Could chocolate predict chemotherapy side-effects?

Friday 1 August, 2014

For the first time, Australian researchers have demonstrated exactly how chemotherapy affects a cancer patient’s ability to taste.

The study, published today in science journal PLOS ONE, proves chemotherapy initially reduces a patient’s taste function, appetite and food enjoyment, but that taste function typically returns two months after treatment finishes.

The study involved 52 Victorian women being treated for breast cancer with the same types of chemotherapy. Researchers tested each patient’s ability to correctly identify salty, sour, bitter, sweet and umami tastes before, during and after chemotherapy.

They also monitored patients’ food intake, and found those who experienced greatest taste change or who lost interest in eating chocolate during chemotherapy consumed fewer kilojoules and protein, and experienced more weight loss.

Lead author Dr Anna Boltong, who is Cancer Council Victoria’s Head of Cancer and Information Support Service, said this was the first time the taste function of cancer patients had been tested more than once within a single chemotherapy cycle, and the first time patients were followed up later to assess all impacts.

“The research proved that taste per se, as opposed to other elements of flavour or related senses like smell, is adversely affected during chemotherapy but – most importantly - that taste function does return,” Dr Boltong said.

“Our findings mean we can now, with confidence, forewarn patients of taste and related side-effects during chemotherapy as well how long such symptoms are likely to last.”

The next step for researchers will be investigating how to establish a simple, predictive test to work out which patients are most likely to lose or gain weight during chemotherapy. Dr Boltong said chocolate could hold the key.

“Among patients tested we found that enjoyment of chocolate decreased significantly after chemotherapy began, and that this was associated with them consuming fewer kilojoules, protein and fat. So, a chocolate taste test could be the answer.”

The study showed symptoms (ability to identify salty, sour and umami tastes, reduced appetite and decreased food enjoyment) appeared within the first 4-6 days after chemotherapy was given, and gradually subsided until the next chemo dose (typically 2-3 weeks later). It also showed, for the first time, that taste function returns for most patients two months after chemotherapy concludes.

To access the full paper titled: “A prospective cohort study of the effects of adjuvant breast cancer chemotherapy on taste function, food liking, appetite and associated nutritional outcomes" visit