What Foods Are Good for Cancer Patients and What Foods to Avoid?

OncoCare

Patient Education

What Foods Are Good for Cancer Patients and What Foods to Avoid?

When it comes to cancer, nutrition is one of the most important factors in the overall health of a patient. This is because diet and nutrition play a vital role in the recovery process and can be especially beneficial during chemotherapy, targeted therapy, immunotherapy, and follow-up visits.

Unfortunately, many patients with cancer are uncertain about what type of nutrition they should be receiving due to conflicting information from well-meaning family and friends as well as from the internet. To help clear up some of this confusion, let's break down why nutrition is so important for cancer patients and identify key nutrients from their diet that are essential for their health.

Side Effects and Nutritional Challenges During Cancer Treatment

But first, why is nutrition an aspect that cannot be overlooked for patients undergoing cancer treatment?

Cancer treatments, while essential for targeting malignant cells, unfortunately often impact healthy cells too. This can lead to various side effects that may potentially complicate a patient’s ability to eat and absorb nutrients effectively, emphasising the importance of good nutrition during this critical time. Side effects from treatments like chemotherapy can also disrupt normal eating patterns.

Common issues include:

  • Appetite Loss: Many patients find their desire to eat decreases significantly.
  • Altered Taste: Foods may taste different or lose their flavour entirely.
  • Digestive Problems: Constipation and diarrhoea can make eating uncomfortable.
  • Oral Discomfort: Soreness in the mouth or throat can make swallowing difficult.
  • Nausea and Vomiting: These symptoms can reduce the desire to eat and lead to weight loss.
  • Fatigue: Lower energy levels may reduce the motivation to eat.

Managing Eating Habits and Nutrition to Combat Treatment Side Effects

Coping with some of the aforementioned side effects is a significant challenge during cancer treatment, but strategic nutritional choices can help mitigate these effects.

For instance, certain practical dietary tips can help with managing the common side effects that patients often encounter. Some of these include:

  • Nausea: Frequent, small meals can help stabilise your stomach. Opt for bland, non-greasy foods and sip clear or ice-cold drinks throughout the day to alleviate nausea.
  • Vomiting: If vomiting occurs, it's crucial to rest your stomach while staying hydrated with small sips of clear liquids. Once settled, gradually reintroduce bland foods like toast and crackers.
  • Constipation: Increase your fibre intake with fruits, vegetables, and whole grains. Drinking plenty of water and regular light exercise can also help keep things moving.
  • Diarrhoea: Opt for low-fiber, starchy foods such as white rice and bananas. Avoid spicy foods, caffeine, and dairy products if lactose intolerant.
  • Fatigue: Foods high in protein and complex carbohydrates provide sustained energy. Small, frequent meals are preferable to maintain energy levels.
  • Loss of Appetite: Try nutrient-dense shakes and smoothies to get essential vitamins and minerals in a more palatable form.
  • Mouth Sores: Soft, cool foods can soothe a sore mouth. Avoid acidic, spicy, or rough-textured foods that may cause further irritation.

Each side effect may necessitate specific dietary adjustments, so it's beneficial to discuss these strategies with a healthcare provider or dietitian who can tailor advice to your unique needs.

The Role of Nutrition in Cancer Treatment

Nutrition is an extremely crucial factor when it comes to fighting cancer. A well-balanced diet, rich in essential vitamins and minerals like vitamins A, C, D, and E, zinc, calcium, selenium, and magnesium, can support the body during this challenging time by:

  • Supporting Immune Function: Proper nutrition boosts the immune system, helping the body fight infections and recover quickly from treatment. A strong immune system, bolstered by good nutrition, is also less susceptible to infections and complications.
  • Supporting Recovery and Healing: Nutrients help repair tissues damaged by cancer treatments, aiding in faster and complete recovery.
  • Managing Side Effects: Eating the right foods can alleviate some of the side effects of treatment, such as nausea, fatigue, and decreased appetite, as mentioned above.
  • Maintains Strength and Energy: Nutrient-rich foods provide the energy needed for healing and can help maintain muscle mass and physical strength.
  • Promotes Healthy Body Weight: Maintaining a healthy weight can prevent additional health complications and support overall well-being.
  • Reduces Inflammatory Response: Foods high in antioxidants and other nutrients can help reduce the body’s inflammatory response, promoting faster recovery.

What Are the Best Foods for Cancer Patients?

There are several different types of nutrients that are particularly beneficial for cancer patients. For example, protein helps rebuild cells damaged by radiation or chemotherapy, while omega-3 fatty acids combat inflammation caused by tumours. Vitamins A and C boost immunity while zinc helps protect against infection; magnesium aids in relaxation, which can reduce stress levels; iron helps prevent anaemia; and antioxidants such as beta carotene fight free radicals that damage cells.

1. Protein

Proteins are essential for cell regeneration and growth, making them an incredibly important part of any cancer patient’s diet. Protein can be found in foods like lean meats, eggs, dairy products and legumes. For those who have difficulty chewing or swallowing, protein shakes and other supplements may be a good option.

Local dishes like sliced fish bee hoon soup provide a substantial amount of protein, with approximately 21.1g per serving. In addition to protein, this dish offers a balance of other essential nutrients, including 8.8g of total fat, 55.2g of carbohydrates, and 3.3g of dietary fibre, making it a nutritious option.

2. Fats

Fat is an important source of energy for cancer patients going through chemotherapy. Fats also provide essential fatty acids that help maintain cell integrity and immunity and reduce inflammation in the body. Healthy sources of fat include avocados, nuts, seeds, and oily fish like salmon and mackerel.

Local dishes can also contribute to healthy fat intake. For instance, Mee Soto contains 13g of fat per serving, including 5.4g of saturated fat and 38mg of cholesterol. While it's important to be mindful of saturated fat intake, Mee Soto can be a part of a balanced diet.

3. Carbohydrates

Carbohydrates provide energy for cells throughout the body, as well as vitamins and minerals that are crucial for good health. Whole grains such as oats or quinoa are excellent sources of carbohydrates, along with fruits, vegetables, and legumes like beans or lentils. All these foods should be included in a cancer patient’s diet while they undergo chemotherapy or other treatments.

For instance, Thunder Tea Rice is a nutritious option, providing a good source of carbohydrates, protein, and fibre. A typical serving contains approximately 430 calories, 10g of fat, 42g of carbohydrates, 18g of protein, and 5g of fibre.

Evaluating the Need for Supplements During Cancer Treatment

When considering nutrition during cancer treatment, supplements often come to mind as well. But are they truly necessary?

Cancer treatment can, no doubt, be taxing on the body, sometimes leading to specific nutritional deficiencies that diet alone might not address. For instance, Vitamin D is a common deficiency among cancer patients, crucial for immune strength, reducing fatigue, and supporting bone health—especially critical for those on steroids, as they face higher risks of bone density loss. In some cases, cancer or its treatment can also hinder the body's ability to absorb nutrients effectively from food. In such situations, your doctor might recommend a multivitamin and mineral supplement to help meet your nutritional needs.

While it can be tempting to self-treat with over-the-counter supplements, it's crucial to consult with your oncologist before incorporating any supplements into your regimen, especially those purchased without a prescription. They can help ensure that any supplements you consider are safe and effective in conjunction with your cancer therapy.

Safeguarding Against Foodborne Illness During Cancer Treatment

Aside from understanding the best foods for cancer patients, it's equally important to know how to handle and prepare these foods safely. This is especially so since cancer treatments may weaken your immune system, increasing your susceptibility to foodborne illnesses.

To minimise this risk, it is essential to maintain meticulous food hygiene practices:

  • Maintain Temperature Control: To prevent bacteria from growing, it's essential to maintain the correct temperature of your food. Keep hot foods hot and cold foods cold. When it comes to frozen foods, most are safe to eat, including frozen fruits and vegetables. However, it's best to avoid soft-serve ice cream and frozen yoghurt dispensed from machines, as these can be vulnerable to contamination if the machines aren't properly sanitised.
  • Thorough Cleaning: Scrub all fruits and vegetables under water before eating or cooking them. This is especially important for items with rough surfaces, like melons, or those with peels, such as oranges and avocados.
  • Careful Thawing and Cooking: Thaw meats in the refrigerator or microwave and cook thoroughly to the recommended temperatures to ensure all bacteria are killed.
  • Separate Preparation Areas: Use separate cutting boards for meats and vegetables to avoid cross-contamination.
  • Hand Hygiene: Wash your hands thoroughly before and after handling food, especially raw meat, poultry, and fish.
  • Check for Pasteurisation: Ensure that milk, juices, and eggs are pasteurised to avoid pathogens that can cause illness.
  • Choose Cooked over Raw: Opt for cooked grains like freshly prepared rice and avoid raw bars and nuts that might harbour bacteria.

What Foods Should Cancer Patients Avoid?

It’s also important to note that certain foods should be avoided completely by people undergoing treatment for cancer. These include:

  • Processed meats like bacon or sausage
  • High-fat dairy products like butter or cheese
  • Fried foods like french fries or doughnuts
  • Refined carbohydrates such as white bread or pasta
  • Sugary snacks like candy bars or cookies
  • Foods with artificial colours or preservatives
  • Alcohol
  • Cigarettes
  • Excessive amounts of caffeine
  • Reheated rice, or any other reheated starchy foods
  • Raw nuts and roasted nuts in shell
  • Fresh salad dressings containing cheese with mould like hollandaise sauce
  • Water from water cooler or dispensers
  • Herbs and herbal supplements
  • Unpasteurised juice, milk, and yoghurt

All these items should be eliminated from a patient’s diet as they can inhibit recovery time and lead to further health complications down the road.

Of course, the specific foods to avoid can also depend on the type of cancer and its treatment.

For instance, individuals with breast cancer may need to limit highly processed foods and refined grains, as these have been linked to an increased risk of breast cancer. Those with prostate cancer might be advised to reduce their intake of processed meats, such as ham and bacon, while individuals with stomach cancer may need to limit foods with natural laxatives like prunes, figs and caffeinated foods.

Always check with your oncologist or dietician for personalised advice on what foods to avoid during your cancer treatment.

What Foods Should You Avoid When Having Radiotherapy?

When undergoing radiotherapy, managing your diet is key to minimising discomfort and potential side effects.

Consider these foods to avoid to make your treatment journey smoother:

  • Avoid Irritants: Steer clear of spicy, acidic, or rough-textured foods that can aggravate mouth and throat discomfort. Foods like chips, raw vegetables, and acidic fruits can cause further irritation.
  • Hydration and Mouth Care: Keep your mouth moist and clean by sipping water throughout the day, using saliva substitutes if necessary, and avoiding high-sodium mouthwashes that can dry out oral tissues.
  • Neutral Tastes and Smells: If you’re sensitive to odours or have changes in taste, choose foods that are mild and not too hot or cold.
  • Limit Gas-Producing Foods: Certain foods can cause gas and discomfort, particularly in prostate cancer patients and for those with digestive sensitivity due to treatment. Limit intake of beans, cruciferous vegetables like broccoli and cabbage, and carbonated beverages.

What Food Should be Avoided During Chemotherapy?

During chemotherapy, being mindful of what to avoid can significantly impact your well-being, too. Some of the foods that are not considered good for chemo patients include:

  • Raw or Undercooked Foods: The risk of infection from bacteria like salmonella or E. coli increases during chemotherapy due to a weakened immune system. It's advisable to avoid raw meat, seafood, and undercooked eggs. Fully cook all meats and eggs to kill any harmful pathogens.
  • Be Cautious with Raw Produce: While fresh fruits and vegetables are essential, ensure they are thoroughly washed. For patients undergoing intense chemotherapy treatments, particularly for conditions like leukaemia or lymphoma, it may be safer to avoid raw produce altogether.
  • Irritants: Foods that are hard, spicy, or highly acidic can exacerbate mouth sores, a common side effect of chemotherapy. Opt for softer, blander meals to ease oral discomfort.
  • Grapefruit: Grapefruit and some other citrus fruits like Seville oranges, and their related products (like marmalade), can interfere with the chemotherapy drugs. It's best to avoid them to prevent any adverse reactions.
  • Alcohol and Tobacco: Alcohol and tobacco can be particularly harsh on your system during chemotherapy. Alcohol, for instance, may worsen dehydration and nausea, while smoking can further compromise your immune system. Both are best avoided to support your treatment and recovery.

Professional Advice on Nutrition for Cancer Patients

From the above, it is clear that when it comes to coping with cancer, having good nutrition is essential. The best way to go about this is by consulting with your doctor or a registered dietitian who specialises in oncology nutrition. They will be able to provide you with recommendations on which foods you should eat (and avoid) based on your specific needs—ensuring that your body has all the necessary nutrients needed for recovery.

At OncoCare Cancer Centre in Singapore, we provide quality care and support for our patients who are undergoing cancer treatment. We partner with you at every step of your journey, and this includes advice on the optimal nutrition you’ll need. Make an appointment to speak to one of our specialists today, and for more information on the importance of your diet during this phase, read our guide on How Diet and Food Choices Can Influence Cancer Risks.

“Expert knowledge means better care for cancer”

Written by:
Dr Angela Pang
MBBS (Singapore)
Grad Dip (GRM)
MRCP (UK)
M Med (Internal Med)