Food and Cancer: unproven dietary treatments

No special food, diets or vitamin supplements have been scientifically proven to cure cancer.

Many unproven alternative dietary treatments, particularly those that cut out food groups such as meat or dairy products, may not provide enough energy (kilojoules/calories) and protein. This can cause unwanted weight loss, tiredness and a decrease in your immune function. Your quality of life may suffer.

The changes you make should be for the better. Talk about any dietary changes with your dietitian or doctor first.

Juice therapies

Juice therapies involve using fresh fruit and vegetable juices as the main source of food. Supporters of juice therapy believe it strengthens the immune system, reduces blood pressure and helps to clean out (detoxify) the body. However, while the health benefits of fruit and vegetables are well documented, the benefits of juice therapy are not.

Juice only contains a fraction of the fibre of whole fruit or vegetables. The protective effect of fruit and vegetables may be related to many factors in the whole fruit and vegetables, not just the juice.

Use fresh fruit and vegetable juices as part of a varied eating plan.

Vitamin supplements

Vitamins and minerals are an essential part of a healthy diet and play an important role in the body's immune system. Some people believe that taking high-dose vitamin supplements will strengthen the body's immune system, but there is little evidence to support this. In fact, many vitamins and herb compounds can be poisonous at high levels, and may interfere with chemotherapy.

The general rule is that dietary supplements should never replace whole foods, which are the best source of vitamins and minerals. However, if supplements are taken, the amount should not exceed the recommended daily intake unless you are under a health professional's supervision.