Dietary n-6 and n-3 Polyunsaturated Fatty Acids and Tooth Loss in Community-Dwelling Older Japanese People

This study investigated the associations between baseline n-6 and n-3 polyunsaturated fatty acid levels and the number of teeth lost subsequently over 5 years.

The relationship between n-3 and n-6 polyunsaturated fatty acids and tooth loss remains unclear. Previous studies have been limited to older individuals aged 70 and above, and no research has been conducted that takes into account a broader age range.

Participants (n = 1534) attended both the baseline survey and the follow-up survey conducted 5 years later. Poisson regression analyses were conducted after converting the number of teeth present at baseline into an adjustment variable. The dependent variable was the number of lost teeth over a five-year period. The exposure variables were each quintile of self-reported n-3 and n-6 polyunsaturated fatty acid intake levels (g/1000 kcal) and the ratio of self-reported n-6 to n-3 polyunsaturated fatty acid intake levels (n-6:n-3 ratio) adjusted by age, sex, smoking, use of dental floss or interdental brush and history of diabetes mellitus.

Higher n-3 fatty acid intake (5th quintile, incidence rate ratio (IRR): 0.21, p < 0.001) and a lower dietary n-6:n-3 ratio (≤ 4.0) significantly lower tooth loss risk. Conversely, higher n-6 intake (5th quintile, IRR: 1.32, p = 0.006) was associated with the likelihood of tooth loss. Younger age, flossing and adequate chewing ability were associated with better dental outcomes.

Balanced dietary intake, particularly higher n-3 fatty acids and a lower n-6:n-3 ratio, helps preserve dental health by reducing tooth loss risk.