SCOTS scientists have discovered that cutting out certain acids from the diet of mice can slow tumour growth and prolong survival, a development that could lead to clinical trials with cancer patients.

Researchers at Glasgow’s Cancer Research UK Beatson Institute and the University of Glasgow removed serine and glycine, two non-essential amino acids – the building blocks of proteins – from the animals’ diets and found it slowed the development of lymphoma and intestinal cancer.

They also found that the special diet made some cancer cells more susceptible to chemicals in cells called reactive oxygen species.

Chemotherapy and radiotherapy boost the levels of these chemicals in the cells, so this research suggests that a specially formulated diet could make conventional cancer treatments more effective.

The research, published in the journal Nature, suggests next stage would be to set up clinical trials with cancer patients to assess the feasibility and safety of such a treatment. Dr Oliver Maddocks, a Cancer Research UK scientist at the University of Glasgow, said: “Our findings suggest that 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.”

Professor Karen Vousden, Cancer Research UK’s chief scientist and co-author of the study 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.”

Amino acids are the building blocks that cells need to make proteins. While healthy cells are able to make sufficient quantities of serine and glycine, cancer cells are much more dependent on getting these vital acids from the diet.

However, the study also found that the diet was less effective in tumours with an activated Kras gene, such as most pancreatic cancers, because the faulty gene 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, Cancer Research UK’s science communication manager, added: “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.”

The charity spent more than £33 million in Scotland last year on some of the UK’s leading scientific and clinical research.

Every day, 88 people in Scotland are diagnosed with cancer and two in four people manage to survive it for at least 10 years.

Cancer Research UK – which has been at the heart of the progress that has seen survival rates double in the last 40 years – wants to accelerate progress so that by 2034, three in four people will survive their cancer for at least a decade.