Diet for Cancer: What to Watch Out For?

Many people with cancer want to play an active role in improving their health and do something themselves for their well-being and recovery. Nutrition plays a significant role in this. For example, it can prevent the weight loss and subsequent malnutrition that are common during cancer and alleviate the side effects of therapy. There is no specific, correct diet that helps all people with cancer. Rather, the general state of health, the type of therapy, age and personal preferences play a role. Which form of nutrition is suitable for a person with cancer should therefore be decided on an individual basis, preferably together with a professional nutrition counselor. In this article, you will learn what you can generally do to eat as healthily as possible during a cancer illness and counteract side effects, and which nutritional concepts you should better avoid. Cancer: these symptoms can be warning signs

How important is diet in cancer?

A wholesome and varied diet is basically important at every stage of life. It can help to stay healthy, protect against disease and increase well-being. In the case of cancer, nutrition is of particular importance. This is because people with cancer are often affected by restrictions in their diet. On the one hand, this can be caused by the disease itself or by the required therapy. It is important for those affected that sufficient energy, vitamins and minerals are taken in daily through the diet in order to avoid the threat of weight loss and possible malnutrition. Because a good nutritional status can:

  • Favorably influence a necessary cancer therapy
  • Promote the tolerability of treatments
  • Shorten the duration of a hospital stay
  • Stabilize the body’s defenses
  • Maintain or improve the quality of life

What diet for cancer?

When it comes to healthy eating for cancer, there are many options, but also many misconceptions. Both physical limitations and mental upsets have an impact on what can be eaten and what tastes good. The diet in cancer should therefore be tailored to the individual situation, the disease and the therapy phase. What should be eaten is what the body needs: energy in the form of fats, proteins and carbohydrates, as well as vitamins and minerals, depending on individual needs. There are no forbidden foods in cancer or foods that cancer patients are not allowed to eat. However, depending on the type of cancer and therapy, some foods are poorly tolerated and should then be avoided. Each patient with cancer must find out for themselves which foods these are. Oncology nutrition counseling can be helpful in this context.

Are there cancer diets?

According to current knowledge, there is no diet that can cure cancer. Nor is there any scientific evidence for a diet that can starve cancer or foods that destroy cancer cells. So-called cancer diets, also known as anti-cancer diets or anti-cancer nutrition, can even be dangerous for people who have cancer.The following list represents a selection of concepts that address nutrition for cancer and certain dietary restrictions that cannot be recommended in cancer:

Name of diet/form of nutrition Features Shall cause
Homotoxin theory according to Reckeweg

Among other things: No pork, no alcohol, nothing smoked.

Detoxify body
Cancer cure total after Breuß 42 days without solid food Starve cancer cells
Budwig diet Diet of linseed oil and curd cheese, fruits and vegetables Inhibit cancer growth by certain fatty acids
Gerson therapy Fat-free, salt-free and herbal, coffee castor enemas, raw calf liver juice. Detoxify body
Anti-cancer diet according to Coy Few carbohydrates, many secondary plant compounds Starve cancer cells
Ketogenic diet No carbohydrates, lots of fat and protein Inhibit cancer growth, improve the effect and tolerability of therapy
Alkaline diet Many alkaline-forming foods (including vegetables, nuts, whole grains), few acid-forming foods (including meat, sausage, egg, sugar) Counteract hyperacidity of the body

Caution with cancer diets

An unbalanced diet in cancer, as found in many of the above cancer diets or nutritional regimens, can have a negative effect on the course of cancer. The consequences of an unbalanced diet or nutrition may include:

  • A deficiency of certain important nutrients develops.
  • Too few calories or fasting diets lead to lack of energy and weight loss.
  • Rigid dietary rules are sometimes difficult to implement, which means an additional daily effort in food preparation.
  • If the food does not taste good and the pleasure is lost, then too little food may be eaten, which can lead to nutrient and energy deficiencies and subsequently weight loss.

Due to the limitations in terms of protein supply, a vegan diet in cancer can also not be recommended. Because just animal protein from meat and dairy products is easily utilized by the body and therefore important for the maintenance of muscle function and energy balance. In addition, a vegan diet often leads to weight loss in the beginning. However, in the case of cancer, this is precisely what should be avoided. Another theory is that sugar and other carbohydrates are the main source of energy for cancer cells and are responsible for their rapid proliferation. Thus, sugar is sometimes considered “toxic” to the body. Accordingly, no sugar in cancer causes cancer cells to be prevented from growing. To date, this connection has not been scientifically proven. However, studies indicate that a diet high in protein and fat and low in carbohydrates is better for cancer than a normal diet. In contrast to the above-mentioned diets, a varied diet with plenty of fruits and vegetables, supplemented with animal foods according to taste, provides the body with energy and all the important nutrients it needs in cancer.

What are the dietary restrictions for cancer?

First, it must be said: Not every cancer disease necessarily entails dietary restrictions. Often, it is possible to eat and drink normally. In this case, the normal, whole-food, balanced diet is the best diet. As with healthy people, eating habits can be guided by the 10 rules of the German Nutrition Society (DGE). These define what is best eaten by all healthy people and in what quantity. However, there are also numerous reasons why eating and digestion may be impaired in cancer:

  • Taste perception changes, so that some foods are no longer eaten (with pleasure).
  • Anxiety and depressive moods reduce appetite and hunger pangs.
  • Eating and digestion cause pain.
  • Side effects of therapy can cause nausea, vomiting, dry mouth or inflammation of the mucous membranes.
  • After surgery on organs of the digestive tract, their function is limited.

Tailor nutrition to personal needs

In addition to the cancer itself, the therapy may also have an impact on the nutritional status of the person with the disease and may involve dietary restrictions. The main treatment modalities for cancer are surgery, chemotherapy, and radiation therapy. Each form of therapy can cause side effects that can be influenced and, if necessary, mitigated by the diet. Even after therapy has ended, nutrition remains a significant factor influencing the course of recovery. Depending on the symptoms or needs, both the selection and preparation of foods can be individually adapted to the specific situation.

Weight loss and nutrient deficiencies in cancer

When not enough food is consumed or digestion is limited, weight loss and nutrient deficiencies can result. Depending on the type of cancer and the prescribed therapy, the risk of this can vary. Therefore, weight should be monitored at all times during the disease. Possible causes of weight loss and nutrient deficiency during cancer include:

  • Nutrients are more poorly utilized.
  • Tumors obstruct organs of the digestive system, for example, stomach or intestines.
  • Surgery removed all or part of organs important for digestion.
  • Cancer increases the total energy consumption of the body.

Both low weight and malnutrition can increase the length of stay in the hospital after surgery or therapy and complicate the recovery process. An already weakened body lacks strength and energy to recover quickly. Therefore, urgent care should be taken to achieve good nutritional status before, during, and even after therapy.

What to do in case of nutritional restrictions?

In any case, if discomfort occurs before, during, or after therapy with regard to nutrition, or if body weight decreases, the attending physician should always be consulted. Professional nutritional counseling can be additionally helpful. Although they do not replace the conversation with the doctor, the following tips can help to facilitate food intake and alleviate possible discomfort.

Taste disturbances and loss of appetite

Those who suffer from taste disorders and loss of appetite can resort to the following tips:

  • Select foods and drinks that you have an appetite for.
  • Try what is good for you and tastes good
  • Eat in company, alone or in front of the TV: Everything is allowed, which facilitates the meal

Nausea and vomiting

Nausea and vomiting are also not uncommon as a side effect of cancer disease and therapy. These tips will help:

  • Chew the food well and eat slowly
  • Avoid fatty and acidic foods, as they stress the stomach
  • Drink plenty of fluids, because you lose a considerable amount of fluid during diarrhea
  • Take anti-nausea medication after consultation with the doctor.

Diarrhea and constipation

For diarrhea and constipation, the following can be considered:

  • Avoid raw foods and hard-to-digest whole grains and fiber during diarrhea.
  • In case of constipation enrich the food with fiber and drink plenty of water
  • Eat smaller, easily digestible meals in small portions throughout the day relieves the stomach and intestines

Inflammation of the mouth, chewing and swallowing difficulties.

Inflammation in the mouth area and chewing and swallowing difficulties also trouble many people suffering from cancer. Here’s where it can help:

  • For oral and dental care use mild toothpastes and soft toothbrushes.
  • Eat unseasoned or weakly seasoned and no spicy or sour foods
  • Drink frequently and in sips to absorb enough fluid
  • Prefer soft foods such as porridge, fish or cooked vegetables
  • Cool foods can relieve pain when chewing and swallowing

For weight loss

To prevent or counteract weight loss, you can try these tips:

  • Enrich the food with fats to absorb more energy.
  • Pay attention to a sufficient protein intake
  • Eat many small meals throughout the day
  • Create a nutrition plan together with a doctor or nutritionist
  • Regularly check the weight

In advanced disease, extensive dietary restrictions and significant weight loss, supportive nutritional measures such as sip feeding (“astronaut food”), parenteral nutrition (infusions) or tube feeding may be necessary.

Astronaut nutrition in cancer patients

“Astronaut food” or “astronaut diet” refers to a drinkable food that contains varying amounts of elemental minerals, vitamins, and nutrients in addition to a great many calories. There are products in different flavors and different compositions. Astronaut food represents a form of artificial nutrition and is intended for patients who are unable to absorb the necessary amount of calories and important nutrients through their normal diet. It is used, for example, for cancer patients who suffer from a metabolic disorder as a result of the disease, leading to severe weight loss (cachexia). Drinkable nutrition is classified as a drug and can be prescribed by a doctor. If it is determined that a sip feed is necessary to improve the nutritional situation, the health insurance company will cover the costs.

Conclusion: with professional support to the right nutrition.

Cancer patients can make use of certified, oncological nutritional counseling and should definitely consult with the attending physician if they are uncertain about the disease and the therapy. An individualized nutrition plan with dietary recommendations and appropriate recipes help prevent weight loss and resulting malnutrition. If it is necessary from a health point of view, the doctor can order additional nutritional measures for support. The goal is the same in all cases: good nutritional care. Because this can significantly improve the quality of life in the case of cancer and prolong life. Nutrition in cancer: 13 golden rules