Good nutrition is beneficial for everyone. A healthy, balanced diet may reduce the risk of numerous diseases, including some forms of cancer. For example, diets low in saturated fat have been shown to decrease the risk for colorectal cancer and prostate cancer.

Over the years, researchers have conducted extensive studies examining the association of diet, nutrition and cancer. Although the association is not completely understood, nutrition plays a significant role in the development of certain cancers. Studies have evaluated dietary factors for the risk and prevention of cancer as well as their effect on treatment. The American Cancer Society’s dietary guidelines for cancer prevention recommend that individuals:

• Eat at least five servings of fruits and vegetables every day.
  
  
• Choose whole grains instead of refined (processed) grains and sugars.
  
  
• Limit consumption of red meat, especially processed meats and those high in fat.
  
  
• Select foods that help achieve and maintain a healthy weight.
  
  

In addition, the National Cancer Institute (NCI) recommends that people limit their salt intake and increase fiber consumption.

Individuals who undergo cancer treatment often experience dietary problems, particularly when they are receiving chemotherapy. Maintaining adequate nutrition can be a challenge for these patients and malnutrition is a common problem. Treatments can reduce the patient's appetite and can affect the body's ability to tolerate certain foods. They also can impair the absorption of essential nutrients and cause side effects that make eating difficult or painful. Cancer patients must have a healthy diet to help them maintain their strength and energy to fight their disease.

The most common nutritional problem facing cancer patients is not consuming enough calories and protein. Nutritional needs depend on factors such as the patient’s size and age, and whether they have experienced significant weight loss because of treatment. Patients need to discuss their nutritional goals with their physician and/or dietitian. Eating well during cancer therapy can help individuals maintain their body weight, tolerate treatment-related side effects, reduce their risk of infection and provide other benefits.

Cancer patients who are unable to exercise proper nutrition because of treatment-related side effects, such as difficulty swallowing or nausea, may benefit from nutritional therapy. Nutritional therapy, which varies according to patient and treatment type, may include:

• A specialized diet plan
• Nutritional supplement beverages
• Enteral nutrition (feeding tube inserted through nose or abdomen)
• Parenteral nutrition (intravenous feeding tube)
• Appetite-improving medications

Most treatment-related side effects disappear after treatment ends. Patients who continue to experience eating-related side effects should address their eating difficulties with their physician, nurse or dietitian.