SLEEPY HEAD

The ideal amount of sleep is at least six hours and no more than eight hours. The consequences of sleeping less or more than this can be dire -- especially for middle-aged adults. Regularly sleeping less than six hours or more than eight hours is linked to a decline in brain function, according to British researchers at the University College London Medical School. HealthDay News reports that the magnitude of this sleep-induced mental decline is equal to being four to seven years older than your real age. The study found:

• Women who slept seven hours a night had the highest score on every cognitive measure, followed by women who had six hours of sleep. 
• Men who slept six, seven or eight hours had similar cognitive function. 
• Men and women who slept less than six hours or more than eight hours had far lower cognitive scores than those who slept around seven hours. 

Many biological processes take place while we sleep. Researchers told HealthDay News, "Sleep provides the body with its daily need for physiological restitution and recovery. While seven hours a night appears to be optimal for the majority of human beings, many people can function perfectly well on regular sleep of less or more hours."