Activity improver and food / beverage for improving activity

Abstract

Provided is an activity improver containing a novel active ingredient. The activity improver contains ethyl lactate as an active ingredient. In one embodiment, the activity improver may have an ethyl lactate content of 2-700 ppm. The activity improver may furthermore contain water as a solvent.

Description

Activity enhancers and food and beverages for improving activity

[0001] The present invention relates to an activity enhancer and a food or drink for enhancing activity.

[0002] Ethyl lactate is an ester compound formed from lactic acid and ethanol, and is naturally found in trace amounts in wine, chicken, fruits, miso, etc. Ethyl lactate is useful as a food flavoring, and its aroma is described as nutty, dairy, and fruity. For example, International Publication No. 2021 / 198199 exemplifies ethyl lactate as an ingredient capable of imparting characteristic flavor notes related to dairy and meat notes contained in flavor compositions that are particularly valued for their mellowness and long-lasting flavor.

[0003] One aspect of the present invention aims to provide an activity enhancer containing a novel active ingredient.

[0004] A first aspect is a physical activity improver containing ethyl lactate as an active ingredient. In one aspect, the physical activity improver may have an ethyl lactate content of 2 ppm to 700 ppm and may contain water as a solvent. In another aspect, the physical activity improver may have an ethyl lactate intake amount of 1 mg to 140 mg per dose and may be taken orally.

[0005] In one embodiment, the activity enhancer may induce a feeling of increased activity, may elevate mood, may induce a feeling of vitality, and may increase cerebral blood flow.

[0006] A second aspect is a food or beverage for improving activity that contains ethyl lactate as an active ingredient. In one aspect, the food or beverage for improving activity may have an ethyl lactate content of 2 ppm to 700 ppm and may contain water as a solvent. In another aspect, the food or beverage for improving activity may contain ethyl lactate in an amount of 1 mg to 140 mg per serving, and may be taken orally.

[0007] In one aspect, the food or beverage for improving activity may be one that gives a feeling of high activity, may elevate mood, may give a feeling of vitality, or may increase cerebral blood flow.

[0008] A third aspect is a method for improving activity in a subject, comprising having the subject ingest the activity-enhancing agent of the first aspect. In one aspect, the method for improving activity may involve having the subject orally ingest the activity-enhancing agent, with the amount of ethyl lactate ingested per dose being 1 mg or more and 140 mg or less.

[0009] According to one aspect of the present invention, it is possible to provide an activity enhancer containing a novel active ingredient.

[0010] FIG. 1 is a diagram showing the test procedure for subjective evaluation. FIG. 1 shows the results of a psychological questionnaire evaluation of the test beverage of Example 1, with a 9-point scale for "low to high activity." FIG. 2 shows the results of a psychological questionnaire evaluation of the test beverage of Example 1, with a VAS scale for "energized." FIG. 3 shows the results of a psychological questionnaire evaluation of the test beverage of Example 2, with a 9-point scale for "low to high activity." FIG. 4 shows the results of a psychological questionnaire evaluation of the test beverage of Example 2, with a VAS scale for "elevated mood." FIG. 5 shows the results of a psychological questionnaire evaluation of the test beverage of Example 3, with a VAS scale for "elevated mood." FIG. 6 shows the results of a psychological questionnaire evaluation of the test beverage of Example 3, with a VAS scale for "energized." FIG. 7 shows the results of a psychological questionnaire evaluation of the test beverage of Example 3, with a VAS scale for "elevated mood."

[0011] In this specification, when a composition contains multiple substances corresponding to each component, the content of each component refers to the total amount of the multiple substances present in the composition, unless otherwise specified. Furthermore, the upper and lower limits of the numerical ranges described in this specification can be arbitrarily selected and combined from the numerical values ​​exemplified as numerical ranges. The following describes in detail the embodiments of the present invention. However, the embodiments described below are intended to exemplify activity enhancers and the like in order to embody the technical concept of the present invention, and the present invention is not limited to the activity enhancers and the like described below.

[0012] Activity Enhancers Activity enhancers contain ethyl lactate as an active ingredient. When a subject ingests an activity enhancer containing ethyl lactate, the subject's activity level is enhanced. As used herein, "enhancing activity" refers to, for example, promoting psychological arousal in the subject. Here, psychological arousal (hereinafter sometimes simply referred to as arousal) refers to an excited state or energy expenditure associated with emotions. Psychological arousal is typically closely related to a person's assessment of the importance of an event and the physical strength of the stimulus. This psychological arousal is also illustrated by Russell's circumplex model, which posits emotions on a two-dimensional axis of "pleasure-displeasure" and "arousal-calming" (or "activation-deactivation"). The ascending reticular activating system, which runs from the midbrain reticular formation to the cerebrum, is believed to be involved in maintaining psychological arousal. Subjective assessments of the promotion of psychological arousal include, for example, a sense of high activity, elevated mood, and a sense of vitality. Subjective evaluation can be performed, for example, by a psychological questionnaire. For example, evaluation can be performed using a 9-point scale with scores ranging from "low activity" to "high activity." Promotion of mood elevation can be evaluated using a VAS with a score for an item such as "elevated mood." A feeling of vitality can be evaluated using a VAS with a score for an item such as "vigorous." Objective evaluation results for promoting psychological alertness can include, for example, an increase in cerebral blood flow. Note that, in the state of increased activity herein, physiological activity may also be improved, or only psychological activity may be improved without substantially improving physiological activity. In other words, the activity enhancer may be a psychological activity enhancer.

[0013] Examples of subjects whose activity is improved by ingesting an activity enhancer include mammals such as humans, insects such as fruit flies, etc. The subject may include at least a mammal, and the mammal may or may not include a human. That is, the subject may be a mammal including a human, or a human or non-human mammal. The details of the mechanism by which activity is improved by ingesting an activity enhancer containing ethyl lactate as an active ingredient are unknown.

[0014] Ethyl lactate has the IUPAC systematic name ethyl-2-hydroxypropanoate and is also known as ethyl lactate. It exists in the R-isomer (CAS number 687-47-8) and S-isomer (CAS number 7699-00-5), with the majority of natural products being the R-isomer. Ethyl lactate is used as a fragrance, food flavoring, and other applications. Ethyl lactate's acute toxicity is low, with a median lethal dose (LD50) of over 2000 mg / kg in oral administration experiments in rats and an LD50 of 5 g / kg in dermal administration to rabbits. Its carcinogenicity and mutagenicity have not been confirmed. Based on the above, it can be said that ethyl lactate is a compound with guaranteed safety as a food additive.

[0015] The content of ethyl lactate in the activity enhancer may be, for example, 2 ppm or more and 700 ppm or less. Preferably, it may be 4 ppm or more, 8 ppm or more, 10 ppm or more, 20 ppm or more, 25 ppm or more, 60 ppm or more, or 80 ppm or more, and may be 675 ppm or less, 500 ppm or less, 300 ppm or less, 200 ppm or less, 150 ppm or less, or 120 ppm or less. In one aspect, the content of ethyl lactate may preferably be 4 ppm or more and 675 ppm or less, 8 ppm or more and 300 ppm or less, or 20 ppm or more and 150 ppm or less. When the content of ethyl lactate is within the above range, activity tends to be further improved.

[0016] The activity enhancer may contain at least water as a solvent in addition to ethyl lactate. By including water, for example, ethyl lactate can be more efficiently ingested. The water content in the activity enhancer may be, for example, 99.9% by mass or more and 99.9998% by mass or less.

[0017] The activity enhancer may be in any desired state, such as a liquid, solid, or semi-solid (eg, gel).

[0018] The activity enhancer may further contain other active ingredients in addition to ethyl lactate. The other active ingredients may have an activity enhancing effect or an activity enhancing effect. Examples of other active ingredients include caffeine.

[0019] The activity enhancer may be substantially free of other active ingredients other than ethyl lactate, which means that the content of other active ingredients is less than the amount that exhibits an activity enhancing effect.

[0020] The activity enhancer may optionally contain carbon dioxide gas, flavorings, acidulants, sweeteners, colorings, antioxidants, pH adjusters, various nutritional components, etc. Details of these components will be described later.

[0021] Furthermore, the activity enhancer may be in any dosage form, such as powder, granules, tablets, capsules, lozenges, syrup, liquid, or injection. The method of ingestion may be selected from commonly used ingestion routes depending on the dosage form of the activity enhancer. Examples of ingestion routes for the activity enhancer include oral administration. The ingestion route is preferably oral administration. Since the activity enhancer can be taken orally, the activity enhancing effect can be easily obtained.

[0022] The amount of ethyl lactate ingested by a subject to achieve an activity-enhancing effect may be, for example, 1 mg to 140 mg per serving, preferably 1.8 mg or more, or 2 mg or more, or 135 mg or less, 120 mg or less, 100 mg or less, 80 mg or less, 60 mg or less, 40 mg or less, 30 mg or less, 26 mg or less, or 24 mg or less. In one embodiment, the amount of ethyl lactate ingested may be 1.8 mg to 80 mg or 2 mg to 30 mg. The activity-enhancing agent may be ingested once a day or several times a day. The ingestion period may be, for example, one day or more, preferably one week or more, and more preferably one month or more.

[0023] The activity enhancer can be prepared by adding ethyl lactate to a composition having a desired composition. The method of adding ethyl lactate may be to add ethyl lactate itself to the composition, or to add a mixture containing ethyl lactate to the composition. The method of adding ethyl lactate may be appropriately selected depending on the composition to be added.

[0024] Foods and beverages for improving activity. Foods and beverages used to improve activity contain ethyl lactate as an active ingredient. Ingestion of foods and beverages containing ethyl lactate can improve activity. Foods and beverages containing ethyl lactate include general foods and beverages, health foods and beverages, and functional foods and beverages. The foods and beverages may preferably be functional foods and beverages. "Functional foods and beverages" refers to foods and beverages that have a certain functionality in the body, and includes, for example, foods and beverages designated as specified health uses (including conditional FOSHUs [specified health foods]) and functional nutritional foods and beverages, special-purpose foods and beverages, dietary supplements, health supplements, supplements (e.g., tablets, coated tablets, sugar-coated tablets, capsules, and liquids), and beauty foods and beverages (e.g., diet foods and beverages). Functional foods and beverages also include health foods and beverages to which a health claim based on the Codex Alimentarius (Joint FAO / WHO Food Standards Commission) applies.

[0025] Examples of foods and beverages include, but are not limited to, health foods and beverages (such as supplements, nutritional supplements, health supplements, and nutritionally balanced foods) in the form of tablets, tablets, chewable tablets, powders, capsules, granules, and drinks, as well as soft drinks, tea drinks, jelly drinks, sports drinks, coffee drinks, carbonated drinks, vegetable drinks, fruit juice drinks, fermented vegetable drinks, fermented fruit juice drinks, fermented milk drinks (such as yogurt), lactic acid bacteria drinks, milk drinks, powdered drinks, cocoa drinks, sweets (such as biscuits, cookies, chocolate, candy, chewing gum, gummies, and tablets), and jellies.

[0026] The food or drink may be a fluid beverage. When the food or drink is a beverage, the ethyl lactate concentration in the beverage may be, for example, 2 ppm or more and 700 ppm or less, preferably 4 ppm or more, 8 ppm or more, 10 ppm or more, 20 ppm or more, 25 ppm or more, 60 ppm or more, or 80 ppm or more, and may be 675 ppm or less, 500 ppm or less, 300 ppm or less, 200 ppm or less, 150 ppm or less, or 120 ppm or less. In one aspect, the content of ethyl lactate may be preferably 4 ppm or more and 675 ppm or less, 8 ppm or more and 300 ppm or less, or 20 ppm or more and 150 ppm or less.

[0027] The beverage may be, for example, a beverage containing ethyl lactate and a liquid medium such as water, fruit juice, etc. The beverage may be, for example, a tea beverage such as green tea, oolong tea, or black tea, a soft drink, a jelly drink, a sports drink, a milk beverage, a carbonated drink, a vegetable beverage, a fruit juice beverage, a fermented vegetable beverage, a fermented fruit juice beverage, a fermented milk beverage (such as yogurt), a lactic acid bacteria beverage, a milk beverage (such as coffee milk or fruit milk), a powdered beverage, a cocoa beverage, or an alcoholic beverage, or may be a beverage containing the composition and having milk, purified water, or the like as a liquid medium.

[0028] The food or drink may contain a sweetener to adjust the sweetness. The sweetener may be a sugar, and the sugar is not particularly limited as long as it is a commonly used sugar, and examples thereof include sucrose, glucose, fructose, fructooligosaccharides, galactooligosaccharides, etc. Alternatively, commonly used synthetic sweeteners such as aspartame and saccharin may be added instead of sugar. These may be used alone or in combination of two or more.

[0029] The food or drink may contain an acidulant. The acidulant is not particularly limited as long as it is a commonly used acidulant, and examples thereof include citric acid, malic acid, acetic acid, tartaric acid, glucono-delta-lactone, gluconic acid, phosphoric acid, succinic acid, ascorbic acid, phytic acid, lactic acid, and salts thereof. These may be used alone or in combination of two or more.

[0030] The food or beverage may contain a flavoring. The flavoring may be any commonly used flavoring, and is not particularly limited thereto. Examples thereof include citrus oils such as lemon, lime, and orange, orange oil, and herb extracts. The flavoring may be a natural flavoring or a synthetic flavoring. The natural flavoring may be any commonly used natural flavoring, and is not particularly limited thereto. Examples thereof include anise oil, angelica oil, allspice oil, orange oil, cassia oil, capsicum oil, guarana extract, cardamom oil, caraway oil, cumin oil, clary sage oil, grapefruit oil, clove oil, coriander oil, coffee oil, cognac oil, cola nut extract, cinnamon oil, ginger oil, thyme oil, nutmeg oil, peppermint oil, vanilla extract, bitter almond oil, fenugreek oil, fennel oil, pepper oil, peppermint oil, perilla oil, bergamot oil, mandarin oil, eucalyptus oil, lemon oil, and rosemary oil. These may be used alone or in combination of two or more.

[0031] The synthetic fragrance is not particularly limited as long as it is a commonly used synthetic fragrance, and examples thereof include allyl caproate, γ-undecalactone, ethyl vanillin, ethyl butyrate, ethyl phenylglycidate, eugenol, geraniol, nerol, diacetyl, cyclotene, cinnamic aldehyde, terpineol, δ-decalactone, decanal, nonanal, γ-nonalactone, furaneol, furfuryl mercaptan, 2-hexenal, 3-hexenol, heliotropin, perillaldehyde, benzaldehyde, maltol, methyl anthranilate, methyl salicylate, menthol, α-ionone, and linalool.

[0032] The food or beverage may contain a coloring agent. The coloring agent is not particularly limited as long as it is a commonly used coloring agent, and examples thereof include caramel color, etc. These may be used alone or in combination of two or more.

[0033] The food or drink may contain an antioxidant. The antioxidant is not particularly limited as long as it is a commonly used antioxidant, and examples thereof include L-ascorbic acid, tocopherol, etc. These may be used alone or in combination of two or more.

[0034] The food or drink may contain a pH adjuster. The pH adjuster is not particularly limited as long as it is a commonly used pH adjuster, and examples thereof include phosphoric acid, lactic acid, etc. These may be used alone or in combination of two or more.

[0035] The activity-improving method includes having a subject ingest an activity-improving agent containing ethyl lactate. When the subject ingests the activity-improving agent, the activity of the subject is improved by the action of the active ingredient, ethyl lactate. The details of the composition of the activity-improving agent are as described above.

[0036] The method of taking the activity enhancer in the activity enhancing method may include oral ingestion, nasal administration, rectal administration, intravenous injection, drip infusion, etc. The method of ingestion may be preferably oral ingestion.

[0037] The amount of intake of the activity enhancer in the activity-enhancing method may be, for example, 1 mg to 140 mg per dose, as the amount of ethyl lactate intake, and preferably 1.8 mg or more, or 2 mg or more, or 135 mg or less, 120 mg or less, 100 mg or less, 80 mg or less, 60 mg or less, 40 mg or less, 30 mg or less, 26 mg or less, or 24 mg or less. In one aspect, the amount of ethyl lactate intake may be 1.8 mg to 80 mg or 2 mg to 30 mg. The activity enhancer may be taken once a day or several times a day.

[0038] Examples of subjects in the activity-enhancing method include mammals such as humans, and insects such as fruit flies. The subject may include at least a mammal, and the mammal may or may not include a human. That is, the subject may be a mammal including a human, a human, or a non-human mammal.

[0039] Other aspects of the present invention may include the use of ethyl lactate in the manufacture of an activity enhancer for use in a method for improving activity, the use of an activity enhancer comprising ethyl lactate as an active ingredient in a method for improving activity, the use of ethyl lactate in a method for improving activity, and ethyl lactate for use in a method for improving activity.

[0040] The invention according to the present disclosure may include, for example, the following aspects: [1] An activity enhancer comprising ethyl lactate as an active ingredient.

[0041] [2] The activity enhancer according to [1], wherein the content of ethyl lactate is 2 ppm or more and 700 ppm or less.

[0042] [3] The activity enhancer according to [1] or [2], further comprising water.

[0043] [4] The activity enhancer according to any one of [1] to [3], wherein the amount of ethyl lactate ingested per dose is 1 mg or more and 140 mg or less.

[0044] [5] The activity enhancer according to any one of [1] to [4], which is taken orally.

[0045] [6] The activity enhancer according to any one of [1] to [5], which gives the feeling of high activity.

[0046] [7] The activity enhancer according to any one of [1] to [6], which elevates mood.

[0047] [8] The activity enhancer according to any one of [1] to [7], which gives a feeling of vitality.

[0048] [9] The activity enhancer according to any one of [1] to [8], which increases cerebral blood flow.

[0049]

[10] A food or drink for improving activity, containing ethyl lactate.

[0050]

[11] A method for improving activity in a subject, comprising having the subject ingest the activity-enhancing agent according to any one of [1] to [9].

[0051]

[12] The method for improving activity according to

[11] , wherein the amount of ethyl lactate ingested per dose is 1 mg or more and 140 mg or less.

[0052]

[13] The method for improving activity according to

[11] or

[12] , wherein the activity enhancer is orally ingested.

[0053] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0054] Test Example 1 (Subjective Evaluation) In Test Example 1, each test beverage was consumed by each subject, and each subject's subjective evaluation was obtained by a psychological questionnaire. Test Example 1 was conducted as a single-dose crossover comparative study with 44 healthy Japanese men and women aged 20 to 39 years old. The subjects provided written informed consent before the study was conducted. The test method and results of Test Example 1 are described below.

[0055] Test Method In Test Example 1, as shown in Table 1, the test beverages used were a commercially available drinking water (Comparative Example 1) and an aqueous solution (Example 1) of commercially available drinking water (the same as Comparative Example 1) containing ethyl lactate at a concentration of 100 ppm. The test was conducted twice, with an interval of at least 12 hours, and subjects were randomly assigned to ingest one of the test beverages. Ingestion of the test beverage in Example 1 corresponds to the ingestion of 20 mg of ethyl lactate.

[0056]

[0057] Before conducting this study, subjects were instructed to refrain from drinking alcohol, excessive exercise, and restricting or overeating from the day before the study, and to try to maintain the same amount and quality of sleep as usual as much as possible.

[0058] On the day of the test, subjects were instructed to avoid stimulants such as chili peppers, and caffeine-containing drinks such as energy drinks, coffee, black tea, and green tea at least two hours before the test, and to refrain from eating or drinking anything other than water thereafter.Subjects were also instructed not to use scented products such as perfume, hair styling products, hand cream, and fabric softener, and to wear similar clothing for each test.

[0059] The test procedure is shown in Figure 1. Subjects were instructed to drink 50 mL of commercially available drinking water at the test site and then rest for 5 minutes. They then consumed 200 mL of either the test beverage of Comparative Example 1 or Example 1 over 15 minutes, and then rested for 30 minutes after the end of the drinking period. A psychological questionnaire was administered to the subjects four times: before ingesting the test beverage, after ingesting a sip, after ingesting the entire amount, 15 minutes after the end of ingestion, and 30 minutes after the end of ingestion. Subsequently, a psychological questionnaire was administered using a test beverage different from the one previously ingested, using the same procedure. The test beverages to be ingested were randomly assigned to each subject, and the test was conducted by having each subject ingest each test beverage once.

[0060] The psychological questionnaire was conducted using a nine-point scale and a visual analogue scale (VAS). The nine-point scale asked subjects to evaluate one item, "low to high activity." The VAS asked subjects to evaluate two items, "elevated mood" and "energy."

[0061] The nine-point scale rating method was presented to the subjects as follows: "Low activity refers to states such as sedation, relaxation, calmness, sluggishness, and sleepiness. If you are completely experiencing these emotions, please select 1. High activity refers to states such as arousal, excitement, enthusiasm, nervousness, and awakeness. If you are completely experiencing these emotions, please select 9. You can answer any feelings in between by scoring 2 to 8." For the VAS rating method, subjects were presented with a 100 mm line with "not at all applicable" written on the left end and "very applicable" on the right end. They were asked to draw the line at the point that best represented their emotion, and the length from the left end to the line was measured to obtain a score from 0 to 100.

[0062] Test Results The test results of Test Example 1 are shown in Figures 2 and 3. In Test Example 1, the test for statistically significant differences between groups was performed using the Wilcoxon signed-rank test. A significance level of p<0.05 was considered to indicate a significant difference, and p<0.1 was considered to indicate a significant tendency. In this test, statistical analysis was performed using the SciPy library (ver. 1.6.2) in the Python language. Unless otherwise specified, the test for significant differences was also performed in the following tests.

[0063] As shown in Figure 2, the "low to high activity" scores were significantly higher in the group that ingested the test beverage of Example 1 after taking a sip, immediately after taking the entire amount, and 30 minutes after the end of ingestion, compared to the group that ingested the test beverage of Comparative Example 1. Also, as shown in Figure 3, the "energy" scores tended to be significantly higher in the group that ingested the test beverage of Example 1 30 minutes after the end of ingestion, compared to the group that ingested the test beverage of Comparative Example 1. These findings confirmed the activity-enhancing effect (the effect of promoting a psychologically alert state) of ingestion of the test beverage of Example 1.

[0064] Test Example 2 (Subjective Evaluation Dose Test 1) In Test Example 2, each test beverage was consumed by each subject, and each subject's subjective evaluation was obtained by a psychological questionnaire. Test Example 2 was conducted as a single-dose crossover comparative study with 57 healthy Japanese men and women aged 20 to 39 years old as subjects. The test was conducted after obtaining written informed consent from the subjects. The test method and results of Test Example 2 are described below.

[0065] Test Method As shown in Table 2, in Test Example 2, the test beverages used were a commercially available drinking water (Comparative Example 1) and a test solution (Example 2) in which commercially available drinking water (the same as Comparative Example 1) contained ethyl lactate at a concentration of 30 ppm. The test was conducted twice, with an interval of at least 12 hours, and subjects randomly ingested one of the test beverages each time. Ingestion of the test beverage in Example 2 corresponds to the ingestion of 6 mg of ethyl lactate. The subsequent evaluation method was the same as in Test Example 1. However, in the test procedure shown in Figure 1, the sitting rest time before ingesting 50 mL of water was changed from 10 minutes to 20 minutes.

[0066]

[0067] Test Results The test results of Test Example 2 are shown in Figures 4 and 5. As shown in Figure 4, the group that ingested the test beverage of Example 2 had significantly higher scores for "low to high activity" after taking a sip and 15 minutes after completing ingestion than the group that ingested the test beverage of Comparative Example 1. Furthermore, as shown in Figure 5, the group that ingested the test beverage of Example 2 had significantly higher scores for "feeling elated" after taking a sip, immediately after ingestion, and 15 minutes after completing ingestion than the group that ingested the test beverage of Comparative Example 1.

[0068] Test Example 3 (Subjective Evaluation Dose Test 2) In Test Example 3, each test beverage was consumed by each subject, and each subject's subjective evaluation was obtained by a psychological questionnaire. Test Example 3 was conducted as a single-dose crossover comparative study with 44 healthy Japanese men and women aged 20 to 39 years old. The subjects provided written informed consent before the study was conducted. The test method and results of Test Example 3 are described below.

[0069] Test Method As shown in Table 3, in Test Example 3, commercially available drinking water (Comparative Example 1) was used as the test beverage. Furthermore, an aqueous solution (Example 3) in which commercially available drinking water (Comparative Example 1) contained ethyl lactate at a concentration of 30 ppm was used as the test beverage. The test was conducted twice, with an interval of at least 12 hours, and one of the test beverages was randomly ingested each time. Ingestion of the test beverage in Example 3 corresponds to the ingestion of 2 mg of ethyl lactate. Subsequent evaluation methods were the same as in Test Example 1.

[0070]

[0071] Test Results: No significant results were obtained in the analysis of all 44 subjects. In an analysis of 34 subjects whose "low to high activity" scores before ingestion were below the median, as shown in Figure 6, the group that ingested the test beverage of Example 3 had a significantly higher "elevated" score 30 minutes after ingestion than the group that ingested the test beverage of Comparative Example 1. Furthermore, as shown in Figure 7, the group that ingested the test beverage of Example 3 had a significantly higher "energy" score 30 minutes after ingestion than the group that ingested the test beverage of Comparative Example 1.

[0072] The results of Test Examples 1, 2 and 3 are summarized in Table 4. From Table 4, it was considered that the activity-enhancing effect (the effect of promoting psychological alertness) of ethyl lactate was particularly strong at concentrations of 10 ppm to 100 ppm.

[0073]

[0074] Test Example 4 (Objective Evaluation: Cerebral Blood Flow Measurement Test) In Test Example 4, each subject ingested each test beverage, and frontal cerebral blood flow before and after ingestion was measured as an objective indicator using an OEG-16 (Spectratech). The OEG-16 is a device capable of measuring changes in oxyhemoglobin and deoxyhemoglobin levels under the scalp using near-infrared light on 16 channels. For details about the OEG-16 and channel layout, see K. KANO et al., N-Back tasks for spatial and vertical working memory using Near-Infrared Spectroscopy (ISASE 2020).

[0075] Test Example 4 was conducted as a single-dose crossover comparative study with 24 adult male and female subjects. The subjects provided written informed consent before the study was conducted. The specific test method and results of Test Example 4 are described below.

[0076] Test Method In Test Example 4, as shown in Table 1, the test beverages used were a commercially available drinking water (Comparative Example 1) and a test solution (Example 1) in which commercially available drinking water (the same as Comparative Example 1) contained ethyl lactate at a concentration of 100 ppm. The test was conducted twice, with an interval of at least 12 hours, and subjects were randomly assigned to ingest one of the test beverages each time. Ingestion of the test beverage in Example 1 corresponds to the ingestion of 20 mg of ethyl lactate.

[0077] In conducting Test Example 4, subjects were instructed to refrain from drinking alcohol, excessive exercise, dieting, and overeating from the day before the test, and to maintain the same amount and quality of sleep as usual.

[0078] On the day of the test, subjects were instructed to avoid stimulants such as chili peppers, and caffeine-containing drinks such as energy drinks, coffee, black tea, and green tea at least two hours before the test, and to refrain from eating or drinking anything other than water thereafter.Subjects were also instructed not to use scented products such as perfume, hair styling products, hand cream, and fabric softener, and to wear similar clothing for each test.

[0079] According to the conditions shown in Figure 8, the subjects completed a questionnaire before ingestion, then attached a cerebral blood flow meter and began measuring cerebral blood flow. They rested for 15 minutes, then ingested 200 mL of the test beverage over 3 minutes. They then rested for 30 minutes, and finally completed the post-ingestion questionnaire. The same measurements were performed once more. The test beverages to be ingested were randomly selected for each subject, and each subject ingested each beverage once.

[0080] Subjects who did not have data for either test beverage were excluded from the analysis. Time-dependent cerebral blood flow oxyhemoglobin data recorded at approximately 1.5 Hz was used to calculate the median value for each two-minute rest period after ingestion as the amount of change from the two minutes immediately before ingestion. The analysis was conducted on 23 subjects.

[0081] Test Results The test results of Test Example 4 are shown in Tables 5 and 6. In Test Example 4, statistically significant differences between groups were tested using a paired t-test for the mean values ​​of each group. A significance level of p<0.05 was considered to indicate a significant difference. In Test Example 4, data analysis was performed using the SciPy library (ver. 1.6.2) of the Python language and Microsoft Excel.

[0082]

[0083]

[0084] As shown in Table 5, for channel 7, the oxyhemoglobin levels from 16 to 17 minutes, 19 to 20 minutes, and 20 to 21 minutes after ingestion were higher in the group that ingested the test beverage of Example 1 than in the group that ingested the test beverage of Comparative Example 1 (p<0.1).The oxyhemoglobin levels from 17 to 18 minutes and 18 to 19 minutes after ingestion were significantly higher in the group that ingested the test beverage of Example 1 than in the group that ingested the test beverage of Comparative Example 1 (p<0.05).

[0085] As shown in Table 6, for channel 10, the group that ingested the test beverage of Example 1 tended to have higher oxyhemoglobin levels 3 to 4 minutes, 6 to 7 minutes, and 19 to 20 minutes after the end of ingestion than the group that ingested the test beverage of Comparative Example 1 (p<0.1). The group that ingested the test beverage of Example 1 also had significantly higher oxyhemoglobin levels 4 to 5 minutes and 5 to 6 minutes after the end of ingestion than the group that ingested the test beverage of Comparative Example 1 (p<0.05). This result was similar to the onset timing in the psychological evaluation in Test 2.

[0086] The OEG-16 used to measure cerebral blood flow is a device that uses near-infrared spectroscopy (NIRS) to measure the state of blood in a living body (relative quantitative changes in oxyhemoglobin and deoxyhemoglobin). When the brain is active, the demand for glucose and oxygen increases in the active area, resulting in an increase in cerebral blood flow (neurovascular coupling). This is accompanied by an increase in total hemoglobin and oxyhemoglobin, while a slight decrease in deoxyhemoglobin. Therefore, areas where an increase in oxyhemoglobin is observed using functional near-infrared spectroscopy (fNIRS) can be determined to be areas where activity is elevated. In other words, the results of Test Example 4 confirmed that the test beverage of Example 1 improves brain activity.

[0087] The disclosure of Japanese Patent Application No. 2024-105577 (filing date: June 28, 2024) is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. An activity enhancer containing ethyl lactate as the active ingredient.

2. The activity enhancer according to claim 1, wherein the content of ethyl lactate is 2 ppm or more and 700 ppm or less.

3. The activity enhancer of claim 1 or 2, further comprising water.

4. The activity enhancer according to claim 1 or 2, wherein the amount of ethyl lactate taken per dose is 1 mg or more and 140 mg or less.

5. The activity enhancer according to claim 1 or 2, which is taken orally.

6. An activity enhancer according to claim 1 or 2 that gives the feeling of high activity.

7. The activity enhancer according to claim 1 or 2, which elevates mood.

8. The activity enhancer according to claim 1 or 2, which provides a feeling of vitality.

9. The activity enhancer according to claim 1 or 2, which increases cerebral blood flow.

10. Foods and drinks containing ethyl lactate to improve activity.

11. A method for improving activity in a subject, comprising having the subject ingest the activity-enhancing agent according to claim 1 or 2.

12. The method for improving activity according to claim 11, wherein the amount of ethyl lactate taken per dose is 1 mg or more and 140 mg or less.

13. The method for improving activity according to claim 11, wherein the activity enhancer is taken orally.

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