Improving Your Nutrition After Cancer: a Simplified Approach

If I had a dollar for every time I heard a cancer patient say “what should I be eating right now”, “what is the best diet to follow after my treatment”, and “I haven’t received any nutrition information from my medical team”, I would be one wealthy mumma.

A quick google search on ‘cancer and nutrition’ will give you a snap shot of the 685,000 reasons why patients’ are so confused. Vegan, vegetarian, gluten-free, green, juicing, raw, paleo, ketogenic, dairy-free, egg-free, sugar-free, refined sugar-free, organic and spray-free are all touted as ‘recommended to follow’. Then there are thousands of websites and articles dedicated to: cancer nutrition, cancer diet, cancer-fighting foods, nutritional supplements for cancer patients, cancer nutrition guideline, anti-inflammatory diet for cancer, integrative oncology nutrition, weight management in cancer care, and more.

Immersed in the common cancer-induced overwhelm, stress, fatigue, insomnia, pain, nausea, brain fog, treatment recovery and decision overload- where does one begin with their diet?

woman showing apple and bitten doughnut

It’s not only the plethora of mixed and contradictory on-line information that is problematic. Food guilt and food regret can become hugely stressful. There are patients who develop food fears and even phobias because they are afraid that eating even some ‘healthy’ foods will cause a cancer reoccurrence.

After my surgery to remove my bowel cancer, I was advised to avoid all fibrous food such as paw paw and bamboo shoots in the short-term as they may cause a bowel blockage. I didn’t receive general nutrition advice or a fibre management plan after my bowel resection. Many women who share their recovery experience with me report similar experiences. With my health professional hat on, I can see that we are missing an important window in a patient’s recovery. We are missing an opportunity to help optimise not only a patient’s recovery, but also their future health.

With the threat of a potentially reduced life expectancy, most of us cancer patients want to know how we can improve our health and we want to control what we can. Our diet is a variable that most of us have some control over. It makes sense to improve our knowledge and follow the best scientific evidence available to reduce our risk of a cancer reoccurrence or metastatic disease (cancer spread).

When you have the right information, you can make an informed decision.

I had a rocky road with my diet after my surgery. I developed a lot of intolerances- essentially anything ‘green’, any fruit or vegetables with a skin, any seeds, nuts and coffee. Yes coffee! FMLN, Ha! Much to my frustration, it took me many months to work out that my intolerances were not ‘normal’ and a side-effect that I simply had to endure after a bowel resection. Many other women in my cancer communities were also in a similar situation and were unable to tolerate fibre.

mother and daughter preparing avocado toast

After months of suffering, my food intolerances became more than an inconvenience. My health was deteriorating. I was experiencing weight loss, muscle wasting, and had nausea and dizziness daily. I couldn’t rely on myself to ‘parent’ and many times I had to call my husband to come home from work because I was too unwell to care for our boys alone. I began to look for answers, I had to find a solution to improve my health for me and for my family.

I reached out to the amazing Bowel Cancer Australia nurses and also to Dr Janet Schloss (PhD) a Clinical Nutritionist and Naturopath. Within a month of linking in with Bowel Cancer Australia and Dr Schloss, my life was finally improving. I had a plan and within days I was seeing results.

I have invited Dr Janet Schloss to answer some important questions which I know will be hugely beneficial to our cancer community. As you will see from Dr Schloss’s bio at the end of her article, she is highly skilled, experienced and knowledgeable in the world of cancer.

Today, my best advice on nutrition in your cancer recovery would be to connect with a cancer nutrition expert, be patient- it will get easier, buy yourself the book ‘CAN FOOD BE MEDICINE AGAINST CANCER‘ and read Dr Schloss’s advice below.

Nutrition and Cancer

Dr Janet Schloss (PhD) – Researcher, Clinical Nutritionist, Naturopath

Hearing the word ‘cancer’ still makes most people fill with dread, but when you are diagnosed with cancer a new world opens up. Suddenly your world is filled with medical appointments, tests, decisions to make and of course the waiting time for results. Amongst the whirlwind that has now become your current life, there are a number of things you can control that can make a difference through and after your treatment. One of these factors is nutrition.

Key nutrition considerations after your diagnosis

The best nutritional plan for you will depend on what type of cancer you have, what type of treatment you are about to undergo and what surgery or removal you have had. Secondly, it will depend on what your cultural or ethnic background is and if you have any food allergies or intolerances. Everyone is different so there is no one diet for everyone. However, there are key nutrition considerations you should know:

  1. Avoid all processed foods as much as possible. The western diet which consists of burgers, fried foods, soft drink, bakery goods and other processed foods is one of the worst diets in the world and has been attributed to around 50% of cancers. Try to keep foods in your diet as whole as possible. This doesn’t mean it has to all be raw, but it does mean it not in a box sitting on the shelf for years before it expires.
  2. Try to consume around 2-3 cups of vegetables every day using a variety of colours such as greens, yellows, reds, orange, and purple. You should eat around 5 or more different types of vegetables.
  3. Consume 2-3 serves of fruit a day. Especially fruits such as berries, cherries and pawpaw.
  4. Keep hydrated. Consume at least 1-2 litres of water a day. If you can’t drink plain water try sparkling water, herbal teas or put something healthy such as a piece of lemon in your water to make it more enjoyable.
  5. Consume enough protein. During treatment and if you have an active cancer, your protein intake becomes very important. Normally you only need 0.8-1 gram of protein per day per kilogram of weight. But during treatment, you require 1.2- 1.5 grams of protein per kilo of bodyweight per day. E.g. a 60 kg person would require 72 – 90 grams of protein a day. Remember that isn’t the amount of a food, it’s the amount of protein in food. For example a 100g piece of chicken contains around 24g of protein, and 1 large egg contains around 6-8g of protein.
  6. During treatment, if you are not a vegetarian keep animal protein in your diet as it will be easier to keep your protein intake up. However for most people post treatment, it would be advisable to reduce animal protein
  7. Avoid or keep alcohol to a minimum.
  8. Reduced processed sugars and high glycaemic index (GI) foods.
  9. Reduce grain product intake. It is recommended to consume around 35-45% carbohydrates for most cancers, which is lower than the average western diet of approximately 55-65% carbohydrates.
woman standing beside pineapple fruits

Breast cancer

There are many types of breast cancers and the dietary suggestions for each can vary. Particularly when you are looking at hormone receptive, HER2 positive or triple negative. Some general rules include:

  1. A majority of the dietary recommendations are for a Mediterranean diet.
  2. If you are hormone positive, avoid all soy-based products unless they have been a normal part of your cultural diet such as tofu, miso soup.
  3. If you are HER-2 positive, include olive oil in your diet.
  4. Generally, keep carbohydrates especially grains to around 30-40% of your diet.
  5. Keep fat intake only to good fats such as oily fish, avocado, chia and other seeds and nuts, and olive oil- rather than bad fats such as deep fried or fried foods. Fat should make up around 35-40% of your diet.
  6. Reduce animal products. E.g. red meat 1-2 times a week and chicken 1-2 times a week. Consume fish and seafood and include vegetarian proteins such as legumes and beans.
  7. Include 2-3 cups of vegetables every day especially cruciferous vegetables like broccoli and cauliflower.
  8. Have 2-3 serves of fruit a day e.g. berries, paw paw.
  9. Ensure enough fibre every day of 30-40grams a day.
  10. Keep hydrated – 1 ½ – 2 litres a day.
  11. Minimise refined sugar and processed food.
  12. Avoid or keep alcohol to a minimum. 
  13. Cease smoking.
  14. Try drinking green tea e.g. sencha or genmai.

Bowel Cancer

For people who have bowel cancer, some of the diet information will depend on how much bowel has been removed and if you need to be on a low fibre diet due to bowel function and the requirement to avoid bowel obstruction. The following suggestions are not based on a low fibre diet, but general advice for people who can consume a general diet. 

For some general suggestions for diet include:

  1. Reduce animal protein. May consume some lean meats (100g in a serve) of chicken, fish or turkey.
  2. Avoid all processed meats e.g. salami, prosciutto, bacon, ham.
  3. Avoid all cured or burnt foods.
  4. Include 2-3 cups of vegetables particularly green vegetables and salads a day.
  5. Include 2-3 serves of fruit a day.
  6. Can include eggs (generally around 8-10 a week).
  7. Include vegetarian protein (unless on a low fibre diet) such as legumes, pulses e.g. lentils, chickpeas, red kidney beans.
  8. Include anti-inflammatory foods such as onions, garlic, ginger, turmeric, rosemary, berries, broccoli, cinnamon, parsley, oily fish, nuts and seeds.
  9. If you consume dairy products, use low fat dairy options.
  10. Limit saturated fatty foods.
  11. Avoid or limit all sugary or processed sugar foods. 
  12. If you are a coffee drinker, consume 2-4 shots of coffee a day (not instant coffee)
  13. Keep your bowels moving at least once a day. 
  14. Stay hydrated.

Key nutrition considerations in chemo/radiation

  • What people eat during chemotherapy has been debated on many fronts.
  • Due to taste changes, smell changes, malaise, and nausea people will vary what they eat.
  • Do not force foods down, even though you think they are good for you. There is a memory that will be triggered later and you won’t eat that food or beverage.
  • Have frozen meals ready to be de-thawed quickly. 
  • Include carbohydrates as they need slow release CHO to help decrease the malaise.
  • Eat small meals often.
  • Keep the diet as unprocessed as possible.
  • Keep hydrated at least 2 litres a day of fluid.
  • Keep foods plain – no hot spices or too acidic foods.
  • Think ‘pregnancy diet’.
man in white and black hijab sitting on white couch

What about keto/sugar free? 

There are many diets around that suggest a ‘one diet’ approach to cancer. However, every cancer is its own disease and all cancers act differently. Keto has been proposed to ‘starve cancer’ however, you can’t starve a cancer. It is also a myth that sugar feeds cancer. Some fast-growing cancers use blood glucose as an energy source, but others use fat, nutrients or amino acids etc. 

Importantly, a high processed sugar diet does increase inflammation which can then disrupt cellular function. 

Keto Diet (KD) and Cancer

  • KD seems to create an unfavourable metabolic environment for cancer cell growth.
  • One benefit of the KD is its potential to increase the response to some drugs used in cancer treatment. This has been widely demonstrated in research. 
  • Further research is required on the benefits of the KD in cancer before the full benefits can be entirely understood.

Conclusion: even though preclinical evidence points towards an overall antitumor effect, it remains hard to draw generalizable conclusions about the actual effect of the KD on cancer growth and survival in humans. The majority of research for keto has been focused on aggressive brain cancers (GBM).

Vegetarian Diets

Vegetarian diets have been shown to decrease the prevalence of certain types of cancers. 

This is due to vegetarians consuming more total fruits and vegetables resulting in a higher uptake of vitamin C and fibre, which have been shown to impact on the development of cancer. Further to this, the overall fat intake on this diet is lower and as a result decreases the prevalence of obesity. Obesity is a risk factor associated with the development of cancer.

The lack of meat consumption by vegetarians could also be advantageous for decreasing the prevalence of developing cancers. Specifically processed meats have been shown to contain potentially carcinogenic materials. Nitrites and nitrates which are added to processed meats can lead to the formation of N-nitroso compounds (NOCs) when oxidised with amines and N-alkylamides. Haemoglobin iron, found in high concentrations of meat, has been shown to catalyze nitrates into NOCs in the gut.  NCOs have been found to be probable carcinogens in humans.

flat lay photography of vegetable salad on plate

Losing weight before surgery

Losing weight before surgery if you are overweight reduces the risk of complications from surgery, so it is highly recommended. Firstly, I would reduce calorie intake to 1500 Kcal and increase your exercise or activity within your ability or limits. This maybe where the keto diet can be assistance in loosing weight quickly for some people.

Cutting back on grains, breads, pasta, and rice will also be of assistance. Avoid eating after 7pm. Sometimes it helps to get an app that helps you track what you are eating and your exercise, like MyfitnessPal. 

Maintaining weight during treatment

During cancer treatment, it is important to keep your weight stable. Loosing weight can affect your chemotherapy dose or radiation planning. Firstly for nausea, ensure you are taking the anti-nausea medication and if it’s not working, let your doctor know. Food wise for nausea and vomiting there are few things you can also do:

  1. Eat small meals regularly. The longer you go without eating, the more nauseous you can become. 
  2. Include small amounts of complex carbohydrates and fats for slow release. This includes foods such as wholegrains and vegetables
  3. One of the best things for some people’s nausea is hot chips. Sometimes having a small amount of these allows you eat more healthy options.
  4. Plain food helps. Roasted vegetables, oven baked pies, vegemite on toast, chicken soup etc
  5. Try ginger or peppermint tea for the nausea
  6. If all else fails for your nausea, try coca cola. (This will be the only time you will hear me say this)

For loose stools, again, stodgy foods help. Consume plain foods that do include bread, pasta, rice, cheese, and meat.  An old remedy that helps with diarrhoea is to grate an apple and let it go brown, and eat. This releases the pectin in it. 

Myth busting/ food phobias

There are many myths associated with cancer and food. Nutrition is very confusing and so many people have their own theories. What is best, is finding what the right diet is for you and what you feel comfortable with. Some of the severe diets and suggestions can be detrimental physically and mentally. 

My first rule of thumb is that your diet should not cause you stress. Eating that piece of fruit is NOT going to make your cancer grow or come back. Diets should be about nurturing your body not causing fear. There is enough fear involved with cancer, let alone thinking that everything you eat and come in contact with will cause you cancer. 

As I said before, sugar doesn’t cause cancer and it does not feed cancer. But a high western style diet full of take away processed foods, soft drinks and empty calories can increase inflammation and disrupt cellular activity. 

Secondly, dairy and eggs do not cause breast cancer. Many epidemiological studies have assessed dairy and egg consumption in patients with breast cancer. None of these studies found that dairy or eggs increased the risk of breast cancer. However last year, the United States of America found that their suggestions of 3 glasses of milk a day (plus other dairy) could be associated with an increased breast cancer risk so they are relooking at what they recommend for daily requirements. 

Lastly, cancer is indiscriminate and even people who eat exceptionally well and lead a health lifestyle still get cancer. What we can do is look at what we have control over including a good diet, exercise, sleeping well and enjoying life. Some people do worse on a vegetarian diet and its not the right diet for them. Listen to your body to find what does and doesn’t sit well with you, and make an educated decision. 

What questions should I ask my GP?

Talk to your GP about any specific questions that you have about your recovery. Your GP will be able to refer you to a cancer nutritional specialist if you would like to learn more about improving your diet after treatment. There are also a number of blood tests that your GP can request to help to monitor your general health during your cancer journey.

Some of these includes:

  1. Vitamin D
  2. Zinc status
  3. Full iron studies
  4. Thyroid tests if required
  5. Microbiome test for gut bacteria
  6. Potential cancer markers

Remember, there is always help out there to support you to have an easier cancer journey.

About Dr Janet Schloss (PhD)

Clinical Research Fellow and Lecturer, Naturopath and Clinical Nutritionist

Dr Janet Schloss is Clinical Research Fellow and Lecturer at the National Centre for Naturopathic Medicine (NCNM). Janet is an accomplished researcher with extensive experience in coordinating clinical trials. In addition to her academic career, Janet is also a practicing clinical nutritionist and naturopath with over 20 years’ experience. 

Following the completion of her doctorate in 2015, Janet has focused her research on supporting people who have cancer through studying the use of complementary medicines to assist side effects of chemotherapy and radiation treatments. 

Janet works with a number of Oncologists, assisting patients with nutrition consultation to help decrease side effects and support them whilst undergoing medical treatments such as chemotherapy, radiation, surgery, immunotherapy and hormone treatment. She consults extensively with clients being treated for cancer and auto-immune conditions to reduce the likelihood of metastasis, tumour growth and inflammation while building immune modulation and improving overall health and wellbeing.

Janet has completed a number of ground-breaking studies and has over 50 publications in clinical naturopathy, cancer and auto-immune diseases, some of which have gained wide-spread national media attention. Through her critical and rigorous research, she helps patients and practitioners to establish evidence-based practice.

Janet has lectured in naturopathy, nutrition and student clinic supervision for over 14 years, and prior to her appointment at NCNM, was the Clinical Trials Manager at Endeavour College of Natural Health. 

She has a strong passion for her profession, which has been shown through many professional speaking engagements throughout Australia and overseas, including the ASCO Annual Meeting in 2015 – the largest, most prestigious oncology conference in the world – where she presented a complementary medicine clinical trial to over 32,000 delegates.

In addition to her role at NCNM, Janet is a Research Fellow and a member of the International Naturopathic Leadership group with the Australian Research Centre for Complementary and Integrative Medicine([ARCCIM), and a member of Australian Traditional Medicine Society, Society of Integrative Oncology and American Society of Clinical Oncology. 

For more information contact Dr Schloss at: 

We hope that you enjoyed this article. Please drop us a comment below, we would love to hear from you.  

X The Awakened Mumma, Author of ‘A Woman’s Guide to Navigating the Invisible Cancer Load

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