1.

sarcopenia, and flail in the elderly are problems. It has also reported that abnormal olfaction and taste (function decline) occur as an early symptom of Alzheimer's dementia. Taste and smell have a close relationship with appetite. It is need to study the provision of meals that enhance and the combination of foods from the middle age to the elderly. Because Alzheimer's dementia gradually progresses from the middle-ages, and symptoms spear after becoming an older adult. For 16 years, we have conducted research on taste and olfaction in Yakumo town in Hokkaido, Japan, Where the population does not move much. In this report, we report on the results of the taste test using TASTDISC (Bitterness) in 2019at Yakumo Town Resident Examination, which has been ongoing since 2007.From the database, 298 participants (169 females and 129 males) were selected form data in August 2019. The bitterness test performed using the bitterness test paper with liquid TASTEDISC (Sanwa Chemical Laboratory Co., Ltd) which include five different densities of Quinine hydrochloride on a liquid with test paper namely:, 1(0.001%), 2(0.02%),3(0.1%), 4(0.5%), 5(4.0%). As a result, 12males out of 129 male participants (9.3%) and 9females of 169 female participants (5.3%) had abnormal values in bitter taste test (Taste disc) results. Feeling bitterness can also protect us from ingesting dangerous foods (various toxins). However, a low threshold of bitterness in important toenjoy the taste of spring vegetables as such as wild vegetables and the delicious beer taste. Bitterness studies are increasingly needed.

apan is aging and has become a super-aged society as of 2020. The Japanese government is working with prefectures to take measures to extend healthy life expectancy, aiming for healthy longevity. We are recruiting participants for various events, such as cooking classes for preventing under nutrition of the elderly, exercise for preventing dementia, and cooking classes. Taste mainly studied for saltiness and sweetness. This is because the salty taste is closely related to cardiovascular areas such as blood pressure, and the government calls for salt reduction from the perspective of preventing hypertension. Also, the sweetness is related to blood sugar level, HbA1c, etc. It is involved in obesity, diabetes, and even Alzheimer's dementia and a great deal of research has reported to improve lifestyle-related diseases. However, the taste has sourness, bitterness, and umami. Therefore, this study tries to understand what is the threshold value of the bitter taste that determines the taste of beer from the middle ages to the elderly. The bitterness is food is known as a poison such as an alkaloid mainly contained in vegetables. A small amount of bitter taste, like spices, can change the taste of a meal and help to create a variety of tastes. The best example is "the hops" which are indispensable for making beer. At first, even if there is resistance to bitterness, it is that we will want to repeat or eat it. We get used to it. A low threshold of bitterness to quickly detect dangerous tastes and avoid poisonous foods and drinks. From the above, it is also necessary to study the threshold of bitterness that decline with age. This time, we will report the results of a bitterness threshold test conducted at the time of resident screening in Yakumo Town in Hokkaido, Japan, where the population does not move much.

Yakumo is located in the south of Hokkaido, the northern island of Japan. Townspeople make a living mainly in agriculture and fisheries. The study in Yakumo is a prospective cohort study. This research has been ongoing since 1981. The reason is that Yakumo Town has the least migration of population in Japan. The participants had managed their everyday life themselves. And the Nagoya University Graduate School of Medicine, professionals in the fields of epidemiology, internal medicine, orthopedics, neuropsychology, ophthalmology, otolaryngology, and urology joined the Yakumo Study. The participants had been engaged in a variety of jobs. Therefore, this town can be regarded as representative of today's Japanese society. From the database, 298participants (169 females and 129 males) were selected form data in August 2019 (Table 1).

The gustatory test was performed using test paper with liquid TASTEDISC (Sanwa Chemical Laboratory Co., Ltd) which include five different densities of Quinine hydrochloride on a liquid with test paper namely:, 1(0.001%), 2(0.02%),3(0.1%), 4(0.5%), 5(4.0%).The inspection method is as follows. 1) Show participants the taste choice paper: Sweet, Salty, Sour, Bitter. Taste something but I don't know, No taste. 2) Hold the filter paper disc with tweezers. The bitterening solution is dropped on it and moistened. 3) The moistened disc is gently placed on the canaliculus chordae tympani innervation area of the participant's tongue. The canaliculus chordaetympani innervation area is located 2 cm left and right from the tip of it. 4) Instruct the user to answer one of the taste choice paper in 2~3 seconds with the mouth open. 5) The examiner then removes the disc from the participant's tongue with tweezers. 6) If a correct answer is not obtained to the participants, the test is continuing to use a solution having a higher concentration in order. 7) After garglling with water to prevent residual teste, perform the next taste test at intervals of 1 minute or more. This method was in accordance with the test method of the teste test kit (TASTEDISC: Sanwa Chemical Laboratory Co., Ltd).

This study is conducted with the approval of the Ethical Review Board (Nagoya women's university Ethics Committee: 'hito wo mochiita kennkyuu ni kansuru iinnkai'). The approval number is 30-14.

The test results were confirmed to be normal distribution by F-test. Data that werethe tolerance range (in this study, it called the normal range) distributed were compared with Student-t without correlation of parametric test. The data that is not normally distributed was compared without correlated Mann-Whitney one of the non-parametric test.

Data on body composition and blood pressure of participants show by age. The males showed in Table 2. And the females showed in Table 3. All data showed as averages by age. For both males and females, the mean values of blood pressure for each generation were in the normal range. Body fat percentage was higher in females than in males, and BMI and body fat were almost the tolerance range (in this study, it called the normal range) for both males and females.

Bitter taste identification performed by using test paper TASTDESC (Sanwa Chemical Laboratory Co., Ltd).Table 4 shows the bitterness measurement results for male and female by age. The bitterness results using TASTDISC can teste for sensitivity to Quinine hydrochloride concentrations. As a result, 12 males of 129 male participants (9.3%) and nine females of 169 female participants (5.3%) had abnormal values in the result of bitterness test. Males almost twice as many as females required consultation.

The bitter test result was statistically processed. Table 5 and Table 6 show the results of comparison of the bitterness test results using TASTDISC with the tolerance range (in this study, it called the normal range) systolic and diastolic blood pressure values and others. The results did not show a statistically significant difference in either case. 7 shows the results of the comparison of the bitterness test results using TASTDISC with the tolerance range (in this study, it called the normal range) BMI and others. The results did not show a statistically significant difference in either case.

Table 8 shows the results of the comparison of the bitterness test results using TASTDISC with the tolerance range (in this study, it called the normal range) Body fat and others. The results showed that there was a statistically significant difference between the tolerance range (in this study, it called the normal range) 10 shows the results of the comparison of the bitterness test results using TASTDISC with the tolerance range (in this study, it called the normal range) Waist circumference range and In Japan, the tolerance range (in this study, it called the normal range) waist circumference of the male is less than 85 cm (Table 9), and female is less than 90 Cm (Table10). The results did not show a statistically significant difference in either case. 10). The results did not show a statistically significant difference in either case.

IV.

The taste is mainly divided into 5 flavors, sweetness, saltiness, sourness, bitterness, and umami 1,2,3,4) . It has reported that the cognitive threshold of taste changes with temperature 5) . Of these five tastes, saltiness and bitterness are to be thin when the temperature is high when the temperature is low 6) . Many medicines have a bitter taste and may be difficult for children to take, especially 7) . Many researchers have reported the results of studies of coating the bitter drug with another taste 8) . However, bitterness is an ability necessary to identify dangerous things (poisonous substances, etc.) 9) . The problem is that with age, the taste may deteriorate, and we may not feel the taste 10) . Particularly today, it has begun to be reported that taste perception due to Alzheimer's dementia deteriorates 11,12,13) . Furthermore, it has reported that patients were suffering from coronavirus report sysgeusia 14,15) . It can say that it is need to study taste. According to the results of our previous research on saltiness, there was no statistically significant difference in saltiness threshold results between all normal ranges, such as blood pressure, BMI, body fat percentage, waist circumference, and the other values 15) . However, this time, when comparing bitterness with the normal range of blood pressure, BMI, body fat percentage, waist circumference as in the case of salty taste, there was a statistically significant difference in body fat percentage. Participants with a low body fat percentage had a high threshold of bitterness, and participants with abundant body fat percentage had a high sensitivity of bitterness. Regarding this result, we need to further investigate. And the relationship between diet and other factors which we need to study in the future.

V.

We obtained bitterness test results, TASTDISC, at the time of health check-up in Yakumo Town, Hokkaido, where population migration is low. From the database, 298 participants (169 females and 129 males) were selected form data in August 2019. The Bitterness test performed using test paper with liquid TASTEDISC (Sanwa Chemical Laboratory Co., Ltd) which include five different densities of Quinine hydrochloride on a liquid with test paper namely:, 1(0.001%), 2(0.02%), 3(-.1%), 4(0.5%), 5(4.0%). As a result, 12 males out of 129 male participants (9.3%) and nine females of 169 female participants (5.3%) had abnormal values in the bitterness taste test (TASTEDISC) results. The tolerance range (in this study, it called the normal range) of bitterness, blood pressure (systole, diastole), and body composition (BMI, body fat percentage, abdominal circumference) compared with other values. As a result, there was no statistically significant difference in the bitterness threshold between the normal range of blood pressure, BMI, and abdominal circumference and the others. However, there was a statistically significant difference in the threshold of bitterness between the normal range of body fat percentage and the other range. Bitterness thresholds were lower in participants with high body fat than in participants with low body fat. It is necessary to increase the number of participants and analyse it in the future.