Understanding Nutrition for Cancer Patients Undergoing Chemotherapy

    A common question often asked is: What should cancer patients eat or avoid during chemotherapy? The general recommendation is to consume a well-balanced diet that includes all five food groups, ensuring proper nutrition. There is no need to seek out special foods to fight cancer cells. Patients can consume carbohydrates, sugars, and proteins from both animal and plant sources, but in appropriate proportions—neither too much nor too little.

Foods to Avoid

    Much of the advice regarding diet and cancer focuses on foods that may increase the risk of cancer, such as red meat, processed meats, high-fat foods, and items cooked in reused frying oil. If a person has already been diagnosed with cancer, avoiding these foods becomes even more crucial, as they may further stimulate cancer growth. While these foods pose risks to everyone, cancer patients should be particularly cautious to minimize exposure.

Diet Challenges During Chemotherapy

    Dietary recommendations become more complex for patients undergoing chemotherapy. Some chemotherapy drugs can cause nausea, vomiting, loss of appetite, and changes in taste, making it difficult for patients to eat. This often leads to stress for both patients and caregivers. Caregivers may insist on restrictive diets, eliminating certain foods that patients previously enjoyed, such as coffee or meat, and replacing them solely with vegetables, fruits, and grains. While the intention is good, these strict dietary changes can cause additional stress, which is counterproductive to recovery.

Managing Nausea and Vomiting

    Most chemotherapy-related nausea and vomiting can be controlled with prescribed medications, which are about 70-80% effective. If symptoms persist despite taking medication, patients should inform their doctor, who may adjust the dosage or type of anti-nausea medication.

• Avoid greasy, spicy, or strong-smelling foods.
• Eat small, frequent meals instead of large portions.
• Choose bland foods and sip ginger tea or sour fruit juice to alleviate nausea.
• Keep prepared food readily available to eat when nausea subsides.
• Avoid forcing food intake, as vomiting after eating can create negative associations, making it harder to eat in the future.

    Patients should prioritize consuming nutritious foods that they can tolerate. If they crave certain foods, including tea, soft drinks, or desserts, these can be consumed in moderation, especially during periods of low appetite.

Foods to Strictly Avoid

    During chemotherapy, the immune system is weakened, increasing the risk of infections from contaminated food. Patients should avoid:

• Raw vegetables and thin-skinned fruits (unless properly peeled and cooked).
• Leftover food or meals that are not freshly prepared.
• Raw or undercooked foods, including sushi, rare meats, and raw eggs.
• Processed meats, pickled foods, and grilled meats.
• Alcoholic beverages.

Managing Mouth and Digestive Tract Ulcers

    Some chemotherapy drugs can cause ulcers in the mouth and digestive tract, making eating painful. To ease discomfort, patients should opt for:

• Soft, mild-tasting foods that are easy to eat and digest.
• Nutrient-rich, high-energy meals such as thick soups and steamed eggs.

Finding Balance in Nutrition

    The diet of a cancer patient should be tailored to their treatment stage and current health challenges. Patients and caregivers should communicate openly and find a balanced approach to nutrition that supports recovery without causing unnecessary stress or conflict. When receiving dietary advice from social media or well-meaning individuals, it is essential to verify the information. The best course of action is to consult with a doctor or healthcare professional who understands the patient’s specific medical needs.

Assoc. Prof. Dr. Nattada Areepiam and Assoc. Prof. Dr. Bodin Tiwasuwan

Faculty of Pharmacy Chulalongkorn University