As the global population ages, understanding the factors influencing older adults’ health and wellbeing becomes increasingly important. Aging can lead to various health complications, including reduced muscle strength, affecting daily activities such as food consumption(1). The decline in oromasticatory muscle function can cause chewing difficulties that limit food choices(2). Given that adequate nutrition is essential for maintaining the quality of life, this study aims to examine the relationship between self-perceived chewing ability and objectively measured biting force to understand the extent of their effect on nutrient intake.

A total of 148 community-dwelling older adults aged 64 to 90 years old (median age 71±8 years) from urban (Bangkok Metropolitan Region) and rural (Chonburi Province) areas of Thailand participated. Maximum biting force (Newtons, N) of the posterior teeth was instrumentally measured, and participants rated the chewing difficulty of 20 commonly consumed foods as easy, difficult, or cannot be chewed at all. Foods were grouped into five difficulty levels by principal component analysis of the ratings and masticatory ability scores (0 to 10) were calculated. Food intake was obtained from 24-hour dietary recalls through interviews and body mass index (BMI) data was obtained.

Participants were grouped into tertiles of low (median=73 N; IQR=37–127), moderate (median=336 N; IQR=241–387), and high (median=512 N; IQR=477–512) biting force. A Kruskal-Wallis test revealed that those with low biting force had significantly (p < 0.01) lower self-assessed masticatory ability scores (median=7.69) compared to those with high biting force (median=8.86). Significant differences in the daily intakes of dietary potassium, magnesium, and vitamins B1, B2, B6, and C were observed between the high and low biting force groups (p < 0.01).

However, multiple regression analyses adjusted for age, sex, education, and location did not show significant predictive power for any nutrient intake from either biting force or masticatory ability, except for positive associations with vitamins C and B2, and fruit intake. A unit increase in mastication ability was associated with an increase in daily intake of 0.21 milligrams of vitamin C (95% CI=3.03, 33.64; p=0.02) and 0.19 milligrams of vitamin B2 (95% CI=−0.01, 0.13; p=0.03).

Additionally, a unit increase in biting force was associated with an increase in daily fruit intake of 0.17 grams (95% CI=−0.02, 0.28; p=0.08). No relationships with BMI were observed for either biting force or masticatory ability.

Higher biting force in older adults improves self-perceived masticatory ability, leading to a higherquality diet with foods rich in vitamins B2 and C, such as meat and fruits. Targeted interventions to enhance biting force could help prevent malnutrition.