19, 32). Exercise regularly, but not in the few hours before you go to bed. And if anxiety keeps you awake at night, try pouring out your thoughts in a journal or make a to-do list so you don’t keep ruminating.While you’re sleeping, your body is busy repairing itself. When you don’t get enough sleep, or don’t sleep deeply, that healing doesn’t happen as well. That can spell big trouble for your immune system as you get older, putting you at increased risk of infection and disease. In a healthy brain, substances related to immunity interact with neurochemical systems to regulate your sleep. But as you age, communication between your immune system and your nervous system begins to break down. A lack of sleep can further upset the balance, aging your immune system so it can’t protect you as well.
Researchers don’t know exactly how sleep impacts immunity, but some suspect that your body’s circadian rhythms affect immune system cells, or that sleep may reduce immunity-weakening oxidative stress (in effect, functioning as an anti-aging free-radical fighter). The sleep-regulating hormone melatonin, which also decreases with age, influences several aspects of immunity as well. In fact, researchers are currently investigating whether supplementing with melatonin can restore immune function in older people.
You need at least seven hours a night to reach healing REM sleep, evidence indicates. A 2009 study in the Archives of Internal Medicine found that volunteers who got less than seven hours of sleep nightly for two weeks were nearly three times as likely to develop a cold when exposed to a virus. Thankfully, putting the following sleep habits into practice may be enough to restore that nightly healing process and keep your immune system functioning at its best as you get older.
In later life, many people don’t sleep as well as they used to, thanks to medications, hormonal shifts, changing responsibilities, and chronic conditions. For example, common drugs like beta-blockers for high blood pressure and nonsteroidal anti-inflammatory drugs (NSAIDs) for joint pain significantly lower melatonin production, thereby aggravating insomnia. If you have trouble sleeping, keeping a sleep journal in which you record activities, what you eat and drink, how you feel, or other factors that influence how well you sleep may shed some light on what’s interfering with a good night’s rest. If your sleep problems last longer than two weeks, talk to your doctor about possible underlying factors.
Some basic steps you can take to set the stage for sleep include reserving your bed (and ideally your bedroom) for sleeping and sex, avoiding stimulating activities before bed, and sticking to a regular sleep schedule (19, 32). Exercise regularly, but not in the few hours before you go to bed. And if anxiety keeps you awake at night, try pouring out your thoughts in a journal or make a to-do list so you don’t keep ruminating.
To minimize sleep interruptions and ensure you get enough immune-boosting REM sleep, keep your bedroom completely dark and quiet, don’t consume caffeine or alcohol for several hours before bedtime (if you’re sensitive, you may need to cut them out completely), and limit nighttime beverages. Napping to make up for lost Zzzs may actually make it harder to fall and stay asleep at night, when the immune system needs it most, so keep daytime snoozing to a minimum if possible.
If you try these approaches and still have trouble falling asleep, have a few sips of chamomile tea or warm milk before bed. Both have relaxing properties, and having something warm in your stomach can be comforting. Two of the best natural sleep aids are valerian (Valeriana officinalis) and melatonin. Valerian, an herbal sedative that’s been used for centuries, is nontoxic and not addictive, but some people find it leaves them feeling fuzzy-headed in the morning. If you’d like to try it, take one or two capsules of a product standardized to 1 percent valerenic acid thirty minutes before bedtime.
Supplemental melatonin is also available over the counter. Other than causing an increase in dreaming, it has no known side effects. Andrew Weil, M.D., an integrative physician, author, and professor, recommends taking 2.5 milligrams at bedtime occasionally if needed. He prefers sublingual tablets that dissolve when you place them under the tongue, but capsules are also an option. For regular use, a much lower dose (0.25 to 0.3 milligrams) may be effective.