A UK trial is investigating whether a curry ingredient can improve the treatment of patients with advanced bowel cancer.
Scientists will supplement standard chemotherapy with pills containing curcumin, a compound found in the yellow curry spice turmeric.
Laboratory tests have suggested that curcumin can boost the ability of chemotherapy drugs to kill bowel cancer cells.
The compound is known to have powerful anti-inflammatory properties and also acts as an antioxidant.
It has traditionally been used as an alternative remedy for a wide range of problems including liver and digestive disorders, allergies and acne.
Some studies have indicated it may slow the spread of cancer, improve the effectiveness of chemotherapy and protect healthy cells from the effects of radiotherapy.
However, hard evidence from properly conducted scientific trials is lacking.
The two-year trial, conducted by scientists from Cancer Research UK and the University of Leicester, aims to recruit about 40 patients with bowel cancer that has spread to the liver.
Patients with advanced bowel cancer are normally given a treatment called FOLFOX which combines three chemotherapy drugs.
But many - between 40% and 60% - do not respond to the therapy, and those who do may suffer side effects such as tingling and nerve pain.
Chief investigator Professor William Steward, director of the Experimental Cancer Medicine Centre (ECMC) at the University of Leicester, said: "Once bowel cancer has spread it is very difficult to treat, partly because the side effects of chemotherapy can limit how long patients can have treatment.
"The prospect that curcumin might increase the sensitivity of cancer cells to chemotherapy is exciting because it could mean giving lower doses, so patients have fewer side effects and can keep having treatment for longer.
"This research is at a very early stage but investigating the potential of plant chemicals to treat cancer is an intriguing area that we hope could provide clues to developing new drugs in the future."
The study will take place at Leicester Royal Infirmary and Leicester General Hospital.
Three-quarters of the patients will be given curcumin tablets for seven days before undergoing FOLFOX treatment. The remainder will only be treated with FOLFOX.
Colin Carroll, a 62-year-old compliance consultant who lives near Loughborough, is one of the first patients to join the trial. He agreed to take part after being diagnosed with advanced bowel cancer in January.
He said: "The diagnosis came as a big shock because I'd had no symptoms apart from some occasional cramps.
"I'd had a few tests which had come back clear and I'd just been booked for a CT (computed tomography) scan when I was rushed to hospital with a suspected intestinal blockage."
Scans revealed bowel cancer which had spread to the liver.
Three days after being admitted to Leicester Royal Infirmary, Mr Carroll underwent emergency surgery to bypass the blockage.
He added: "It's been like a whirlwind. To have something creep up on you like that when you have absolutely no control over it really makes you want to fight back.
"That's why I had no difficulty in agreeing to take part in the trial.
"I've met some amazing people since January and my treatment on the NHS has been fantastic. The way I see it is that I'm being given the best possible chance so in that sense I feel very fortunate."
Dr Joanna Reynolds, Cancer Research UK's director of centres, said: "The Experimental Cancer Medicine Centres network supports research into some of the most novel and exciting new anti-cancer therapies, often providing the first insights into their effect on cancer patients.
"By doing a clinical trial like this we will find out more about the potential benefits of taking large amounts of curcumin, as well as any possible side effects this could have for cancer patients."