Millions of Americans would like to lose weight – but for cancer patients, weight loss can decrease treatment response and tolerance, quality of life, and even survival time. Chemotherapy is infamous for side effects of nausea and vomiting. Patients may suffer severe weight loss as they lose their appetites and feel too weak to eat. Over the last few decades, medical researchers have made great progress in treating nausea, but some patients still don't feel like eating. A recent article in Nutrition Journal reports that taste disorder can be another important factor.
Chemotherapy agents kill many types of rapidly growing cells, possibly including the taste buds. In addition, drugs in the bloodstream may permeate saliva or diffuse from blood to the taste receptors. Changes in taste are commonly associated with the following chemotherapeutic drugs:
1. Cisplatin
2. Carboplatin
3. Cyclophosphamide
4. Doxorubicin
5. 5-fluorouracil
6. Methotrexate
To quantify what's happening, a research team in Mexico City performed a taste test for sweet (sucrose), bitter (urea), and savory or umami (sodium glutamate) flavors on 30 chemotherapy patients and 30 control subjects without cancer. They found that cancer patients have a higher detection threshold for sweet taste, and a higher recognition threshold for bitter. There was no difference for the sodium glutamate.
Thus, patients on chemotherapy need more sugar in foods before they can recognize a sweet taste, and have trouble distinguishing between bitter and other flavors. The Nutrition Journal article does not suggest a specific treatment, but points out the significance of taste disorder.
Cachexia is the term for severe weight loss and wasting associated with cancer, AIDS, and other major chronic diseases. The dietary supplement melatonin has been used successfully to prevent cachexia in cancer patients who have disrupted sleep patterns due to hospital treatment schedules, unusual noise and lights, and other stress. When traveling to Europe and back, I found out for myself that sleep disruption can cause loss of appetite. I don't know whether I had a true taste disorder, but food lost its appeal until I adjusted to the new time zone. Melatonin is used as an aid for normal sleep cycles.
Good nutrition is essential for successful cancer treatment. If you're on chemotherapy and nothing tastes good, talk to your doctor about maintaining your caloric intake.
References:
Sanchez-Lara K et al, “Influence of taste disorders on dietary behaviors in cancer patients under chemotherapy”, Nutrition Journal 2010; 9:15.
Nausea:
https://www.empowher.com/cancer/content/dealing-nausea-chemotherapy
Cachexia:
http://www.medterms.com/script/main/art.asp?articlekey=11065
Melatonin may prevent cachexia:
http://vrp.com/articles.aspx?ProdID=art890&zTYPE=2
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.