Is poor chewing ability a risk factor for malnutrition? A six-year longitudinal study of older adults in Sweden.

OBJECTIVE

To investigate if poor chewing ability increases the risk of malnutrition and to compare its impact with other contributing factors.

DESIGN

Longitudinal observational study.

SETTING

Population-based survey.

PARTICIPANTS

1,596 community dwelling individuals aged 60 years or older who participated in the Swedish National Study on Aging and Care at Kungsholmen in 2001-2004 (baseline) and in 2007-2011 (follow-up) and were not at risk for malnutrition nor malnourished at baseline.

MEASUREMENTS

The exposures were baseline chewing ability and change in chewing ability at follow-up. The primary outcome was malnutrition risk or being malnourished, as assessed by the Mini Nutritional Assessment Short-Form. The secondary outcome was weight loss over 10% at follow-up. Logistic regressions assessed the associations between the exposures and the outcomes. The average marginal effects (percentage points) compared the effect of the exposure versus covariates on outcome probability.

RESULTS

150 (9.4%) reported having difficulty chewing hard food, while 191 (12.0%) had persistent difficulties chewing hard food or lost the ability during the follow-up. At the time of follow-up, 212 (13.3%) were at risk or malnourished, while 179 (11.2%) had weight loss of more than 10%. Self-reported difficulty chewing hard food increased the odds of being at risk or malnourished at follow-up (OR = 1.64, 95% CI = 1.06, 2.53) and having weight loss of more than 10% (OR = 1.72, 95% CI = 1.10, 2.68). Individuals who had persistent difficulty chewing hard food or lost the ability to chew hard food during the follow-up period were more likely to be at risk or malnourished (OR = 1.87, 95% CI = 1.26, 2.79) or had a weight loss of more than 10% (OR = 1.73, 95% CI = 1.12, 2.65). Having difficulty chewing hard food at baseline increased the probability of the two outcomes by approximately 6 percentage points, whereas the covariates increased or decreased the probabilities by 4-16 percentage points.

CONCLUSION

Poor chewing ability may be a low-risk factor for malnutrition in older individuals. Self-reported difficulty chewing hard food during dental visits should be addressed.