What to eat and how to live for healthy immune function
We’re right in the middle 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 dedicated to protecting you from foreign invaders. How to keep these trusty defenders healthy and balanced? Here’s the best advice.
How to Move
Studies show that regular exercise elevates levels of compounds involved in immune function. The exception is exercising to the point of exhaustion, which diminishes resistance. Otherwise, dance, swim, jog, do yoga—whatever moves you.
Walking. Brisk walking appears to be better for overall immunity than hard-core running. In one study, women who engaged in brisk walking or other moderate exercise for 30 minutes each day had half the risk for colds as those who didn’t exercise.
Yoga helps prevent alterations in the number of immune cells. It's also associated with stress reduction and a corresponding drop in cortisol—a hormone that’s linked to suppressed immune function. In most studies, yoga has shown auxiliary benefits such as reduced blood pressure, increased muscle strength, and reduced anxiety and depression.
Tai chi, a Chinese martial art, benefits immune and autoimmune conditions, in addition to decreasing heart rate, blood pressure, and cholesterol. Research shows that Qigong has similar benefits. One study showed that a moderate Tai Chi and Qigong practice improved immune response in older adults after only five months.
What to Eat
The immune system is like an army protecting the body from invaders, so it’s important to keep the soldiers well nourished.
Brazil nuts. They’re high in selenium, which has been shown to improve immune response in several studies. Other sources of selenium include halibut, turkey, and sardines.
Easy fix: Make a pesto of puréed Brazil nuts, garlic, fresh basil, and olive oil.
Oysters are rich in zinc, an antioxidant that’s essential for immune function. Many studies have shown that even mild zinc deficiency depresses immunity. Beef, crab, turkey, and kidney beans are other good sources of zinc.
Easy fix: Combine oysters, crab, and fish in a seafood stew.
Pumpkin is packed with vitamin A, which enhances immune functions including white blood cell activity. Studies have shown that a vitamin A deficiency actually increases risk of infectious disease. Carrots, sweet potatoes, spinach, collards, and kale are other good sources.
Easy fix: Add puréed pumpkin to pasta sauce.
Sunflower seeds are high in vitamin E, essential for overall immune function. In studies, even a small vitamin E deficiency has been shown to impair immune response. Other good sources: almonds, turnip greens, spinach, and beet greens.
Easy fix: Swap sunflower butter for peanut butter on sandwiches.
Papayas are packed with vitamin C, which improves many components of the immune system, including natural killer cell activity. Strawberries, grapefruit juice, peaches, peppers, broccoli, and Brussels sprouts are other good sources.
Easy fix: Combine chopped papayas and peaches with minced jalapeños, red onion, and lime juice for salsa.
Red peppers contain vitamin B6, which is necessary for the production of several important immune cells. Other good B6 sources: tuna, spinach, cod, bananas, soy, and beans.
Easy fix: Purée roasted red peppers and white beans for a quick dip.
AHCC: Go-to winter wellness remedy
AHCC, or active hexose correlated compound, is an alpha glucan—rich extract of the mycelia (the cottony, tangled “roots”) of hybridized Basidiomycete mushrooms. AHCC strengthens and maintains peak performance of healthy immune cells, including natural killer (NK) cells, T-cells, and cytokines (the body’s own biochemical and cellular defense network).
In addition to helping immune-compromised individuals, AHCC has also been shown to enhance immunity in healthy people. A study involving 30 healthy subjects showed that those who took AHCC after getting a flu shot had higher levels of essential T-Cells than those who received only the shot. In another study from Yale University School of Medicine, supplementing with AHCC for 30 days helped enhance long-term immunity among healthy elderly adults.
Worried about more than just the flu? Well, numerous animal studies show that AHCC helps boost immunity in response to a variety of viral, bacterial, and fungal infections, including MRSA and West Nile Virus.
—James J. Gormley
What to Take
In addition to food, supplements can help give your immune system a healthy boost. Some of the best:
Ashwagandha. Traditionally used as an adaptogen to combat stress, it may also help enhance immune function. One study suggested that ashwagandha may also help protect against colon cancer.
Propolis, a substance produced by honeybees, is strongly antibacterial. In one study, it was more effective than an antibiotic against a strain of Enterococcus bacteria.
Astragalus, traditionally used to treat diabetes, also has immune-supportive effects. It’s especially useful in supporting the immune system during chemotherapy.
Reishi mushroom (Ganoderma lucidum) is traditionally used in Chinese medicine for health, longevity, and recuperation. Many studies have pointed to its immune-supportive effects, and recent research suggests that it inhibits tumor growth.
Probiotics have a wide range of immune-supportive actions that are especially effective in cases of diarrhea, allergies, eczema, viral infection, and irritable bowel syndrome. They may also help reduce inflammation.
Olive leaf extract has strong antiviral properties. In one study, it inhibited HIV-1 replication. It’s also been shown to lower blood pressure and reduce LDL cholesterol.
What to Avoid
Some foods, toxins, and drugs upset immune system balance. The worst:
Sugar can decrease the ability of white blood cells to engulf bacteria by as much as 40 percent. The same is true for pasta, bread, and other refined carbohydrates. Stick to low-glycemic carbs, and use sugar in moderation.
Alcohol. Excess alcohol inhibits the ability of white blood cells to protect against cancer. Additionally, heavy drinking can result in deficiencies of immune-boosting nutrients.
Allergenic foods. Food allergies put a great deal of stress on the immune system. If you suspect that you’re allergic, work with a nutritionist to identify offending foods.
Coffee. In excess, coffee can tax the adrenal glands and central nervous system, which impacts immunity.
Obesity. Excess fat can upset the immune system. Obesity can also lead to resistance to leptin—a hormone that supports white blood cell production and enhances immune function.
American Health Ester-C with Probiotics These vegetarian tablets are ideal for supporting your immune system, helping to prevent colds and flu, and improving digestion.
Barlean’s Olive Leaf Complex Use this fresh-pressed tonic for seasonal wellness and immune strength. Little-known fact: Olive leaf has more antioxidant power than açai
and green tea.
New Chapter Lifeshield Immunity Reishi and several other medicinal mushrooms are combined for powerful immune defense against colds and flu; this also promotes overall immune health.
Source Naturals Wellness Formula This herbal immune booster is popular for a reason—it works! Vitamins A, C, and D are blended with andrographis, elderberry, olive leaf, and other key immune herbs.
Quality of Life Labs Kinoko Gold AHCC Help bolster your immune system with this extra-strength version of AHCC, which has a low molecular weight that allows for high absorption.