Subjective-Physiological Coherence during Food Consumption in Older Adults.

BACKGROUND: Subjective-physiological emotional coherence is thought to be associated with enhanced well-being, and a relationship between subjective-physiological emotional coherence and superior nutritional status has been suggested in older populations. However, no study has examined subjective-physiological emotional coherence among older adults while tasting food. Accordingly, the present study compared subjective-physiological emotional coherence during food consumption among older and younger adults. METHODS: Participants consumed bite-sized gel-type foods with different flavors and provided their subjective ratings of the foods while their physiological responses (facial electromyography (EMG) of the corrugator supercilia, masseter, and suprahyoid, and other autonomic nervous system signals) were simultaneously measured. RESULTS: Our primary findings were that (1) the ratings of liking, wanting, and valence were negatively correlated with corrugator EMG activity in older and young adult participants; (2) the positive association between masseter EMG activity and ratings of wanting/valence was weaker in the older than in the young adult group; and (3) arousal ratings were negatively correlated with corrugator EMG activity in the older group only. CONCLUSIONS: These results demonstrate commonalities and differences in subjective-physiological emotional coherence during food intake between older and young adults.

Brow and Masticatory Muscle Activity Senses Subjective Hedonic Experiences during Food Consumption.

Sensing subjective hedonic or emotional experiences during eating using physiological activity is practically and theoretically important. A recent psychophysiological study has reported that facial electromyography (EMG) measured from the corrugator supercilii muscles was negatively associated with hedonic ratings, including liking, wanting, and valence, during the consumption of solid foods. However, the study protocol prevented participants from natural mastication (crushing of food between the teeth) during physiological data acquisition, which could hide associations between hedonic experiences and masticatory muscle activity during natural eating. We investigated this issue by assessing participants' subjective ratings (liking, wanting, valence, and arousal) and recording physiological measures, including EMG of the corrugator supercilii, zygomatic major, masseter, and suprahyoid muscles while they consumed gel-type solid foods (water-based gellan gum jellies) of diverse flavors. Ratings of liking, wanting, and valence were negatively correlated with corrugator supercilii EMG and positively correlated with masseter and suprahyoid EMG. These findings imply that subjective hedonic experiences during food consumption can be sensed using EMG signals from the brow and masticatory muscles.

Pairing of white wine made with shade-grown grapes and Japanese cuisine.

This study investigated the effect of pairing of wine vinified from shade-grown grapes before onset of ripening on the palatability of sashimi, a typical Japanese cuisine. GC-MS analyses of volatile chemicals revealed that shading reduced phenolic compounds and terpenoids, and added fatty acid ethyl esters which are also known to contribute to the flavor of Japanese sake. When the pairing of sashimi with wine was evaluated by individuals who regularly drink Japanese sake during meals, shade wine was more highly rated than wine made from normally-grown grapes.

Facial EMG Activity Is Associated with Hedonic Experiences but not Nutritional Values While Viewing Food Images.

The physiological correlates of hedonic/emotional experiences to visual food stimuli are of theoretical and practical interest. Previous psychophysiological studies have shown that facial electromyography (EMG) signals were related to subjective hedonic ratings in response to food images. However, because other data showed positive correlations between hedonic ratings and objective nutritional values of food, whether the facial EMG reactions to food images could reflect the hedonic evaluation or nutritional assessment of food remains unknown. To address this issue, we measured subjective hedonic ratings (liking, wanting, valence, and arousal) and physiological signals (facial EMG of the corrugator supercilii, zygomatic major, masseter, and suprahyoid muscles, skin potential responses, and heart rates) while participants observed food images that had objective nutritional information (caloric, carbohydrate, fat, and protein contents). The results revealed that zygomatic major EMG activity was positively correlated with ratings of liking, wanting, and valence, but not with any objective nutritional value. These data indicate that facial EMG signals in response to food images reflect subjective hedonic experiences, but not objective nutritional values, associated with the food item.

Image database of Japanese food samples with nutrition information.

BACKGROUND: Visual processing of food plays an important role in controlling eating behaviors. Several studies have developed image databases of food to investigate visual food processing. However, few databases include non-Western foods and objective nutrition information on the foods. METHODS: We developed an image database of Japanese food samples that has detailed nutrition information, including calorie, carbohydrate, fat and protein contents. To validate the database, we presented the images, together with Western food images selected from an existing database and had Japanese participants rate their affective (valence, arousal, liking and wanting) and cognitive (naturalness, recognizability and familiarity) appraisals and estimates of nutrition. RESULTS: The results showed that all affective and cognitive appraisals (except arousal) of the Japanese food images were higher than those of Western food. Correlational analyses found positive associations between the objective nutrition information and subjective estimates of the nutrition information, and between the objective calorie/fat content and affective appraisals. CONCLUSIONS: These data suggest that by using our image database, researchers can investigate the visual processing of Japanese food and the relationships between objective nutrition information and the psychological/neural processing of food.

Facial EMG Correlates of Subjective Hedonic Responses During Food Consumption.

An exploration of physiological correlates of subjective hedonic responses while eating food has practical and theoretical significance. Previous psychophysiological studies have suggested that some physiological measures, including facial electromyography (EMG), may correspond to hedonic responses while viewing food images or drinking liquids. However, whether consuming solid food could produce such subjective-physiological concordance remains untested. To investigate this issue, we assessed participants' subjective ratings of liking, wanting, valence, and arousal while they consumed gel-type food stimuli of various flavors and textures. We additionally measured their physiological signals, including facial EMG from the corrugator supercilii. The results showed that liking, wanting, and valence ratings were negatively correlated with corrugator supercilii EMG activity. Only the liking rating maintained a negative association with corrugator supercilii activity when the other ratings were partialed out. These data suggest that the subjective hedonic experience, specifically the liking state, during food consumption can be objectively assessed using facial EMG signals and may be influenced by such somatic signals.

Hunger promotes the detection of high-fat food.

Efficient detection of food is important for an organism's survival. The results of previous experimental studies are consistent with this statement: food is detected in photographs faster than non-food items. Moreover, fat content modulates the speed of food detection. However, it is not known whether such sensitivity to the fat content of food is modulated by participants' internal states. To investigate these issues, we measured reaction times during a visual search task in which participants in fasting and postprandial states detected high-fat food (fast food), low-fat food (Japanese diet), and non-food (kitchen utensils) targets within crowds of non-food distractors (cars). Our results indicate that both hungry and satiated groups detected food targets more rapidly than non-food targets. The high-fat foods were detected more rapidly than low-fat foods in the hungry group, whereas no difference was observed between reaction times when satiated participants detected high-fat and low-fat food targets. These results suggest that food captures our visual attention even when we are satiated, and that fat detection efficiency is heightened when we are hungry.

Amygdala activation during unconscious visual processing of food.

Hedonic or emotional responses to food have important positive and negative effects on human life. Behavioral studies have shown that hedonic responses to food images are elicited rapidly, even in the absence of conscious awareness of food. Although a number of previous neuroimaging studies investigated neural activity during conscious processing of food images, the neural mechanisms underlying unconscious food processing remain unknown. To investigate this issue, we measured neural activity using functional magnetic resonance imaging while participants viewed food and mosaic images presented subliminally and supraliminally. Conjunction analyses revealed that the bilateral amygdala was more strongly activated in response to food images than to mosaic images under both subliminal and supraliminal conditions. Interaction analyses revealed that the broad bilateral posterior regions, peaking at the posterior fusiform gyrus, were particularly active when participants viewed food versus mosaic images under the supraliminal compared with the subliminal condition. Dynamic causal modeling analyses supported the model in which the subcortical visual pathway from the pulvinar to the amygdala was modulated by food under the subliminal condition; in contrast, the model in which both subcortical and cortical (connecting the primary visual cortex, fusiform gyrus, and the amygdala) visual pathways were modulated by food received the most support under the supraliminal condition. These results suggest the possibility that unconscious hedonic responses to food may exert an effect through amygdala activation via the subcortical visual pathway.

Chronic high corticosterone with voluntary corn oil ingestion induces significant body weight gain in mice.

Corticosterone (CORT) is a powerful regulator of energy metabolism, and chronically high CORT levels cause obesity and diabetes in mice. It is reported that a chronically high CORT level changes food preference, increasing the intake of comfort foods such as fatty foods. Previously, we demonstrated that unlike a high fat diet, voluntary ingestion of 100% pure corn oil increased energy expenditure and thermogenesis through the activation of the interscapular brown adipose tissue (IBAT). In the present study, we investigated whether chronically high CORT affected corn oil intake, energy expenditure, and body weight gain. We delivered CORT to mice via water bottles and placed corn oil in a separate drinking bottle in the home cage. Voluntary corn oil ingestion with CORT induced significant body weight gain, while corn oil ingestion or CORT alone had a modest effect. CORT increased corn oil intake without reducing chow intake, which further increased the total daily caloric intake. CORT suppressed mRNA related to thermogenesis in IBAT. In the hypothalamus, CORT upregulated mRNA expression of the orexigenic neuropeptide, agouti-related protein. These data suggest that chronically high CORT might increase the desire to consume dietary fat, suppressing BAT function, thereby causing obesity.

Evaluating the palatability of fermented foods.

The present review deal with the novel studies which present possibility of generating a novel sensory evaluation instrument for describing comprehensive food palatability. These studies suggest the palatability can be dissected into its componential subdomains and the subdomains in turn reconstitute comprehensive palatability with evaluation of the quantitative contribution of each subdomain. The studies suggest the novel instrument is useful for comprehensive evaluation of palatability of multifarious fermented foods.

Voluntary Corn Oil Ingestion Increases Energy Expenditure and Interscapular UCP1 Expression Through the Sympathetic Nerve in C57BL/6 Mice.

SCOPE: Previously, it has been found that corn oil ingestion activates both the gustatory system and brain reward system, stimulating motivation for eating. In the present study, the effect of voluntary corn oil ingestion on body weight gain and energy metabolism in mice is investigated. METHODS AND RESULTS: Voluntary corn oil ingestion with normal chow feeding does not lead to higher body weight than that of only the chow-fed control group. Mice that ingested corn oil have a higher total caloric intake and energy expenditure than did mice in the control group. Further, voluntary corn oil ingestion significantly upregulates Ucp1 mRNA and protein in interscapular brown adipose tissue (IBAT). Finally, the sympathetic nerve connected to IBAT was surgically transacted, then the body weight is measured for 8 weeks. IBAT sympathetic nerve transection surgery does not affect the body weight gain and food intake; however, when mice ingested corn oil, it induces significant body weight gain without changing the total caloric intake. IBAT sympathetic nerve transection surgery significantly suppresses UCP1 upregulation by corn oil ingestion. CONCLUSION: The present data suggest that corn oil ingestion activates IBAT through the sympathetic nerve, upregulating UCP1 expression and increasing energy expenditure.

Alterations in energy substrate metabolism in mice with different degrees of sepsis.

BACKGROUND: Nutritional management is crucial during the acute phase of severe illnesses. However, the appropriate nutritional requirements for patients with sepsis are poorly understood. We investigated alterations in carbohydrate, fat, and protein metabolism in mice with different degrees of sepsis. MATERIALS AND METHODS: C57BL/6 mice were divided into three groups: control mice group, administered with saline, and low- and high-dose lipopolysaccharide (LPS) groups, intraperitoneally administered with 1 and 5 mg of LPS/kg, respectively. Rectal temperature, food intake, body weight, and spontaneous motor activity were measured. Indirect calorimetry was performed using a respiratory gas analysis for 120 h, after which carbohydrate oxidation and fatty acid oxidation were calculated. Urinary nitrogen excretion was measured to evaluate protein metabolism. The substrate utilization ratio was recalculated. Plasma and liver carbohydrate and lipid levels were evaluated at 24, 72, and 120 h after LPS administration. RESULTS: Biological reactions decreased significantly in the low- and high-LPS groups. Fatty acid oxidation and protein oxidation increased significantly 24 h after LPS administration, whereas carbohydrate oxidation decreased significantly. Energy substrate metabolism changed from glucose to predominantly lipid metabolism depending on the degree of sepsis, and protein metabolism was low. Plasma lipid levels decreased, whereas liver lipid levels increased at 24 h, suggesting that lipids were transported to the liver as the energy source. CONCLUSIONS: Our findings revealed that energy substrate metabolism changed depending on the degree of sepsis. Therefore, in nutritional management, such metabolic alterations must be considered, and further studies on the optimum nutritional intervention during severe sepsis are necessary.

Allyl isothiocyanate increases carbohydrate oxidation through enhancing insulin secretion by TRPV1.

The transient receptor potential (TRP) V1 is a cation channel belonging to the TRP channel family and it has been reported to be involved in energy metabolism, especially glucose metabolism. While, we have previously shown that intragastric administration of allyl isothiocyanate (AITC) enhanced glucose metabolism via TRPV1, the underlying mechanism has not been elucidated. In this study, we examined the relationship between insulin secretion and the increase in carbohydrate oxidation due to AITC. Intragastric administration of AITC elevated blood insulin levels in mice and AITC directly enhanced insulin secretion from isolated islets. These observations were not reproduced in TRPV1 knockout mice. Furthermore, AITC did not increase carbohydrate oxidation in streptozotocin-treated mice. These results suggest that intragastric administration of AITC could induce insulin secretion from islets via TRPV1 and that enhancement of insulin secretion was related to the increased carbohydrate oxidation due to AITC.

Homeostatic modulation on unconscious hedonic responses to food.

OBJECTIVE: Hedonic/affective responses to food play a critical role in eating behavior. Previous behavioral studies have shown that hedonic responses to food are elicited consciously and unconsciously. Although the studies also showed that hunger and satiation have a modulatory effect on conscious hedonic responses to food, the effect of these homeostatic states on unconscious hedonic responses to food remains unknown. RESULTS: We investigated unconscious hedonic responses to food in hungry and satiated participants using the subliminal affective priming paradigm. Food images or corresponding mosaic images were presented in the left or right peripheral visual field during 33 ms. Then photographs of target faces with emotionally neutral expressions were presented, and the participants evaluated their preference for the faces. Additionally, daily eating behaviors were assessed using questionnaires. Preference for the target faces was increased by food images relative to the mosaics in the hungry, but not the satiated, state. The difference in preference ratings between the food and mosaic conditions was positively correlated with the tendency for external eating in the hungry, but not the satiated, group. Our findings suggest that homeostatic states modulate unconscious hedonic responses to food and that this phenomenon is related to daily eating behaviors.

Fat Content Modulates Rapid Detection of Food: A Visual Search Study Using Fast Food and Japanese Diet.

Rapid detection of food is crucial for the survival of organisms. However, previous visual search studies have reported discrepant results regarding the detection speeds for food vs. non-food items; some experiments showed faster detection of food than non-food, whereas others reported null findings concerning any speed advantage for the detection of food vs. non-food. Moreover, although some previous studies showed that fat content can affect visual attention for food, the effect of fat content on the detection of food remains unclear. To investigate these issues, we measured reaction times (RTs) during a visual search task in which participants with normal weight detected high-fat food (i.e., fast food), low-fat food (i.e., Japanese diet), and non-food (i.e., kitchen utensils) targets within crowds of non-food distractors (i.e., cars). Results showed that RTs for food targets were shorter than those for non-food targets. Moreover, the RTs for high-fat food were shorter than those for low-fat food. These results suggest that food is more rapidly detected than non-food within the environment and that a higher fat content in food facilitates rapid detection.

The contribution of aromatic components in Katsuobushi to preference formation and reinforcement effect.

Katsuodashi, a dried bonito broth, is very basic and indispensable in Japanese cuisine and contains taste-exhibiting components and unique aroma. We previously reported that its unique aroma contributes to the preference and reinforcement effect associated with dried bonito. This study aims to elucidate the contribution of aromatic components in Katsuobushi to preference formation and reinforcement effect. Volatile components obtained from dried bonito were fractionated and the fractions were subjected to two-bottle choice test. The fractionation test suggested that the component responsible for the preference is not one but comprises multiple components. In the GC-MS analysis/reconstruction test, solution with aromatic flavor narrowed down to 125 compounds had preference, and also had reinforcement effect. Moreover, GC-MS-olfactometry analysis narrowed down the candidate components to 28 out of 125. Mice showed preference for the test solution with aromatic flavor reconstructed with 28 components but did not show reinforcement behavior.

Evaluation of the comprehensive palatability of Japanese sake paired with dishes by multiple regression analysis based on subdomains.

Many factors contribute to palatability. In order to evaluate the palatability of Japanese alcohol sake paired with certain dishes by integrating multiple factors, here we applied an evaluation method previously reported for palatability of cheese by multiple regression analysis based on 3 subdomain factors (rewarding, cultural, and informational). We asked 94 Japanese participants/subjects to evaluate the palatability of sake (1st evaluation/E1 for the first cup, 2nd/E2 and 3rd/E3 for the palatability with aftertaste/afterglow of certain dishes) and to respond to a questionnaire related to 3 subdomains. In E1, 3 factors were extracted by a factor analysis, and the subsequent multiple regression analyses indicated that the palatability of sake was interpreted by mainly the rewarding. Further, the results of attribution-dissections in E1 indicated that 2 factors (rewarding and informational) contributed to the palatability. Finally, our results indicated that the palatability of sake was influenced by the dish eaten just before drinking.

Assessment of direct interaction between CD36 and an oxidized glycerophospholipid species.

Cluster of differentiation 36 (CD36) is a transmembrane protein that recognizes multiple diverse ligands. It is believed that (i) oxidized glycerophosphatidylcholine species having a terminal γ-hydroxyl(or oxo)-α,ß-unsaturated carbonyl on the sn-2 acyl group (oxGPCCD36), which can occur on the surface of lipoprotein particles, serve as high-affinity ligands for CD36, and (ii) the amino acid 150-168 of CD36 (CD36150-168) is responsible for recognizing oxGPCCD36. However, it remains uncertain whether CD36150-168 directly interacts with oxGPCCD36 alone. In this study, we addressed this issue by investigating and comparing the banding pattern by non-denaturing polyacrylamide gel electrophoresis of a glutathione S-transferase (GST) fusion protein containing CD36150-168 (GST-CD36150-168), in the presence and absence of an oxGPCCD36 species, 1-(palmitoyl)-2-(5-keto-6-octenedioyl)phosphatidylcholine (KOdiA-PC). It was shown that GST-CD36150-168 pre-incubated with KOdiA-PC produced bands at upper positions than did the fusion protein alone. Further analyses revealed that the bands produced by the loading of GST-CD36150-168/KOdiA-PC mixture represent complexes consisting of the fusion protein and lipid. To our knowledge, this is the first evidence for direct interaction between CD36150-168 and oxGPCCD36 alone. It is also notable that the electrophoresis-based technique provides a convenient means to evaluate protein-lipid interactions.

Dammarane-type triterpene extracts of Panax notoginseng root ameliorates hyperglycemia and insulin sensitivity by enhancing glucose uptake in skeletal muscle.

Skeletal muscle is an important organ for controlling the development of type 2 diabetes. We discovered Panax notoginseng roots as a candidate to improve hyperglycemia through in vitro muscle cells screening test. Saponins are considered as the active ingredients of ginseng. However, in the body, saponins are converted to dammarane-type triterpenes, which may account for the anti-hyperglycemic activity. We developed a method for producing a dammarane-type triterpene extract (DTE) from Panax notoginseng roots and investigated the extract's potential anti-hyperglycemic activity. We found that DTE had stronger suppressive activity on blood glucose levels than the saponin extract (SE) did in KK-Ay mice. Additionally, DTE improved oral glucose tolerance, insulin sensitivity, glucose uptake, and Akt phosphorylation in skeletal muscle. These results suggest that DTE is a promising agent for controlling hyperglycemia by enhancing glucose uptake in skeletal muscle.