Healthy Habits: Enhancing Immunity

Key points

  • The immune system is the body's way of protecting itself from infection and disease, including chronic diseases.
  • Your immune system fights everything from cold and flu viruses to serious conditions such as cancer.
  • A healthy lifestyle offers many benefits including enhancing your immunity. See six tips below.
Mother and daughter smiling and posing for camera.


A healthy lifestyle offers many benefits, including helping to prevent heart disease, type 2 diabetes, obesity, and other chronic diseases. Another important benefit is that healthy routines enhance your immunity.

Your immune system fights everything from cold and flu viruses to serious conditions such as cancer. Immune systems are complex and influenced by many factors.

Vaccines, such as the flu vaccine, build immunity against specific diseases. You can also strengthen your immune system by eating well, being physically active, and maintaining a healthy weight. In addition, get enough sleep, don't smoke, and avoid excessive alcohol use.

Taking care of yourself will help your immune system take care of you. See six tips below.

1. Eat well

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, salt, and added sugars.

Eating well provides multiple nutrients that support optimal immune function.12 However, too much of some vitamins and minerals can be harmful. Talk to your health care provider if you think you need nutritional supplements.


Food Asisstance. 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 (English) or 1–877–8–HAMBRE (Spanish). The Hotline will help you find resources such as meal sites, food banks, and other social services.

2. 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

Following the physical activity recommendations for your age provides immediate and long–term benefits. For example, being physically active may help lower your chances of dying from the flu or pneumonia. Emerging research also suggests that physical activity may potentially benefit immunity.45

Reduced Risk of Death‎

In a study of more than 500,000 US adults, those who met aerobic and muscle-strengthening physical activity guidelines were about half as likely to die from flu and pneumonia as adults who met neither guideline. For adults, weekly physical activity guidelines call for at least 150 minutes of moderate-intensity aerobic activity plus two days of muscle-strengthening activities. Aerobic activity can be done over several days, such as 30 minutes a day, five days a week.

3. Maintain a healthy weight

Obesity, defined as a body mass index (BMI) of 30 or more in adults, is linked to impaired immune functions.67

Safe ways to help maintain a healthy weight include reducing stress, eating healthy foods, staying within your daily calorie needs, getting enough sleep, and engaging in regular physical activity.

Obesity may also lower vaccine effectiveness for numerous diseases, including influenza,8 hepatitis B,91011 and tetanus. 12

If you have are concerned about your health, consult with your health care provider.

4. Get enough sleep

Scientific evidence is building that sleep loss13 can negatively affect different parts of the immune system. This can lead to the development of a wide variety of disorders.

See the recommended hours of sleep per day for your age.

5. Quit smoking

Smoking can make the body less successful at fighting disease. Smoking increases the risk for immune system problems, including rheumatoid arthritis.

6. Avoid too much alcohol

Over time, excessive alcohol use can weaken the immune system.

Take care of yourself‎

Immunity is your body's defense against foreign organisms. Taking care of yourself will help your immune system take care of you.
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  2. Christ A, Lauterbach M, Latz E. Western diet and the immune system: an inflammatory connection. Immunity. 2019;51(5):794–811. Accessed May 13, 2021.
  3. US Department of Health and Human Services. Physical Activity Guidelines for Americans, 2nd edition. Washington, DC: US Department of Health and Human Services; 2018. Accessed May 13, 2021.
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  8. Neidich SD, Green WD, Rebeles J, et al. Increased risk of influenza among vaccinated adults who are obese. Int J Obes (Lond). 2017;41(9):1324–1330. Accessed May 13, 2021.
  9. Weber DJ, Rutala WA, Samsa GP, Santimaw JE, Lemon SM. Obesity as a predictor of poor antibody response to hepatitis B plasma vaccine. JAMA. 1985;254(22):3187–3189. Accessed May 13, 2021.
  10. Simó Miñana J, Gaztambide Ganuza M, Fernández Millán P, Peña Fernández M. Hepatitis B vaccine immunoresponsiveness in adolescents: a revaccination proposal after primary vaccination. Vaccine. 1996;14(2):103–106. Accessed May 13, 2021.
  11. Young MD, Gooch WM III, Zuckerman AJ, Du W, Dickson B, Maddrey WC. Comparison of a triple antigen and a single antigen recombinant vaccine for adult hepatitis B vaccination. J Med Virol. 2001;64(3):290–298. doi:10.1002/jmv.1049. Accessed May 13, 2021.
  12. Eliakim A, Schwindt C, Zaldivar F, Casali P, Cooper DM. Reduced tetanus antibody titers in overweight children. [published correction appears in Autoimmunity. 2006 Jun;39(4):349. Swindt, Christina [corrected to Schwindt, Christina]]. Autoimmunity. 2006;39(2):137–141. Accessed May 13, 2021.
  13. Zee PC, Turek FW. Sleep and health: Everywhere and in both directions. Arch Intern Med. 2006;166(16):1686-1688.