Cancer Care Parcel Logo

No products in the basket.

Cancer Care Parcel Logo

No products in the basket.

For Everyone Touched By Cancer

Suggestions For An Optimal Cancer Diet: Hoaxes And Myths Not Discussed

Written by Dr Shara Cohen on 
20th August, 2017
Updated: 30th January, 2024
Estimated Reading Time: 4 minutes

Stories in the media

There are often stories in the media about certain foods or nutrients in the cancer diet that will

  • increase the risk of cancer
  • decrease the risk of cancer
  • feed cancer
  • cure cancer

It is beyond the scope of this article to discuss fads, hoaxes, current research or scientific evidence.  Except to say the obvious, that not everything you read, especially on the internet is true.  The best way to avoid hoaxes and common cancer myths is to look at

  • Current official guidelines
  • Specific cancer treatments and their likely side effects on the cancer diet

Official recommendations for the ideal cancer diet

It is clear that having a healthy cancer diet can help people cope better with both treatment and the illness. But it can sometimes be hard to maintain a healthy balanced diet when both treatment and cancer symptoms can have nutrition-related side effects, as discussed below.

How cancer symptoms can affect a healthy diet

Different people are diagnosed at different stages of cancer and different types of cancer can produce different symptoms.  Generally speaking, most people who have cancer are advised to eat a healthy diet.  In some cases, a high-calorie diet is recommended. This is because weight loss can be a problem and a high-calorie diet keeps energy levels up during treatment.  However, in the majority of cases, a normal healthy diet will be good enough.

How treatment can directly affect the cancer diet

It is important to recognise that some foods and supplements can counteract cancer treatments, so it is very wise to let your doctor or pharmacist know of any supplements you might be taking or any dietary changes.


A common herbal remedy taken at times of stress can be St John’s wort, which is used as a complementary therapy for mild to moderate depression. But it also interacts with several cancer medicines, such as tamoxifen,  irinotecan, docetaxel and imatinib.

Grapefruit, although often recommended for a healthy diet can increase and decrease the potency of many cancer drugs.

How treatment can cause symptoms which affect the cancer diet

Many of the diet issues that cancer patients have are due to the side effects of cancer therapy they are having but these could also be due to the effects of cancer itself.

These may cause

  • loss of appetite
  • taste changes
  • mouth problems
  • diarrhoea and/or  constipation
Cancer therapy side effects can cause nausea

Loss of appetite

When cancer treatment causes weight loss and loss of appetite there are a number of things to do

  • Don't fill your stomach with a large amount of liquid before eating.
  • Eat small amounts of high protein and calorie foods every 2 or 3 hours.
  • Ask friends and relatives to help prepare your meals.
  • Add extra calories and protein to the food that you eat such as using butter, milk, cream, sugar, honey and cheese.
  • Eat cold or slightly warm food if the smell of cooking puts you off eating.
  • Have small servings of your favourite foods prepared ahead of time.
  • Keep a stock of convenience foods in the cupboard.
  • Eat puddings and desserts.
  • Try new foods and tastes.

Don't give yourself a hard time if you don't want to eat much for a few days after treatment.

You might not want to eat after chemotherapy


Diarrhoea is a common side effect of some treatments.  Here are some diet changes you can make to cope

  • Drink plenty of liquid (up to two litres a day) to replace fluid lost.
  • Avoid alcohol and coffee.
  • Small, frequent meals made from light foods such as dairy produce, white fish, poultry, well-cooked eggs, white bread, pasta or rice can help
  • Eat meals slowly.
  • Avoid greasy and fried food
  • Eat less fibre until the diarrhoea improves.
  • Avoid spicy food

Sore Mouth

Treatment side-effects for cancer patients, such as feeling sick, mouth ulcers and a dry or sore mouth can make it hard to eat and drink as much as you need to.

Cool drinks may soothe a sore mouth. For sores, pain, or trouble swallowing, stick with soft foods.  Avoid anything rough or scratchy, and spicy or acidic food, as these can sting your mouth. In addition, you could try eating meals lukewarm (not hot or cold). And use a straw for soups or drinks.


  • Drink plenty of fluids using few but frequents sips
  • Have 5 or 6 small meals a day
  • Stay away from fried, spicy, sweet, or salty foods.
  • Peppermint and ginger can both help with nausea.  This can be in any form such as teas or sweets


Some drugs can cause constipation, particularly painkillers, but also some chemotherapy drugs.  Mild laxatives which you can get from your doctor can help.  It can also help to drink plenty of fluids and eat as much fresh fruit and vegetables as you can.

Final thoughts

Small diet changes can make a huge difference, and the above suggestions can help, but it is always important to let your doctor know if you have any symptoms which are bothering you and if you make any dietary changes or are thinking of taking supplements.

Food controversies and cancer

Beware of grapefruit with chemo drugs

Cancer: Home Treatment for Nausea or Vomiting

Further suggested reading

Chemotherapy Side Effects: Dealing With Short And Long Term Issues

Related Posts

34 Best Ways to Help Someone Before, During and After a Mastectomy

We Consulted With Our Community And We Came Up With 34 Practical And Effective Ways To Support A Friend Before, During, And After Mastectomy.

Read More
Cancer Care Parcel Reviews From "A Mum Reviews"

We would like to give a big thank you to A Mum's Review who wrote a very comprehensive review of our gift for children with cancer.

Read More
Gifts For Female Cancer Patients: Hugs, Gifts And A Lot More Discussed.

A woman with cancer is different. Her type of cancer, personality and support network are all unique, so what you give her should be too.

Read More
This Is Me, I Will Not Hide: A Personal Account From A Cancer Survivor

I Wanted To Share A Portion Of My Journey With You. I Am A Cancer Survivor. Cancer Has Given Me Many Challenges And A Few Gifts.

Read More
1 2 3 51
We strongly advise you to talk with a health care professional about specific medical conditions and treatments. The information on our site is meant to be helpful and educational but is not a substitute for medical advice.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sign up for more information
3 Days Of Tips For People With Cancer
3 Days Of Tips To Help You Help Your Friend

Newsletter For
Anyone Touched By Cancer
Sustainability Matters
Every purchase, big or small, has a footprint. But sustainability challenges don’t have a quick fix.
Organisation for Responsible Businesses.
Cancer Care Parcel Ltd. Registered in England and Wales.
Trading Address: Highstone House, 165 High Street, Barnet, Herts. EN5 5SU, UK. Registered Office: 7a High Street, Barnet, Herts, EN5 5UE.
Company Number 14415197, VAT number is GB428826076,  EORI number is XI428826076000