Proteins help to protect our cells, heal wounds and build up the muscles. If your body doesn't get enough protein, it may break down muscle to get the fuel it needs. This may negatively impact the time it takes you to recover from illness and also lower your resistance to infection.
When you have cancer, your need for this important nutrient increases2: While 0.8 – 1g of protein per kg of body weight per day is sufficient for a healthy person, in cancer patients, this requirement is increased to 1.2 – 1.5g per kg per day. This is due to increased inflammatory and immune reactions in the body. Moreover, your muscle mass must be constantly protected from loss. This means your diet must be particularly rich in high quality protein to meet the increased demand.
Sources of protein include fish, poultry, lean red meat, eggs, low-fat dairy products, nuts and nut butters, dried beans, peas and lentils, and soy foods.
Fats are used to store energy, insulate body tissues, and transport some types of vitamins through the blood.
For many cancer patients, fat is a particularly recommended nutrient. Because of the changes in your metabolism, it is a better energy provider than carbohydrates. Additionally, fats provide essential fatty acids and transport fat-soluble vitamins. Though the exact amount of fat you need every day is different, people with cancer should modify the quality and quantity of fat in their diet. In all case, ask your doctor or dietician about nutrition counseling and advice.
Different fats have different properties that determine their nutritional value. Certain omega-3 fatty acids play an important role in a healthy diet: They help positively modulate the inflammatory response, lower blood pressure, stabilize cardiac function and may even prevent depression. Furthermore, they can stimulate the appetite and may help increase body weight.
Omega-3 fatty acids can be found especially in fatty, cold-water fish such as salmon.
Carbohydrates are a major source of energy. They give the body the fuel it needs for physical activity and proper organ function. Starch and sugar are the main sources of carbohydrates in our daily diet. Our brain in particular needs sugar (glucose). When we get tired or hungry, it’s possible our blood sugar level has dropped.
Valuable sources of carbohydrates are fruits, vegetables, and whole grains. They also supply needed vitamins and minerals, fiber, and phytonutrients which are bioactive substances (e.g. antioxidants) synthetized by plants. Other sources of carbohydrates include bread, potatoes, rice, spaghetti, pasta, cereals, corn, peas, and beans. Highly processed sweets such as desserts, candy and drinks with sugar supply calories but provide very little in the way of vitamins, minerals, or phytonutrients.
Fiber is a plant component that the body can’t digest. Altough fiber does not provide significant amount of calories it is very useful to us, since it regulates digestion and can improve digestive health, immune protection and our blood cholesterol level. Dietary fiber is also the nutritional basis for our gut bacteria, called the microbiome.
Fiber can be found in plant foods, such as fruits, vegetables, whole grains and legumes.
Vitamins & minerals
Vitamins and minerals are essential substances that the body needs but with the exception of Vitamin D can’t produce itself. Natural foods contain many vitamins. For prophylactic or therapeutic purposes, vitamins and minerals are available in form of pills and liquid supplements.
You will typically obtain plenty of vitamins and minerals if you eat a balanced diet with enough calories and protein. However, it can be challenging to consume a healthy diet while receiving cancer treatment, particularly if you experience side effects. In these cases our doctor or dietician might advise taking a daily multivitamin and mineral supplements. Tell your doctor if your food intake has been restricted for several weeks or months as a result of the effects of the treatment. Checking for vitamin or mineral deficits may be necessary.
In case you are considering taking a supplement, make sure to discuss this with your doctor first. Some cancer patients take large amounts of vitamins, minerals and other dietary supplements to try to boost their immune systems or even destroy cancer cells. However, some of the substances can be harmful, especially in high concentrations.
Water is the main component of our body and vital to your health since all body cells need water to function. Water also transports nutrients. You can get fluids from the food you eat, but in addition, you should also drink several glasses of liquids each day to ensure that your body cells get the fluids they need.
In case you are vomiting or have diarrhea, or even if you are not eating enough, you may need extra fluids to keep your body functioning.
You can get fluids not only from water, but also from milk, juices, broth or other.
What are your benefits?
A diet, based on the principles described above and adjusted by your healthcare team may help you avoid the negative effects of malnutrition on tissues, body structures and organ functions. Studies show that the overall outcome of the various steps in cancer treatment (from surgery to chemotherapy) may be better if the patient’s nutritional status is consistently maintained.1
- Side effects of cancer treatment may be reduced.
- Energy intake (and, with it, body weight) could be improved.
- Treatment outcome may improve.
- Overall quality of life may improve.
- Long-term prognosis may be better.1
 Arends J, Baracos V, Bertz H, et al. ESPEN expert group recommendations for action against cancer-related malnutrition. Clin Nutr. 2017; 36(5): 1187-1196.
 Arends J, Bachmann P, Baracos V, Barthelemy N, Bertz H, Bozzetti F, et al. ESPEN guidelines on nutrition in cancer patients. Clin Nutr. 2017;36(1):11-48