PHILADELPHIA — If you’re older, here’s another great reason to get your Z’s:

Better sleep helps you stay sharp at work, play with the grandkids, and, new research shows, prevent dementia.

New evidence reveals that sleep apnea, insomnia, and poor sleep hygiene may be linked to early-stage cognitive decline, dementia, and even Alzheimer’s disease.

Thomas Jefferson University and the University of Pennsylvania offer clinics focusing on sleep as we age, and techniques such as meditation and cognitive-behavioral therapies.

Penn Medicine physician Nalaka Gooneratne says research shows that older adults need the least sleep of any age bracket.

The recommended night’s sleep decreases as we age: eight to 10 hours for teenagers; seven to nine hours for young and middle-aged adults; and seven to eight hours starting at age 65.

“That’s one positive of getting older,” Gooneratne says.

Sleep apnea is more common in older adults: Some studies suggest that one-fifth to one-quarter have it, vs. one-tenth of middle-age adults.

Many also don’t know it: They’re single or widowed, and don’t have someone telling them, “You snore and kept me awake all night.”

So if you’re visiting over the holidays or traveling with a group and someone tells you that you snore, it could be a sign of sleep apnea.

Dementia is one of the biggest fears of our modern era — and can lead to personality changes and expensive memory-care facilities or nursing homes.

“There’s moderately strong evidence, from observational studies and small randomized studies, showing sleep apnea is linked to dementia,” Gooneratne says.

Sleep apnea leads to lower oxygen levels, and since you’re not breathing normally, that can lead to brain damage.

To treat sleep disorders, consider cognitive behavioral therapy for insomnia, which includes sessions with a therapist and is available at most sleep clinics. Or ask for a doctor certified in sleep medicine.

Sleep masks (also known as CPAP masks) and dental devices also are recommended treatments for sleep apnea. Gooneratne’s research lab at the University of Pennsylvania offers some clinical studies that are open to enrollment.

Jefferson also offers a new upper-airway stimulation therapy, a neurostimulator device implanted under the skin of the chest.

“It’s an electrical signal to the muscles of the throat to expand instead of close,” says physician Karl Doghramji, medical director of Jefferson Sleep Disorders Center.

“Many people who have sleep apnea can’t tolerate a mask or device. We were the first to bring this to the area.”

—Napping. Older adults tend to take more naps, since they have more flexible schedules. That’s fine, experts say — as long as you don’t sleep less at night.

For example, if you need 71/2 hours of sleep in a 24-hour period and you take a two-hour nap, you shouldn’t be surprised if you only need 51/2 hours that night.

“If you took a two-hour nap, the logical thing is to go to bed later. Don’t go to bed at your usual time. Many people don’t appreciate that and get frustrated with insomnia, and it becomes a vicious cycle,” said Gooneratne, who has insomnia himself.

—Mindfulness. Jefferson runs a popular Mindfulness-Based Stress Reduction Program available to the public. Mindfulness is “paying attention, on purpose, in the present moment with an attitude of curiosity and openness,” says Diane Reibel, director of Jefferson’s Mindfulness Institute.

Research studies at Jefferson show mindfulness is effective in reducing chronic pain, medical symptoms, anxiety, and depression. Other studies show it is helpful in treating sleep disorders, high blood pressure, heart disease and asthma.

To learn more or register, visit www.jefferson.edu/mindfulness or call 1-800-533-3669.

—Medications. Senior citizens consume the most medicine, some of which can disrupt sleep. Certain beta blockers, diabetes drugs, antidepressants, and other pharmaceuticals are major culprits.

Sleeping pills such as Ambien and over-the-counter sleep aids should not be taken every night — at most once or twice a week, experts say. Melatonin isn’t approved by the Food and Drug Administration, and should be taken at least two hours before bedtime.

Online resources. SHUTi (myshuti.com) and SleepIO (sleepio.com) both offer online products for insomnia — you pay for instructions on cognitive behavioral therapy, which trains you to use techniques that address the mental (or cognitive) factors associated with insomnia, such as the "racing mind," and to overcome the worry and other negative emotions that accompany the experience of being unable to sleep.