Chemical Fingerprints of Emotional Body Odor.

Chemical communication is common among animals. In humans, the chemical basis of social communication has remained a black box, despite psychological and neural research showing distinctive physiological, behavioral, and neural consequences of body odors emitted during emotional states like fear and happiness. We used a multidisciplinary approach to examine whether molecular cues could be associated with an emotional state in the emitter. Our research revealed that the volatile molecules transmitting different emotions to perceivers also have objectively different chemical properties. Chemical analysis of underarm sweat collected from the same donors in fearful, happy, and emotionally neutral states was conducted using untargeted two-dimensional (GC×GC) coupled with time of flight (ToF) MS-based profiling. Based on the multivariate statistical analyses, we find that the pattern of chemical volatiles (N = 1655 peaks) associated with fearful state is clearly different from that associated with (pleasant) neutral state. Happy sweat is also significantly different from the other states, chemically, but shows a bipolar pattern of overlap with fearful as well as neutral state. Candidate chemical classes associated with emotional and neutral sweat have been identified, specifically, linear aldehydes, ketones, esters, and cyclic molecules (5 rings). This research constitutes a first step toward identifying the chemical fingerprints of emotion.

High Bioavailability from Ferric Pyrophosphate-Fortified Bouillon Cubes in Meals is Not Increased by Sodium Pyrophosphate: a Stable Iron Isotope Study in Young Nigerian Women.

BACKGROUND: It is challenging to find an iron compound that combines good bioavailability with minimal sensory changes when added to seasonings or condiments. Ferric pyrophosphate (FePP) is currently used to fortify bouillon cubes, but its bioavailability is generally low. Previously, the addition of a stabilizer, sodium pyrophosphate (NaPP), improved iron bioavailability from a bouillon drink. OBJECTIVE: We assessed whether there is a dose-response effect of added NaPP on iron bioavailability from local meals prepared with intrinsically labeled FePP-fortified bouillon cubes in young Nigerian women using iron stable isotope techniques. METHODS: In a double-blind, randomized, cross-over trial, women (n = 24; aged 18-40 y; mean BMI 20.5 kg/m2) consumed a Nigerian breakfast and lunch for 5 d prepared with bouillon cubes containing 2.5 mg 57Fe (as FePP) and 3 different molar ratios of NaPP: 57Fe (0:1, 3:1, and 6:1). Iron bioavailability was assessed by measuring 57Fe incorporation into erythrocytes 16 d after each 5 d NaPP: 57Fe feeding period. Data were analyzed using a linear regression model of log iron absorption on NaPP ratio, with body weight and baseline body iron stores as covariates and subject as a random intercept. RESULTS: Of the women included, 46% were anemic and 26% were iron deficient. Iron bioavailability was 10.8, 9.8, and 11.0% for the 0:1, 3:1, and 6:1 NaPP:57Fe treatments, respectively. There was no dose-response effect of an increasing NaPP:57Fe ratio (ß ± SE: 0.003 ± 0.028, P = 0.45). CONCLUSIONS: In this study, the addition of NaPP did not increase iron bioavailability from FePP-fortified bouillon cubes. However, iron bioavailability from the Nigerian meals prepared with FePP-fortified bouillon cubes was higher than expected. These results are encouraging for the potential of bouillon cubes as a fortification vehicle. Further studies are needed to assess the effect of FePP-fortified bouillon cubes on improving iron status in low-income populations. This trial was registered at clinicaltrials.gov as NCT02815449.

The effect of consumption temperature on the homeostatic and hedonic responses to glucose ingestion in the hypothalamus and the reward system.

Background: Excessive consumption of sugar-sweetened beverages (SSBs) has been associated with obesity and related diseases. SSBs are often consumed cold, and both the energy content and temperature might influence the consumption behavior for SSBs. Objective: The main aim of this study was to elucidate whether consumption temperature and energy (i.e., glucose) content modulate homeostatic (hypothalamus) and reward [ventral tegmental area (VTA)] responses. Design: Sixteen healthy men participated in our study [aged 18-25 y; body mass index (kg/m2): 20-23]. High-resolution functional magnetic resonance imaging data were collected after ingestion of 4 different study stimuli: plain tap water at room temperature (22°C), plain tap water at 0°C, a glucose-containing beverage (75 g glucose dissolved in 300 mL water) at 22°C, and a similar glucose drink at 0°C. Blood oxygen level-dependent (BOLD) changes from baseline (7 min preingestion) were analyzed over time in the hypothalamus and VTA for individual stimulus effects and for effects between stimuli. Results: In the hypothalamus, water at 22°C led to a significantly increased BOLD response; all other stimuli resulted in a direct, significant decrease in BOLD response compared with baseline. In the VTA, a significantly decreased BOLD response compared with baseline was found after the ingestion of stimuli containing glucose at 0°C and 22°C. These responses were not significantly modulated by consumption temperature. The consumption of plain water did not have a significant VTA BOLD effect. Conclusions: Our data show that glucose at 22°C, glucose at 0°C, and water at 0°C lowered hypothalamic activity, which is associated with increased satiation. On the contrary, the consumption of water at room temperature increased activity. All stimuli led to a similar VTA response, which suggests that all drinks elicited a similar hedonic response. Our results indicate that, in addition to glucose, the low temperature at which SSBs are often consumed also leads to a response from the hypothalamus and might strengthen the response of the VTA. This trial was registered at www.clinicaltrials.gov as NCT03181217.

A sniff of happiness.

It is well known that feelings of happiness transfer between individuals through mimicry induced by vision and hearing. The evidence is inconclusive, however, as to whether happiness can be communicated through the sense of smell via chemosignals. As chemosignals are a known medium for transferring negative emotions from a sender to a receiver, we examined whether chemosignals are also involved in the transmission of positive emotions. Positive emotions are important for overall well-being and yet relatively neglected in research on chemosignaling, arguably because of the stronger survival benefits linked with negative emotions. We observed that exposure to body odor collected from senders of chemosignals in a happy state induced a facial expression and perceptual-processing style indicative of happiness in the receivers of those signals. Our findings suggest that not only negative affect but also a positive state (happiness) can be transferred by means of odors.

Effects of dietary lipids on immune function in a murine sensitisation model.

We have tested the effect of dietary fatty acids on aspects of innate and specific adaptive T helper (Th) 1- and Th2-driven immune responses in a murine sensitisation model using dinitrochlorobenzene as sensitiser. Six groups of fifteen BALB/c mice were fed diets containing 30 % fat (by energy) for 8 weeks. Diets were rich in saturated fatty acids, n-6 polyunsaturated fatty acid (PUFA), or n-3 PUFA, each at a sufficient (11, 35 and 68 mg/kg) and a supplemented vitamin E level (1028, 1031 and 1030 mg/kg respectively). Feeding n-6 PUFA marginally decreased % phagocytosing cells at the low vitamin E level, but had no other effects on immune function. The n-3 PUFA diets decreased production of prostaglandin E2 while increasing oxidative burst and tumour necrosis factor alpha production. In addition adaptive Th1-driven responses (immunoglobulin, Ig)G2a, IgG2b, interferon-gamma:interleukin 4) were decreased, whereas Th2-driven and mucosal immune responses were increased (IgE) or unaffected (IgG1, IgA). Combination with high levels of alpha-tocopherol did not affect the reduced prostaglandin E2 production, augmented the increase of tumour necrosis factor alpha production and tended to ameliorate the selective suppressive effects of n-3 PUFA on certain Th1-driven effects (interferon-gamma:interleukin 4 ratio and IgG2a levels). We conclude that the sensitisation model appears useful for application in nutrition research. It allows a broad assessment of the effects of dietary intervention on various aspects of immune responsiveness, and as such provides a valuable model to assess, characterise and rank effects of foods and/or nutrients on a range of immune functions, including Th1-Th2 polarisation.