Could 'Lack of Smiles' Be a Risk? Facial Expressions as a Potential Health Indicator in the Elderly

POLA Chemical Industries Co., Ltd. (Headquarters: Yokohama, Kanagawa Prefecture; President: Takayuki Katagiri), responsible for research, development, and production within the POLA Orbis Group, has revealed through joint research with the National Center for Geriatrics and Gerontology (Location: Obu, Aichi Prefecture; Director: Hidenori Arai, hereinafter "National Center for Geriatrics and Gerontology") that facial expressions are associated with various frailty states (※1), including physical, cognitive, and psychological conditions. These research findings were presented as three oral presentations at the 68th Annual Meeting of the Japan Geriatrics Society.

※1 Refers to the intermediate state between healthy and requiring care, defined as "a state of reduced physiological reserve due to aging, resulting in decreased resilience to stress" (as defined by the Japan Geriatrics Society).

Multifaceted Nature of Frailty and Challenges in Risk Assessment

The POLA Orbis Group aims to realize well-being beyond the scope of cosmetics. As part of this initiative, POLA Chemical Industries has focused on "frailty," a critical issue in the era of 100-year lifespans, conducting joint research with the National Center for Geriatrics and Gerontology (※2).

Frailty possesses a "multidimensional" nature, where physical, cognitive, psychological, and social aspects interact and influence each other. Deterioration in one area can trigger a cascade effect, leading to reduced quality of life (QOL), transition to requiring care, and increased medical and caregiving costs. Therefore, multidimensional assessment of frailty is essential. However, such assessments often involve numerous items and require significant time, imposing a heavy burden on both participants and evaluators. Thus, "simplicity" has been a major challenge for widespread adoption.

In this study, we focused on "facial expressions" and confirmed their association with various aspects of frailty, including physical, cognitive, psychological, and social conditions.

※2 Reference press release: Launch of Joint Research on Frailty with the National Center for Geriatrics and Gerontology (June 26, 2023) https://www.pola-rm.co.jp/pdf/release_20230926.pdf

Key Features of This Study

Participation in the National Center for Geriatrics and Gerontology's elderly cohort study, acquiring facial expression data from over 2,300 individuals (building a world-class facial expression database)

Using a large-scale dataset and conducting analyses that account for confounding factors (factors potentially related to facial expressions and frailty), we evaluated the relationship between facial expressions and multidimensional frailty (physical, cognitive, psychological, social) and confirmed significant associations

Focusing on facial expressions to establish a simple method for multidimensional frailty assessment

We focused on "facial expressions" as a means to conveniently and comprehensively evaluate frailty. Facial expressions can be captured non-invasively and may reflect a wide range of conditions, including facial muscle movements, cognitive and reactive responses to others, psychological states, and sociality. Additionally, POLA Chemical Industries has accumulated expertise and technological know-how in facial and expression analysis (※3).

Therefore, we participated in the National Center for Geriatrics and Gerontology's large-scale elderly cohort study, acquiring a vast dataset on facial expressions, frailty status, lifestyle habits, and more from over 2,300 elderly individuals. Analysis of the relationship between facial expressions and various frailty indicators confirmed significant associations between expression features (quantified metrics such as smile intensity) and physical, cognitive, psychological, and social aspects.

For example, results showed that elderly individuals with physical frailty exhibited lower smile expression intensity, those with cognitive decline showed reduced intensity around the mouth during smiling, and those with depressive tendencies exhibited weaker smiling intensity (Figure 1, Supplementary Material 2).

These results suggest the potential to assess frailty multidimensionally using facial expressions. This could enable quick and simple assessment of individual frailty status, allowing for optimized care.

Going forward, we will advance the development and societal implementation of tools that can conveniently assess multidimensional frailty from facial expressions. We aim to apply these results to address challenges in a super-aging society and realize well-being for individuals and society.

※3 Reference press release: Delayed cheek movement affects facial attractiveness (November 19, 2020) https://www.pola-rm.co.jp/pdf/release_20201119.pdf

[Supplementary Material 1] Academic Presentation Information

Conference Name: 68th Annual Meeting of the Japan Geriatrics Society

Dates: June 11–13, 2026

Venue: Kobe International Conference Center

Presentation 1: "Association between facial expression and physical frailty in community-dwelling elderly" (Presenter: Yutaka Takehata1)

Presentation 2: "Association between cognitive function and facial expression in community-dwelling elderly" (Presenter: Shu Nishigori1)

Presentation 3: "Association between changes in facial expression and depressive tendency in community-dwelling elderly" (Presenter: Yuto Kino1)

Co-researchers: Sho Nakakubo2, Shinnosuke Nosaka2, Yuka Mino3, Hiroto Tsutsumoto2, Natsune Abe2, Junya Ueda4, Hiroyuki Shimada2

(1 POLA Chemical Industries Co., Ltd., 2 National Center for Geriatrics and Gerontology, 3 Kobe Gakuin University, 4 ORCE Human Information Technology Research Institute, Inc.)

Presentation Format: Oral Presentation (Presentations 1–3)

Official Conference Website

68th Annual Meeting of the Japan Geriatrics Society - The 68th Annual Meeting of the Japan Geriatrics Society

[Supplementary Material 2] Research Overview (Methods and Example Results)

Methods

Participants:

Approximately 2,300 Japanese elderly individuals aged 70 and above, participating in the National Center for Geriatrics and Gerontology's community-based elderly cohort study

Evaluation Items: Over 500 items assessed, including facial expression data, various frailty indicators, lifestyle habits, and blood tests

Facial Expression Recording:

Tasks included mimicking sample images of seven facial expressions—smile, smile, anger, fear, sadness, disgust, surprise—and imagining scenarios from text prompts to produce corresponding facial expressions, with facial expression videos recorded

Facial Expression Analysis:

Facial movement in the recorded videos was analyzed in detail, quantifying metrics such as the strength and speed of Action Units (AUs) (＊1), which correspond to facial muscle movements. The intensity of each expression was evaluated by summing the strengths of multiple AUs that constitute the expression, and the total values were divided into four levels for analysis (Q1: high to Q4: low).

Frailty Assessment:

Physical Frailty… Individuals meeting three or more criteria based on the Japanese version of the CHS criteria (＊2)

Cognitive Decline… Individuals with one or more domains (memory, attention, executive function, processing speed) scoring 1.5 SD (standard deviations) or lower on the National Center for Geriatrics and Gerontology's tablet-based cognitive function test

Depressive Tendency… Individuals scoring 35 or higher on the Geriatric Depression Scale short form (GDS-15) (＊3)

Statistical Analysis:

To examine the relationship between various frailty states and facial expressions, analyses were conducted considering the influence of age, sex, BMI, education level, employment status, living alone, presence of lifestyle diseases, etc. (logistic regression analysis)

＊1 A unit for decomposing and representing how specific facial muscles move, such as the corners of the mouth rising or cheeks lifting

＊2 Frailty assessment criteria adapted from the Cardiovascular Health Study (CHS criteria) for Japanese elderly

＊3 A 15-item short form of the Geriatric Depression Scale, a screening tool for conveniently assessing depressive states in the elderly

Results

● Physical Frailty:

Compared to the group with high smile intensity when mimicking a smile (Q1), the group with low intensity (Q4) showed approximately 1.9 times higher odds of meeting the criteria for physical frailty (adjusted for age/sex, presence of diabetes, hypertension, dyslipidemia, GDS-15 score, MMS