How to Eat as a Cancer Patient?

There are many studies showing the effect of nutrition on the risk of developing cancer. However, what should you eat if you already suffer from cancer? How does it affect the course of the disease? What are cancer patients actually eating and what is the effect of the distinct cancer diets?

Sugar free

Many patients try to „starve“ their cancer dead by means of a sugar free diet. This is because cancer cells need much more readily available energy than normal cells. And the truth is: in a laboratory test tube cancer cells die within 24 hours without glucose.

Within the human body however, it is not that simple. Firstly, all carbohydrates are broken down into glucose molecules in order to be burnt thereafter. If necessary, even proteins and fat molecules can be metabolized into glucose molecules. Secondly, the body needs a certain blood sugar level to function properly. With zero blood sugar, the cancer cells will die, but the whole body will die with them.

However, reducing sugar is always a good idea, as sugar harms the body in many ways. The „good“ carbohydrates, seen particularly in whole grains which contain complex carbohydrates and numerous other vital nutrients, should definitely remain as a part of your diet.

Fruit juices

Some alternative treatments use plenty of fruit and vegetable juices. Those contain significant amounts of essential vitamins, minerals, fibres and protective antioxidants. As animal products are often omitted from such diets, they are also very low in fat and sometimes also in proteins. However, they can be a problem if they are too high in sugar.

Unfortunately, the effects of these diets are poorly documented. There is a lack of reliable data.


A ketogenic cancer diet is based on the observation that cancer cells metabolise glucose differently than normal cells. A diet very low in carbohydrates also leads to lower insulin levels, which is a hormone similar to growth hormones and thus also stimulates growth of cancer cells..

Ketogenic diets often are high in fat and / or proteins. Thus they may be detrimental in other health aspects.


Oncologists have recommended to refrain from fasting. It was believed that fasting would weaken the already stressed body even more, and it was assumed that after fasting the cancer cells would grow and spread the more. Recent American studies have brought this to light. Doctor Valter Longo had patients with blood cancer fasting before chemotherapy. The effect was surprising: Fasting noticeably increased the tolerability of chemotherapy as well as the effectiveness. In any case, these studies show that fear of a detrimental effect of fasting in cancer patient is not justified.

Low protein

In more than twenty studies, Campbell together with several research groups subjected rats to high dosages of aflatoxin. Aflatoxin is a poison produced by mould and leads to liver cancer in humans and rats. Animals which got the „normal“ diet thereafter, meaning 20% protein, developed liver cancer. Animals on only 5% protein did not develop liver cancer, not even those exposed to the highest doses of aflatoxin.

Encouraged by these surprising findings, they investigated different kinds of protein and found that animal protein was cancer promoting, but plant protein was not. The worst among the animal proteins however was casein, the main milk protein.

These studies have limitations. They often deal with precursors of cancer, not definite cancer cells, and almost all studies investigated cancer development while only little information is available about the effect on existing cancer cells.

The project „Food and Cancer“ starts exactly there and wants to encourage cancer patients to only eat plant derived foods and to investigate the effect on their disease. With plant-based nutrition you choose the diet richest in nutrients, you will not do harm to your body with this simple and realistic way of nutrition. We sincerely believe you will improve your tolerance of the necessary therapy and thereby your chance of survival.

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