White blood cells are infection-fighting cells produced in the bone marrow. When a type of white blood cell called a neutrophil is lowered in the body -- a condition called neutropenia -- the immune system is weakened and a person becomes vulnerable to infections. Common causes of neutropenia include viruses and chemotherapy. While increasing the white blood cell count back to normal can prevent infection, there are no specific foods or nutrients that have been proven to do this, unless the neutropenia is due to certain severe but rare nutritional deficiencies.
Replenishing Nutrients if Deficient
According to a review article in the August 2014 issue of "Blood," severe nutritional deficiencies of vitamin B12, folate or copper can lead to neutropenia. Severe protein-calorie malnutrition -- which may occur in people with anorexia nervosa -- can also lead to neutropenia. These nutritional deficiencies are uncommon and can only be diagnosed by a healthcare professional and specific blood tests. While foods rich in the deficient nutrient may be helpful, a medically supervised, prescription dose of the nutrient is often needed to correct the deficiency and raise the white blood cell count back to normal.
Following a Neutropenic Diet
The neutropenic diet (ND) has been traditionally recommended for people with low white blood cell counts. This diet does not raise white blood cell counts. Instead, the goal is to counter the increased infection risk and prevent foodborne illness. While the specific ND restrictions may vary, this diet restricts foods that typically have higher bacterial counts such as raw, uncooked fruits and vegetables, yogurt, soft cheeses, raw fish and deli meats. However, a report in the September 2015 issue of "Nutrition and Cancer" reviewed 4 studies that compared a regular, unrestricted diet to the ND in people with cancer and neutropenia and found no difference in infection or death rates. While this study questions the necessity of the ND restrictions, it's still wise for anyone with neutropenia to prepare food safely by washing raw fruits and vegetables thoroughly and cooking meats and fish to safe internal temperatures.
Eating a Healthy Diet
A strong, infection-fighting immune system is built on nourishing foods, with adequate calorie intake that supports a healthy weight. According to the U.S. Department of Health and Human Services, a healthy diet incorporates a variety of foods including:
- vegetables and fruit
- whole grains
- fat-free or low-fat milk or other calcium-rich foods
- lean meats, poultry, eggs, seafood and plant proteins such as tofu, nuts, seeds and legumes
In addition to eating nutritious foods for a healthy immune system, it's helpful to minimize foods of low nutritional value, such as desserts, chips and other snack foods, fried foods and candy.
Care From Your Medical Team
If you are diagnosed with a low white blood cell count, talk with your doctor about the cause and treatment options. Obtain guidance from your medical team about preparing foods safely, and whether you should abstain from or eat certain foods based on your diagnosis. Also, if you are neutropenic, the signs and symptoms of an infection are typically subtle and may progress quickly. Speak with your doctor about what to watch out for -- like chills or a new onset of pain -- and when to seek emergent medical attention.