World Cancer Day: learn how umami can help cope with taste alterations

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Dysgeusia and xerostomia can be symptoms caused by cancer treatment and can be alleviated with foods rich in the fifth taste

São Paulo, February 2023 – According to the World Health Organization (WHO)¹, one in five people worldwide is diagnosed with some type of cancer annually. On this February 4, when World Cancer Day is celebrated, many patients are undergoing treatments in search of a cure or relief of the disease’s symptoms.

Among the side effects that occur during chemotherapy or radiotherapy treatments against cancer are the symptoms of dysgeusia (loss or reduction of taste) and xerostomia (sensation of dry mouth). According to food science PhD and Umami Committee consultant, Hellen Maluly, studies with different patients show that therapies can act against cancer cells, but also affect taste and olfactory cells, altering or destroying them.

“The first reports are the loss of taste sensitivity, mainly to sweet, bitterness and metallic sensation in the mouth, in addition to the perception of dry mouth,” explains the specialist. These perceptions lead individuals to reduce food intake, which can cause nutritional changes with direct impacts on the patient’s quality of life.

HOW UMAMI CAN CONTRIBUTE

Umami is the fifth taste of the human palate, alongside sweet, salty, sour, and bitter. It is mainly characterized by the amino acid glutamate, naturally found in foods such as tomato, Parmesan cheese, corn, peas, fish, mushrooms, among others. Monosodium glutamate (MSG) is an industrially produced flavor enhancer that provides umami taste and is safe for human consumption.

Recently, research conducted in Brazil and abroad has shown that umami can help alleviate the effects of dysgeusia and xerostomia. One study² to verify sensitivity to the fifth taste included a group of 30 patients with head and neck cancer undergoing radiotherapy. For the tests, the sensitivity thresholds to basic tastes were measured during different radiation cycles. “The results showed that sensitivity to umami was more pronounced than in relation to the other four tastes,” comments Hellen.

In another study³, 52 patients undergoing radiation were evaluated over nine weeks of treatment. During the period, they showed sensitivity to umami until the third week, followed by a decrease and then improvement after the eighth week. “Here, it was suggested that there is sensitivity, but that it is limited due to the duration and intensity of the treatments,” says the Umami Committee consultant.

A study⁴ conducted by the School of Public Health at the University of São Paulo (USP) with a group of 102 children aged six to 15 years, diagnosed with ALL (Acute Lymphoblastic Leukemia) and NHL (Non-Hodgkin’s Lymphoma), detected umami taste starting from the second concentration of the solutions offered in the test in two sessions in which they participated. The study suggested that proper dietary guidance, with ingredients containing umami, could help improve nutrition and quality of life during and after treatment.

Finally, studies carried out in Japan with groups of hospitalized elderly⁵ ⁶ ⁷ ⁸ , also with taste alterations, showed a significant increase in salivation when stimulated with monosodium glutamate solutions compared to citric acid solutions. These patients started to eat better and showed improvement in their nutritional status.

“More studies are needed to verify sensitivity to the fifth taste, as well as the mechanisms that promote increased salivation and acceptance of umami-containing foods in children and adults with different types of cancer. But, from the few studies already published, it is possible to see that menu diversity, as well as the constant stimulation of taste sensations, can help patients not to lose their sense of taste, which is fundamental for improving nutritional status and quality of life during and after treatment,” suggests Dr. Hellen Maluly.

References:

• https://www.who.int/pt/news/item/03-02-2021-breast-cancer-now-most-common-form-of-cancer-who-taking-action

1. SHI H., MASUDA M, UMEZAKI T, KURATOMI Y, KUMAMOTO Y, YAMAMOTO T, KOMIYAMA S. Irradiation impairment of umami taste in patients with head and neck cancer. Auris Nasus Larynx 2004, v. 31,n. 4, p. 401-406.
2. YAMASHITA H, NAKAGAWA K, HOSOI Y, KUROKAWA A, FUKUDA Y, MATSUMOTO I, MISAKA T, ABE K. Umami taste dysfunction in patients receiving radiotherapy for head and neck cancer. Oral Oncology, 2009, v.45, n.3, p. e19-e23.
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5. HAYAKAWA, Y., KAWAY, M., TORII, K., UNEYAMA, H. The effect of umami taste on saliva secretion. JPN J Taste Smell Research, 2008, v.15, p. 367-370.
6. UNEYAMA, H.; KAWAI, M.; SEKINE-HAYAKAWA, Y.; TORII, K. Contribution of umami taste substances in human salivation during meal. The Journal of Medical Investigation, 2009, v. 56 Suppl., p. 197-204.
7. TOMOE, M.; INOUE, Y.; SANBE, A.; TOYAMA, K.; YAMAMOTO, S.; KOMATSUD, T. Clinical trial of glutamate for the improvement of nutrition and health in the eldery. Annals of the New York Academy Science, 2009, v. 1170, p. 82-6.

UMAMI
It is the fifth basic taste of the human palate, discovered in 1908 by Japanese scientist Kikunae Ikeda. It was scientifically recognized in the year 2000, when researchers at the University of Miami confirmed the existence of specific receptors for this taste on the taste buds. The amino acid glutamic acid and the nucleotides inosinate and guanylate are the main umami substances. The two main characteristics of umami are increased salivation and the continuity of taste for a few minutes after food ingestion. To learn more, visit www.portalumami.com.br.