66).Aging affects your immune system in several ways. By the time you reach sixty, your thymus gland has mostly stopped producing T cells, which are critical to immunity. That means your body has to depend on the T cells you’ve already stored up, and as those cells gradually change and die off, you’re less able to make antibodies and your immune system doesn’t “remember” past illnesses as well. (That “memory” is why you normally don’t get infected with the same strain of a cold virus a second time.) Additionally, a 2008 study in the journal Neuroimmunomodulation found that as you get older, your immune cells—especially white blood cells—are fighting off more inflammatory compounds and free radicals with fewer antioxidant defenses to draw from. By itself, that’s enough to raise your risk of infection (such as flu and pneumonia), cancer, and autoimmune diseases as you age. But chronic stress adds an extra burden, suppressing your immune system and wearing it down even faster.
Short-term stress can actually boost your immune system, sending it into overdrive to protect you from infection and disease. But chronically elevated levels of stress hormones like cortisol and adrenaline put you in a constantly heightened state of arousal and inflammation that damages your body over time and makes your immune system less able to respond to signals to turn off that inflammation. To keep your immune system strong and healthy as you get older, managing chronic stress is crucial. You may not be able to change the source of your stress, but by taking time for yourself you can change your response to anxiety-inducing situations. Try these proven stress busters to start.
One smart strategy: Make it a point to pursue hobbies. People who participate in a variety of fun activities in their leisure time have reduced cortisol levels, along with several other indicators of good health, according to a 2009 study in Psychosomatic Medicine.
Whether it’s your daily walk or a stretching session, exercise can be important “me” time. A mindfulness-based stress reduction program of twenty minutes of meditative breathing and stretching per day was enough to lower workers’ stress levels by nearly 10 percent, according to a 2009 study in the journal Health Education & Behavior. And moderate exercise boosts immunity as well (66).
Even small acts of self-care can reduce stress. If you’re stuck at the office or your home, surround yourself with calming scents to strengthen your immune system. Study participants who sniffed lavender or rosemary essential oils for five minutes lowered cortisol levels and increased their bodies’ abilities to fight off aging free radicals, according to a 2007 study in the journal Psychiatry Research. If you can, bring in a few sprigs of fresh lavender or a potted rosemary plant—exposing yourself to nature even in small doses can snuff out stress. For example, Japanese researchers found that volunteers who stayed in a hospital room decorated with natural materials had 20 percent lower cortisol levels than those who stayed in a typical hospital room.
Laughter not only makes you feel good, but it boosts your immune system as well, and researchers believe that the benefit stems from stress reduction. In a study published in Alternative Therapies in Health and Medicine, researchers asked fifty-two healthy men to watch a comedy video. After that one hour of laughing, several markers of immune function increased for up to twelve hours afterward. Further research shows that exposure to a humorous stimulus or the act of laughing can increase the activity and number of natural killer cells in the immune system. And a few small studies demonstrate an increase in salivary IgA levels (a measure of immune function) following exposure to a humorous video.
Even anticipating laughter can reduce stress and improve immunity, according to research presented at the 2008 Annual Meeting of the American Physiological Society. The study authors measured the hormones of volunteers who expected to watch a funny film, and they found that feel-good endorphins and human growth hormone (HGH), which helps with immunity, increased by 27 and 87 percent, respectively. They also found reductions in three stress hormones, including cortisol.
