The research, published in Frontiers in Aging, draws on the Cohort of Obesity, Sarcopenia, and Frailty of Older Mexican Adults, a population-based prospective study launched in 2014. For this cross-sectional analysis, the team started with 1,677 adults aged 60 and older and narrowed the sample to 1,075 after excluding participants who did not complete the interview or clinical oral examination, reported implausible energy intake below 500 or above 6,500 kilocalories per day, or left gaps in their food-frequency questionnaire. Each participant underwent a standardized oral examination performed by a trained dental surgeon using a headlamp, a No. 5 mirror, and a World Health Organization-type probe. Tooth counts were sorted into four categories: 21 to 28 natural teeth, 11 to 20, 1 to 10, and complete edentulism — the loss of every natural tooth.

Dietary assessment was equally rigorous. Participants completed a semi-quantitative food-frequency questionnaire covering 110 items over the previous year, capturing how often they ate each food, in what portion sizes, and how many portions. Daily gram intake for each item was estimated and then converted into energy, macronutrient, and micronutrient values using the USDA FoodData Central database. From those data, the researchers calculated each person’s Dietary Inflammatory Index, or DII, a validated tool that scores the overall inflammatory potential of the diet on a continuous scale from anti-inflammatory to pro-inflammatory. The index weighs 45 food parameters — including energy, macronutrients, fiber, vitamins, minerals, fatty acids, and polyphenols — according to the published evidence for each one’s effect on inflammation. Of those 45 parameters, 38 were available in the Mexican food-frequency questionnaire; the seven missing items, such as turmeric, ginger, and green or black tea, are rarely consumed in Mexico, minimizing any distortion.

The mechanics of the DII calculation are worth appreciating, because they reveal how scientists turn a plate of food into a number. For each food parameter, the individual’s intake is compared against a global reference database: the difference between the person’s intake and the world mean is divided by the standard deviation to produce a z-score. That z-score is transformed through an empirical cumulative distribution function, converted to a symmetric distribution centered at zero, multiplied by the parameter’s literature-derived inflammatory effect score, and summed across all parameters. The result is then energy-adjusted using the residual method to strip out the confounding influence of how much food a person eats overall. Higher scores signal a diet that promotes chronic low-grade inflammation; lower scores signal one that damps it.

The demographic portrait that emerged was strikingly consistent with earlier research on tooth loss. Participants with more teeth tended to be younger — averaging 65.7 years in the 21-to-28-tooth group versus 70.3 years among the edentulous — better educated, more likely to be married, less likely to smoke, and to score higher on the Mini-Mental State Examination. Smoking showed a particularly sharp gradient: 44.9 percent of those with full dentition were current smokers, compared with 57.5 percent of those with 1 to 10 teeth and 63.9 percent of the edentulous. Diabetes and hypertension, by contrast, were distributed evenly across tooth-count groups, suggesting the dietary association was not simply a proxy for metabolic disease. Roughly half the sample — 51.6 percent — retained 21 to 28 natural teeth, while 6.9 percent had lost them all.

When the researchers cross-tabulated tooth count against DII quartiles, the pattern was unmistakable. As dietary inflammatory potential rose, the proportion of people with full functional dentition fell. Among those eating the least inflammatory diets, 32.9 percent kept 21 to 28 teeth; among those in the most inflammatory quartile, only 5.9 percent did. Conversely, severe tooth loss and edentulism concentrated in the pro-inflammatory group: 15.7 percent of that group had 1 to 10 teeth and 16.7 percent were edentulous, compared with 16.5 and 22.2 percent respectively in the least inflammatory quartile. The same gradient appeared for functional dentition — defined as having at least 20 teeth, the minimum generally considered necessary for effective chewing. Fully 81.3 percent of people on the most inflammatory diets lacked functional dentition, against 67.2 percent of those on the least inflammatory diets.

The nutrient-level data added a telling detail. Edentulous participants consumed significantly more carbohydrates than those with complete dentitions — a median of roughly 188 grams per 150-gram unit versus 149 grams — and their sugar and cholesterol intakes trended higher, though the latter differences did not reach statistical significance. The researchers interpret this as a classic dietary adaptation to limited chewing capacity: when teeth are gone, people drift toward softer, refined, energy-dense foods such as desserts, juices, and ultra-processed products. Fiber intake showed no significant difference across groups, which the authors note could reflect the bluntness of tooth count as a measure of actual chewing performance, since denture use, occlusal support, and masticatory efficiency were not assessed.

The statistical heart of the paper lies in its ordinal logistic regression models, adjusted for age, education, marital status, smoking status, and cognitive impairment. Compared with participants who had 21 to 28 teeth, those with 1 to 10 teeth had 2.19 times the odds of belonging to a more pro-inflammatory DII category — a highly significant result with a 95 percent confidence interval of 1.44 to 3.33. In the unadjusted model, edentulous participants also showed elevated odds (2.13), though after adjustment the association weakened and fell just short of significance. People without functional dentition had 1.37 times the odds of a more inflammatory diet in the crude analysis, a signal that attenuated after adjustment. The dose-response-like pattern — significant odds concentrated in the most severely affected groups — reinforces the biological plausibility of the association rather than pointing to a statistical artifact.

Which direction does the causation run? The authors are refreshingly candid that a cross-sectional design cannot answer that question, and they outline two mechanisms that could operate simultaneously. Pro-inflammatory diets, rich in refined carbohydrates and poor in anti-inflammatory micronutrients and polyphenols, may accelerate periodontal disease and caries, hastening tooth loss. Alternatively — and the carbohydrate data lend this path weight — tooth loss itself may impair the ability to chew raw vegetables, fruits, nuts, and meats, pushing people toward softer, more processed foods that happen to carry higher inflammatory potential. Prior research lends support to both routes: higher DII scores have been linked to periodontitis and tooth loss in analyses of the U.S. NHANES database, while studies in China have shown that older adults with fewer teeth eat less diverse diets and have poorer nutritional status. Tooth loss has also been tied to cardiovascular events, cognitive decline — with each additional missing tooth raising dementia risk by an estimated 1.1 percent — malnutrition, and sarcopenia.

The cognitive thread deserves particular attention. Participants with more teeth and more anti-inflammatory diets scored higher on the Mini-Mental State Examination, and the authors point to emerging work suggesting that chronic low-grade inflammation bridges oral health, diet, and the aging brain. Neuroimaging studies have found that tooth loss is associated with reduced volume in brain regions governing learning and memory, and a 15-year longitudinal study reported that dietary diversity and anti-inflammatory eating may mediate the link between tooth loss and mild cognitive impairment. With roughly 20 percent of older adults worldwide affected by complete tooth loss according to the World Health Organization, the public-health stakes are considerable. The Mexican team argues that oral health should be woven directly into nutritional assessment and healthy-aging strategies — that a dentist’s chair and a dietitian’s office may be, in effect, stops on the same clinical journey. Longer follow-up will be needed to disentangle the potentially bidirectional relationship, and future studies, the authors note, should measure periodontal status, caries, prosthetic use, and chewing ability directly. But the headline finding stands: in the mouth and on the plate, what remains — and what is lost — may shape how the body ages.

Subject of Research: Association between tooth retention and the inflammatory potential of diet in older adults

Article Title: Association between tooth retention and lower inflammatory dietary pattern in older adults

Article References: Association between tooth retention and lower inflammatory dietary pattern in older adults. (n.d.). https://doi.org/10.3389/fragi.2026.1945744

Image Credits: AI Generated

DOI: 10.3389/fragi.2026.1945744

Keywords: tooth loss, Dietary Inflammatory Index, older adults, oral health, nutrition, healthy aging, edentulism, functional dentition, chronic inflammation, cross-sectional study, Mexican population, public health