The scapegoat effect on food aversions after chemotherapy

D2 Receptors and Sodium Ion Channel Blockades of the Basolateral Amygdala Attenuate Lithium Chloride-Induced Conditioned Taste Aversion Applying to Cancer Chemotherapy Nausea and Vomiting

Cancer patients regularly suffer from the behavioral symptoms of chemotherapy-induced nausea and vomiting. Particularly, it is involved in Pavlovian conditioning. Lithium chloride (LiCl) was used as the unconditioned stimulus (US) and contingent with the tastant, for example, a saccharin solution (i.e., the conditioned stimulus; CS), resulted in conditioned taste aversion (CTA) to the CS intake. The present study employed an animal model of LiCl-induced CTA to imitate chemotherapy-induced nausea and vomiting symptoms. Recently, the basolateral amygdala (BLA) was shown to mediate LiCl-induced CTA learning; however, which brain mechanisms of the BLA regulate CTA by LiCl remain unknown. The present study was designed to test this issue, and 4% lidocaine or D2 blocker haloperidol were microinjected into BLA between the 0.1% saccharin solution intake and 0.15M LiCl. The results showed lidocaine microinjections into the BLA could attenuate the LiCl-induced CTA. Microinjections of haloperidol blunted the CTA learning by LiCl. Altogether, BLA via the sodium chloride ion channel and D2 receptors control LiCl-induced conditioned saccharin solution intake suppression. The findings can provide some implications and contributions to cancer chemotherapy-induced nausea and vomiting side effects, and will help to develop novel strategies to prevent the side effects of cancer chemotherapy.

Food Aversion during Cancer Treatment: A Systematic Review

Individuals with cancer often present food aversion after initiation of anti-tumor treatment, which may impair nutritional status. We aim to assess the prevalence and factors associated with food aversion during cancer treatment. Articles from three databases were searched: MEDLINE, EMBASE and Cochrane Library. English was used, with no restriction on the year of publication. Inclusion criteria were original articles that evaluated food aversion in adults and the elderly undergoing chemotherapy and/or radiotherapy treatment. Fifteen articles were included. A high prevalence of food aversion (21-62%) was observed, with meat considered the most aversive food. The aversion is usually transient and may be due to gastrointestinal problems, such as nausea and vomiting, caused by chemotherapy or radiotherapy treatment, and even psychological and emotional issues. Offering a new food before the beginning of treatment seems to be an effective strategy to reduce aversion, combined with nutritional and psychological monitoring. Cancer patients have a high prevalence of food aversion. Multidisciplinary care can minimize the consequences of cancer treatment.

Changes in taste among pediatric patients with cancer and hematopoietic stem cell transplantation recipients

PURPOSE

Changes in taste is a common bothersome symptom in children receiving cancer treatments. However, little is known about how pediatric cancer patients experience this symptom. The objective was to describe how children receiving cancer treatments experience taste alterations and the approaches they use to address the issue.

METHODS

In this qualitative study, we included English-speaking children 4-18 years of age with cancer or hematopoietic stem cell transplantation recipients who were actively receiving cancer treatment or who had completed therapy. Using a semi-structured questionnaire, we asked questions about the experience of altered taste sensation. We asked about its characteristics, impacts and identified coping strategies.

RESULTS

We included 50 children. Children experienced changes in taste in a heterogeneous fashion although commonly described food as tasting "different", "not right" or "funny". While change in food preferences due to taste alterations was common, specific choices varied. Many found changes started with treatment initiation or mid-way through treatment, and some found that symptoms persisted up to 9 months following treatment completion. Actions taken to address taste changes were sucking on candy, brushing teeth and modifying food choices.

CONCLUSIONS

The experience of changes in taste was common yet highly variable in its presentation and resultant changes in food preferences. Taste changes did not always resolve soon after treatment completion. Future research should identify ways to manage this symptom in pediatric cancer patients.

The CS-Preexposure Effect in Conditioned Taste-Aversion Learning in Golden Hamsters

In Experiment 1, golden hamsters were injected with either 0.9% saline or the nausea-inducing agent, lithium chloride (LiCL), immediately after consuming a flavored diet that was either novel or familiar. The LiCl-induced aversion was strong in hamsters for which the flavored diet was novel, but no significant aversion was observed in hamsters that were familiar with the flavored diet. In Experiment 2, the strength of the LiCl-induced aversion was related inversely to the amount of conditioned-stimulus (CS) preexposure and directly to the duration of the preexposure-conditioning interval. Thus, although some previous researchers have suggested that hamsters may not demonstrate the CS-preexposure effect in a conditioned taste-aversion paradigm, they clearly did so under the conditions of the present experiments, and moreover, the characteristics of the CS-preexposure effect in hamsters were generally similar to those observed in rats.

Development of food preferences

Using a developmental systems perspective, this review focuses on how genetic predispositions interact with aspects of the eating environment to produce phenotypic food preferences. Predispositions include the unlearned, reflexive reactions to basic tastes: the preference for sweet and salty tastes, and the rejection of sour and bitter tastes. Other predispositions are (a) the neophobic reaction to new foods and (b) the ability to learn food preferences based on associations with the contexts and consequences of eating various foods. Whether genetic predispositions are manifested in food preferences that foster healthy diets depends on the eating environment, including food availability and child-feeding practices of the adults. Unfortunately, in the United States today, the ready availability of energy-dense foods, high in sugar, fat, and salt, provides an eating environment that fosters food preferences inconsistent with dietary guidelines, which can promote excess weight gain and obesity.

Role of nausea in the development of aversions to a beverage paired with chemotherapy treatment in cancer patients

Previous experimental research has demonstrated that patients can develop conditioned aversions to foods and beverages after a single pairing with chemotherapy administration for cancer. The present study used a prospective longitudinal design to examine the role of posttreatment nausea in the development of learned food aversions in these patients. Chemotherapy patients sampled a distinctive beverage immediately prior to their first and second chemotherapy infusions. We assessed nausea, and other chemotherapy side effects, for the 24-h period following chemotherapy administration. Food aversion, at the second infusion, was assessed in terms of behavior (decreased consumption) and affect (decreased hedonic rating). Consistent with previous research, patients showed both decreased consumption and decreased hedonic rating after a single chemotherapy infusion. Nausea was found to be related to decreases in hedonic rating, but not to decreases in consumption. No other treatment side effects predicted either decreased consumption or hedonic rating. These results are consistent with the hypothesis that there is a special link between nausea and changes in affective response to food items. These results also highlight the unique opportunities for studying food aversion formation in the oncology setting.

Prevention of food aversions in cancer patients during treatment

Food aversions are a common complication of cancer treatment. This study evaluated an approach for blocking the formation of aversions to dietary items in 209 cancer patients treated with chemo- and/or radiotherapy. Patients were exposed to a sensory stimulus (fruit beverage, halava, odor) before initial treatments to provide a target for aversion formation, thereby sparing dietary items. Patients who developed an aversion to the "scapegoat" stimulus experienced a statistically significant 30% reduction in dietary aversion formation relative to patients without a scapegoat aversion or those not exposed to the scapegoat. The most effective scapegoat was the beverage, probably because it was consumed in greatest quantity. Exposure of patients to a "scapegoat" food or beverage just before chemo- and, probably, radiotherapy can markedly reduce the incidence of treatment-related aversions to foods in the patients' customary diet.

Formation of food aversions in cancer patients receiving repeated infusions of chemotherapy

Patients receiving emetogenic chemotherapy for cancer have been found to develop aversions to normal dietary items consumed in close temporal relation to treatment administrations. These aversions are presumed to develop via conditioning processes as demonstrated in experimental studies of food aversion learning. The present study used a prospective, longitudinal design to evaluate the possible role of conditioning in the formation of aversions to normal dietary items in women receiving adjuvant chemotherapy for breast cancer. Patients were monitored for the development of aversions to foods and beverages consumed in the 24 hr periods before and after each of eight consecutive chemotherapy infusions beginning with the initial infusion. Data on the prevalence, course, and prediction of aversions to normal dietary items are reported. These results pointed to similarities and differences between aversions formed to normal dietary items during chemotherapy treatment and aversions formed to taste stimuli during experimental conditioning studies. In addition to their theoretical significance, results also suggest possible strategies for preventing the clinical problem of aversions to normal dietary items in chemotherapy patients.

Clinical implications of learned food aversions in patients with cancer treated with chemotherapy or radiation therapy

BACKGROUND

The nutritional implications of learned food aversions were evaluated in patients with newly diagnosed cancer receiving either chemotherapy (n = 53) or radiation therapy (n = 49).

METHODS

Aversion incidence was determined by questionnaires and a food challenge. Measures of dietary and nutritional status included ratings of appetite and chemosensory function; reported shifts of food selection and measured body weight; lymphocyte count; hematocrit; and plasma albumin, transferrin, and hemoglobin levels. Quality of life was assessed by self-ratings of mood and well-being.

RESULTS

Subsequent to the initiation of treatments, aversions formed in 56% and 62% of patients receiving chemotherapy and radiation therapy, respectively. The aversions were specific (two to four items per afflicted patient) and transient (mean duration, 0.25-2 months). All types of foods and beverages were targeted. No significant association was observed between food aversion incidence and any measure of dietary complications, nutritional status, or quality of life.

CONCLUSIONS

Although food aversions are a common sequela of chemotherapy and radiation therapy, they generally have limited clinical significance.