Cancer deaths down, but millions of new ones projected

The report, released last week, notes that the overall death rate for cancer in the United States has fallen significantly, primarily because of reductions in smoking and improved cancer screening.

The report is based on data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the National Center for Health Statistics. Those sources show that cancer deaths dropped 20 percent from their peak in 1991 to 2009, the most recent date available.

According to the report, about half of all new cancers found in men will involve the prostate, lungs, colon or rectum. Among women, the three most common types of cancer that will be diagnosed are breast, lung and colorectal.

In 2013, lung cancer is expected to account for 26 percent of all female cancer deaths and 28 percent of all male cancer deaths.

Although cancer rates are declining for most types of cancer, they are rising among both sexes for melanoma of the skin and cancers of the liver, thyroid and pancreas.

The report notes also that cancer rates are disproportionate among racial, education and income groups, and that more must be done to eliminate these differences.

Cancer mortality rates among African-American and white men with 12 or fewer years of education are almost three times higher than those of college graduates for all cancers combined.

Scientists have been looking into the association between sleep deprivation and weight gain in adults and children. One study concluded that people who slept less than five hours per night were 73 percent more likely to experience weight gain than those getting seven to nine nightly hours.

Research of sleep deprivation in men found that it increased their desire for foods higher in calories, along with overall calorie intake. A study of women who consistently slept less than six hours or more than nine hours found they were more likely to gain 11 pounds, compared with women who slept seven hours a night. Similar findings were seen in children and adolescents.

Along with increased daytime fatigue that contributes to lesser amounts of physical activity, the amount of sleep we get influences the hormones insulin, glucose and cortisol, as well as leptin and ghrelin, two hormones that are responsible for regulating hunger.

Leptin signals the brain to stop eating, and people who are sleep-deprived have less of this hormone. Ghrelin's job is to signal you to eat. It has been shown that those who are sleep-deprived have more of this hormone. The combination of more ghrelin and less leptin promotes weight gain.

How efficient leptin is at sending these signals is still being studied. The body's production rate of leptin, its resistance to it, or a combination of these factors, can all influence eating behaviors and amount of calories burned. Scientists hope to uncover important clues into what effect leptin has not only on obesity but also other conditions such as diabetes.

If found to be true, then leptin therapy may help people maintain weight loss after dieting. The amount of leptin in the bloodstream correlates to percentage of body fat and body mass index (BMI). Generally, greater body mass and percentage of fat equate to higher leptin levels, although this can vary from person to person.