Have bad dreams? Caution, they may indicate the risk of contracting this disease

For years, scientists have believed that a good night's sleep is the key to preventing deadly diseases. They also thought that dreams were a sign of good brain health. But two new studies have shown otherwise.

Sleep experts from China and Sweden say sleep duration in the elderly may be an indicator of dementia risk. The findings, published in the Journal of the American Geriatrics Society, revealed that the risk of dementia was 69 percent higher in those who slept more than eight hours.

This was compared to those who slept between seven and eight. This risk was also twice as high for those who went to bed before nine o'clock. Another study found that middle-aged people who experience frequent nightmares are more likely to be diagnosed with dementia later in life.

Researchers from the University of Birmingham found that nightmares can become more common years or even decades before brain problems appear. Also, the experts emphasized that men are more at risk than women, reports the British newspaper The Sun.