Sugar supplement could be used to fight cancer, research suggests

A sugary nutritional supplement used to combat cystitis has anti-cancer properties that could soon be tested in patients.

New research suggests that mannose can slow the growth of multiple cancers.

In laboratory tests it was also found to boost the effectiveness of chemotherapy cancer drugs.

Mannose, a type of sugar found in cranberries and other fruits, is widely available as an alternative treatment for cystitis and urinary tract infections.

It is thought to suppress cancer by interfering with the ability of tumours to take up glucose.

However, the studies so far suggest that it works for some cancers and not for others.

When mice with pancreatic, lung or skin cancer were given mannose in their drinking water, the growth of their tumours slowed significantly with no obvious side effects.

Professor Kevin Ryan, from the Cancer Research UK Beatson Institute in Glasgow, who led the research, said: “Tumours need a lot of glucose to grow, so limiting the amount they can use should slow cancer progression.

“The problem is that normal tissues need glucose as well, so we can’t completely remove it from the body.

“In our study, we found a dosage of mannose that could block enough glucose to slow tumour growth in mice, but not so much that normal tissues were affected.

“This is early research, but it is hoped that finding this perfect balance means that, in the future, mannose could be given to cancer patients to enhance chemotherapy without damaging their overall health.”

To see how mannose might affect cancer treatment, mice were treated with two of the most widely used chemotherapy drugs, cisplatin and doxorubicin.

Prof Ryan’s team found that the nutrient enhanced the effects of chemotherapy, slowing the growth of tumours and reducing their size. It also increased the lifespan of some mice.

In further tests cells from other types of cancer including leukaemia, osteosarcoma (bone cancer), ovarian and bowel cancer were exposed to mannose in the laboratory.

Some cells responded well, while others did not. The anti-cancer potential of mannose appeared to depend on whether an enzyme that breaks down the sugar was present in cells.

The research is reported in the latest issue of the journal Nature.

Prof Ryan added: “Our next step is investigating why treatment only works in some cells, so that we can work out which patients might benefit the most from this approach.

“We hope to start clinical trials with mannose in people as soon as possible to determine its true potential as a new cancer therapy.”

Cancer Research UK’s head nurse Martin Ledwick warned cancer patients not to leap ahead and treat themselves with mannose.

He said: “Although these results are very promising for the future of some cancer treatments, this is very early research and has not yet been tested in humans.

“Patients should not self-prescribe mannose as there is a real risk of negative side effects that haven’t been tested for yet.

“It’s important to consult with a doctor before drastically changing your diet or taking new supplements.”

Dr George Poulogiannis, from The Institute of Cancer Research, London, said: “This study highlights how interfering with key characteristics of tumour metabolism can help identify cancer’s Achilles heels, and could lead to more effective therapeutic strategies.

“However, there is a lot of work to do before this research can be translated into the clinic – including clinical trials to test whether the treatment is safe and can slow tumour growth in cancer patients.”