Nutrition: Colorectal cancer (post treatment) or post treatment of digestive tract

Tuesday 08 May 2018


I want to write about supporting the digestive system after treatment for bowel cancer (colorectal cancer) has finished. Of course, you will take guidance from your medical team but in time you should be able to slowly reintroduce different foods that you have had to avoid. Eventually you should be able to eat according to the healthy eating guidelines that I wrote about in July 2017.

This blog follows last month’s blog on colorectal cancer and is to help to rebuild and heal the gut after treatment. But this blog would actually suit anyone who has been through chemotherapy or radiotherapy that has been specifically targeted anywhere on the digestive tract.

The reason is that chemotherapy and radiotherapy are designed to attack rapidly dividing cells such as cancer cells. But the cells that line the digestive tract are also rapidly dividing and so they are adversely affected by the treatment. This is why so many people experience and really suffer from digestive problems like mouth ulcers, acid reflux, low stomach acid, nausea, diarrhoea, excess wind etc.

Here are a few facts that will make you realise the importance of the gut.

  • 80% of our immune cells reside in the gut so a healthy gut will support the immune system.
  • We have approximately 2 kilos of bacteria in our gut, more than the number of cells in our entire body.
  • This gut flora plays a crucial role in maintaining our health including: sustaining a healthy immune system and efficient digestion of food, absorbing nutrients, supporting the detoxification of toxins, and preventing the overgrowth of harmful bacteria, yeasts and parasites.

So you can see that once the digestive tract has been damaged, it is important to take steps to rebuild and heal it. There are many ways that this can be done.

In January 2016 I wrote a blog on fermented foods and their health benefits on the gut, because using them replants into the gut the beneficial bacteria that will have been damaged. There is a lot of detail in the blog which may be good to read. Fermented foods provide what are called probiotics (beneficial bacteria). You can also of course buy probiotic capsules from any good health foods shop which is another way of introducing them. It is important to point out here that they must not be taken until all treatment is finished. (Some research has the opposite opinion that they are beneficial through treatment but this is controversial and not mainstream thinking at the moment).

Another blog in July 2016 talks about the use of prebiotics. Basically, these are foods that help to support and feed the beneficial bacteria once they have been reintroduced into the system and helps them to grow. The blog explains in detail their role and where they come from.

One of the most effective of healing foods is home-made broth using bones from poultry or meat. It is rich in collagen and glucosamine which are restorative nutrients for the gut lining. Simply drink a cup daily or use it as a base for soups and casseroles. I buy chicken bones and put them in my slow cooker overnight. Sometimes I add an onion and carrot to the stock to add flavour. Once the bones have simmered for at least 8 hours I strain them, cool the stock, skim off the fat and I freeze it in pint portions. It really is not difficult, just a process that is really worth the effort. I did try beef bones once but they were so large and difficult to handle, I gave up and just used chicken. I did hear that chicken feet make the best broth. I can get them from the local organic farm shop but I am not sure that they are easily available.

If you have low stomach acid levels, a simple remedy that may help is to put 2-3 tsps of apple cider vinegar in a small amount of water and drink this just before or during a meal.

To help kick start digestive secretions add the juice of ½ lemon to a small glass of warm water and drink this first thing in the morning.

To make protein foods more digestible try marinating them in lemon or lime juice or vinegar or wine to help break down the protein before cooking. This will make them much easier to digest and so be kinder to the digestive system.

Try slow cooking; the process breaks down the tough collagen fibres in the meat, producing a delicious melt-in-the-mouth consistency which is easy to digest.

Include some zinc rich foods. For optimum digestion and the production of stomach acid your body needs sufficient levels of zinc. Foods rich in zinc include seafoods, beef, spinach, pork, chicken, pumpkin seeds, cashew nuts, raw cacao powder, mushrooms and sea vegetables.

Include some bitter foods in the diet. Bitter greens and sour foods helps to stimulate digestive secretions, Foods like endive, rocket, watercress and dandelion. Use them in salads, smoothies or vegetable juice.

Soak nuts and seeds before use. They contain substances that inhibit enzyme activity. Soaking them or sprouting them can aid their digestion.

Foods that will support the liver and gallbladder are apples, artichokes, asparagus, beetroot, berries, bitter leaves, brassicas like broccoli, Brussels sprouts, cabbage and cauliflower. Remember that the gallbladder and liver are responsible for secreting digestive enzymes that help with the breakdown of foods like proteins, fats and carbohydrates.

Please remember that when you start to make changes in your eating and introducing new foods, it is really important that this is done slowly over a matter of weeks and not as a full blown launch. The slow approach is kinder to the gut and will not lead to any adverse side effects like excess wind, bloating or possible loose stools.

Blog originally written by Caroline in November 2017 - links updated 2021

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