WO2025004650A1 - Agent and composition for reducing fatigue in middle-aged and older persons - Google Patents

Abstract

The present invention addresses the problem of providing a novel agent and composition for reducing fatigue in middle-aged and older persons.　The present invention provides an agent for reducing fatigue in middle-aged and older persons, the active ingredient of the agent being a medium-chain fatty acid.

Description

Agent and composition for reducing fatigue in middle-aged and elderly people

The present invention relates to an agent and composition for reducing fatigue in middle-aged and elderly people.

　In modern society, while convenience has improved, it is known that the number of people feeling fatigue and other symptoms is increasing.

"Fatigue" can be broadly divided into mental fatigue and physical fatigue, and although it can be alleviated by improving lifestyle habits such as sleep and diet, it is not necessarily easy to put this into practice every day.

On the other hand, various compositions that have a recovery effect on fatigue have been proposed (for example, Patent Documents 1 and 2).

JP 2021-20881 A JP 2018-2621 A

Here, "feeling of fatigue" is a subjective sensation regarding the presence of fatigue, and is distinguished from "fatigue" which indicates an objective decrease in activity state.
The present inventors have focused on the fact that middle-aged and elderly people in particular tend to feel fatigue in their daily lives. Therefore, they aimed to develop an agent that can be easily and continuously taken by middle-aged and elderly people and has a fatigue-reducing effect without the risk of side effects.

The present invention was made in consideration of the above circumstances, and aims to provide a new agent and composition for reducing fatigue in middle-aged and elderly people.

The inventors discovered the novel finding that medium-chain fatty acids can reduce fatigue in middle-aged and elderly people, and have now completed the present invention. More specifically, the present invention provides the following:

(1) An agent for reducing fatigue in middle-aged and elderly people, comprising:
The active ingredient of the agent is a medium-chain fatty acid.

(2) The agent according to (1), wherein the fatigue is mental fatigue and/or physical fatigue.

(3) The agent comprises a triglyceride,
The agent according to (1), wherein the medium-chain fatty acid is in the form of a constituent fatty acid of the triglyceride.

(4) The agent according to (3), wherein the triglyceride is a medium-chain fatty acid triglyceride.

(5) The agent according to any one of (1) to (4), wherein the medium-chain fatty acid includes octanoic acid and/or decanoic acid.

(6) A composition for reducing fatigue in middle-aged and elderly people, comprising:
A composition, wherein the active ingredient of the composition comprises at least a medium chain fatty acid.

(7) The composition according to (6), wherein the fatigue is mental fatigue and/or physical fatigue.

(8) The composition comprises a triglyceride,
The composition according to (6), wherein the medium-chain fatty acid is in the form of a constituent fatty acid of the triglyceride.

(9) The composition according to (8), wherein the triglyceride is a medium-chain fatty acid triglyceride.

(10) The composition according to (6), wherein the medium-chain fatty acid includes octanoic acid and/or decanoic acid.

(11) The composition according to any one of (6) to (10), wherein the composition is in the form of a drug, a quasi-drug, or a food or beverage.

(12) The composition according to (11), wherein the composition is administered so that 1 g or more of the medium-chain fatty acid is ingested per day.

(13) The composition according to (11), wherein the medium-chain fatty acid is administered in an amount of 1 g or more per day, and the intake of octanoic acid is greater than the intake of decanoic acid.

The present invention provides a novel agent and composition for reducing fatigue in middle-aged and elderly people.

The following describes an embodiment of the present invention, but the present invention is not limited to this.

<Definition>
Hereinafter, unless otherwise specified, each term in the present invention has the following meaning.

(1) Middle-aged and Elderly People In the present invention, the term "middle-aged and elderly people" includes those who are at least halfway through their average life expectancy.

In the present invention, "living organisms" include, but are not limited to, humans and non-human mammals (pets, livestock, etc.).

In the case of humans, "middle-aged or elderly people" preferably include those aged 40 or older, more preferably 50 or older, and even more preferably 60 or older. Furthermore, in the case of humans, those aged 65 or older may also be referred to as "elderly people."

In the present invention, middle-aged or elderly people are preferably humans aged 60 or older, more preferably humans aged 65 or older, and even more preferably healthy elderly humans.
In the present invention, the term "healthy" includes a state in which the person is not suffering from any mental or physical disease and a state in which the person is free from any impediment in daily life.

The agent and composition of the present invention can reduce fatigue and other symptoms associated with daily life, and is therefore preferably applied to healthy elderly people among middle-aged and elderly people.

The agent and composition of the present invention can be more effective for middle-aged and elderly people who do not exercise much in their daily lives, or who are physically weak and subject to a high level of oxidative stress.
On the other hand, the desired effects may be difficult to achieve in athletes who are subject to a high level of oxidative stress due to regular exercise, or in frail individuals whose health has declined and whose bodies are chronically accumulated with oxidative stress.
Therefore, in a preferred embodiment of the present invention, the middle-aged and elderly people in the present invention do not include athletes or people with frailty.

In the present invention, the term "athlete" includes anyone who regularly exercises or participates in sports.
Athletes include, for example, those who perform any of the following exercises and sports of intensities, and preferably those who perform them continuously (for example, for one month or more). Note that "METs" (metabolic equivalents) is an index that indicates the intensity of exercise or sports, and expresses the intensity of various exercises or sports when the calories burned by a person at rest are taken as "1 MET."
・Yoga and stretching (2.5 METs) at least once a week for about 1 hour・Golf driving range and bowling (3.0 METs) at least once a week for about 1 hour・Flexibility exercises at home (3.5 METs) at least once a week for about 1 hour・Water walking (4.0 METs) at least once a week for about 1 hour・Light jogging (6.0 METs) at least once a week for about 30 minutes・Swimming (8.0 METs) at least once a week for about 30 minutes

(2) Fatigue In the present invention, the term "fatigue" refers to the awareness of the presence of fatigue in either the mind or the body, or both. The term "fatigue" includes chronic fatigue and transient fatigue.

"Fatigue" is the subjective feeling regarding the presence of fatigue.
Therefore, "fatigue" is to be distinguished from "fatigue" (defined by the Japan Society for Fatigue Studies as "a state of reduced physical activity accompanied by specific discomfort and a desire for rest resulting from excessive physical and mental activity, or from illness"), which indicates an objective decrease in activity state.
"Fatigue" is also distinguished from "frailty" (defined by the Japan Geriatrics Society as "an intermediate state between a healthy state and a state requiring nursing care (a state in which support is required in daily life)"), which indicates an objective decline in health status.
Furthermore, "fatigue" is also distinguished from "frailty" diagnosed by the "Cardiovascular Health Study (CHS) criteria" (Fried LP, et al: Frailty in older adults: evidence for a phenotype. J Gerontol A Biol Sci Med Sci 2001; 56(3)).
For example, there are situations in which a person may subjectively feel a "feeling of fatigue" even when there is no objective "fatigue" or "frailty," and the present invention contributes to reducing such a "feeling of fatigue."

In the present invention, "fatigue" can be roughly divided into "mental fatigue" and "physical fatigue".
"Mental fatigue" includes fatigue felt by the mind and spirit.
"Physical fatigue" includes fatigue felt by the body.

The presence or absence and degree of fatigue in the present invention can be determined using various conventionally known evaluation methods.

An example of a method for evaluating fatigue is the self-report health status questionnaire "SF-36 (trademark) v2" (MOS Short-Form 36-Item Health. Survey ver. 2). "SF-36 (trademark) v2" is a scale for evaluating quality of life (QOL) using multiple health concepts common to all people (health concepts).
The following health concepts can be used to evaluate fatigue: For each index, a higher value means a higher QOL (i.e., less fatigue).
・Indicators of physical fatigue: "Vitality (VT)", etc. ・Indicators of mental fatigue: "Mental Health (MH)", "Mental component summary (MCS)", etc.

In the present invention, "relief of fatigue" includes suppression of the onset of fatigue, alleviation of the degree of fatigue, recovery from fatigue, and the like.
If the fatigue is mental fatigue, the effects of reducing fatigue include being less likely to become depressed, having a more positive mood, being less irritable, becoming calmer, improving restrictions or reductions in activity due to psychological reasons, and increasing social interactions.
When the fatigue is physical fatigue, the reduction of fatigue may include increased vitality, feeling full of energy, and the like.

(3) Active Ingredient In the present invention, the term "active ingredient" refers to a physiologically active substance having a desired effect (such as an effect of reducing fatigue).

<Agent for reducing fatigue in middle-aged and elderly people>
The agent for reducing fatigue in middle-aged and elderly people according to the present invention (hereinafter also referred to as "the agent of the present invention") contains a medium-chain fatty acid as an active ingredient.

Middle-aged and elderly people are prone to aging-related disorders and tend to feel fatigued on a daily basis even if they are not suffering from any disease. Therefore, there is a high demand for a method of reducing fatigue that can be easily incorporated into the daily lives of middle-aged and elderly people.
On the other hand, there has been insufficient knowledge about ingredients that can reduce fatigue, can be easily taken continuously by middle-aged and elderly people, and have no concerns about side effects, etc.

In light of these circumstances, the present inventors conducted extensive research and discovered a new finding that the intake of medium-chain fatty acids can reduce fatigue in middle-aged and elderly people. Medium-chain fatty acids are components that can be incorporated into foods and beverages, can be taken continuously on a daily basis, and are free from concerns about side effects. The effect of reducing fatigue was significantly higher than that of long-chain fatty acids.
Therefore, by taking the agent of the present invention, middle-aged and elderly people can easily reduce fatigue and are expected to improve their daily QOL (quality of life).

The agent of the present invention is described in detail below.

(1) Medium-Chain Fatty Acids Medium-chain fatty acids (also referred to as MCFA) are a general term for linear saturated fatty acids having 6 to 12 carbon atoms, and are fat and oil components contained in ordinary foods and the like (e.g., edible fats and oils, dairy products, etc.).
Therefore, the agent of the present invention is highly safe and can be taken on a daily basis.

As described above, the medium-chain fatty acid is a general term for linear saturated fatty acids having a specific number of carbon atoms, but in the present invention, the medium-chain fatty acids as a whole are treated as one component.
However, the medium-chain fatty acid in the present invention may consist of only one type of linear saturated fatty acid, or may contain multiple types of linear saturated fatty acids.

The agent of the present invention contains at least a medium-chain fatty acid as an active ingredient. The medium-chain fatty acid in the present invention is an active ingredient having a fatigue reducing effect.
In addition, the agent of the present invention may contain, together with the medium-chain fatty acid, an active ingredient having a fatigue-reducing effect or other effects, provided that the effect of the present invention is not impaired. However, preferred embodiments of the present invention include embodiments in which the active ingredient is only a medium-chain fatty acid.

(1-1) Types of Medium-Chain Fatty Acids The medium-chain fatty acids in the present invention have 6 or more and 12 or less carbon atoms, preferably 8 or more and 12 or less carbon atoms, and more preferably 8 and/or 10 carbon atoms.

The medium-chain fatty acids in the present invention include caproic acid (hexanoic acid), caprylic acid (octanoic acid), capric acid (decanoic acid), and lauric acid. Of these, caprylic acid (octanoic acid) and/or capric acid (decanoic acid) are preferred.

The medium-chain fatty acid may be obtained by hydrolyzing palm kernel oil or coconut oil and then refining it. In addition, commercially available products or reagents may be used as the medium-chain fatty acid.

(1-2) Form of Medium-Chain Fatty Acid The form of the medium-chain fatty acid is not particularly limited, and may be the medium-chain fatty acid itself (free fatty acid, free form), a fatty acid precursor that is converted into the medium-chain fatty acid in the body (e.g., a salt, an ester (such as a glyceride described later)), or a mixture thereof.

Glycerides are preferred as the form of medium-chain fatty acids, as they are closer to the usual food form.

Glycerides have a structure in which fatty acids and glycerin are ester-bonded, and exist in one of three forms (monoglyceride, diglyceride, and triglyceride) depending on the number of fatty acids bonded to glycerin.
The glyceride in the present invention may be in any of the above three forms, but at least one of its constituent fatty acids must be a medium-chain fatty acid.
In addition, a triglyceride in which all of the constituent fatty acids are medium-chain fatty acids is also called a medium-chain triglyceride (MCT).

The fatty acids constituting the diglycerides and triglycerides may be of the same type or different types. In the case of glycerides composed of different types of fatty acids, the bonding position of each fatty acid to glycerin is not particularly limited. Furthermore, the constituent fatty acids of the glycerides may or may not contain fatty acids other than medium-chain fatty acids (e.g., long-chain fatty acids having 14 to 22 carbon atoms, etc.).

In the present invention, the lower limit of the proportion of medium-chain fatty acids in the total constituent fatty acids of the glyceride is preferably 10% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more. The upper limit is preferably 100% by mass or less.
When the ratio of medium-chain fatty acids is within the above range, the effect of reducing fatigue is more easily achieved.

In the present invention, the medium-chain fatty acid is preferably in the form of a constituent fatty acid of a triglyceride, and more preferably in the form of a constituent fatty acid of a medium-chain fatty acid triglyceride.
In other words, the agent of the present invention preferably contains a triglyceride containing a medium-chain fatty acid (a triglyceride in which one or more of the constituent fatty acids are medium-chain fatty acids), and more preferably contains a medium-chain fatty acid triglyceride (a triglyceride in which all of the constituent fatty acids are medium-chain fatty acids).

When the medium-chain fatty acid is in the form of a constituent fatty acid of a triglyceride, it is preferable that the triglyceride is one or more selected from the group consisting of triglycerides whose constituent fatty acids are only medium-chain fatty acids with 8 or 10 carbon atoms, and triglycerides whose constituent fatty acids are medium-chain fatty acids with 8 carbon atoms and medium-chain fatty acids with 10 carbon atoms.

When the medium chain fatty acid is in the form of a constituent fatty acid of a triglyceride, the triglyceride is a triglyceride having a medium chain fatty acid with 8 carbon atoms and a medium chain fatty acid with 10 carbon atoms as constituent fatty acids, and the mass ratio of the medium chain fatty acid with 8 carbon atoms and the medium chain fatty acid with 10 carbon atoms (medium chain fatty acid with 8 carbon atoms:medium chain fatty acid with 10 carbon atoms) is preferably 20:80 to 90:10, more preferably 30:70 to 85:15, and even more preferably 60:40 to 80:20.

There is no particular limitation on the method for producing glycerides, but for example, glycerides can be obtained by esterifying medium-chain fatty acids derived from palm kernel oil or coconut oil with glycerin. Examples of esterification reactions include a method in which the reaction is carried out under pressure without a catalyst or solvent, a method in which the reaction is carried out using a synthetic catalyst such as sodium methoxide, and a method in which the reaction is carried out using lipase as a catalyst.

(1-3) Amount of Medium-Chain Fatty Acids The agent of the present invention is not particularly limited in amount as long as it contains medium-chain fatty acids.
For example, the amount of medium-chain fatty acids in the agent of the present invention may be 30% by mass or more and 100% by mass or less.
However, from the viewpoint of easily achieving the effects of the present invention, it is preferable to adjust the amount of medium-chain fatty acids to be taken per day, as described below.

The content of medium-chain fatty acids contained in the agent of the present invention can be determined by gas chromatography.

(2) Other Components The agent of the present invention may consist only of medium-chain fatty acids (medium-chain fatty acids themselves, or fatty acid precursors (particularly glycerides) that are converted into medium-chain fatty acids in the body), but may also contain other components in addition to the medium-chain fatty acids.
The other components are not particularly limited so long as they do not impair the effects of the present invention, and examples of such components include active ingredients other than medium-chain fatty acids, emulsifiers, antioxidants, long-chain fatty acid triglycerides, solvents, and the like.

However, a preferred embodiment of the present invention includes an agent of the present invention that consists only of medium-chain fatty acids (medium-chain fatty acids themselves, or fatty acid precursors (particularly glycerides) that are converted to medium-chain fatty acids in the body).

(3) Form of the Agent of the Present Invention The agent of the present invention may be in any form.

The agent of the present invention is preferably in the form of an oral agent since it is suitable for daily intake.
(4) Method for Producing the Agent of the Present Invention The method for producing the agent of the present invention is not particularly limited, and any suitable method can be adopted depending on the form of the agent.

(5) Use of the Agent of the Present Invention The agent of the present invention is used to relieve fatigue in middle-aged and elderly people.
Therefore, the subjects to which the agent of the present invention is administered are middle-aged and elderly people.

The fatigue that can be alleviated by the agent of the present invention includes mental fatigue and/or physical fatigue.
In particular, the fact that medium-chain fatty acids have an alleviating effect on the mental state could not be predicted from conventional knowledge, and such an effect of alleviating mental fatigue is extremely unexpected.

The agent of the present invention can be taken at any time during daily life. Examples of times for taking the agent include before or after meals, upon waking up, before sleeping, etc.

The dosage and frequency of administration of the agent of the present invention are not particularly limited and can be set appropriately depending on the condition of the subject, etc.

From the viewpoint of making it easier to achieve the effects of the present invention, the agent of the present invention is administered so that preferably 1 g or more, more preferably 1 g to 10 g, even more preferably 1 g to 5 g, and even more preferably 1 g to 2.5 g of medium-chain fatty acids are ingested per day.

From the viewpoint that the effects of the present invention are particularly likely to be achieved, it is preferable that the agent of the present invention is administered so that 1 g or more and 5 g or less of medium-chain fatty acids are ingested per day, and the amount of octanoic acid ingested is greater than the amount of decanoic acid ingested. In such an embodiment, it is more preferable that the medium-chain fatty acids ingested are only octanoic acid and decanoic acid.

<Composition for reducing fatigue in middle-aged and elderly people>
The composition for reducing fatigue in middle-aged and elderly people according to the present invention (hereinafter also referred to as "the composition of the present invention") contains a medium-chain fatty acid as an active ingredient.

The composition of the present invention is common to the agent of the present invention in terms of composition, use, etc., except that it is a mixture containing medium-chain fatty acids (including the type and form of medium-chain fatty acids) and components other than medium-chain fatty acids.
However, while the composition of the present invention contains medium-chain fatty acids and other components (i.e., contains two or more components), the agent of the present invention includes both an embodiment consisting of only medium-chain fatty acids and an embodiment containing medium-chain fatty acids and other components. Thus, the composition of the present invention and the agent of the present invention may overlap in composition.

In a preferred embodiment of the invention, the medium chain fatty acids may be the only active ingredient in the compositions of the invention.
In this embodiment, the components other than the medium-chain fatty acids contained in the composition of the present invention may be one or more inactive components. In this embodiment, the "inactive components" include, for example, substances that are harmless to the living body but do not have a fatigue reducing effect.

(1) Constitution of the composition of the present invention The composition of the present invention may contain medium-chain fatty acids and other ingredients, as explained in the section <Agent for reducing fatigue in middle-aged and elderly people> above.

The amount of medium-chain fatty acid contained in the composition of the present invention is not particularly limited.
The lower limit of the amount of medium-chain fatty acids is preferably 0.5% by mass or more, more preferably 5.0% by mass or more, and even more preferably 10.0% by mass or more, based on the composition of the present invention.
The upper limit of the amount of medium-chain fatty acids is preferably 95.0% by mass or less, more preferably 70.0% by mass or less, and even more preferably 50.0% by mass or less, based on the composition of the present invention.
However, from the viewpoint of easily achieving the effects of the present invention, it is preferable to adjust the amount of medium-chain fatty acids to be taken per day, as described below.

(2) Form of the Composition of the Present Invention The composition of the present invention may be in the form of a drug, a quasi-drug, or a food or drink.

(2-1) Pharmaceuticals and Quasi-Drugs Pharmaceuticals include both oral and parenteral pharmaceutical compositions, with oral pharmaceutical compositions being preferred from the viewpoint of ease of continuous intake.

Forms of pharmaceutical compositions for oral administration include capsules, tablets, pills, powders, fine granules, granules, liquids, syrups, etc.

Forms of pharmaceutical compositions for parenteral administration include preparations such as injections and infusions.

The pharmaceutical product of the present invention may contain pharmacologically and pharmacologic acceptable additives together with the medium-chain fatty acids. As "pharmacologically and pharmacologic acceptable additives", substances that are commonly used as excipients in the pharmaceutical field and do not react with medium-chain fatty acids can be used.

The nature of the quasi-drugs in this invention is similar to the pharmaceutical products listed above.

(2-2) Food and Beverages Beverages include soft drinks, soups, etc.

The form of the soft drink is not particularly limited, and may be, for example,
Carbonated drinks (carbonated water, cider, ginger ale, etc.),
Fruit drinks (orange juice, grapefruit juice, apple juice, etc.),
Coffee drinks (black coffee, cafe au lait, espresso, etc.),
Tea beverages (green tea, barley tea, black tea, etc.),
Milk drinks (lactic acid bacteria drinks, etc.),
Mineral water, etc.

The form of the soup is not particularly limited, and may be, for example,
Japanese style soup (miso soup, pork soup, etc.),
Western-style soup (potage soup, minestrone, chowder, etc.),
Chinese-style soup (chicken soup, etc.),
Ethnic soups (Tom Yum Goong, Tom Kha Gai, etc.)
etc.

(2-3) Foods Foods include supplements, general foods, animal foods, and animal feed.
The food and drink of the present invention also includes so-called health foods, such as functional foods (specified health foods, nutrient functional foods, functional food, etc.) whose efficacy has been approved by a designated organization.

The form of the supplement is not particularly limited, and it may be either a solid preparation or a liquid preparation. Examples include tablets, coated tablets, capsules, granules, powders, powders, sustained-release preparations, suspensions, emulsions, oral liquids, sugar-coated tablets, pills, fine granules, syrups, elixirs, etc.

The form of the general food is not particularly limited, and examples thereof include:
Bakery products and confectionery (bread, cakes, cookies, biscuits, donuts, muffins, scones, chocolates, snacks, whipped cream, ice cream, ice cream mixes, confectionery bars, chocolate bars, high fat bars, UHT desserts, pasteurized desserts, etc.),
Beverages (fruit juices, energy drinks, sports drinks, etc.),
Condiments and processed foods (dressings, sauces, mayonnaise, butter, margarine, prepared margarine, fat spreads, shortening, bakery mixes, etc.),
Dairy products (cheese spreads, processed cheese, dairy desserts, flavored milk, cultured dairy products, cheese, butter, condensed milk products, yogurt, cream, etc.),
Soups, stir-frying oils, frying oils, fried foods, processed meat products, frozen foods, fried foods, noodles, retort foods, liquid foods, swallowing foods, soy products, pasteurized liquid eggs, gels, jellies, fillings (fat-based or water-containing fillings)
etc.

When the composition of the present invention is used for the production of general foods, the medium-chain fatty acids are preferably in the form of medium-chain fatty acid triglycerides. In such cases, it is preferable to add medium-chain fatty acid triglycerides to the raw materials or to use the medium-chain fatty acid triglycerides in place of the oils and fats in the raw materials.

(3) Method for Producing the Composition of the Present Invention The method for producing the composition of the present invention is not particularly limited, and any suitable method can be adopted depending on the form of the composition.

(4) Uses of the Composition of the Present Invention The composition of the present invention can be used for the same purposes as those explained in the section "Agent for Relieving Fatigue in Middle-aged and Elderly People" above.

The amount and frequency of ingestion of the composition of the present invention are not particularly limited and can be set appropriately depending on the condition of the subject, etc.

From the viewpoint of making it easier to achieve the effects of the present invention, the composition of the present invention is administered so that preferably 1 g or more, more preferably 1 g to 10 g, even more preferably 1 g to 5 g, and even more preferably 1 g to 2.5 g of medium-chain fatty acids are ingested per day.

From the viewpoint that the effects of the present invention are particularly likely to be achieved, it is preferable that the composition of the present invention is administered so that 1 g or more and 5 g or less of medium-chain fatty acids are ingested per day, and the amount of octanoic acid ingested is greater than the amount of decanoic acid ingested. In such an embodiment, it is more preferable that the medium-chain fatty acids ingested are only octanoic acid and decanoic acid.

Other Aspects of the Invention
The present invention also includes, for example, the following aspects.
A method for reducing fatigue, comprising the step of administering a medium-chain fatty acid or a composition to a middle-aged or elderly person suffering from fatigue.
- A medium chain fatty acid or composition for use in reducing fatigue in middle-aged and elderly people.
- Use of medium-chain fatty acids or compositions in the manufacture of medicines, quasi-drugs, or food and beverage products for reducing fatigue in middle-aged and elderly people.
- Use of medium-chain fatty acids or compositions in the manufacture of medicines, quasi-drugs, or food and beverage products for reducing fatigue in middle-aged and elderly people.
A method for producing a medicine, quasi-drug, or food or beverage product for reducing fatigue in middle-aged and elderly people using a medium-chain fatty acid or composition.

(1) Method for Reducing Fatigue The method for reducing fatigue according to the present invention comprises the step of administering a medium-chain fatty acid, which is the active ingredient of the agent of the present invention, or a composition containing the medium-chain fatty acid, to a middle-aged or elderly person suffering from fatigue.
In other words, medium-chain fatty acids or compositions containing the medium-chain fatty acids can be suitably administered to middle-aged and elderly people who need to reduce fatigue.

Details of the medium-chain fatty acid or the composition containing the medium-chain fatty acid to be administered are as described above.

The method of administration of medium-chain fatty acids or compositions containing the medium-chain fatty acids can be appropriately selected depending on the form, etc., and includes oral administration and parenteral administration (injection, drip infusion, etc.).

The dosage and frequency of administration of the medium-chain fatty acids or compositions containing the medium-chain fatty acids can be set appropriately depending on the condition (fatigue level, age, body weight, etc.) of the middle-aged or elderly person to whom the medium-chain fatty acids are administered.

(2) Medium-chain fatty acid or composition for use in reducing fatigue The medium-chain fatty acid, which is an active ingredient of the agent of the present invention, or a composition containing the medium-chain fatty acid can be used in reducing fatigue in middle-aged and elderly people.

Details of the medium-chain fatty acids used or the composition containing the medium-chain fatty acids are as described above.

The method of use of medium-chain fatty acids or compositions containing the medium-chain fatty acids can be appropriately selected depending on their form, etc., and includes oral administration and parenteral administration (injection, drip infusion, etc.).

The dosage and frequency of administration of the medium-chain fatty acids or compositions containing the medium-chain fatty acids can be set appropriately depending on the condition (fatigue level, age, body weight, etc.) of the middle-aged or elderly person to whom the medium-chain fatty acids are administered.

(3) Application of medium-chain fatty acids or compositions in the production of medicines, quasi-drugs, or foods and beverages for reducing fatigue The medium-chain fatty acids, which are active ingredients of the agent of the present invention, or compositions containing the medium-chain fatty acids can be used in the production of medicines, quasi-drugs, or foods and beverages for reducing fatigue in middle-aged and elderly people.
In other words, the medium-chain fatty acid or a composition containing the medium-chain fatty acid can be used as an ingredient (active ingredient) in medicines, quasi-drugs, or food and beverage products for reducing fatigue in middle-aged and elderly people.

Details of the medium-chain fatty acids used or the composition containing the medium-chain fatty acids are as described above.

(4) Use of medium-chain fatty acids or compositions in the production of medicines, quasi-drugs, or food and beverage products for relieving fatigue in middle-aged and elderly people The medium-chain fatty acids that are the active ingredients of the agent of the present invention, or compositions containing the medium-chain fatty acids, can be used for the production of medicines, quasi-drugs, or food and beverage products for relieving fatigue in middle-aged and elderly people.
In other words, the medium-chain fatty acid or a composition containing the medium-chain fatty acid can be used as an ingredient (active ingredient) in medicines, quasi-drugs, or foods and beverages for reducing fatigue in middle-aged and elderly people.

Details of the medium-chain fatty acids used or the composition containing the medium-chain fatty acids are as described above.

The phrase "use of medium-chain fatty acids in the manufacture of medicines, quasi-drugs, or food and beverage products for reducing fatigue in middle-aged and elderly people" is used interchangeably with expressions such as "use of medium-chain fatty acids or compositions in the manufacture of medicines, quasi-drugs, or food and beverage products for reducing fatigue in middle-aged and elderly people."

(5) Method for producing a medicine, quasi-drug, or food or beverage product for relieving fatigue in middle-aged and elderly people using a medium-chain fatty acid or a composition The medium-chain fatty acid, which is an active ingredient of the agent of the present invention, or a composition containing the medium-chain fatty acid, can be used for producing a medicine, quasi-drug, or food or beverage product for relieving fatigue in middle-aged and elderly people.
In other words, the medium-chain fatty acid or a composition containing the medium-chain fatty acid can be used as an ingredient (active ingredient) in medicines, quasi-drugs, or foods and beverages for reducing fatigue in middle-aged and elderly people.

Details of the medium-chain fatty acids used or the composition containing the medium-chain fatty acids are as described above.

The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

Using the following method, middle-aged and elderly people were given medium-chain fatty acids orally and their effects on fatigue were examined.

(1) Subjects One hundred twenty people who met all of the following requirements were selected as subjects. All of these subjects were middle-aged or elderly (including healthy elderly people).
- Japanese men and women aged 60 to 75 years.
- Body mass index (BMI) is 19 kg/m2 or ^greater and less than 24 kg/ ^m2 .
- Exercise or walk less than once a week for less than 30 minutes each time.
- Those who do not regularly (more than four hours a week) provide childcare or elderly care.
- Participants do not meet the exclusion criteria regarding health and lifestyle (daily intake of medium-chain fatty acids, being a patient with a serious illness, undergoing dietary or exercise therapy under the supervision of a doctor, etc.).

(2) Test Foods Four types of test foods were prepared using various fatty acids.

(2-1) Preparation of fatty acid samples The following fatty acid samples were used:
Oils and fats containing long-chain fatty acids as constituent fatty acids (LCT): carbon number = 16 to 24, product name "Nissin Canola Oil" (manufactured by Nisshin Oillio Group Co., Ltd.)
Oils and fats containing medium-chain fatty acids as constituent fatty acids-1 (MCT1): Medium-chain fatty acid triglyceride (triacylglycerol) whose constituent fatty acids are only octanoic acid (carbon number = 8) and decanoic acid (carbon number = 10) and whose mass ratio of octanoic acid:decanoic acid is 3:7, product name "Nissin MCT-C10R" (manufactured by Nisshin Oillio Group, Ltd.)
Oils and fats containing medium-chain fatty acids as constituent fatty acids-2 (MCT2): Medium-chain fatty acid triglyceride (triacylglycerol) whose constituent fatty acids are only octanoic acid and decanoic acid, and whose mass ratio of octanoic acid to decanoic acid is 75:25, product name "Nissin MCT Oil" (manufactured by Nisshin Oillio Group, Ltd.)

(2-2) Preparation of Test Foods Four types of test foods were obtained by blending the ingredients in the proportions shown in Table 1 using the method described below.
First, the emulsifier and the gelling agent were mixed and stirred in hot water to be uniformly dissolved.
Next, the flavor and fatty acid sample (LCT and/or MCT) were added and pre-emulsified with a homomixer, and further homogenized with a homogenizer.
15 g of the obtained emulsion was packed and sealed into a stick-shaped plastic film, sterilized by heating, and then gelled to obtain a test food.

(3) Administration of test food to subjects A randomized, double-blind, parallel-group comparative study was conducted using the following method, with the "control food" set as a placebo.

The subjects were randomly assigned to one of four test food intake groups (30 subjects per group).
The study period was set to 12 weeks.
During the test period, subjects were instructed to orally ingest one packet of the test food after two of the three meals per day (i.e., two packets per day).
The test food contained 3 g of fats and oils (fatty acid sample) per packet, so that the subjects were asked to ingest 6 g of fats and oils (fatty acid sample) per day.
The details of the daily intake of fats and oils (fatty acid samples) and medium-chain fatty acids given to the subjects are shown in Table 2. The amount of medium-chain fatty acids in each food (equivalent amount of octanoic acid, equivalent amount of decanoic acid, total amount of medium-chain fatty acids) was determined by gas chromatography.

During the study period, subjects were instructed to continue living their normal lives while refraining from excessive exercise.

(4) Evaluation and Results of Fatigue A survey of health-related quality of life (H-QOL) was conducted on the subjects before the start of the study and at 4, 8, and 12 weeks after the start of the study.
The survey used a self-report health status questionnaire, "SF-36 (trademark) v2" (MOS Short-Form 36-Item Health. Survey ver. 2).
Based on "SF-36 (trademark) v2," raw scores were calculated from the answers given for each health concept and converted into a score (summary score) ranging from 0 to 100. A higher summary score indicates a higher quality of life (QOL) (i.e., less fatigue).

The following summary scores were used in this study:
・Physical fatigue index: Summary score of "Vitality (VT)" among health concepts ・Mental fatigue index: Summary score of "Mental Health (MH)" and "Mental component summary (MCS)" among health concepts

The summary scores obtained for each test food intake group are shown in Tables 3 and 4. In Tables 3 and 4, "actual value" refers to the summary score obtained from the results of "SF-36 (trademark) v2." "Change value" refers to the fluctuation of the "actual value" from measurement week 0.

Some of the results of the muscle strength tests performed on each subject are shown in Table 5. The "actual value of right knee extension muscle strength" in Table 5 means the average value of right knee extension muscle strength. Table 5 shows the results of the subjects before the start of the test.
In the muscle strength test, knee extension muscle strength of both the left and right legs was measured using a lower limb muscle strength measuring device (Locomo Scan-II, manufactured by Alcare Co., Ltd.).

In each table, each value is shown as "mean value ± standard error." Also, an asterisk (*) indicates that there was a significant difference compared to the group that consumed the "control food" (p<0.05, Dunnett's test).

The group taking "Test Food A" showed a significant increase in the change score of "Mental QOL" 8 weeks after the start of the study, compared to the group taking "Control Food".
Furthermore, the group that consumed "Test Food A" showed significant increases in the actual value and change score of "Vitality", the actual value score of "Mental Health", and the actual value and change score of "Mental QOL" 12 weeks after the start of the study, compared to the group that consumed the "Control Food".

The group taking "Test Food B" showed a significant increase in the change score of "vitality" 8 weeks after the start of the study, compared to the group taking the "Control Food".
Furthermore, the group taking "Test Food B" showed a significant increase in the change scores of "vitality" and "mental QOL" 12 weeks after the start of the study, compared to the group taking the "Control Food".

The group that consumed "Test Food C" showed significant increases in the actual scores of "vitality,""mentalhealth," and "mental QOL" eight weeks after the start of the study, as well as the change in the scores of "vitality" and "mental QOL," compared to the group that consumed the "control food."
Furthermore, the group that consumed "Test Food C" showed significant increases in the actual scores of "vitality,""mentalhealth," and "mental QOL" 12 weeks after the start of the study, as well as the change in the scores of "vitality" and "mental QOL," compared to the group that consumed the "Control Food."

From the above results, it was found that continuous intake of medium-chain fatty acids (particularly preferably octanoic acid and decanoic acid) can reduce fatigue in middle-aged and elderly people.
Furthermore, continuous intake of medium-chain fatty acids (particularly preferably octanoic acid and decanoic acid) is expected to have the effect of enhancing vitality, recovering from fatigue, and suppressing fatigue in middle-aged and elderly people.

As medium-chain fatty acids, the effects of both octanoic acid and decanoic acid were confirmed, but the test food containing octanoic acid tended to be particularly effective in achieving the effects of the present invention.
In addition, in this study, the muscle strength of the subjects in the "Test Food B" group was higher than that of the other groups (Table 5). This is thought to be due to the fact that the effect of improving fatigue in the "Test Food B" group, which had the highest intake of octanoic acid, was somewhat lower than that of the other groups.
However, when comparing subjects with roughly the same muscle strength, the greater the intake of octanoic acid, the more likely it was to improve fatigue.

In this study, the total intake of medium-chain fatty acids was set at a maximum of 5.4 g per day, but it is believed that an intake of 1 g or more per day would be sufficient to produce a sufficient effect.
In particular, it was estimated that the effects of the present invention are more easily achieved when the total intake of medium-chain fatty acids per day is 1 g or more and 5 g or less, and the intake of octanoic acid is greater than the intake of decanoic acid.

Claims (13)

An agent for reducing fatigue in middle-aged and elderly people,
The active ingredient of the agent is a medium-chain fatty acid. The agent according to claim 1, wherein the fatigue is mental fatigue and/or physical fatigue. the agent comprises a triglyceride;
The agent according to claim 1 , wherein the medium-chain fatty acid is in the form of a constituent fatty acid of the triglyceride. The agent according to claim 3, wherein the triglyceride is a medium-chain fatty acid triglyceride. The agent according to any one of claims 1 to 4, wherein the medium chain fatty acid includes octanoic acid and/or decanoic acid. A composition for reducing fatigue in middle-aged and elderly people, comprising:
A composition, wherein the active ingredient of the composition comprises at least a medium chain fatty acid. The composition according to claim 6, wherein the feeling of fatigue is mental fatigue and/or physical fatigue. the composition comprises a triglyceride;
The composition according to claim 6 , wherein the medium chain fatty acid is in the form of a constituent fatty acid of the triglyceride. The composition according to claim 8, wherein the triglyceride is a medium chain triglyceride. The composition of claim 6, wherein the medium chain fatty acid comprises octanoic acid and/or decanoic acid. The composition according to any one of claims 6 to 10, wherein the composition is in the form of a drug, a quasi-drug, or a food or drink. The composition of claim 11, wherein the composition is administered so that 1 g or more of the medium chain fatty acid is ingested per day. The composition of claim 11, wherein the composition is administered such that 1 g or more of the medium chain fatty acid is administered per day and the intake of octanoic acid is greater than the intake of decanoic acid.