Understanding the impact of oral processing ability on food consumption behaviour and nutrient intake in older Thai adults

Background: Age-related declines in oral function can impair nutrient intake and increase malnutrition risk in older adults. Thailand is one of the fastest-aging countries in Southeast Asia, however, the relationship between oral processing ability and nutrient intake remains underexplored. This study investigated associations between oral processing ability, nutrient intake, and food consumption behaviour in community-dwelling older Thai adults.

Methods: The systematic review and meta-analysis identified associations between compromised oral factors and lower nutrient intake, highlighting gaps in oral physiological assessments. To address this, a cross-sectional study was conducted with 154 community-dwelling older Thai adults (median age: 71 years) in the Bangkok Metropolitan Region and Chonburi. Oral physiological measures, both subjective (denture status, oral dryness risk, and masticatory ability) and objective (maximum tongue pressure and biting force), were collected. Nutritional status was assessed using body mass index and 24-hour dietary recalls. Multiple linear regression examined associations between oral physiology and nutrition, with sensitivity analyses for location, low energy intake, and number of teeth.

Results: Oral processing was not associated with BMI and macronutrient intake. However, several micronutrients (vitamins C, E, B2, and calcium), as well as cereals and grains, were affected. Vitamin C was of particular concern, as a 14% higher self-perceived masticatory ability was associated with a 32 mg higher daily intake (95% CI: 2.5 to 61.8). Compared to other oral function measures, self-perceived masticatory ability showed the most statistically significant associations, highlighting the nutritional vulnerability of individuals with poor self-perceived masticatory ability.

Conclusion: Despite compromised oral processing, older Thai adults appeared to maintain nutrient intake, possibly through selective food choices. Several micronutrients, particularly vitamin C, were affected. Self-perceived masticatory ability showed the most associations with nutrient intake, likely because it best reflected oral processing and compensatory behaviours. Nonetheless, due to the study’s cross-sectional design, if compromised oral processing reduced nutrient intake or worsened existing issues remain inconclusive. Longitudinal studies in national samples are needed to confirm findings and guide targeted interventions.