Archives of Gerontology and Geriatrics 59 (2014) 497–505
Contents lists available at ScienceDirect
Archives of Gerontology and Geriatrics journal homepage: www.elsevier.com/locate/archger
Review
Systematic review of the association of mastication with food and nutrient intake in the independent elderly Akio Tada a,*, Hiroko Miura b a b
Department of Health Science, Hyogo University, 2301 Shinzaike Hiraoka-cho, Kakogawa, Hyogo 675-0195, Japan Department of International Health and Collaboration, National Institute of Public Health, 2-3-6, Minami, Wako, Saitama 351-0197, Japan
A R T I C L E I N F O
A B S T R A C T
Article history: Received 12 September 2012 Received in revised form 5 July 2014 Accepted 7 August 2014 Available online 17 August 2014
Substantial number of elderly people suffer from poor mastication, which is considered to have a detrimental effect on their dietary habits. However, the association between mastication and diet is far from conclusive. The objective of this systematic review was to assess the association of mastication with food and nutrient intake in the community dwelling elderly. We searched the PubMed, Web of Science, Cochrane Library, and Scirus databases to obtain information on the epidemiological studies in this research area. The included publications were analyzed for study design, main conclusions, and strength of evidence. A comprehensive quality assessment of all the included studies (28 cross-sectional and 7 intervention studies) was performed. In 22 of the 28 cross-sectional studies, elderly persons with better mastication and dentition reported significantly higher consumption of foods and intake of some nutrients than those with poorer oral health; however, the remaining studies showed no such differences. Five of the 7 intervention studies with an intervention involving the provision of new prostheses did not show significant improvement in food and/or nutrient intake. These discrepant findings suggest that masticatory ability explains only part of the variance in food and nutrient intake of the elderly. Two intervention studies with the combination of prosthetic treatment and dietary intervention produced changes in intake of foods such as fruits and vegetables. ß 2014 Elsevier Ireland Ltd. All rights reserved.
Keywords: Mastication Prosthesis Oral health Food intake Nutrient intake Elderly
Contents 1. 2.
3.
4.
5.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Literature search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1. Methodological assessments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2. Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Literature searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1. Impact of mastication on dietary habits and nutritional intake . 3.2. Cross-sectional studies . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.1. Intervention studies. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.2. Quality of studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Quality assessment of studies . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1. Is mastication associated with food and/or nutrient intake? . . . 4.2. Association of other factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
* Corresponding author. Tel.: +81 79 427 5111; fax: +81 79 427 5112. E-mail addresses: [email protected], [email protected] (A. Tada). http://dx.doi.org/10.1016/j.archger.2014.08.005 0167-4943/ß 2014 Elsevier Ireland Ltd. All rights reserved.
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498 498 498 498 498 498 500 500 501 501 502 503 503 504 504 504 504
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A. Tada, H. Miura / Archives of Gerontology and Geriatrics 59 (2014) 497–505
1. Introduction Dietary intake is considered as one of the important lifestyle of health promotion in the independent elderly of community dwelling. However, many elderly people suffer from tooth loss due to dental caries and/or periodontal disease. The number and distribution of teeth influence the ease of chewing. Tooth loss has been reported to cause impaired masticatory function (Miura, Araki, & Umenai, 1997; Tsuga, Carlsson, Osterberg, & Karlsson, 1998; Wayler, Muench, Kapur, & Chauncey, 1984; Witter, Cramwinckel, van Rossum, & Ka¨yser, 1990). Tooth loss is not satisfactorily compensated for by removable prostheses since the masticatory efficiency of denture wearers is far less than that of fully dentate persons (Manly & Breley, 1950). Edentulous people have difficulty chewing foods that are hard or tough in texture, even when wearing well-made dentures (Chauncey, Kapur, Feller, & Wayler, 1981; Hartsook, 1974). There is broad agreement in the association of mastication with food and/or nutrient intake. A number of studies have been conducted to elucidate this association, resulting in a growing body of literature. Studies concerning the associations of mastication (masticatory ability and mastication associated factors [MAFs] such as tooth number, dentition status, and denture status) with food and/or nutrient intake have been reviewed in several articles (Hutton, Feine, & Morais, 2002; N’gom & Woda, 2002; Walls & Steele, 2004; Walls, Steele, Sheiham, Marcenes, & Moynihan, 2000). However, these review articles do not cover the wide range of literature describing this association. Furthermore, original articles concerning this topic include a great variety of indices to evaluate mastication and data from cross-sectional and intervention surveys. Researchers have discussed this association but present various, partly contradictory conclusions. In this article, we systematically review the published findings on the association of mastication and MAFs with food and/or nutrient intake in the independent elderly of community dwelling to increase understanding of the role of masticatory function in dietary intake and to critically evaluate the methods used in the investigations performed to date. 2. Methods 2.1. Literature search Four electronic databases (PubMed, Web of Science, Cochrane Library, and Scirus) were searched using the following key words: (‘‘denture’’ OR ‘‘mastication’’) AND (‘‘nutrition’’ OR ‘‘diet’’) AND (‘‘aged’’ OR ‘‘elderly’’). Articles with the aforementioned combination of words anywhere in the paper were selected. Observational studies investigating the association of mastication with food and/ or nutrient intake in the elderly published between 1991 and 2013 were eligible for inclusion. Only English publications were included because almost all the articles included in the databases used in this study are written in English. Two reviewers (AT and HM) independently screened each retrieved document for eligibility by examining the titles and the abstracts, according to the inclusion and exclusion criteria shown in Table 1. After the literature search was completed, no additional publications were included. The reference list of each retrieved paper was also reviewed and any journal appearing in the reference list was added to a list of journals to be manually searched. 2.2. Methodological assessments The 2 reviewers independently scrutinized articles. For each article, the following items were tabulated: authors, country, study design, settings, sample characteristics (size, age, sex, mastication, and intake of food and nutrients) and main findings. Differences between the reviewers’ extraction results were resolved by discussion.
Table 1 Inclusion and exclusion criteria used for the present review. Inclusion criteria
Exclusion criteria
Sample
Subjects aged 50 years or older, or population with a mean age >55 years Subjects who are living independently
Outcome
Self-reported or interviewed food intake Nutrient intake calculated from food intake Nutrient profile measured on serum and blood Any association between oral health and food and/or nutrient intake
Subjects who received oral and maxillofacial surgery or, radiotherapy Subjects who are institutionalized Subjects who have systemic illness Data on food intake is not obtained
Analysis
Descriptive studies, review, or studies with no analyses investigating the association between oral health and food and/or nutrient intake
Mastication covered masticatory ability, and MAFs, including number of teeth, number of occlusion pairs, dentition status (dentate or edentate), dentition adequacy (adequate or inadequate), and denture status. The methods designed to evaluate masticatory performance included self-assessment of masticatory function by means of scales and questionnaires, and measurement of the subjects’ ability to reduce food into smaller particles. A standardized quality assessment form was developed taking the external and internal validity of the studies into consideration. External validity was determined by evaluating the presence of selection bias and whether the sample selection was representative or from highly selective populations. For internal validity, the following criteria were evaluated: (1) whether dental health status was objectively measured; (2) dietary assessment methods (dietary diary, dietary recall, food frequency), and (3) the presence of control for confounding variables, evaluating if results were presented separately for groups of variables related to intake of food and/or nutrient, and if any adjustment for the variable was made in the analysis. Selected papers were then classified according to the Oxford Centre for Evidence-based Medicine (Heneghan & Badenoch, 2006).
3. Results 3.1. Literature searches In total, 691 papers were retrieved by the primary search of the 4 databases. First round screening of the references based on title and abstract excluded 623 references. Sixty-eight potentially relevant references were obtained as full texts, of which 33 references that did not fit the inclusion criteria were excluded. Finally, 35 publications (28 cross-sectional studies and 7 intervention studies) were selected as the ‘key articles’ scrutinized for study design and ordered according to the strength of evidence, from the strongest (type-1) to the weakest (type-5) evidence, following the principles of evidence-based medicine. The strength of evidence ranged from type 1b to 3. Most articles described crosssectional studies, in which the subjects were elderly people living in communities. Seven intervention studies including 4 randomized controlled trials (RCTs) (type-1b evidence), investigated patients who received prosthetic treatment in dental school hospitals for 6 studies, and one on community-living elderly. The follow-up period of the intervention studies ranged from 1 month to 3 years. The sample size of the target populations varied considerably from 30 to 83,104. The intervention and crosssectional studies are summarized in Tables 2 and 3, respectively.
A. Tada, H. Miura / Archives of Gerontology and Geriatrics 59 (2014) 497–505
499
Table 2 Summary of the important cross-sectional studies on the relationship between mastication and food and/or nutrient intake. Reference Brodeur et
Lin et
al. (1993)
al. (2010)
Level of Study sample evidence
Primary classification
Primary outcome
Key results
2c
Mastication (objective evaluation)
Food intake Nutrient intake
Lower intake of fruits, vegetables, and vitamin A was observed in subjects with poor masticatory performance
Food intake
Subjects satisfied with their dentures had a significantly higher vegetable intake than those who were unsatisfied Significant negative relationships existed between masticatory ability and the dietary intake of vitamin B6, sodium, thiamin, riboflavin, carbohydrates and folacin Full-denture groups consumed significantly lower levels of protein, fiber, thiamin, iron, folic acid, vitamin A, and carotene than other dentition status groups Fiber and vitamin A intake was significantly lower in women with poor masticatory performance Masticatory ability was significantly associated with shortage of green and yellow vegetables. There was no significant association between dietary adequacy and masticatory ability
2c
Noninstitutionalized healthy elderly
(n = 367) aged 60 years and over Edentulous subjects aged Mastication (level of 65 and older (n = 103) comfort)
Ernest (1993)
2c
Elderly with complete natural dentition (n = 30) aged 60 and above
Mastication (objective evaluation)
Nutrient intake
Krall et
2c
Middle-aged and elderly men (n = 638)
Dentition status Mastication (objective evaluation)
Nutrient intake
2c
Noninstitutionalized healthy elderly (n = 367) from 60 to 89 years old Community dwelling aged 60 and over (n = 1535) Randomly chosen noninstitutionalized individuals (n = 796) aged 60–89 years Participants of the National Survey of Adult Oral Health, aged 55 years or older (n = 14, 123) Randomly selected Nigerians, aged 50 and above (n = 500)
Mastication (objective evaluation)
Nutrient intake
Masticatory ability
Food intake
Mastication (objective evaluation)
Nutrient intake
Number of teeth
Food intake
Adjusting for income, infrequent consumption of some fruit and vegetable items was associated with having
Contents lists available at ScienceDirect
Archives of Gerontology and Geriatrics journal homepage: www.elsevier.com/locate/archger
Review
Systematic review of the association of mastication with food and nutrient intake in the independent elderly Akio Tada a,*, Hiroko Miura b a b
Department of Health Science, Hyogo University, 2301 Shinzaike Hiraoka-cho, Kakogawa, Hyogo 675-0195, Japan Department of International Health and Collaboration, National Institute of Public Health, 2-3-6, Minami, Wako, Saitama 351-0197, Japan
A R T I C L E I N F O
A B S T R A C T
Article history: Received 12 September 2012 Received in revised form 5 July 2014 Accepted 7 August 2014 Available online 17 August 2014
Substantial number of elderly people suffer from poor mastication, which is considered to have a detrimental effect on their dietary habits. However, the association between mastication and diet is far from conclusive. The objective of this systematic review was to assess the association of mastication with food and nutrient intake in the community dwelling elderly. We searched the PubMed, Web of Science, Cochrane Library, and Scirus databases to obtain information on the epidemiological studies in this research area. The included publications were analyzed for study design, main conclusions, and strength of evidence. A comprehensive quality assessment of all the included studies (28 cross-sectional and 7 intervention studies) was performed. In 22 of the 28 cross-sectional studies, elderly persons with better mastication and dentition reported significantly higher consumption of foods and intake of some nutrients than those with poorer oral health; however, the remaining studies showed no such differences. Five of the 7 intervention studies with an intervention involving the provision of new prostheses did not show significant improvement in food and/or nutrient intake. These discrepant findings suggest that masticatory ability explains only part of the variance in food and nutrient intake of the elderly. Two intervention studies with the combination of prosthetic treatment and dietary intervention produced changes in intake of foods such as fruits and vegetables. ß 2014 Elsevier Ireland Ltd. All rights reserved.
Keywords: Mastication Prosthesis Oral health Food intake Nutrient intake Elderly
Contents 1. 2.
3.
4.
5.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Literature search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1. Methodological assessments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2. Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Literature searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1. Impact of mastication on dietary habits and nutritional intake . 3.2. Cross-sectional studies . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.1. Intervention studies. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.2. Quality of studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Quality assessment of studies . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1. Is mastication associated with food and/or nutrient intake? . . . 4.2. Association of other factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
* Corresponding author. Tel.: +81 79 427 5111; fax: +81 79 427 5112. E-mail addresses: [email protected], [email protected] (A. Tada). http://dx.doi.org/10.1016/j.archger.2014.08.005 0167-4943/ß 2014 Elsevier Ireland Ltd. All rights reserved.
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498 498 498 498 498 498 500 500 501 501 502 503 503 504 504 504 504
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A. Tada, H. Miura / Archives of Gerontology and Geriatrics 59 (2014) 497–505
1. Introduction Dietary intake is considered as one of the important lifestyle of health promotion in the independent elderly of community dwelling. However, many elderly people suffer from tooth loss due to dental caries and/or periodontal disease. The number and distribution of teeth influence the ease of chewing. Tooth loss has been reported to cause impaired masticatory function (Miura, Araki, & Umenai, 1997; Tsuga, Carlsson, Osterberg, & Karlsson, 1998; Wayler, Muench, Kapur, & Chauncey, 1984; Witter, Cramwinckel, van Rossum, & Ka¨yser, 1990). Tooth loss is not satisfactorily compensated for by removable prostheses since the masticatory efficiency of denture wearers is far less than that of fully dentate persons (Manly & Breley, 1950). Edentulous people have difficulty chewing foods that are hard or tough in texture, even when wearing well-made dentures (Chauncey, Kapur, Feller, & Wayler, 1981; Hartsook, 1974). There is broad agreement in the association of mastication with food and/or nutrient intake. A number of studies have been conducted to elucidate this association, resulting in a growing body of literature. Studies concerning the associations of mastication (masticatory ability and mastication associated factors [MAFs] such as tooth number, dentition status, and denture status) with food and/or nutrient intake have been reviewed in several articles (Hutton, Feine, & Morais, 2002; N’gom & Woda, 2002; Walls & Steele, 2004; Walls, Steele, Sheiham, Marcenes, & Moynihan, 2000). However, these review articles do not cover the wide range of literature describing this association. Furthermore, original articles concerning this topic include a great variety of indices to evaluate mastication and data from cross-sectional and intervention surveys. Researchers have discussed this association but present various, partly contradictory conclusions. In this article, we systematically review the published findings on the association of mastication and MAFs with food and/or nutrient intake in the independent elderly of community dwelling to increase understanding of the role of masticatory function in dietary intake and to critically evaluate the methods used in the investigations performed to date. 2. Methods 2.1. Literature search Four electronic databases (PubMed, Web of Science, Cochrane Library, and Scirus) were searched using the following key words: (‘‘denture’’ OR ‘‘mastication’’) AND (‘‘nutrition’’ OR ‘‘diet’’) AND (‘‘aged’’ OR ‘‘elderly’’). Articles with the aforementioned combination of words anywhere in the paper were selected. Observational studies investigating the association of mastication with food and/ or nutrient intake in the elderly published between 1991 and 2013 were eligible for inclusion. Only English publications were included because almost all the articles included in the databases used in this study are written in English. Two reviewers (AT and HM) independently screened each retrieved document for eligibility by examining the titles and the abstracts, according to the inclusion and exclusion criteria shown in Table 1. After the literature search was completed, no additional publications were included. The reference list of each retrieved paper was also reviewed and any journal appearing in the reference list was added to a list of journals to be manually searched. 2.2. Methodological assessments The 2 reviewers independently scrutinized articles. For each article, the following items were tabulated: authors, country, study design, settings, sample characteristics (size, age, sex, mastication, and intake of food and nutrients) and main findings. Differences between the reviewers’ extraction results were resolved by discussion.
Table 1 Inclusion and exclusion criteria used for the present review. Inclusion criteria
Exclusion criteria
Sample
Subjects aged 50 years or older, or population with a mean age >55 years Subjects who are living independently
Outcome
Self-reported or interviewed food intake Nutrient intake calculated from food intake Nutrient profile measured on serum and blood Any association between oral health and food and/or nutrient intake
Subjects who received oral and maxillofacial surgery or, radiotherapy Subjects who are institutionalized Subjects who have systemic illness Data on food intake is not obtained
Analysis
Descriptive studies, review, or studies with no analyses investigating the association between oral health and food and/or nutrient intake
Mastication covered masticatory ability, and MAFs, including number of teeth, number of occlusion pairs, dentition status (dentate or edentate), dentition adequacy (adequate or inadequate), and denture status. The methods designed to evaluate masticatory performance included self-assessment of masticatory function by means of scales and questionnaires, and measurement of the subjects’ ability to reduce food into smaller particles. A standardized quality assessment form was developed taking the external and internal validity of the studies into consideration. External validity was determined by evaluating the presence of selection bias and whether the sample selection was representative or from highly selective populations. For internal validity, the following criteria were evaluated: (1) whether dental health status was objectively measured; (2) dietary assessment methods (dietary diary, dietary recall, food frequency), and (3) the presence of control for confounding variables, evaluating if results were presented separately for groups of variables related to intake of food and/or nutrient, and if any adjustment for the variable was made in the analysis. Selected papers were then classified according to the Oxford Centre for Evidence-based Medicine (Heneghan & Badenoch, 2006).
3. Results 3.1. Literature searches In total, 691 papers were retrieved by the primary search of the 4 databases. First round screening of the references based on title and abstract excluded 623 references. Sixty-eight potentially relevant references were obtained as full texts, of which 33 references that did not fit the inclusion criteria were excluded. Finally, 35 publications (28 cross-sectional studies and 7 intervention studies) were selected as the ‘key articles’ scrutinized for study design and ordered according to the strength of evidence, from the strongest (type-1) to the weakest (type-5) evidence, following the principles of evidence-based medicine. The strength of evidence ranged from type 1b to 3. Most articles described crosssectional studies, in which the subjects were elderly people living in communities. Seven intervention studies including 4 randomized controlled trials (RCTs) (type-1b evidence), investigated patients who received prosthetic treatment in dental school hospitals for 6 studies, and one on community-living elderly. The follow-up period of the intervention studies ranged from 1 month to 3 years. The sample size of the target populations varied considerably from 30 to 83,104. The intervention and crosssectional studies are summarized in Tables 2 and 3, respectively.
A. Tada, H. Miura / Archives of Gerontology and Geriatrics 59 (2014) 497–505
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Table 2 Summary of the important cross-sectional studies on the relationship between mastication and food and/or nutrient intake. Reference Brodeur et
Lin et
al. (1993)
al. (2010)
Level of Study sample evidence
Primary classification
Primary outcome
Key results
2c
Mastication (objective evaluation)
Food intake Nutrient intake
Lower intake of fruits, vegetables, and vitamin A was observed in subjects with poor masticatory performance
Food intake
Subjects satisfied with their dentures had a significantly higher vegetable intake than those who were unsatisfied Significant negative relationships existed between masticatory ability and the dietary intake of vitamin B6, sodium, thiamin, riboflavin, carbohydrates and folacin Full-denture groups consumed significantly lower levels of protein, fiber, thiamin, iron, folic acid, vitamin A, and carotene than other dentition status groups Fiber and vitamin A intake was significantly lower in women with poor masticatory performance Masticatory ability was significantly associated with shortage of green and yellow vegetables. There was no significant association between dietary adequacy and masticatory ability
2c
Noninstitutionalized healthy elderly
(n = 367) aged 60 years and over Edentulous subjects aged Mastication (level of 65 and older (n = 103) comfort)
Ernest (1993)
2c
Elderly with complete natural dentition (n = 30) aged 60 and above
Mastication (objective evaluation)
Nutrient intake
Krall et
2c
Middle-aged and elderly men (n = 638)
Dentition status Mastication (objective evaluation)
Nutrient intake
2c
Noninstitutionalized healthy elderly (n = 367) from 60 to 89 years old Community dwelling aged 60 and over (n = 1535) Randomly chosen noninstitutionalized individuals (n = 796) aged 60–89 years Participants of the National Survey of Adult Oral Health, aged 55 years or older (n = 14, 123) Randomly selected Nigerians, aged 50 and above (n = 500)
Mastication (objective evaluation)
Nutrient intake
Masticatory ability
Food intake
Mastication (objective evaluation)
Nutrient intake
Number of teeth
Food intake
Adjusting for income, infrequent consumption of some fruit and vegetable items was associated with having
