Chemotherapy destroys cancer cells. Unfortunately, it also kills healthy, infection-fighting cells at the same time, suppressing the immune system and thereby making patients more vulnerable to infection.

"Most chemotherapies will decrease the activity of your bone marrow," says Stephen I. Shibata, M.D., associate professor of medical oncology at City of Hope National Medical Center in Duarte, California. "The drugs reduce the production of red blood cells, which may lead to anemia, and white blood cells, which can affect your immune system." Even a mildly depressed white cell count can reduce the body's ability to fight off foreign invaders.

Here are eight simple ways to boost your immunity and prevent post-chemotherapy infections.

  1. Wash your hands frequently. Be especially diligent about washing before and after eating, using the bathroom, and touching animals or children. And make sure you scrub your hands well. Doctors recommend washing for 20 seconds with soap and warm water — time yourself by singing the "Happy Birthday" song twice through.
  2. Eat a healthy, balanced diet. Some chemotherapy patients experience anorexia (a loss of appetite), nausea, and subsequent weight loss, says Shibata. In such cases, it's important to work with a dietitian to ensure a good diet and adequate calorie intake. Protein is especially important, because it is a basic building block used by your immune system to prevent and fight infections. Regarding supplements, there are no specific recommendations, but many physicians advise their patients to take a multivitamin to ensure that they get the necessary vitamins and minerals.
  3. Be aware of food safety issues. Careful food handling is important to avoid illness. Cook meat and poultry — and marinades, if necessary — thoroughly to kill any bacteria and other microorganisms that may be contained in raw foods, and be careful to avoid contaminating kitchen surfaces, cutting boards, and cooking utensils with raw meat juices. Additionally, steer clear of raw foods like fish, seafood, meat, and eggs. All of these foods pose a high risk for causing illness.
  4. Take care of your teeth and gums. Brush your teeth after meals and before bedtime, using an extra-soft toothbrush that won't hurt your gums. Floss gently, but talk to your doctor about whether flossing is the best way to protect your gums during chemotherapy treatment.
  5. Cultivate healthy skin. Keep your skin hydrated and moisturized. Dry, cracked skin is more likely to break and become susceptible to infections. Furthermore, squeezing or scratching pimples can create open sores that would also place you at higher risk of infection. The same is true of biting or tearing at your cuticles.
  6. Keep your body clean. Take a warm bath or shower every day and be sure to gently clean your rectal area after you use the toilet. It's important to tell your physician if you develop hemorrhoids or dry, irritated skin.
  7. Stay away from people who are sick. Because chemotherapy makes you more vulnerable to infections, it's important to avoid people who have colds, the flu, chicken pox, measles, and other contagious illnesses. It's also a good idea to steer clear of people who have recently had a "live virus" vaccination, such as the chicken pox and polio vaccines.
  8. Avoid accidents and injuries. Wear gloves when gardening; be careful when handling sharp objects; and shave with an electric razor to prevent cuts. In the unfortunate event that you do get cut, scraped, or otherwise injured, be sure to clean the area with warm water and an antiseptic. The quicker you clean and cover the injury, the less risk there will be of infection.