Combining medicines with the right food could improve the effectiveness of drugs and reduce the costs of treating patients, experts say.
Taking a breast cancer drug with food boosted its absorption
The comments come after research showed taking a breast cancer drug with fatty food, rather than on an empty stomach, boosted absorption of the drug.
This means patients could take lower doses, which would reduce costs.
The comments were made by oncologists from the University of Chicago in a Journal of Clinical Oncology editorial.
Previously experts have warned of the potential dangers of interactions between food and drugs - they could lead to drugs becoming toxic, or less effective.
But professors Mark Ratain and Ezra Cohen said recent findings about the interactions between foods and anti-cancer drugs could be exploited to help decrease costs and increase the benefits from such drugs.
Researchers have found that taking the breast cancer drug lapatinib (TYKERB) with food, rather than on an empty stomach as suggested on the label, increased the availability of the drug in the body by 167%, meaning the drug could work more effectively.
And taking it with a meal rich in fat boosted levels by 325%.
Grapefruit is known to boost absorption of certain drugs
Professor Ratain said: "Simply by changing the timing, taking this medication with a meal instead of on an empty stomach, we could potentially use 40% of the drug."
He said drinking grapefruit juice, which is known to increase the rate at which some drugs enter the blood stream, at the same time could increase these savings even further.
And eating such "value meals" at the same time as taking drugs could have other benefits too.
For example, a major toxicity associated with lapatinib is diarrhoea, which is thought to be caused by unabsorbed drug, so taking lower doses with food to boost its absorption should help reduce this side-effects.
But the authors warned patients against trying their own experiments, calling instead for more research to assess the effects of drug-combinations on patients.
They are currently conducting such a study of their own, testing effect of combining a drug with grapefruit juice, and have called for more such studies to be carried out.
Professor Cohen said: "If we understood the relationship between, say, grapefruit juice and common drugs, such as the statins, which are taken daily by millions of people to prevent heart disease, we could save a fortune in drug costs," Cohen said.
Dr Joanne Lunn, a nutrition scientist at the British Nutrition Foundation, agreed that more research was needed, because diet and prescription drugs can interfere with each other in many ways.
She said: "More research is vital to help us to understand exactly how drugs interact with our diet so we can ensure that the drugs work effectively, but also that by taking the drugs we do not compromise our nutritional status.
"In the meantime, it is always very important to read the label on any medication and to speak to your GP if there is anything you are unsure about."
A spokesperson for the Medicines and Healthcare Products Regulatory Agency, said any new recommendations about drug dosages would need to be backed up by evidence and full testing through clinical trials.