A literature search was conducted via PubMed to find articles published in and after 2000 by using the following search terms: Selleck Roxadustat elderly, nutrition, tooth, tooth loss, mastication, and oral function. English articles and the papers they referenced were used to summarize

the relationship between nutrition and oral status. In the early 2000s, large cross-sectional studies on the relationship between nutritional and oral status were conducted in Britain and the United States. Sheiham et al. [3] used 753 healthy subjects aged 65 years and older from Britain’s National Diet and Nutrition Survey (NDNS) to investigate the relationship between the oral condition and the results of a 4-day meal survey. The results showed significantly less serum ascorbic acid and retinol intake in edentulous subjects, even when considering confounding factors such as age, sex, and educational history. Nowjack-Raymer and Sheiham [4] used the results of the U.S. National Health and Nutrition Examination Survey (NHANES) III to compare the nutritional state of dentulous and edentulous subjects. Edentulous subjects accounted for 36% (1373 of 3794) of the total population. The results of a 24-h meal survey showed that this group consumed 2.1 times fewer carrots and 1.5 times

less salad, which were both significant differences. Further, multivariate analyses considering confounding factors found that serum beta-carotene, folic acid, and vitamin C levels Axenfeld syndrome selleck chemicals were significantly lower in edentulous subjects. Many other studies were conducted using this NHANES III which compared among the subjects with the number of occlusal contact unit [5], those who had at least 1 remaining tooth without dentures [6], and those who had ill fitting denture

or not [7]. Similar results were reported in later studies on the NHANES 1999–2002 [8] and [9]. And the study on the NHANES 1999–2004 that considered the confounding factors of age, race, and educational history reported that dentulous men consumed significantly more total calories and vitamin C, and dentulous women ingested significantly more beta-carotene [10]. These studies used multivariate analysis to attempt to eliminate the influence of confounding factors that are known to affect the relationship between tooth loss and nourishment, including age, sex, educational history, and smoking history. Furthermore the race and economic status were also confounding factors [11]. It was well-known that edentulousness affects nutrition more in white subjects than in black subjects [12]. To eliminate these confounding factors, relatively homogeneous sample were used such as the same race [13], and low-income earners [14]. Moreover, some studies were designed to use medical profession as subjects because their educational history and incomes might be almost equal. Hung et al.