A nutritional supplement can slow the development of some cancers and improve the effects of treatment, suggests a study of mice.
Mice with pancreatic, pulmonary, or skin cancer are given mannose, sugar found in raspberries and other fruits.
It significantly slowed down the growth of their tumors, with no apparent side effects, researchers found.
However, patients were told not to start to supplement with mannose because of the risk of side effects.
Scientists hope they will soon test the supplement.
Mannose, which can be bought in health food stores and is sometimes used to treat urinary tract infections, is thought to hinder the ability of tumors to use glucose to grow.
- Hospitals that fail to treat patients on time
- Early risers have a lower risk of breast cancer
Scientists also considered how mannose can affect the treatment of cancer, giving it mice treated with two of the most widely used chemotherapy drugs, cisplatin and doxorubicin.
They consider that they improve the effects of chemotherapy, slow down tumor growth and reduce their size. It also increased the life span of some mice.
In further tests, cells from other types of cancer, including leukemia, osteosarcoma (bone cancer), ovarian cancer, and intestines were exposed to mannose in the laboratory.
Some cells respond well, while others do not.
How well the cells reacted seemed to depend on the levels they had on an enzyme that disturbs the mannose.
Lead author, Professor Kevin Ryan, of Britain's Bitson Research Institute for Cancer Research, said his team discovered a dose of mannose that "can block enough glucose to slow tumor growth in mice, but not so much as they were busy normal tissues ".
Bodies seek energy from glucose, but carcinogenic tumors also use it to stimulate their growth.
"This is an early research, but we hope finding this perfect balance means that in the future mannose can be given to patients with cancer to improve chemotherapy without damaging the overall health," he said.
One advantage of malnutrition is that it is cheaper than medicines produced by pharmaceutical companies.
And prof. Ryan said he hoped that people's tests could start shortly.
However, he and other experts warn that the findings do not mean that people with cancer should begin to supplement with malnutrition.
Martin Ledwick, a British breast cancer research nurse, said: "While these results are very promising for the future of some cancer treatments, this is a very early study and has not yet been tested in humans.
"Patients do not have to prescribe mannose independently, because there is a real risk of adverse side effects that have not yet been tested.
"It's important to consult a doctor before drastically changing your diet or taking new supplements."
Professor Ryan said his team next will ask to investigate why mannose worked in some cancer cells rather than others, so that they could determine which patients could benefit most.
The research is published in the journal Nature.