Fiber

Fibre is a carbohydrate found in plants that is not digested or absorbed by the body. Dietary fibre has many benefits and can be a true ally, especially after a breast cancer diagnosis:

• It promotes the feeling of being full, helps reduce cravings, and maintains weight.
• It can act as a prebiotic and make intestinal microbiota healthier by stimulating the production of good intestinal bacteria and health-promoting molecules. Healthy microbiota play a vital role, particularly for the immune system and mental health.
• It helps regulate intestinal transit, prevents and helps better manage intestinal side effects such as diarrhea and constipation.
• It also helps delay glucose absorption and lower cholesterol levels, playing a role in the prevention of cardiovascular disease.

Despite its many benefits, too few Quebecers get the recommended daily fibre intake of between 20 and 40 g.

Where is fibre found?

Foods that are rich in fibre include:

• Vegetables
• Nuts and seeds
• Fresh fruit, dried fruit, oleaginous fruit (avocado)
• Legumes (beans, lentils, edamame, peas, etc.)
• Whole-grain cereals (whole wheat, oats, barley, wild rice, etc.)

How can you ensure you get enough fibre?

Canada’s Food Guide recommends the following:

• Fill half your plate with fruits and vegetables.
• Fill a quarter of your plate with cereals (preferably whole-grain cereals).
• Fill a quarter of your plate with protein-rich foods, which can also be protein- and fibre-rich plants (legumes, seeds and nuts).

Tips for gradually increasing your consumption of a wide variety of fibre-rich foods:

• Choose whole fruit rather than fruit juices.
• Choose cereals and flours made from whole grains; for example, substitute half of the all-purpose white flour with whole-wheat flour in your recipes.
• Add wheat bran, oat bran, psyllium, seeds, nuts, and fresh or dried fruit to your yoghurts, muffins or salads.
• Opt for high-fibre snacks such as fruits and vegetables with hummus or guacamole dips.

Depending on your situation and if you suffer from a digestive pathology, ask your doctor or dietitian for personalized recommendations.

Some drug treatments for breast cancer can cause constipation, diarrhea or both alternately. Adapting your fibre intake to your needs is an integral part of the strategy for managing digestive side effects.

Your healthcare team will try to find the cause of your digestive symptoms and suggest ways to treat it. You could also try the following complementary measures.

Votre équipe de soins tentera de déterminer la cause de vos symptômes digestifs et vous proposera des façons de la traiter. Vous pourriez également essayer les mesures complémentaires suivantes.  

Some medications used to treat breast cancer or manage side effects can cause constipation.

These tips can prevent or help better manage constipation:

• Drink at least two liters of fluids throughout the day.
• Practice regular physical activity, according to your abilities, one step at a time
• Gradually increase your intake of high-fiber foods, according to your tolerance. Some foods are particularly rich in fibre and have a natural laxative effect (prunes, rhubarb, and more).

Depending on your situation, your healthcare team may recommend commercial fibre supplements or medication to help relieve constipation.

Chemotherapy drugs target fast-reproducing cells. Because the digestive tract is lined with rapidly dividing cells, they can be damaged by treatments. This is why diarrhea is a common side effect of some chemotherapy. Diarrhea can also be exacerbated by stress and anxiety, certain intolerances, or personal sensitivities.

Severe and/or prolonged diarrhea can lead to dehydration, weight loss, fatigue and electrolyte imbalances. If you have more frequent, watery bowel movements or if you have pain or cramps, talk to your healthcare team right away. Management may include medication or an infusion, combined with certain dietary measures.

A few tips to prevent dehydration and avoid making diarrhea worse:

• Drink plenty of fluids throughout the day (water, salty liquids such as light broths, rice water, rehydration solutions).

• Avoid drinks and foods that could speed up transit:
• Avoid very sweet, carbonated or caffeinated beverages (coffee, tea, cola, energy or sports drinks), alcohol, and icy or very hot liquids.
• Avoid milk and dairy products if they are poorly tolerated; choose lactose-free dairy products instead.
• Avoid chewing gum, candy or “sugar-free” products that contain sugar alcohols (sugars ending in “ol” in the list of ingredients: sorbitol, mannitol).
• Avoid high-sugar, high-fat or spicy foods.

• Eat more often and in smaller quantities.

• Avoid high-fibre foods:
• Avoid legumes, nuts or seeds; instead, choose eggs, meat, poultry or steamed or boiled fish.
• Avoid whole-grain cereals; instead, choose white bread, white pasta, white rice or semolina.
• Avoid raw vegetables and fresh or dried fruit; instead, choose pulp-free fruit and vegetable juices, cooked, ripe or canned fruit without seeds or peels: ripe bananas, apple or pear compotes, mashed potatoes, and peeled carrots.

Ask your healthcare team when you can resume your usual diet after your last bout of diarrhea.

1 –  La consommation alimentaire des adultes québécois selon le poids corporel EXPLORATION DES DONNÉES DE L’ENQUÊTE SUR LA SANTÉ DANS LES COLLECTIVITÉS CANADIENNES 2.2 – NUTRITION 

2 –  Jayedi A, Emadi A, Khan TA, Abdolshahi A, Shab-Bidar S. Dietary Fiber and Survival in Women with Breast Cancer: A Dose-Response Meta-Analysis of Prospective Cohort Studies. Nutr Cancer. 2021;73(9):1570-1580. doi: 10.1080/01635581.2020.1803928. Epub 2020 Aug 14. PMID: 32795218. 

3 –  Santé Canada 

4 –  Société canadienne de recherche intestinale  

5 –  Société canadienne du cancer, Bien s’alimenter lorsqu’on a le cancer  

6 –  CHU de Québec, Université Laval, Conseils nutritionnels pour soulager la diarrhée.