To determine the association between geriatric disorders and dietary intake, validation of a food frequency questionnaire (FFQ) for elderly individuals is needed. We compared energy and nutrient intakes derived from dietary records (DR) and FFQ in an elderly population and compared the data against results from middle-aged individuals (30–68 years) from a previous study. Current participants included 65 women and 78 men (65–88 years) who completed FFQ and 7-day DR in a subpopulation of the Kyoto-Kameoka study. Our FFQ was created for middle-aged individuals. To validate the FFQ, we investigated equivalent precision by comparing the correlation coefficients between the present and previous study. Median correlations for energy and nutrient intake between the DR and FFQ in the current and previous studies were 0.24 and 0.30 (p = 0.329) in women and 0.24 and 0.28 (p = 0.399) in men, respectively. The median ratio of FFQ to DR for these intakes were also similar. The accuracy and precision of the FFQ for energy and nutrient intake in elderly individuals did not differ compared with previous findings in a middle-aged population. A validation study evaluating energy and nutrient intake using recovery biomarkers is further needed.

L-histidine is one of the essential amino acids for humans, and it plays a critical role as a component of proteins. L-histidine is also important as a precursor of histamine. Brain histamine is synthesized from L-histidine in the presence of histidine decarboxylase, which is expressed in histamine neurons. In the present study, we aimed to elucidate the importance of dietary L-histidine as a precursor of brain histamine and the histaminergic nervous system. C57BL/6J male mice at 8 wk of age were assigned to 2 different diets for at least 2 wk: the control (Con) diet (5.08 g L-histidine/kg diet) or the low L-histidine diet (LHD) (1.28 g L-histidine/kg diet). We measured the histamine concentration in the brain areas of Con diet-fed mice (Con group) and LHD-fed mice (LHD group). The histamine concentration was significantly lower in the LHD group [Con group vs. LHD group: histamine in cortex (means ± SEs): 13.9 ± 1.25 vs. 9.36 ± 0.549 ng/g tissue; P = 0.002]. Our in vivo microdialysis assays revealed that histamine release stimulated by high K(+) from the hypothalamus in the LHD group was 60% of that in the Con group (P = 0.012). However, the concentrations of other monoamines and their metabolites were not changed by the LHD. The open-field tests showed that the LHD group spent a shorter amount of time in the central zone (87.6 ± 14.1 vs. 50.0 ± 6.03 s/10 min; P = 0.019), and the light/dark box tests demonstrated that the LHD group spent a shorter amount of time in the light box (198 ± 8.19 vs. 162 ± 14.1 s/10 min; P = 0.048), suggesting that the LHD induced anxiety-like behaviors. However, locomotor activity, memory functions, and social interaction did not differ between the 2 groups. The results of the present study demonstrated that insufficient intake of histidine reduced the brain histamine content, leading to anxiety-like behaviors in the mice.

Eccentric exercise results in prolonged muscle weakness and muscle soreness, which are typical symptoms of muscle damage. Recovery from muscle damage is related to mammalian target of rapamycin (mTOR) activity. Leucine-enriched essential amino acids (LEAAs) stimulate muscle protein synthesis via activation of the mTOR pathway. Therefore, we investigated the effect of LEAAs on muscle protein synthesis and muscle soreness after eccentric contractions (EC). Male Sprague–Dawley rats (9–11 weeks old) were administered an LEAA solution (AminoL40; containing 40 % leucine and 60 % other essential amino acids) at 1 g/kg body weight or distilled water (control) 30 min before and 10 min after EC. Tibialis anterior (TA) muscle was exposed to 500 EC by electrical stimulation under anesthesia. The fractional synthesis rate (FSR; %/h) in the TA muscle was measured by incorporating l-[ring-2H5] phenylalanine into skeletal muscle protein. Muscle soreness was evaluated by the paw withdrawal threshold using the Randal–Selitto test with some modifications from 1 to 3 days after EC. The FSR in the EC-control group (0.147 ± 0.016 %/h) was significantly lower than in the sedentary group (0.188 ± 0.016 %/h, p < 0.05). AminoL40 administration significantly mitigated the EC-induced impairment of the FSR (0.172 ± 0.018 %/h). EC decreased the paw withdrawal threshold at 1 and 2 days after EC, which indicated that EC induced muscle soreness. Furthermore, AminoL40 administration alleviated the decreased paw withdrawal threshold. These findings suggest that LEAA supplementation improves the rate of muscle protein synthesis and ameliorates muscle soreness after eccentric exercise.

Bonito extract, i.e., dried bonito broth (DBB), has been reported to counteract mental fatigue and to increase performance in a simple calculation task, but the mechanism by which DBB increases task performance is not known. The brain neurotransmitter histamine is biosynthesized only from histidine in the tuberomammillary nucleus. Histamine neurons are projected to almost all areas of the cerebral cortex, and histamine has various behavioral and neurobiological functions, particularly in recognition memory. Here we used a mouse model to investigate the effects of the oral ingestion of DBB, which contains abundant histidine, as well as the ingestion of histidine on cognitive function. In a retention trial of novel object recognition test, the administration of 1.6 g/ kg of DBB and 500 mg/kg of histidine significantly increased the animals' exploratory behavior toward a novel object, and that these agents significantly increased the spontaneous alternation behavior ratio in a Y-maze under conditions of scopolamine-induced amnesia, which induced learning and memory impairment. These results suggested the improvement of spatial short-term working memory in a scopolamine amnesia model, as well as the strengthening of visual cognitive function by a single ingestion of DBB and histidine. Interestingly, the administration of αFMH, which is an inhibitor of histamine biosynthesis, eliminated the increase in the spontaneous alternation behavior ratio by DBB ingestion in the scopolamine-induced amnesia model, suggesting that DBB may improve working memory impairment via activation of the histaminergic neuron system. Bonito (skipjack tuna, Katsuwonus pelamis) is known as katsuo in Japan and is very familiar to Japanese people from ancient times. Dried bonito broth (katsuobushi-dashi, DBB), a hot-water extract of dried bonito muscle, is ubiquitous in the Japanese diet, enhancing the taste and flavor of dishes (12,19). DBB has also traditionally been considered a folk remedy for fatigue in the southern part of Japan. In previous works, DBB was confirmed to be effective against fatigue in animal and human studies (22,32). We demonstrated that the daily ingestion of DBB by humans improves mood, especially by alleviating mental fatigue (31), and that it increases performance on a simple calculation task (21). However, the mechanisms underlying the ability of DBB to increase task performance are not yet known. The brain neurotransmitter histamine is synthesized from histidine by tuberomammillary nuclei neurons of the posterior hypothalamus, and histaminergic neurons are projected to almost all areas of the cerebral cortex (34). Histamine is known to be involved in behavioral and neurobiological functions such as sleep-cycle maintenance and adjustment (16,37), eating behavior and energy metabolism (17,26,36), stress response (38,40), and learning and mem-

Background: Adequate nutrition during childhood is essential to promote child growth and development. Objective: The study evaluated the relationship of habitual nutrient intake and protein adequacy to the prevalence of child malnutrition. Methods: Data were derived from a nationally representative sample of children aged 6–12 years. Two nonconsecutive day 24-h dietary recalls (24hR) were collected to estimate the individual food intake. PC-SIDE version 1.0 software (Software for Intake Distribution Estimation) was used to estimate the habitual intake of key nutrients accounting for between- and within-person differences in dietary intake. The 2007 WHO Protein Digestibility Corrected Amino Acid Score (PDCAAS) method was used to measure the protein quality or the utilizable protein intake. The nutritional status of the participants is reflected in the weight-for-age, height-for-age, and body mass index (BMI)-for-age z-scores using the WHO Growth Reference Standard (WHO, 2007). Results: Undernourished school-aged children were found to have high protein inadequacy. Higher consumption of grains and cereal products, meat, and high-quality protein foods was associated with a lower risk of stunting. Higher intake of milk and milk products, grains and cereal products, high-quality protein foods, calcium, riboflavin, and vitamin C was associated with a lower risk of underweight. Higher consumption of grains and cereal products, riboflavin, thiamine, and fiber was associated with a lower risk of wasting. On the contrary, higher consumption of meat, milk and milk products, grains and cereal products, high-quality protein foods, and vitamin C was associated with a higher risk of obesity. Furthermore, linear growth of children was found to be associated with high-quality protein foods, calcium, vitamin B12, vitamin C, and vitamin D. Conclusions: Malnutrition among Filipino children is influenced by nutrient intakes. However, the existence of malnutrition among children may be specifically attributed to the quality of protein consumed. Therefore, the study suggests that nutrition interventions and policies focusing on child malnutrition should improve not just the quantity but also the quality of protein sources consumed by children to aid in proper growth and development.