almost 40 percent have pre-diabetes, meaning elevated blood sugar levels that could lead to full-fledged disease. Studies have shown lifestyle changes can delay or prevent diabetes in these people.

Whites had lower diabetes rates than Hispanics, blacks and Asian-Americans.

The study is based on surveys involving in-home exams and questionnaires. It was published in Tuesday’s Journal of the American Medical Association.

Eating spicy food is associated with a reduced risk for death, an analysis of dietary data on more than 485,000 people found.

Study participants were enrolled from 2004 to 2008 in a large Chinese health study, and researchers followed them for an average of more than seven years, recording 20,224 deaths. The study is in BMJ.

After controlling for family medical history, age, education, diabetes, smoking and many other variables, the researchers found that compared with eating hot food, mainly chili peppers, less than once a week, having it once or twice a week resulted in a 10 percent reduced overall risk for death. Consuming spicy food six to seven times a week reduced the risk by 14 percent.

Studies have shown that the use of oral contraceptives lowers the risk for endometrial cancer. Now a new study has found that the protection continues for many years after women stop using them.

Researchers, writing in Lancet Oncology, pooled data from 36 prospective and retrospective epidemiological studies that included 27,276 women with endometrial cancer and 115,743 healthy controls.

The longer women had used oral contraceptives, the greater the protection. Each five years of use was associated with a 24 percent lower risk compared with those who had never used them.

For 10 to 15 years of use, the risk was cut nearly in half, and the protection persisted for more than 30 years after they stopped taking the pills.

The researchers concluded that in developed countries, the use of oral contraceptives has prevented about 400,000 cases of endometrial cancer over the past 50 years.

Vitamin D supplements may be ineffective in improving bone density or bone strength in postmenopausal women, a clinical trial has found.

Researchers randomized 230 women to one of three groups: a low-dose group who took 800 units of vitamin D daily; a high-dose group who took 50,000 units twice a month; and a group that received placebo pills.

All had similar vitamin D blood levels at the start of the study, about 20 milligrams per deciliter. By the end of one year, the average vitamin D levels were 42 in the high-dose group, 27 in the low-dose group, and 18 in the placebo group.

“Right now, our patients are getting mixed messages from ‘don’t bother taking D at all’ to ‘take 2,000 too 4,000 units a day,’ so what are we to do?” said the lead author, Dr. Karen E. Hansen of the University of Wisconsin. “This study supports a middle-of-the-road approach. If your D level is 20 or higher, that’s enough, and if you’re low, you can achieve that with 600 to 800 units a day.”

Wire reports