The aim of this systematic review was to examine the association between malnutrition and oral health in older people (≥ 60 years of age). A comprehensive systematic literature search was performed in four databases (PubMed, CINAHL, Dentistry and Oral Sciences Source, and Embase) for literature from January 2000 to May 2020. Both observational and intervention studies were screened for eligibility. Two reviewers independently screened the search results to identify potential eligible studies, and assessed the methodological quality of the full-text studies. A total of 3240 potential studies were identified. After judgement for relevance, 10 studies (cross-sectional (n = 9), prospective cohort (n = 1)) met the inclusion criteria. Three studies described malnourished participants as having fewer teeth, or functional (tooth) units (FTUs), compared to well-nourished participants. Four studies reported soft tissue problems in malnourished participants, including red tongue with blisters, and dry or cracked lips. Subjective oral health was the topic in six studies, with poorer oral health and negative self-perception of oral health in malnourished elderly participants. There are associations between (at risk of) malnutrition and oral health in older people, categorized in hard and soft tissue conditions of the mouth, and subjective oral health. Future research should be focused on longitudinal cohort studies with proper determination of malnutrition and oral health assessments, in order to evaluate the actual association between malnutrition and oral health in older people.

Malnutrition adversely influences a broad range of physical and psychological symptoms. Although polypharmacy is often mentioned to be associated with malnutrition, especially in older people it is unclear to what extent. The aim of this systematic review was to investigate the extent of the association between polypharmacy and malnutrition in older people. The methodology followed the guidelines of the Cochrane Collaboration. Literature search was performed in PubMed, CINAHL and Embase. The population of interest for this systematic review were people of 65 years and older with polypharmacy. Because there is ambiguity with regard to the actual definition of malnutrition and polypharmacy, in this systematic review all articles describing malnutrition prevalence rates were included, regardless of the criteria used. Both observational and intervention studies were screened for eligibility. Selection and quality assessment of the included full text studies was assessed by two reviewers independently. A level of evidence and methodological quality score was adjudged to each article based on this assessment. A total of 3126 studies were retrieved by the literature search, of which seven studies were included in this systematic review. There was considerable variation in the definition of polypharmacy between studies. Two studies defined polypharmacy as the use of five or more drugs, two studies as the use of six or more drugs, two studies provided a mean and standard deviation that corresponded to the minimum of five drugs, and one study distinguished between polypharmacy (five or more drugs) and excessive polypharmacy (ten or more drugs). However, all studies showed a statistically significant association between (the risk) of becoming malnourished and polypharmacy regardless the instrument or criterion used to define risk of malnutrition. Studies presented the associations respectively as OR ≥ 1.177, p-value ≤ 0.028, β ≥ -0.62 and r ≥ -0.31. This review demonstrated a statistically significant association between polypharmacy and malnutrition. Further research is required to determine the magnitude of the effect by increased number of drugs in combination with the type of drugs, on the risk of malnutrition.