Composition for suppressing decline in curiosity or improving curiosity

Abstract

The purpose of the present invention is to provide a composition for suppressing a decline in curiosity or improving curiosity. The present invention relates to a composition for suppressing a decline in curiosity or improving curiosity, the composition containing L-ergothioneine or a salt thereof.

Description

Composition for suppressing or improving decline in curiosity

[0001] The present invention relates to a composition for suppressing or improving a decline in curiosity.

[0002] Human abilities can be broadly divided into cognitive abilities and non-cognitive abilities. Cognitive abilities are intellectual abilities necessary for information acquisition and reasoning, and representative examples include memory, executive function, and attention. Non-cognitive abilities are abilities that cannot be measured by cognitive abilities, and include curiosity and the ability to persevere (resilience).

[0003] Curiosity has been considered the driving force (intrinsic motivation) behind free-flowing activities such as "wanting to know" and "wanting to experience," or so-called exploratory behavior. The motivation for exploratory behavior, which is the basis of curiosity, is driven by target information or stimuli. Curiosity is categorized based on the type and direction of this information. For example, intellectual curiosity is motivated by intellectual information, while interpersonal curiosity is motivated by interpersonal information. High levels of curiosity are believed to lead to various beneficial effects, such as improved physical and mental health, and curiosity has attracted attention in a variety of contexts. Research is also being conducted on scales for measuring curiosity (Non-Patent Documents 1-3).

[0004] L-ergothioneine is a sulfur-containing amino acid known to have various useful effects. For example, Non-Patent Document 4 describes that mice were administered ergothioneine and subjected to a novel object exploration test to evaluate the effect on learning function, and the result was that the time spent exploring the novel object increased.

[0005] Nishikawa et al., "The relationship between individual differences in curiosity and mental health and psychological well-being," Journal of the Japanese Society of Health and Medicine, 24(1): pp. 40-48, 2015; Nishikawa et al., "Creation of an intellectual curiosity scale - divergent curiosity and specific curiosity," Educational Psychology Research, 2015, Vol. 63, No. 4, pp. 412-425; Nishikawa et al., "Development of an interpersonal curiosity scale - curiosity exploration regarding people's emotions, secrets, and attributes," Psychology Research, 2022, Vol. 93, No. 5, pp. 436-446; Mitamura et al., "The effect of ergothioneine, a component of Pleurotus cornucopiae, on improving learning function," Proceedings of the 63rd Annual Meeting of the Japanese Society for Food Science and Technology, p. 95 (2Ep1), 2016

[0006] The evaluation system in Non-Patent Document 4 utilizes the tendency of mice to show interest in new objects, and is an experiment in which a previously memorized object and a new object are presented side by side to evaluate the relative exploration time for the novel object. This evaluation system is used as a memory and learning test to evaluate whether the mouse remembers a previous object, and is not a test to evaluate curiosity. In fact, Non-Patent Document 4 concludes that ergothioneine improved the learning function of mice. Non-Patent Document 4 does not examine the effect of ergothioneine on curiosity.

[0007] An object of the present invention is to provide a composition for suppressing or improving a decline in curiosity.

[0008] As a result of intensive research to solve the above problems, the present inventors have found that L-ergothioneine or a salt thereof has the effect of suppressing a decrease in curiosity or improving curiosity.

[0009] That is, the present invention relates to the following compositions for suppressing or improving a decline in curiosity, etc., although not limited thereto. [1] A composition for suppressing or improving a decline in curiosity, comprising L-ergothioneine or a salt thereof. [2] The composition according to [1] above, wherein the curiosity is at least one selected from the group consisting of everyday curiosity, intellectual curiosity, and interpersonal curiosity. [3] The composition according to [1] or [2] above, which is a composition for suppressing or improving a decline in human curiosity. [4] The composition according to any of [1] to [3] above, which is an oral composition. [5] The composition according to any of [1] to [4] above, which is a food or drink. [6] Use of L-ergothioneine or a salt thereof for suppressing or improving a decline in curiosity. [7] A method for suppressing or improving a decline in curiosity, which comprises administering L-ergothioneine or a salt thereof.

[0010] According to the present invention, a composition for suppressing or improving a decline in curiosity can be provided.

[0011] The composition of the present invention for suppressing or improving a decline in curiosity contains L-ergothioneine or a salt thereof. The composition of the present invention for suppressing or improving a decline in curiosity contains L-ergothioneine or a salt thereof as an active ingredient. Hereinafter, the composition of the present invention for suppressing or improving a decline in curiosity may also be referred to as the composition of the present invention.

[0012] L-ergothioneine is a type of sulfur-containing amino acid. The salt of L-ergothioneine is not particularly limited as long as it is a pharmacologically acceptable salt or a salt acceptable for use in foods and beverages, and may be either an acidic salt or a basic salt. Examples of acidic salts include inorganic acid salts such as hydrochloride, sulfate, nitrate, and phosphate; and organic acid salts such as acetate, citrate, maleate, malate, oxalate, lactate, succinate, fumarate, and propionate. Examples of basic salts include alkali metal salts such as sodium salt and potassium salt; and alkaline earth metal salts such as calcium salt and magnesium salt.

[0013] L-ergothioneine or a salt thereof is not limited in any way by its form, production method, etc. L-ergothioneine or a salt thereof may be a chemically synthesized product, or may be extracted and purified from a natural product. L-ergothioneine is contained in large amounts in Golden / Yellow Oyster Mushroom (scientific name: Pleurotus cornucopiae var. citrinopileatus), a mushroom of the Pleurotus genus in the family Pleurotus. L-ergothioneine is found in mushrooms such as white button mushrooms, crimini mushrooms, and portabella mushrooms (Agaricus bisporus), Grey Oyster Mushrooms (Pleurotus ostreatus), shiitake mushrooms (Lentinula edodes), Maitake mushrooms (Grifola frondosa), reishi mushrooms (Ganoderma lucidum), Yamabushitake mushrooms (Hericium erinaceus), Yanagimatsutake mushrooms (Agrocybe aegerita), and chanterelle mushrooms (Cantharella verruca). It is also contained in mushrooms such as Pleurotus cibarius, porcini mushroom (scientific name: Boletus edulis), and morel mushroom (scientific name: Morchella esculenta). When obtaining L-ergothioneine from a natural product, it is preferably extracted from Pleurotus cornucopiae. L-ergothioneine or a salt thereof can also be produced by microbial fermentation. L-ergothioneine or a salt thereof may be isolated.

[0014] L-ergothioneine or a salt thereof is a compound that is contained in natural products and foods and beverages and has been consumed as a dietary source. Therefore, from the viewpoint of safety, L-ergothioneine or a salt thereof is considered to pose few problems, even when taken over a long period of time. According to the present invention, a highly safe composition for suppressing or improving a decrease in curiosity can be provided.

[0015] The composition of the present invention is used to suppress a decline in curiosity or improve curiosity. Curiosity refers to the driving force behind exploratory behavior (intrinsic motivation). Exploratory behavior is a free activity driven by a desire to learn or experience something. In the present invention, curiosity also includes having an interest in something and the ability to engage in something with interest. In the present invention, suppressing or improving a decline in curiosity usually refers to suppressing or improving a decline in the level of curiosity.

[0016] Suppressing a decline in curiosity includes suppressing a decline in curiosity, preventing a decline in curiosity, maintaining curiosity, slowing the progression of a decline in curiosity, stopping a decline in curiosity, etc. Improving curiosity includes increasing curiosity, reducing the degree of decline in curiosity, restoring declined curiosity, etc. Restoration includes at least partial restoration.

[0017] The intrinsic motivation for exploratory behavior, which is the basis of curiosity, is provided by target information, stimuli, etc. Curiosity is classified into everyday curiosity, intellectual curiosity, interpersonal curiosity, etc., depending on the type of information. The composition of the present invention may be used to suppress or improve a decline in one type of curiosity, or to suppress or improve a decline in two or more types of curiosity. In one aspect of the present invention, the curiosity is preferably at least one selected from the group consisting of everyday curiosity, intellectual curiosity, and interpersonal curiosity, and more preferably intellectual curiosity. The composition of the present invention can be preferably used to suppress or improve a decline in at least one type of curiosity selected from the group consisting of everyday curiosity, intellectual curiosity, and interpersonal curiosity. The level of curiosity can be evaluated using a curiosity scale.

[0018] Everyday curiosity is a type of curiosity related to motivation that influences one's attitude and attitude toward life, as well as one's mid- to long-term responses to opportunities and events that may occur in daily life. Everyday curiosity includes mid- to long-term approaches to various opportunities in daily life and active acceptance of various events. High levels of everyday curiosity have been reported to have a positive effect on health and well-being (Non-Patent Document 1).

[0019] The level of everyday curiosity can be assessed using the Japanese version of the Curiosity Exploration Inventory (CEI-II) (see Non-Patent Document 1 above). The Japanese version of the Curiosity Exploration Inventory (CEI-II) (hereinafter referred to as the Japanese version of the CEI-II) is a Japanese translation of The Curiosity and Exploration Inventory-I (CEI-II) (see Reference Document 1 below) developed by Kashdan et al. Reference Document 1: Kashdan TB et al. “The Curiosity and Exploration Inventory-II: Development, Factor Structure, and Psychometrics”, Journal of research in personality 43: 987-998, 2009.

[0020] The Japanese version of the CEI-II consists of nine items (nine scales). Subtypes of everyday curiosity include stretching curiosity and embracing curiosity. Stretching curiosity is the curiosity to seek out new opportunities to promote personal growth. Embracing curiosity is the curiosity to actively embrace even unexpected events. Stretching curiosity expresses the desire to expand into new areas, while embracing curiosity expresses the tolerance and enjoyment of novelty and uncertainty. It has been pointed out that these types of curiosity broaden the scope of knowledge and skills, contribute to goal-oriented efforts and self-acceptance, and lead to health and well-being ("Introduction" in the aforementioned non-patent document 1).

[0021] The nine items in the Japanese version of the CEI-II are 1 to 9 below (see Non-Patent Document 1 mentioned above): 1. I am the type of person who truly enjoys uncertainty in everyday life 2. I am at my best when I am tackling complex and difficult challenges 3. Wherever I go, I get out and seek out new things and experiences 4. I see difficult situations as opportunities to grow and learn 5. I like to do things that surprise me a little 6. I am always seeking experiences that challenge the way I think about myself and the world 7. I want to do work that is stimulating and unpredictable 8. I am always looking for opportunities to be challenged and grow as a person 9. I am the type of person who welcomes unfamiliar people, events, and places

[0022] Subjects rate the extent to which the above nine statements apply to them, and the results are used to evaluate the level of curiosity, such as extensive curiosity and comprehensive curiosity. Extensive curiosity is evaluated using items 2, 4, 6, and 8 above. Comprehensive curiosity is evaluated using items 1, 3, 5, 7, and 9 above. Furthermore, everyday curiosity is evaluated using the average of items 1 to 9 (all items) above (referred to as the CEI-II scale score). In evaluating everyday curiosity using the Japanese version of the CEI-II, the stronger the degree to which the above items apply, the higher the curiosity related to that item is evaluated. Evaluation can be performed using the method described in the Examples below.

[0023] In one aspect, everyday curiosity is preferably curiosity assessed by the Japanese version of the CEI-II, more preferably at least one selected from the group consisting of extensive curiosity, comprehensive curiosity, and everyday curiosity assessed using the CEI-II scale score, and even more preferably comprehensive curiosity and / or everyday curiosity. In one aspect, the composition of the present invention is preferably used for inhibiting or improving a decline in at least one curiosity selected from the group consisting of extensive curiosity, comprehensive curiosity, and everyday curiosity assessed by the Japanese version of the CEI-II, and more preferably for inhibiting or improving a decline in comprehensive curiosity and / or everyday curiosity.

[0024] Daily curiosity has a positive effect on health and well-being. The composition of the present invention can be used, for example, to maintain health, prevent a decline in well-being, or improve well-being by suppressing or improving a decline in curiosity.

[0025] Intellectual curiosity refers to the intrinsic motivation for exploratory behavior in intellectual information domains such as problems and challenges, and includes having an interest in intellectual information and the ability to engage with intellectual information with interest. Intellectual curiosity is divided into two types: divergent curiosity and specific curiosity. Divergent curiosity motivates the broad search for new information. Specific curiosity motivates the search for specific information to resolve cognitive inconsistencies such as discrepancies and contradictions. Divergent curiosity can also be understood as curiosity that broadly seeks new information without setting a specific goal. Specific curiosity can also be understood as curiosity that sets a specific goal and delves deeply into known information. In one aspect of the present invention, the suppression or improvement of a decline in intellectual curiosity may be the suppression or improvement of a decline in divergent curiosity and / or specific curiosity, or may be the suppression or improvement of a decline in divergent curiosity and specific curiosity, or specific curiosity.

[0026] Intellectual curiosity can be assessed using an intellectual curiosity scale. For example, the following 12 items (12 scales) can be used as an intellectual curiosity scale (see Non-Patent Document 2 mentioned above). The level of intellectual curiosity can be assessed by assessing the degree to which the following 12 items apply to the individual. 1. I think about new ideas 2. I like trying new things 3. I am not satisfied until I have learned all the knowledge necessary to understand an idea 4. I feel uneasy when I do not understand the answer and feel the need to understand it somehow 5. I seek out new things and experiences wherever I go 6. I keep thinking until I find a clear, clear answer 7. I am very curious about everything 8. When something unexpected happens, I will investigate until I find the cause 9. I am very interested in things that no one has done before 10. I enjoy tackling tasks that have never been done before 11. I think carefully for long periods of time to solve problems 12. I like to research things thoroughly when learning something

[0027] Divergent curiosity is assessed by items 1, 2, 5, 7, 9, and 10 above. Specific curiosity is assessed by items 3, 4, 6, 8, 11, and 12 above. The stronger the degree to which the above items apply, the higher the curiosity related to those items is assessed. The assessment can be performed using the method described in the Examples below.

[0028] In the present invention, intellectual curiosity is preferably evaluated using an intellectual curiosity scale, and is more preferably divergent curiosity evaluated using items 1, 2, 5, 7, 9, and 10 above, and / or specific curiosity evaluated using items 3, 4, 6, 8, 11, and 12 above, and even more preferably specific curiosity.

[0029] The role of divergent curiosity has been pointed out in adapting to complex and changing environments, such as the transition from student life to work life or changing jobs. Preventing or improving the decline in divergent curiosity can have effects such as improving the ability to adapt to changing environments. Specific curiosity is also related to sensitivity to inconsistencies and contradictions and the persistence in pursuing problem-solving. Preventing or improving the decline in specific curiosity can have effects such as increasing interest in learning.

[0030] Interpersonal curiosity is the motivation to acquire interpersonal information. More specifically, it is the intrinsic motivation for exploratory behavior in the area of ​​interpersonal information, such as human psychology and secrets. Interpersonal curiosity includes interest in interpersonal information. There are three types of interpersonal curiosity: emotions, secrets, and attributes. The level of interpersonal curiosity can be assessed using the Interpersonal Curiosity Scale.

[0031] For example, the following 11 items (11 scales) can be used as an interpersonal curiosity scale (Non-Patent Document 3 mentioned above, Reference 2: Nishikawa Kazuji (2017). Three types of interpersonal curiosity tendencies - Progress report on the development of the interpersonal curiosity scale (3) - Proceedings of the 26th Annual Meeting of the Japanese Society of Personality Psychology, 72). The level of interpersonal curiosity can be assessed by assessing the degree to which the following 11 items apply to you. 1. I'm interested in the contents of other people's diaries. 2. I try to understand other people's emotions from their voices. 3. I try to understand other people's feelings from their gestures. 4. I pry into other people's thoughts by looking at their facial expressions. 5. I want to know other people's secrets. 6. I want to ask where they live now. 7. I like to gossip. 8. I try to understand other people's feelings by observing their behavior. 9. I want to ask where they're from. 10. I want to know what special skills other people have. 11. I want to know their relationship history.

[0032] The above items 2, 3, 4, and 8 evaluate curiosity about people's emotions. The above items 1, 5, 7, and 11 evaluate curiosity about people's secrets. The above items 6, 9, and 10 evaluate curiosity about people's attributes. The stronger the degree to which the above items apply, the higher the curiosity related to the item is evaluated. The evaluation can be performed using the method described in the Examples below.

[0033] In the present invention, interpersonal curiosity may be at least one selected from the group consisting of curiosity about other people's emotions, curiosity about other people's secrets, and curiosity about other people's attributes. Among these, curiosity about other people's secrets is preferred. Interpersonal curiosity is preferably evaluated using an interpersonal curiosity scale, and is preferably at least one curiosity selected from the group consisting of curiosity about other people's emotions evaluated by items 2, 3, 4, and 8 above; curiosity about other people's secrets evaluated by items 1, 5, 7, and 11 above; and curiosity about other people's attributes evaluated by items 6, 9, and 10 above, with curiosity about other people's secrets evaluated by items 1, 5, 7, and 11 above being more preferred.

[0034] Interpersonal curiosity is said to affect empathy, sociability, social abilities, psychological well-being, and the like (see Non-Patent Document 3, supra). Interpersonal curiosity is also thought to affect social roles, such as building friendly relationships and establishing social status. Suppressing or improving a decline in interpersonal curiosity can have effects such as suppressing or improving a decline in empathy and a decline in sociability. In one aspect, the composition of the present invention can be used to suppress or improve a decline in empathy, or to suppress a decline in sociability or improve sociability, by suppressing or improving a decline in interpersonal curiosity.

[0035] In one embodiment of the present invention, the curiosity is preferably at least one type selected from the group consisting of comprehensive curiosity, specific curiosity, and curiosity about people's secrets, with comprehensive curiosity being even more preferred. The curiosity is preferably curiosity assessed using the curiosity scale described above. The composition of the present invention is preferably used to inhibit or improve a decline in the curiosity described above.

[0036] As shown in the examples below, L-ergothioneine has the effect of suppressing or improving a decline in curiosity. L-ergothioneine or a salt thereof can be used as an active ingredient for suppressing or improving a decline in curiosity. As mentioned above, Non-Patent Document 4 describes that ergothioneine improved memory and learning functions in mice. However, curiosity, particularly in humans, is considered to be complex. Non-Patent Document 4 only describes an investigation into the exploratory behavior of mice toward novel objects, and does not confirm any effect on human curiosity. Furthermore, there is no report that compounds that improve memory and learning functions are effective in suppressing or improving a decline in curiosity. The effect of suppressing or improving a decline in curiosity confirmed in the examples below is a previously unknown effect of L-ergothioneine or a salt thereof.

[0037] Because the composition of the present invention has the effect of suppressing or improving a decrease in curiosity, it can be used to prevent or improve conditions or diseases that can be prevented or improved by suppressing or improving a decrease in curiosity. Examples of conditions or diseases that can be expected to be prevented by suppressing or improving a decrease in curiosity include dementia, depression, and schizophrenia. Prevention of a condition or disease includes preventing the onset of a condition or disease, delaying onset, reducing the incidence, and reducing the risk of onset. Improvement of a condition or disease includes recovering a subject from the condition or disease, alleviating symptoms, improving symptoms, delaying or preventing the progression of symptoms, and the like. Recovery includes partial recovery.

[0038] The composition of the present invention may be either an oral composition or a parenteral composition, but is preferably an oral composition. Specific examples of oral compositions include foods and beverages, oral pharmaceuticals, and oral quasi-drugs, and are preferably foods and beverages or oral pharmaceuticals, and more preferably foods and beverages. Examples of parenteral compositions include parenteral pharmaceuticals, parenteral quasi-drugs, and cosmetics. The composition of the present invention may be a material or preparation to be incorporated into foods and beverages, pharmaceuticals, quasi-drugs, cosmetics, etc.

[0039] The compositions of the present invention can be used for either therapeutic (medical) or non-therapeutic (non-medical) purposes, the latter being a concept that does not include medical procedures, i.e., surgery, treatment, or diagnosis of humans.

[0040] The form of the composition of the present invention is not particularly limited, and may be a solid (powder, granules, tablet, etc.), liquid, paste, etc. The composition of the present invention may contain any additives and any components in addition to L-ergothioneine or a salt thereof, as long as the effects of the present invention are not impaired. These additives and components can be selected depending on the form of the composition, etc. For example, when the composition of the present invention is an oral composition, additives that can generally be used in oral compositions such as foods and beverages, pharmaceuticals, and quasi-drugs can be used.

[0041] For example, when the composition of the present invention is made into a food or beverage, various foods and beverages can be prepared by blending L-ergothioneine or a salt thereof with ingredients that can be used in foods and beverages (e.g., food ingredients, food additives used as needed, etc.). The foods and beverages are not particularly limited, and examples include general foods and beverages, health foods, health supplements, health drinks, functional foods, foods for specified health uses, and foods and beverages for patients. The health foods, health supplements, functional foods, foods for specified health uses, and foods and beverages for patients can be used in various dosage forms, such as fine granules, tablets, granules, powders, capsules, chewable tablets, dry syrups, syrups, liquids, beverages, drinks, and liquid diets.

[0042] When the composition of the present invention is used as a pharmaceutical or quasi-drug, for example, L-ergothioneine or a salt thereof can be blended with a pharmacologically acceptable carrier and, if necessary, additives to produce a pharmaceutical or quasi-drug in various dosage forms. Such carriers, additives, etc. may be any pharmacologically acceptable carriers that can be used in pharmaceuticals or quasi-drugs, and examples thereof include one or more of excipients, binders, disintegrants, lubricants, antioxidants, colorants, etc. The pharmaceutical or quasi-drug may be administered (ingested) orally or parenterally (transdermally, transmucosally, enterally, by injection, etc.). When the composition of the present invention is used as a pharmaceutical or quasi-drug, it is preferably an oral pharmaceutical or oral quasi-drug. Dosage forms for oral administration of pharmaceuticals or quasi-drugs include liquids, tablets, powders, fine granules, granules, sugar-coated tablets, capsules, suspensions, emulsions, chewable tablets, etc. Dosage forms for parenteral administration include, for example, injections, drip infusions, ointments, lotions, patches, suppositories, nasal preparations, and pulmonary preparations (inhalants).

[0043] When the composition of the present invention is used as a cosmetic, L-ergothioneine or a salt thereof can be blended with carriers, additives, etc. that are acceptable for cosmetics. The product form of the cosmetic is not particularly limited.

[0044] When the composition of the present invention is used in the form of, for example, a food or drink, a pharmaceutical product, a quasi-drug, a cosmetic, or the like, the method for producing it is not particularly limited, and it can be produced by a general method using L-ergothioneine or a salt thereof.

[0045] The content of L-ergothioneine or a salt thereof in the composition of the present invention is not particularly limited and can be set depending on the form, etc. The content of L-ergothioneine or a salt thereof in the composition of the present invention is, for example, preferably 0.0001% by weight or more, more preferably 0.001% by weight or more, and preferably 90% by weight or less, more preferably 50% by weight or less, calculated as L-ergothioneine. In one aspect, the content of L-ergothioneine or a salt thereof in the composition of the present invention is preferably 0.0001 to 90% by weight, more preferably 0.001 to 50% by weight, calculated as L-ergothioneine. The content of L-ergothioneine or a salt thereof can be measured by liquid chromatography mass spectrometry (LC-MS).

[0046] In this specification, an amount converted to L-ergothioneine or an expression similar thereto means the amount of L-ergothioneine, and in the case of a salt of L-ergothioneine, means the value obtained by multiplying the number of moles of the salt by the molecular weight of L-ergothioneine.

[0047] The composition of the present invention can be ingested or administered in an appropriate manner depending on its form. In one embodiment, the composition of the present invention is preferably ingested orally (orally administered). The dosage (also referred to as intake amount) of the composition of the present invention is not particularly limited, and may be an amount that can suppress or improve a decrease in curiosity, and may be appropriately determined depending on the dosage form, administration method, subject weight, etc.

[0048] The subject to which the composition of the present invention is ingested or administered (which can also be referred to as the administration subject) is not particularly limited. The administration subject may be a human or a non-human mammal, preferably a human. The composition of the present invention is preferably a composition for suppressing or improving a decline in curiosity in humans. In one embodiment, the administration subject may be a subject who needs or desires to suppress or improve a decline in curiosity. Examples of such subjects include middle-aged and elderly people. In one embodiment, the composition of the present invention is preferably used as a composition for suppressing or improving a decline in curiosity in middle-aged and elderly people. Middle-aged and elderly people include elderly people. Elderly people may be, for example, people aged 60 or older. Middle-aged and elderly people may be, for example, people aged 40 or older. In one embodiment, among middle-aged and elderly people, subjects aged 40 or older and younger than 65 are preferred. The administration subject may be a healthy individual. The composition of the present invention can be used in healthy individuals, for example, to suppress or improve a decline in curiosity. In one embodiment of the present invention, a particularly preferred subject is a healthy individual aged 40 or older and younger than 65.

[0049] In one embodiment, when the composition of the present invention is orally ingested or administered to a human (adult), the dosage of L-ergothioneine or a salt thereof is preferably 2 mg or more, more preferably 5 mg or more, even more preferably 7 mg or more, and preferably 50 mg or less, more preferably 25 mg or less, and even more preferably 20 mg or less per day, in terms of L-ergothioneine. In one embodiment, the dosage of the composition of the present invention is preferably 2 to 50 mg, more preferably 5 to 25 mg, even more preferably 5 to 20 mg, and even more preferably 7 to 20 mg per day, in terms of L-ergothioneine, for a human (adult). The above amount is preferably ingested or administered once or more times a day, for example, once a day or in divided doses (e.g., 2 to 3 times a day). In one embodiment, the above amount of L-ergothioneine or a salt thereof is preferably orally ingested or administered to a human. The above dosage may be per 60 kg of body weight. In one embodiment, the composition of the present invention can be used to make a human ingest or administer the above-mentioned amount of L-ergothioneine or a salt thereof per 60 kg of body weight per day.

[0050] The content of L-ergothioneine or a salt thereof in the composition of the present invention is preferably 2 to 50 mg, more preferably 5 to 25 mg, even more preferably 5 to 20 mg, and particularly preferably 7 to 20 mg, of L-ergothioneine per daily intake for an adult.

[0051] The composition of the present invention may be labeled with, for example, a function indicating that it has an effect of suppressing or improving a decline in curiosity, or a function exhibited by said effect. Such a label may be labeled with, for example, a function such as "enhancing curiosity," "maintaining curiosity," or "suppressing a decline in curiosity." In one aspect, the composition of the present invention is preferably a food or beverage labeled with the above label. The above label may also be a label indicating that the composition is used to obtain the above function. The above label may be labeled on the composition itself, or on the container or packaging of the composition.

[0052] The present invention also encompasses the following method: A method for suppressing or ameliorating a decrease in curiosity, which comprises administering L-ergothioneine or a salt thereof. The method may be a therapeutic method or a non-therapeutic method.

[0053] The present invention also encompasses the following uses: Use of L-ergothioneine or a salt thereof for suppressing or improving a decrease in curiosity. The above use may be therapeutic or non-therapeutic. By administering L-ergothioneine or a salt thereof to a subject, it is possible to suppress a decrease in curiosity or improve curiosity. Curiosity and its preferred embodiments are the same as those of the composition of the present invention described above.

[0054] In the above-mentioned methods and uses, the preferred embodiment of L-ergothioneine or a salt thereof is the same as that of the composition of the present invention described above. As L-ergothioneine or a salt thereof, one or more types of L-ergothioneine or a salt thereof may be used. In the above-mentioned methods and uses, it is preferable to administer (ingest) L-ergothioneine or a salt thereof to a subject at least once a day, for example, once to several times (e.g., 2 to 3 times) a day. In the above-mentioned methods and uses, it is preferable to orally administer (ingest) L-ergothioneine or a salt thereof. The above-mentioned uses are preferably used in humans.

[0055] In the above-mentioned methods and uses, L-ergothioneine or a salt thereof may be used in an amount sufficient to achieve the desired effect (which may also be referred to as an effective amount). The preferred dosage and administration targets of L-ergothioneine or a salt thereof are the same as those for the composition of the present invention described above. L-ergothioneine or a salt thereof may be administered directly or as a composition containing it. For example, the composition of the present invention described above may be used.

[0056] The present invention also encompasses use of L-ergothioneine or a salt thereof for producing a composition for suppressing or ameliorating a decrease in curiosity. The present invention also encompasses L-ergothioneine or a salt thereof for use in suppressing or ameliorating a decrease in curiosity.

[0057] In this specification, a numerical range expressed by a lower limit and an upper limit, i.e., "lower limit to upper limit," includes both the lower limit and the upper limit. For example, a range expressed by "1 to 2" means 1 or more and 2 or less, including 1 and 2. In this specification, the upper and lower limits may be any combination of ranges. All academic literature and patent documents described in this specification are incorporated herein by reference.

[0058] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0059] Example 1 A randomized, double-blind, placebo-controlled clinical trial was conducted on healthy men and women aged 40 to 65 (50 in the test food group and 50 in the control group) with the aim of investigating the effect of L-ergothioneine (hereinafter referred to as ergothioneine) on curiosity.

[0060] Method The following test and control foods were used for evaluation. Test food: Hard capsules (HPMC (hydroxypropyl methylcellulose) White No. 2) filled with 8 mg of ergothioneine (GMP certified >99.5% L-EGT, Tetrahedron, France) per tablet. Control food: Hard capsules (HPMC White No. 2) filled with 8 mg of food-grade dextrin (Matsutani Chemical Industry Co., Ltd., Japan) per tablet. The control food is the same as the test food except that it contains 8 mg of dextrin instead of 8 mg of ergothioneine. The test and control foods were made indistinguishable from each other in terms of appearance, flavor, etc.

[0061] Before starting to take the test food or control food (week 0), each subject's curiosity was assessed using a curiosity scale (pre-intake test). Subjects in the test food group took one tablet of the test food per day, and subjects in the control group took one tablet of the control food per day for 16 weeks. After taking the test food or control food for 16 weeks, the subjects' curiosity was measured again (post-16-week test).

[0062] Curiosity was assessed through a questionnaire, which assessed "everyday curiosity," "intellectual curiosity," and "interpersonal curiosity."

[0063] Everyday curiosity To evaluate everyday curiosity, the Japanese version of the Curiosity Exploration Scale (CEI-II) (Japanese version CEI-II) created by Nishikawa et al. was used (Non-Patent Document 1 mentioned above).

[0064] The Japanese version of the CEI-II has a total of nine items (nine scales), and the sub-types of curiosity are expansive curiosity and inclusive curiosity. The survey used a questionnaire consisting of the following nine items: 1. I am the type of person who truly enjoys uncertainty in everyday life. 2. I feel at my best when tackling complex and difficult tasks. 3. Wherever I go, I get out and seek out new things and experiences. 4. I view difficult situations as opportunities to grow and learn. 5. I like to do things that surprise me a little. 6. I am always seeking experiences that challenge the way I think about myself and the world. 7. I want to do work that is stimulating and unpredictable. 8. I am always looking for opportunities to be challenged and grow as a person. 9. I am the type of person who welcomes unfamiliar people, events, and places.

[0065] The subjects read the nine items above and answered to what extent they applied to their usual feelings and behaviors by selecting from the following five options: 1: Not at all applicable, 2: Somewhat applicable, 3: Applicable, 4: Quite applicable, 5: Very applicable.

[0066] The level of curiosity was evaluated using the numbers (1 to 5) of the answer options. For example, selecting "1: Not at all applicable" from the above options was given a score of 1, and selecting "5: Very applicable" was given a score of 5. Extensive curiosity was evaluated using items 2, 4, 6, and 8 above. Comprehensive curiosity was evaluated using items 1, 3, 5, 7, and 9 above. For each subject, the average of items 2, 4, 6, and 8 above (the average of the scores for each item) was calculated to obtain the extensive curiosity scale score. The average of items 1, 3, 5, 7, and 9 above was calculated to obtain the comprehensive curiosity scale score. Furthermore, the average of all items (1 to 9 above) was calculated for each subject to obtain the CEI-II scale score. Everyday curiosity can be evaluated using the CEI-II scale score. The average of the extensive curiosity scale score, the comprehensive curiosity scale score, and the CEI-II scale score were then calculated for each group. The higher the score on the curiosity scale, the higher the curiosity is evaluated. The results are shown in Table 1.

[0067] Intellectual curiosity Intellectual curiosity was assessed by evaluating divergent and specific curiosity. A questionnaire consisting of the following 12 items (12 scales) was used (Non-Patent Document 2 mentioned above). 1. I think about new ideas 2. I like trying new things 3. I am not satisfied until I have learned all the knowledge necessary to understand an idea 4. I feel uneasy when I do not understand the answer and feel the need to understand it somehow 5. I seek out new things and experiences wherever I go 6. I keep thinking until I find a clear and clear answer 7. I am very curious about everything 8. When something unexpected happens, I will investigate until I find the cause 9. I am very interested in things that no one has done before 10. I am happy to tackle tasks that I have never done before 11. I think carefully for long periods of time to solve a problem 12. I like to research things thoroughly when learning something

[0068] The subjects responded to the extent to which the above 12 statements applied to them by selecting from the following five options: 1: Not at all applicable, 2: Not very applicable, 3: Can't say either way, 4: Somewhat applicable, 5: Very applicable.

[0069] As with the assessment of everyday curiosity above, the level of curiosity was assessed using the numbers (1-5) of the answer options as a score. In assessing intellectual curiosity, divergent curiosity was assessed using items 1, 2, 5, 7, 9, and 10 above. Specific curiosity was assessed using items 3, 4, 6, 8, 11, and 12 above. For each subject, the average scores for items 1, 2, 5, 7, 9, and 10 (average of the scores for each item) were calculated to represent the divergent curiosity scale score. The average scores for items 3, 4, 6, 8, 11, and 12 above were calculated to represent the specific curiosity scale score. The average scores for the divergent curiosity scale and the specific curiosity scale were then calculated for each group. The results are shown in Table 1.

[0070] Interpersonal curiosity Interpersonal curiosity was assessed by assessing curiosity about other people's emotions, secrets, and attributes. A questionnaire consisting of the following 11 items (11 scales) was used (Non-Patent Document 3, Reference 2 mentioned above). 1. I'm interested in the contents of other people's diaries 2. I try to understand other people's emotions from their voices 3. I try to understand other people's feelings from their gestures 4. I pry into other people's thoughts by looking at their facial expressions 5. I want to know other people's secrets 6. I want to know where they live now 7. I like to gossip 8. I try to understand other people's feelings by observing their behavior 9. I want to know where they're from 10. I want to know what special skills other people have 11. I want to know their relationship history with the opposite sex

[0071] The subjects answered to what extent they thought the above 11 statements applied to them by selecting from the following five options: 1: Not applicable, 2: Not very applicable, 3: Can't say either way, 4: Somewhat applicable, 5: Applicable

[0072] As with the assessment of everyday curiosity above, the level of curiosity was assessed using the numbers (1-5) of the answer options as a score. In assessing interpersonal curiosity, curiosity about other people's emotions was assessed using items 2, 3, 4, and 8 above. Curiosity about other people's secrets was assessed using items 1, 5, 7, and 11 above. Curiosity about other people's attributes was assessed using items 6, 9, and 10 above. For each subject, the average scores for items 2, 3, 4, and 8 above (average of the scores for each item) were calculated to represent the curiosity about other people's emotions scale score. The average scores for items 1, 5, 7, and 11 above were calculated to represent the curiosity about other people's secrets scale score. The average scores for items 6, 9, and 10 above were calculated to represent the curiosity about other people's attributes scale score. Then, for each group, the average scores for the curiosity about other people's emotions scale score, the average scores for the curiosity about other people's secrets scale score, and the average scores for the curiosity about other people's attributes scale score were calculated. The results are shown in Table 1.

[0073] Statistical analysis: Efficacy was evaluated in 99 patients, excluding one patient who dropped out. Unpaired t-tests were used to compare changes between groups. Paired t-tests were used to compare changes within groups. The significance level was set at p<0.05.

[0074] Results: A total of 100 subjects (50 in the test food group and 50 in the control group) participated in this clinical trial. The final number of subjects was 50 in the test food group and 49 in the control group. Of the total subjects, 51 were female (26 in the test food group and 25 in the control group) and 49 were male (24 in the test food group and 25 in the control group). The mean age was 53.4 ± 6.0 years in the test food group and 53.6 ± 6.2 years in the control group, with no statistically significant difference between the groups (p > 0.05).

[0075] Table 1 shows the results of the curiosity evaluation for each group. The results are shown as the mean ± standard deviation of the curiosity scale score. Within group: Paired t-test (†: p<0.1, #: p<0.05) Between groups: Unpaired t-test (†: p<0.1, *: p<0.05) In Table 1, week 0 indicates the result of the test before the start of intake, and week 16 indicates the result of the test after 16 weeks. The change in Table 1 is the difference between the curiosity scale score of the test after 16 weeks and the curiosity scale score of the test before the start of intake. p-value (1) is an intra-group comparison of the scores of the test before the start of intake and the test after 16 weeks, and p-value (2) is an inter-group comparison of the change.

[0076]

[0077] In the test food group, there was a smaller decrease in curiosity scale scores or a greater increase in curiosity scale scores for everyday curiosity, intellectual curiosity, and interpersonal curiosity compared to the control group. This indicates that the decrease in curiosity was suppressed or curiosity was improved in the test food group compared to the control group. In particular, significant differences were confirmed before and after ergothioneine intake in specific curiosity, comprehensive curiosity, CEI-II, and curiosity about people's secrets. There was no significant difference before and after intake in the control group. Regarding the difference between the groups, specific curiosity showed a tendency to improve with ergothioneine intake (p<0.1).

Claims

1. A composition for suppressing or improving the decline in curiosity, containing L-ergothioneine or a salt thereof.

2. The composition according to claim 1, wherein the curiosity is at least one selected from the group consisting of daily curiosity, intellectual curiosity, and interpersonal curiosity.

3. The composition according to claim 1 or 2, which is a composition for suppressing or improving the decline in human curiosity.

4. The composition according to claim 1 or 2, which is an oral composition.

5. The composition according to claim 1 or 2, which is a food or drink.

6. Use of L-ergothioneine or a salt thereof for suppressing or improving the decline in curiosity.

7. A method for suppressing or improving the decline in curiosity, which comprises administering L-ergothioneine or a salt thereof.

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