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Chemotherapy can affect patients' ability to smell and taste food, in addition to making them feel sick. Many patients don’t want to eat when they feel like this, and if they can’t taste the food, the incentive isn’t there. This can lead to weight loss, decreased quality of life and decreased chance of survival. Because of this, doctors are looking at ways that patients can maintain a good diet during and after chemotherapy treatment.

Researchers in Canada studied a small group of 21 patients with advanced cancer (except brain cancer) between May 2006-December 2008. The patients had all been eating less for at least two weeks and all were having chemotherapy or had it in the past.

The patients were separated into two groups, and one group was given a placebo capsule, or ‘sham’ medication and the other group was given capsules containing delta-9-tetrahydrocannabinol (THC) – the main active ingredient in cannabis. They took the capsules once a day for three days and twice a day after that for 18 days.

Patients were given questionnaires to fill out before, during and after the treatment. From the results of the questionnaires, the researchers found that the majority of patients taking THC reported increased appreciation of food (73%) compared with placebo patients, and that more said the medication "made the food taste better" (55%), compared with only 10% of the placebo group.

64% of the THC patients had increased appetite, whereas half of the placebo patients had decreased appetite or no change. The THC patients also had improved taste and they reported better quality of sleep and relaxation than the placebo group.

Dr. Wendy Wismer, Ph.D., leader of the study and associate professor at the University of Alberta, said that this was the first randomized controlled trial to show that THC makes food taste better and improves appetites for patients with advanced cancer, as well as helping them to sleep and to relax better. Wismer feels that the findings are important, as there is no accepted treatment for chemosensory alterations experienced by cancer patients, and she is excited about the possibilities that THC could be used to improve patients’ enjoyment of food.

“Decreased appetite and chemosensory alterations can be caused by both cancer and its treatment; untreated tumors cause loss of appetite, and by itself, chemotherapy also causes loss of appetite. In any individual patient, some part of both of these effects is usually present," Wismer said.

“It’s very important to address these problems as both appetite loss and alterations to taste and smell lead to involuntary weight loss and reduce an individual’s ability to tolerate treatment and to stay healthy in general. Additionally, the social enjoyment of eating is greatly reduced and quality of life is affected. For a long time everyone has thought that nothing could be done about this. Indeed, cancer patients are often told to ‘cope’ with chemosensory problems by eating bland, cold and odorless food. This may well have the result of reducing food intake and food enjoyment.”

Further, larger studies are planned to confirm their findings. Wismer believes that doctors should contemplate using THC treatment for their cancer patients, whatever their stage of cancer is.

Sources:

Delta-9-tetrahydrocannabinol may palliate altered chemosensory perception in cancer patients: "results of a randomized, double-blind, placebo-controlled pilot trial”. Annals of Oncology. doi:10.1093/annonc/mdq727

http://www.sciencenewsline.com/medicine/2011022212000022.html

Joanna is a freelance health writer for The Mother magazine and Suite 101 with a column on infertility, http://infertility.suite101.com/. She is author of the book, 'Breast Milk: A Natural Immunisation,' and co-author of an educational resource on disabled parenting, in addition to running a charity for people damaged by vaccines or medical mistakes.