Cutting out certain amino acids - the building blocks of animal proteins - extended the lives of mice by starving tumours.
Removing two in particular - known as serine and glycine - from the lab rodents' diets slowed the development of lymphoma and intestinal cancer.
Glasgow University researchers also found the special diet made some cancer cells more susceptible to reactive oxygen species.
Chemotherapy and radiotherapy boost levels of these chemicals in the cells - so a specially formulated vegan diet could make conventional cancer treatments more effective.
The next stage would be to set up clinical trials with patients to assess the feasibility and safety of such a treatment.
Dr Oliver Maddocks said: “Our findings suggest restricting specific amino acids through a controlled diet plan could be an additional part of treatment for some cancer patients in future, helping to make other treatments more effective.”
Amino acids are the building blocks that cells need to make proteins.
While healthy cells are able to make sufficient serine and glycine, cancer cells are much more dependent on getting these vital amino acids from the diet.
Co-author Professor Karen Vousden, Cancer Research UK's chief scientist, said: “This kind of restricted diet would be a short term measure and must be carefully controlled and monitored by doctors for safety.
“Our diet is complex and protein - the main source of all amino acids - is vital for our health and well-being.
“This means that patients cannot safely cut out these specific amino acids simply by following some form of home-made diet.”
The study published in Nature also found the diet was less effective in tumours fuelled by a faulty gene known as Kras, such as most pancreatic cancer.
This is because it boosted the ability of the cancer cells to make their own serine and glycine.
This could help to select which tumours could be best targeted by diet therapy.
Dr Emma Smith, science communication manager at Cancer Research UK, said: “This is a really interesting look at how cutting off the supply of nutrients essential to cancer cell growth and division could help restrain tumours.
“The next steps are clinical trials in people to see if giving a specialised diet that lacks these amino acids is safe and helps slow tumour growth as seen in mice.
“We'd also need to work out which patients are most likely to benefit, depending on the characteristics of their cancer.”
Three years ago a study found eating too much protein could be as dangerous as smoking for middle-aged people.
Research which tracked thousands of adults for nearly 20 years found those who ate a diet rich in animal protein were four times more likely to die of cancer than someone with a low protein diet.
The risk is nearly as high as the danger of developing cancer by smoking 20 cigarettes each day.
Post a Comment