You can make your brain as sharp as someone 4 to 7 years younger just by getting a little more sleep.

Most Americans fall short of the recommended 6 to 8 hours. But in a recent study of middle-aged folks, those who consistently slept 6 to 8 hours a night scored the best on cognitive-function tests.

The Long and Short of It
In the study, people reported how many hours of sleep they got on an average weeknight. And then they did so again more than 5 years later. They also took cognitive-function tests on both occasions. And those who fell short of the recommended 6 to 8 hours of sleep had the lowest scores. In fact, their scores were akin to someone many years older. But interestingly, getting too much sleep was problematic as well. Those who got more than 8 hours also had super-low scores on the cognitive-function tests. So while you're getting more ZZZs, try not to be a total sleepyhead. 

Sleep and Your Brain
It's not clear why too little or too much sleep affects the brain. But we do know that sleep trouble is linked to everything from depression, heart disease, stroke, and high blood pressure. Probably because sleep issues affect blood levels of a host of different hormones and chemicals in the body. And now it appears that those same changes in hormones and body chemicals affect cognitive function, too.

Sleep Hygiene

Sleep hygiene refers to a list of recommended behaviors and environmental conditions that can improve the quality of your sleep. Research indicates that 70% to 80% of people with sleep disorders achieve some benefits when practicing good sleep hygiene.

Behaviors to avoid:

• Having caffeine after lunch
• Having alcohol within 6 hours of bedtime
• Watching television right before going to bed
• Having a cigarette before bedtime
• Going to bed hungry or when you've had a big meal
• Going to bed before you are sleepy
• Exercising too close to bedtime

Behaviors to adopt:

• Using your bedroom only for sleep and sex
• Exercising regularly, preferably in the morning or early afternoon
• Keeping a regular bedtime and waking time, even on the weekends
• Creating a relaxing bedtime routine, such as taking a leisurely stroll, soaking in a tub, listening to soothing music, or massaging your legs or feet before bed
• Practicing relaxation techniques, such as progressive muscle relaxation, guided imagery, and deep-breathing exercises
• Creating a comfortable environment that is conducive to sleep by eliminating uncomfortable bedding, wearing loose clothing, keeping the bedroom temperature slightly cool, and eliminating any bothersome noise or light