Science and Medicine

Overall, 10,729 central nervous system tumors occurred in the study period, 1990 to 2007.

There is no link between long-term use of mobile phones and tumors of the brain or central nervous system, finds new research published online in the British Medical Journal.

In what is described as the largest study on the subject to date, Danish researchers found no evidence that the risk of brain tumors was raised among 358,403 mobile phone subscribers over an 18-year period.

The number of people using mobile phones is constantly rising with more than five billion subscriptions worldwide in 2010. This has led to concerns about potential adverse health effects, particularly tumors of the central nervous system.

Previous studies on a possible link between phone use and tumors have been inconclusive particularly on long-term use of mobile phones. Some of this earlier work took the form of case control studies involving small numbers of long-term users and were shown to be prone to error and bias. The International Agency for Research on Cancer (IARC) recently classified radio frequency electromagnetic fields, as emitted by mobile phones, as possibly carcinogenic to humans.

Read more: Biggest Ever Study Shows No Link Between Mobile Phone Use and Tumors

It is widely accepted that the sleep patterns of adolescents are fundamentally different from children and adults

Ben Franklin was right, at least on the healthy part. “Early to bed and early to rise” appears to have helped a cross-section of early-bird Australian youths keep slimmer and more physically active than their night-owl peers, even though both groups got the same amount of sleep.

A study in the Oct. 1 issue of the journal Sleep recorded the bedtimes and wake times of 2,200 Australian participants, ages 9 to 16, and compared their weights and uses of free time over four days. Children who went to bed late and got up late were 1.5 times more likely to become obese than those who went to bed early and got up early. Furthermore, late-nighters were almost twice as likely to be physically inactive and 2.9 times more likely to sit in front of the TV and computer or play video games for more hours than guidelines recommend.

“The children who went to bed late and woke up late, and the children who went to bed early and woke up early got virtually the same amount of sleep in total,” said co-author Carol Maher, PhD, a postdoctoral fellow with the University of South Australia. “Scientists have realized in recent years that children who get less sleep tend to do worse on a variety of health outcomes, including the risk of being overweight and obese. Our study suggests that the timing of sleep is even more important.”

Read more: Early to Bed and Early to Rise: Study Suggests It’s Keeping Kids Leaner