Disclaimer. This article is for information and knowledge purposes only. It is imperative that you get clearance and are monitored if you plan to undertake any form of diet therapy especially if you have Cancer or and Chronic Illness.

What is radiation-induced gastrointestinal syndrome (RIGS)?

There is a lot to think about after a cancer diagnosis. Things tend to happen fast, and there is too much to take in at once. When embarking on radiation, the cancer care provider will go quickly over what side effects may occur due to the therapy. However, generally, this is the last thing to worry about as the only thought is on treating the cancer.  

The issue with cancer treatment side effects is that they can turn into debilitating health issues after treatment has been well and truly stopped. One of the treatments that can pose this problem is radiation therapy. 

In this article, I will focus on the radiation and the potential damage to the gastrointestinal tract. RIGS is a very real and very common side-effect of radiation therapy. There are specific names for the areas of the digestive tract affected by radiation. However, this article will be viewing the gastrointestinal tract as a whole.

In technical terms, small bowel damage is called radiation enteritis; large bowel damage is referred to as radiation colitis; damage to the rectum is called radiation proctitis. 

Why may I get RIGS

Any radiation that is given in close proximity to the digestive tract will generally affect the surrounding tissue. Pelvic radiation causes the most problems as the radiation is directly over the gastrointestinal tract. The irradiated gastrointestinal tract undergoes varying degrees of adverse structural and functional changes, resulting in transient or long-term complications. RE is characterised by inflammation in the tissues and organs and their surrounding areas that have been irradiated.

It is important to be educated about the symptoms of radiation damage early as there are many treatments that a person can implement to protect the gut. We will go through these in the article and look at diet and lifestyle changes for prevention and treatment.

If a patient has had radiation and is experiencing negative side effects, it is recommended that they seek the assistance of a gastroenterologist. 

Radiation location and possible side-effects

Mouth, pharynx and esophagus injuries can occur when the patient undergoes radiation to the head, neck and thoracic area.

Stomach and duodenal injury can occur when the stomach is near a treatment zone for radiation.

Small intestine injury is possible when there is radiotherapy treatment to the pelvic and abdominal areas.

The colon and rectum are commonly affected as their location falls within the areas of many different cancer types that require radiation.

Risk

The risk of developing radiation-induced gastrointestinal damage depends on the dose of radiation, fractionation and type of radiation administered. The most likely radiation to create an issue of RIGS is that which is delivered from outside the body. Radiation in general is given over many weeks but largely depends on the type of cancer being treated and whether they are going for curative or palliative objectives.

The symptoms usually occur during the second week of treatment when tissue damage and inflammation are at their maximum. The symptoms then peak by the fourth or fifth week of radiation therapy.

What symptoms may I have?

Signs and symptoms of radiation-induced gastrointestinal injury can be acute, and the effects can continue for a long time after treatment.

Acute RIGS effects are as follows. These symptoms generally occur during radiation and in the short period after.

• Nausea
• Abdominal pain
• Diarrhea
• Fatigue
• Bloating
• Colic-like pain
• Loss of appetite
• Fecal urgency

Symptoms of delayed injury

These symptoms can occur from 3 months to 30 years after radiation therapy.

• Mucosal Atrophy – The loss of the mucous-secreting glands in the gut due to inflammation. These glands can be replaced by scar tissue, rendering them ineffective. The loss of this function can severely compromise the GI tract leading to increased gut permeability and inflammation.

• Vascular sclerosis – the hardening and scarring of the tissue that facilitates the blood flow to the gastrointestinal tract. Loss or reduced function means that blood and oxygen are unable to get to the gut to keep it alive. This can result in the death of parts of the gut.

• Progressive Intestinal Wall Fibrosis – Stiffening and scarring of the gut wall due to the body trying to repair inflammation and damage. This can then hinder gut movement leading to an array of associated problems.

Current standard medical care can offer few options to prevent this damage, so here we explore the many medical foods and botanical supplements that can help in the prevention and treatment of RGD.

Often patients do not have a lot of time before they know they will be undergoing radiation. Therefore there is not a lot of time to implement protection strategies. However, in the case of cancers such as triple-negative breast cancer, there is a fairly long window to prepare for radiation that is usually done after a course of chemotherapy.

Medical Foods that could help protect against RIGS

There are many foods that can be eaten to help protect the intestine from radiation damage. Although the majority of the research cited here was done with high-dose, targeted nutritional compounds, using food as medicine gives the body the perfect balance of nutrients. It has also been shown extensively that the entire food or herb works together in a beautiful synergy. 

These foods below can be included in the diet very easily. Please stay tuned for a Radiation Care Diet Plan and Recipes.

A note on supplements. Always consult with your Health Care Practitioner before taking any supplements. It is best to liaise with an Integrative Health Care Provider who can source the best quality supplements.

Vitamin E (y-tocotrienols)

Vitamin E is one of the main components of the cells membranes of the gastrointestinal tract; therefore, it makes sense to ensure that this level is adequate enough to assist in protection from radiation injury (1).

As Vitamin E is a potent antioxidant, it is best to liaise with your Oncologist and Radiation Oncologists regarding the timing of any supplements.

Food Source: Wheat germ, wheat germ oil, tahini, almonds, pumpkin.

Genistein

Radiation damage can change the gut microbiome significantly, leaving the gut vulnerable to infection. Genistein has been shown in clinical studies to protect the body against endotoxins which are poisons that undesirable bacteria can produce within the cells. These endotoxins can then contribute to inflammation of the gut. The protection of the gut happens due to stimulating the gut’s secretion of chloride and bicarbonate. 

Genistein has also been shown to stimulate muscles of the intestine that may have been damaged due to radiation. Damage to the muscles in the intestine can, in turn, cause slow intestinal movement creating issues with constipation and reabsorption of toxins into the system (4).

We know that Genistein can help protect the gut but some studies have also found that this isoflavone may also be able to enhance the killing power of radiation (5) 

Food Source: Soy Products: Although all soy products contain genistein, the best choice is fermented soy foods such as Tempeh and Miso. 

Lycopene

Lycopene is the beautiful red pigment that is found particularly in tomatoes but also in watermelon as well. One study has demonstrated that oral lycopene given on seven consecutive days prior to radiation significantly protected the intestinal structure.

Food Source: Tomatoes, pink guava, paw paw, watermelon.

Vitamin C

Radiation induces something called ROS, which is short for ‘reactive oxygen species’. This basically means that the radiation is causing damage to cells, and that process creates free radicals in the body. Whilst this is the aim for radiation, these excess and leftover free-radical can then go on to cause damage to the body well after they are generated. Vitamin C is a powerful antioxidant or ‘free-radical scavenger’ which could be used after radiation to help mop up free radicals.

Food Source: Guava, cherries, rosehips, capsicum, blackcurrant, rockmelon, kiwi fruit, citrus

Resveratrol

Resveratrol is the darling of antioxidants and potentially has far better antioxidant capabilities than Vitamin C. Resveratrol contains a substance called polyphenol, and polyphenols are known to have anti-inflammatory and anti-cancer properties. Polyphenols are the master compounds for scavenging free radicals that can be left over from radiation treatment.

Although resveratrol is such a superstar, one downside is that its availability to the body is low. Resveratrol has to undergo more metabolism in the body, and that may mean that organs at distant sites from the digestive tract may not benefit. The good news here is that resveratrol’s first port of call is the digestive tract, therefore making it suitable for helping the intestine with radiation damage.

Studies have shown that resveratrol, given at 10mg/kg/day for ten days before and ten days after radiation therapy, significantly suppresses intestinal damage. (9)

Although the highest levels of resveratrol are found in red wine, alcohol is not a good choice if you are suffering from RIGS as it can significantly irritate the gut lining.

Food Source: Grapes, mainly in the skin.

Berberine

Berberine is the gorgeous yellow substance found in foods such as Globe Artichoke and also the endangered and powerful plant, Goldenseal. Berberine has a plethora of therapeutic functions and has also become a mainstay therapy for metabolic blocking of nutrition to the cancer cell.

Berberine has been shown to regulate a number of intestinal functions such as glucose metabolism and barrier dysfunction (aka leaky gut syndrome)

Berberine has a beautiful duality in that it helps fight cancer in a number of ways, and it also has a great affinity for protecting the intestine. Not only can it perform these critical roles in protection, but it has also been shown to make cancer cells more sensitive to radiation; this also includes cancers of the digestive tract (10).

As well as enhancing cancer’s vulnerability to being killed, Berberine, at 300 mg three times per day in the third to the fifth week following radiation, has been shown in clinical studies to reduce the severity of radiation-induced intestinal injury. 

Although Berberine is often taken in isolated form in a supplement, I personally believe that the synergism of all of the properties in the plants is more important than the isolated active component. 

Food Source: Globe Artichoke; Herbal Tincture of Globe Artichoke; Herbal Tincture of GoldenSeal; Herbal Tincture of Philodendron

Curcumin

Curcumin likely needs no introduction into the world of cancer care. Most people that I consult will come to me already taking some form of Curcumin supplement. Curcumin is the substance that gives the food that wonderful yellow colour.

The internet is saturated with a plethora of research looking into the benefits of Curcumin not only as a possible preventative for cancer, but also as a potent adjunct treatment to standard of care Oncology therapies such as radiation and chemotherapy. 

Although there are many studies, one in particular, has looked at Curcumin’s ability to protect the gut from radiation damage. Curcumin given to mice at a dosage of 10mg/kg/day for 10-14 days before and 4 days after radiation demonstrated a reversal of the damage that had been induced by the radiation (12).

Curcumin supplements saturate the market, and it is hard to determine which one is best. Adding curcumin to the diet is one of the best ways as it is easy and the food has all of the synergistic compounds to facilitate its absorption. If you do decide on a curcumin supplement, look for something that has a high curcumin content. Mixing curcumin with oil can also aid its absorption.

Food Source: Turmeric Root

Garlic

Garlic is such a well-known healing food used by cultures all over the world as delicious food medicine. Garlic contains over 2000 compounds that exert some kind of role in the human body.

The therapeutic value of garlic in suppressing disorders of the gastrointestinal tract has long been studied (1). Garlic regulates disease-causing bacteria. This action is exerted by the bioactive role of the sulphur-containing compound in the garlic (14).

Experiments performed that looked at the effects of garlic administration on intestinal damage after exposure to radiation showed positive results and that garlic could be used as a medical food to help mitigate the effects of radiation damage (15).

A word of caution. If you are already suffering from intestinal radiation damage, garlic will most likely exacerbate your symptoms. I would suggest that this medical food be used as a prevention measure before radiation as opposed to something afterwards if there is damage present.

Ginkgo Biloba

Ginkgo is quite possibly one of my all-time favourite botanical medicines for the support of cancer patients. When looking at gastrointestinal function, ginkgo biloba’s positive role in helping the GI tract is well-documented.

In a particular study, Ginkgo Biloba extract was shown to protect the intestinal mucosa against a lack of blood flow to the tissue that could possibly result in the death of gastrointestinal tissue (16). This same study also demonstrated that Ginkgo Biloba also suppresses pathogenic (disease-causing) bacteria, which may have the opportunity to flourish with the effects of radiation on the intestinal microbiome.

When I am looking at medicines to help patients manage their symptoms from cancer treatment, I am also keen to look at what substances can do several roles. Ginkgo is one of these soldiers as it has also been shown to not only sensitise cancer cells to the killing but also to protect healthy cells from damage from radiation (19).

One interesting field of research is on whether the increase in blood circulation from Ginkgo Biloba can also play a critical role in the enhancement of radiation. It is well known that tumours that have a better blood flow, therefore, better oxygenation are also more susceptible to dying from radiation.

Food Source: Herbal Tincture – Ginkgo Biloba.

Goat/Camel Milk Kefir

We know that exposure to radiation can severely disrupt the body’s microbiome. Microbiome health can also play a part in cancer therapy effectiveness, so it makes sense that we need to look after it during and after radiation therapy. Goats milk kefir is an amazing source of diverse beneficial bacteria that can be used to help radiation-induced injury, especially colitis. 

What to do if you have developed radiation-induced gastrointestinal damage.

Avoid dairy foods as a general rule as they promote inflammation of the gastrointestinal tract. The exception here is the goat’s milk kefir, as the benefit outweighs the risk.

Foods that are high in fibre should be avoided if there are acute symptoms. Fibre is hard for the body to break down, so this can exacerbate the problem. Fibre makes the bowel move faster, which may increase discomfort.

Examples of these foods include nuts and seeds, whole grains and most fruits. Cooked and strained fruits are the exception here as their fibre content can be reduced during this process.

Foods that can irritate the stomach should also be avoided. Any caffeine, cola, chocolate or alcohol. If you are taking a herbal extract, it is advisable to evaporate the alcohol off the mixture during this time.