We’re at the start of cold and flu season, and inside your body, a series of small battles is being waged. The army, your immune system, is made up of a number of key players, all dedicated to protecting you from foreign invaders. How to keep immunity healthy and balanced? In part one, we looked at what to eat and what to avoid. Here, in part two, we’ll look at what to take, and how to live.
What to take.
The studies on herbs and supplements are mixed, but a few contenders shine through. The best:
Ashwagandha, an Ayurvedic herb traditionally used as an adaptogen to combat stress and boost energy, may also enhance immune function by increasing production of certain key players.7 One recent study suggested that Ashwagandha may also help protect against colon cancer.8
Propolis, a sticky, glue-like substances produced by honeybees and used to construct their hives, is strongly anti-bacterial actions. In one study, propolis was more effective than an antibiotic mixture against a strain of Enterococcus bacteria.9
Ganoderma lucidum (reishi mushroom) is a fungus traditionally used in Chinese medicine for health, longevity and recuperation. Many studies have pointed to the potent immune-supportive effects of reishi mushroom, and more recent research suggests that reishi inhibits tumor growth. 10
Olive leaf extract—from the Mediterranean olive tree—is rich in antioxidants and has strong anti-viral activities.11 In one study, olive leaf extract inhibited HIV-1 replication.12 It’s also been shown to lower blood pressure and reduce LDL cholesterol.
Astragalus, traditionally used in Chinese medicine to treat diabetes and speed healing, also has immune-supportive effects, and can help combat HIV.13 It’s especially useful in supporting the immune system during chemotherapy,14 and other studies have suggested that astragalus may also protect against some kinds of cancer. 15
Probiotics have a wide range of immune-supportive actions, especially in diarrhea, allergy, eczema and viral infections.16 Other studies point to their effectiveness in treating irritable bowel syndrome 17 and reducing inflammation. 18
How to live
Diet and supplements can go a long way toward boosting resistance and improving immune system function. But that’s only part of the story; if you’re sleeping too little, stressing too much and moving not at all, you’ll impact your immune system. Some important tips on how to live, to boost resistance:
Move more. Studies show that regular exercise diminishes inflammation and elevates compounds involved in immune function.19 The one exception is consistently exercising to the point of exhaustion, which seems to diminish resistance. Otherwise, dance, swim, jog, do yoga—whatever moves you.
• Walking versus running. Brisk walking appears to be better for overall immunity than hard-core running. While vigorous, intense activities like running can weaken immune function, more moderate exercise seems to strengthen it. In one study, women who engaged in brisk walking or other moderate exercise for about 30 minutes a day had half the risk for colds over the course of a year as those who didn’t exercise on a regular basis.
• Yoga supports overall immunity, through a couple of different mechanisms. First, a regular yoga practice helps prevent alterations in the number of immune cells.20 Second, yoga is associated with a reduction in stress, and a corresponding drop in levels of cortisol, a stress hormone that’s linked to suppressed immune function. In one recent study, breast cancer survivors who practiced yoga daily had lower cortisol rates and reductions in other markers of stress.21 In most studies, yoga also has auxiliary benefits, like reduced heart rate and blood pressure, increasing muscle strength, and lessening the risk of anxiety and depression.22
• Tai chi, a type of Chinese martial art, benefits both immune and autoimmune conditions, in addition to decreasing heart rate, blood pressure and cholesterol.23 Other studies show that qigong also has similar benefits.24 One study showed that a moderate Tai Chi and Qigong practice improved immune response of older adults, after only five months of practice.25
Reduce stress. It’s one of the most important factors for improving immune function. Researchers have known for years that a wide variety of conditions and illnesses, from digestive disorders to heart disease, are linked to emotional stress. Most studies show that chronic, long-term stress—versus sudden, short-lived, intense stress—causes more damage to the immune system. Stress may impact immunity by disrupting communication between the immune system and other body systems, by causing a chronic release of stress hormones, like cortisol, that affect immune regulation, or by decreasing T-cell activity. 26
Have lots of friends. In an early and famous experiment on immune response and social life, researchers exposed healthy volunteers to the cold virus, and found that those with stronger social networks and friendships were less likely to develop colds. Other studies have consistently linked a strong support system with better immune function, as well as lower blood pressure and reduced mortality. 27
Meditate, with love. Mindfulness-based meditation practices have been linked in many studies with improved immune function. One recent study also noted that similar practices, called loving-kindness meditation and compassion meditation—geared toward encouraging a loving, kind mindset—improved immune response.28
Laugh. A good belly laugh can boost immunity and increase natural endorphins, the body’s natural feel-good chemicals. In one recent study, laughter appeared to specifically impact the activity of natural killer cells.29 Rent a funny movie, go to a comedy show, invite your funniest friend to lunch. Your immune system will thank you.