The immune system is the body’s way of protecting itself from infection and disease; it fights everything from cold and flu viruses to serious conditions such as cancer.
Our immune systems are complex and influenced by many factors. Vaccines build immunity against specific diseases. Some additional ways you can strengthen your immune system are eating well, being physically active, maintaining a healthy weight, getting enough sleep, not smoking, and avoiding excessive alcohol use.
Eating well means emphasizing plenty of fruits and vegetables, lean protein, whole grains, and fat–free or low–fat milk and milk products. Eating well also means limiting saturated fats, cholesterol, salt, and added sugars.
Eating well provides multiple nutrients that support optimal immune function.1,2 Be aware, however, that too much of some vitamins and minerals can be harmful. Talk to your health care provider if you think you need nutritional supplements.
If you need help obtaining nutritious food, see resources at USDA Nutrition Assistance Program. You can also call the USDA National Hunger Hotline at 1–866–3–HUNGRY or 1–877–8–HAMBRE to find resources such as meal sites, food banks, and other social services.
Be Physically Active
Regular physical activity helps you feel better, sleep better, and reduce anxiety. Combined with eating well, physical activity can help a person maintain a healthy weight.3
Maintain a Healthy Weight
Excess weight can affect how your body functions. Obesity, defined as a body mass index (BMI) of 30 or more in adults, is linked to impaired immune functions.6,7 Obesity may also lower vaccine effectiveness for numerous diseases, including influenza,8 hepatitis B,9,10,11 and tetanus.12
Safe ways to help maintain a healthy weight include reducing stress, eating healthy foods, getting enough sleep, and engaging in regular physical activity.
Get Enough Sleep
Scientific evidence is building that sleep loss can negatively affect different parts of the immune system. This can lead to the development of a wide variety of disorders.
Smoking can make the body less successful at fighting disease. Smoking increases the risk for immune system problems, including rheumatoid arthritis.
Avoid Too Much Alcohol
Over time, excessive alcohol use can weaken the immune system.
Immunity is your body’s defense against foreign organisms. Taking care of yourself will help your immune system take care of you.