Can diet help cancer treatment?

Diet is already a key part of managing diseases like diabetes and hypertension, but new research adds to a growing body of evidence that it could help cancer treatment too.

The study, published last week in the journal Nature, found restricting intake of an amino acid found in red meat and eggs significantly enhanced cancer treatment in mice, slowing tumour growth.

“These are very strong effects, and they are effects that are as strong as we would see with drugs that work,” said lead researcher Jason Locasale, an associate professor at Duke University’s School of Medicine.

“What this study is showing is that there are many situations where a drug by itself doesn’t work, but if you combine the drug with the diet, it works. Or the radiation therapy doesn’t work well, but if you combine … with the diet, it works well,” he said.

The study focused on restricting intake of the amino acid methionine, which is key to a process called one-carbon metabolism that helps cancer cells grow.

Methionine restriction has already been associated with both anti-ageing and weight loss, but its importance to cancerous cells suggested it could also be a promising way to enhance cancer treatment.

The researchers first tested methionine restriction in healthy mice to confirm it was having the desired effects on metabolism and then moved to testing it in mice with colorectal cancer and soft tissue tumours known as sarcomas.

They found that a low dose of chemotherapy, which on its own had no effect on colorectal cancer, led to “marked inhibition of tumour growth” when combined with methionine restriction. Similarly, combining methionine restriction with radiation therapy in the case of the soft tissue sarcoma reduced tumour growth.

“You’re starving the cancer cells of certain nutrients, at a very basic level,” explained Locasale.