Umami foods can help cancer patients eat better

Think of a pizza: coming out of the oven, with juicy toppings and an irresistible smell. Mouthwatering, right? Literally. When we smell it, we already imagine the food, and our body receives a stimulus, causing the nervous system to increase saliva production, which contains enzymes responsible for digestion.

While chewing, saliva helps moisten and soften food, making it easier to swallow and, most importantly, aiding the work of taste buds, which are responsible for detecting the five basic tastes of the human palate. Taste buds can only perform their role when in contact with liquid or pasty substances.

Now, imagine how the entire eating process would be without the help of salivation. Digestion would be impaired, swallowing would be difficult, and we wouldn’t be able to appreciate tastes and flavors. Eating would no longer be pleasurable.

But what is the connection with cancer?

Unfortunately, patients undergoing certain types of cancer treatments suffer from altered saliva production – called xerostomia or “dry mouth.” Radiotherapy waves, for example, damage the tissue of the salivary glands, which consequently reduce production. Meanwhile, the drugs used during chemotherapy can cause thicker saliva, generating the side effect of dryness.

Such problems can directly affect patients’ nutrition, since they make food intake and digestion more difficult. “Studies show that saliva contributes to the healthy condition of taste buds, improving appetite and nutritional status in people,” says Priscila Santos, coordinator of Clinical Nutrition at GRAACC (Support Group for Adolescents and Children with Cancer).

In addition, it is very common for debilitated patients to have no desire to eat. But by not eating properly, they fail to strengthen an already weakened body, which can even harm treatment. This is where umami and all the “power” of the fifth taste come in.

Hellen Maluly, PhD in food science and umami specialist, explains: “to understand how we can stimulate the salivation process, you can massage the glands by running your finger along the cheek, the jaw area, right under the chin. With this stimulus, you can feel the increase in salivation. Glutamate also plays this role.”

According to Priscila Santos, some researchers speculate that the fifth taste may help with saliva secretion. “Clinical data showed that most patients with appetite loss related to ‘dry mouth’ had their symptoms relieved through the consumption of foods containing monosodium glutamate (one of the substances that provides the fifth taste). The improvement in palatability it exerts significantly contributes to greater acceptance and satisfaction in groups with nutritional needs compromised by illness and hospitalized patients. Some authors suggest the use of ‘kombucha’ (Japanese tea made with seaweed powder), which is rich in glutamate, as an alternative to reduce symptoms related to ‘dry mouth’.”

Umami and children undergoing treatment

When the patient is a child, the situation can be even more delicate: in addition to losing appetite and experiencing a sharp decrease in saliva production, there is the aggravating factor that not all children like to eat vegetables, which are necessary for good nutrition. And this is where monosodium glutamate comes in again. Here in Brazil, Dr. Ilana Elman Grinberg, nutritionist, master and PhD from the School of Public Health at USP, coordinated a study aimed at detecting the sensitivity to basic tastes in children undergoing chemotherapy and improving food intake in this population.

The study was carried out with 69 pediatric patients aged six to 15 years diagnosed with acute lymphoblastic leukemias and non-Hodgkin lymphomas undergoing chemotherapy in specialized institutions in São Paulo, from April 2008 to June 2009. In the test, specialists offered the children plain water and a solution of water with monosodium glutamate. Even without being able to identify the fifth taste, most preferred the water with glutamate.

All this work led to one conclusion: “yes, glutamate can be used to improve food acceptance by enhancing flavor. After all, using small amounts of glutamate in meal preparation is healthier than using salt, since it contains about 30% less sodium than table salt,” explains Grinberg.

In her daily work, the GRAACC coordinator explains that it is essential to consider each patient’s food preferences. However, she suggests some options for those undergoing cancer treatment. “The foods suggested for these cases are those with umami taste, such as breast milk, corn, mushrooms, tomato, cheeses, fish, shellfish, spinach, among others.”