Accepted Manuscript Dietary counseling emphasizing low-saturated-fat and low-cholesterol intake may influence salivary properties Benjamin W. Chaffee, DDS MPH PhD PII:
S1532-3382(14)00196-1
DOI:
10.1016/j.jebdp.2014.07.007
Reference:
YMED 995
To appear in:
The Journal of Evidence-Based Dental Practice
Please cite this article as: Chaffee BW, Dietary counseling emphasizing low-saturated-fat and lowcholesterol intake may influence salivary properties, The Journal of Evidence-Based Dental Practice (2014), doi: 10.1016/j.jebdp.2014.07.007. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Article Analysis and Evaluation – Diagnosis/Treatment/Prognosis DECLARATIVE TITLE: Dietary counseling emphasizing low-saturated-fat and low-cholesterol intake may influence salivary properties
RI PT
ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: The effect of dietary intervention on paraffin-stimulated saliva and dental health of children participating in a randomized controlled trial. Laine MA, Tolvanen M, Pienihäkkinen K, Söderling E, Niinikoski H, Simell O, Karjalainen S. Arch Oral Biol 59(2):217-25, 2014
SC
PURPOSE/QUESTION: Does a dietary counseling intervention that stresses low intakes of cholesterol and saturated fat from an early age result in changes in salivary flow rate and buffering capacity?
M AN U
SOURCE OF FUNDING: None reported TYPE OF STUDY/DESIGN: Randomized controlled trial
AC C
EP
TE D
REVIEWER NAME and CONTACT INFORMATION: Benjamin W. Chaffee, DDS MPH PhD Center to Address Disparities in Children’s Oral Health University of California San Francisco 3333 California Street, Suite 495 San Francisco, CA 94118 phone: 1-415-476-9226 [email protected]
1
ACCEPTED MANUSCRIPT
RI PT
Summary Subjects: The study sample numbered 148 children (80 intervention group, 68 control group) recruited from a larger randomized controlled trial that had originally enrolled 1062 infants from wellbaby clinics in Turku, Finland from 1990 to 1992. The dental sub-study randomly sampled from the 881 children who remained in the main study at age 3 years. After follow-up visits at ages 6, 9, 12, and 16 years, 88 children (59%) remained in the dental sub-study (46 intervention group, 42 control group). The salivary flow rate in the study population increased with age and was 1.6 ml/min (SD 0.7 ml/min) at age 16 years. Dental caries was observed during at least one study visit in 130 of the 148 participants. Caries prevalence at age 16 years was not reported.
M AN U
SC
Key Exposure/Study Factor: In the Special Turku Risk Factor Intervention Project (STRIP), infants and their families were randomly assigned at age 7 months either to an intervention group who received individualized dietary counseling that encouraged limiting dietary cholesterol to less than 200 mg/day and achieving fat intake at 30% to 35% of daily energy with a 1:2 ratio of saturated to mono- and polyunsaturated fat or to a control group who received basic health education.1 Intervention group families received counseling every 1 to 3 months to age 2 years and semiannually to age 20; control group health education occurred semiannually through age 6 years and annually to age 20 years.
TE D
Main Outcome Measure: At ages 6, 9, 12, and 16 years, calibrated technicians masked to intervention grouping collected saliva samples. In the primary analysis, the authors compared two variables between intervention and control groups: (1) Salivary flow rate (ml/min), measured by collecting 4 ml of stimulated whole saliva after 1 minute of chewing paraffin wax and at least 1 hour of fasting, and (2) salivary buffering capacity, based on color changes observed visually on commercial test strips and classified as good (pH ≥ 6.0), normal (pH 4.5 to 5.5), or low (pH ≤ 4.0).
AC C
EP
Main Results: At each age evaluated, salivary flow rate, on average, was 0.1 to 0.2 ml/min greater among intervention group children than among children in the control group (p = 0.04 from repeatedmeasures generalized linear model). A greater percentage of children were classified as having “good” salivary buffering capacity in the intervention group than in the control group (p < 0.01 from repeated-measures generalized linear model). The authors also stated that the dietary intervention produced no difference in dental health between the study groups but did not quantify this finding. Conclusions: Repeated, individualized dietary counseling focusing on fat and cholesterol intake from an early age may increase salivary flow rate and buffering capacity. At this time, there is insufficient evidence that dietary modification of this particular nature leads to caries prevention.
2
ACCEPTED MANUSCRIPT
RI PT
Commentary Dental health and diet are strongly linked, and dietary habits from an early age have lasting oral health implications.2 The World Health Organization3 promotes healthful nutrition under a common risk factor approach to disease prevention, seeking to improve multiple dimensions of population health by targeting shared determinants. While caries preventive efforts usually stress less frequent intake of fermentable carbohydrates, other aspects of a healthy diet could positively influence oral health, potentially through diverse mechanisms.
M AN U
SC
In this paper, children assigned to an intervention encouraging diets lower in saturated fat and cholesterol beginning in infancy demonstrated increased salivary flow rate and buffering capacity compared to children in the control group. Few prior studies have shown impacts on salivary flow downstream of dietary modification. In one study, moderate short-term sodium restriction lowered salivary sodium concentration but not flow rate.4 Elsewhere, short-term dietary supplementation with white button mushroom did not appreciably affect salivary flow.5 Among older adults, adequate salivary flow itself may be a key driver of nutrient intake by facilitating the ingestion of a wider variety of foods.6
TE D
As for caries, authors of the current study reported no impact of the dietary intervention, although no measure of association was provided. Several factors could account for a null effect. Salivary flow is one of many influences of the caries process, and the magnitude of the difference in flow rate between intervention and control children was small; nearly all children maintained good or normal buffering capacity throughout the study. Also, any positive dental effect mediated through salivary properties might have been balanced by the increased carbohydrate intake seen with the intervention, although intake of sucrose did not differ by group. Importantly, the study may have lacked sufficient statistical power to detect dental effects. The authors categorized caries outcomes so that participants who developed caries at any age between 3 and 16 years (80% of children analyzed) were classified together, leaving few individuals in other outcome categories. Alternative outcome measures might have afforded greater power.
AC C
EP
In a number of secondary observational analyses conducted within the study cohort, statistically significant associations between dental health and salivary calcium concentration and between dental health and tooth brushing habits were reported. However, there were no statistically significant associations between caries outcomes and salivary flow rate, buffering capacity, or daily sucrose and carbohydrate intakes, perhaps also due to limited power. The intervention group did experience greater dietary fiber intake, which the authors speculate could be responsible for the observed increase in salivary flow. On the other hand, the authors reported no direct correlation between salivary variables and intakes of individual dietary compounds, including fiber. Whether and to what extent dietary fiber might influence salivary properties is a question awaiting further research. The authors reported no external funding. However, other STRIP publications7,8 acknowledge support from multiple government and foundation sources. Presumably, these sources did not directly fund the dental sub-study; yet, this valuable dental research might not have occurred
3
ACCEPTED MANUSCRIPT
without the existence of the overall study infrastructure. Greater detail is recommended when reporting sources of support.
SC
Strength of Recommendation Taxonomy (SORT) Grading
RI PT
By SORT criteria9, the level of evidence score was 3, because salivary properties represented disease-oriented outcomes (i.e. intermediate or surrogate end points), rather than patient-oriented outcomes (i.e. morbidity or quality-of-life measures). This does not preclude further research into whether dietary modification can meaningfully impact caries development through salivarymediated processes. In conclusion, although caries and the diet are closely intertwined, current evidence does not support encouraging patients to achieve low-saturated-fat and/or high-fiber diets explicitly for dental health promotion.
M AN U
LEVEL OF EVIDENCE: Level 3 Other evidence STRENGTH OF RECOMMENDATION GRADE: N/A Not applicable
AC C
EP
TE D
References 1. Niinikoski H, Lagstrom H, Jokinen E, Siltala M, Ronnemaa T, Viikari J, et al. Impact of repeated dietary counseling between infancy and 14 years of age on dietary intakes and serum lipids and lipoproteins: the STRIP study. Circulation 2007;6:1032-1140. 2. Feldens CA, Giugliani ER, Vigo A, Vitolo MR. Early feeding practices and severe early childhood caries in four-year-old children from southern Brazil: a birth cohort study. Caries Res 2010:44:445-52. 3. World Health Organization. 2008-2013 Action plan for the global strategy for the prevention and control of noncommunicable diseases. (2009) Geneva, Switzerland: World Health Organization. 4. Christensen CM, Bertino M, Beauchamp GK, Navazesh M, Engelman K. The influence of moderate reduction in dietary sodium on human salivary sodium concentration. Arch Oral Biol 1986;31:825-8. 5. Jeong SC, Koyyalamudi SR, Pang G. Dietary intake of Agaricus bisporus white button mushroom accelerates salivary immunoglobulin A secretion in healthy volunteers. Nutrition 2012;28:527-31. 6. Ernest SL. Dietary intake, food preferences, stimulated salivary flow rate, and masticatory ability in older adults with complete dentitions. Spec Care Dentist 1993;13:102-6. 7. Hakanen M, Ronnemaa T, Talvia S, Rask-Nissila L, Koulu M, Viikari J, et al. Serum leptin concentration poorly reflects growth and energy and nutrient intake in young children. Pediatrics 2004;113:1273-8. 8. Niinikoski H, Jula A, Viikari J, Ronnemaa T, Heino P, Lagstrom H, et al. Blood pressure is lower in children and adolescents with a low-saturated-fat diet since infancy: the special turku coronary risk factor intervention project. Hypertension 2009;53:918-24.
4
ACCEPTED MANUSCRIPT
AC C
EP
TE D
M AN U
SC
RI PT
9. Newman MG, Weyant R, Hujoel P. JEBDP improves grading system and adopts strength of recommendation taxonomy grading (SORT) for guidelines and systematic reviews. J Evid Based Dent Pract 2007;7:147-50.
5
S1532-3382(14)00196-1
DOI:
10.1016/j.jebdp.2014.07.007
Reference:
YMED 995
To appear in:
The Journal of Evidence-Based Dental Practice
Please cite this article as: Chaffee BW, Dietary counseling emphasizing low-saturated-fat and lowcholesterol intake may influence salivary properties, The Journal of Evidence-Based Dental Practice (2014), doi: 10.1016/j.jebdp.2014.07.007. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Article Analysis and Evaluation – Diagnosis/Treatment/Prognosis DECLARATIVE TITLE: Dietary counseling emphasizing low-saturated-fat and low-cholesterol intake may influence salivary properties
RI PT
ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: The effect of dietary intervention on paraffin-stimulated saliva and dental health of children participating in a randomized controlled trial. Laine MA, Tolvanen M, Pienihäkkinen K, Söderling E, Niinikoski H, Simell O, Karjalainen S. Arch Oral Biol 59(2):217-25, 2014
SC
PURPOSE/QUESTION: Does a dietary counseling intervention that stresses low intakes of cholesterol and saturated fat from an early age result in changes in salivary flow rate and buffering capacity?
M AN U
SOURCE OF FUNDING: None reported TYPE OF STUDY/DESIGN: Randomized controlled trial
AC C
EP
TE D
REVIEWER NAME and CONTACT INFORMATION: Benjamin W. Chaffee, DDS MPH PhD Center to Address Disparities in Children’s Oral Health University of California San Francisco 3333 California Street, Suite 495 San Francisco, CA 94118 phone: 1-415-476-9226 [email protected]
1
ACCEPTED MANUSCRIPT
RI PT
Summary Subjects: The study sample numbered 148 children (80 intervention group, 68 control group) recruited from a larger randomized controlled trial that had originally enrolled 1062 infants from wellbaby clinics in Turku, Finland from 1990 to 1992. The dental sub-study randomly sampled from the 881 children who remained in the main study at age 3 years. After follow-up visits at ages 6, 9, 12, and 16 years, 88 children (59%) remained in the dental sub-study (46 intervention group, 42 control group). The salivary flow rate in the study population increased with age and was 1.6 ml/min (SD 0.7 ml/min) at age 16 years. Dental caries was observed during at least one study visit in 130 of the 148 participants. Caries prevalence at age 16 years was not reported.
M AN U
SC
Key Exposure/Study Factor: In the Special Turku Risk Factor Intervention Project (STRIP), infants and their families were randomly assigned at age 7 months either to an intervention group who received individualized dietary counseling that encouraged limiting dietary cholesterol to less than 200 mg/day and achieving fat intake at 30% to 35% of daily energy with a 1:2 ratio of saturated to mono- and polyunsaturated fat or to a control group who received basic health education.1 Intervention group families received counseling every 1 to 3 months to age 2 years and semiannually to age 20; control group health education occurred semiannually through age 6 years and annually to age 20 years.
TE D
Main Outcome Measure: At ages 6, 9, 12, and 16 years, calibrated technicians masked to intervention grouping collected saliva samples. In the primary analysis, the authors compared two variables between intervention and control groups: (1) Salivary flow rate (ml/min), measured by collecting 4 ml of stimulated whole saliva after 1 minute of chewing paraffin wax and at least 1 hour of fasting, and (2) salivary buffering capacity, based on color changes observed visually on commercial test strips and classified as good (pH ≥ 6.0), normal (pH 4.5 to 5.5), or low (pH ≤ 4.0).
AC C
EP
Main Results: At each age evaluated, salivary flow rate, on average, was 0.1 to 0.2 ml/min greater among intervention group children than among children in the control group (p = 0.04 from repeatedmeasures generalized linear model). A greater percentage of children were classified as having “good” salivary buffering capacity in the intervention group than in the control group (p < 0.01 from repeated-measures generalized linear model). The authors also stated that the dietary intervention produced no difference in dental health between the study groups but did not quantify this finding. Conclusions: Repeated, individualized dietary counseling focusing on fat and cholesterol intake from an early age may increase salivary flow rate and buffering capacity. At this time, there is insufficient evidence that dietary modification of this particular nature leads to caries prevention.
2
ACCEPTED MANUSCRIPT
RI PT
Commentary Dental health and diet are strongly linked, and dietary habits from an early age have lasting oral health implications.2 The World Health Organization3 promotes healthful nutrition under a common risk factor approach to disease prevention, seeking to improve multiple dimensions of population health by targeting shared determinants. While caries preventive efforts usually stress less frequent intake of fermentable carbohydrates, other aspects of a healthy diet could positively influence oral health, potentially through diverse mechanisms.
M AN U
SC
In this paper, children assigned to an intervention encouraging diets lower in saturated fat and cholesterol beginning in infancy demonstrated increased salivary flow rate and buffering capacity compared to children in the control group. Few prior studies have shown impacts on salivary flow downstream of dietary modification. In one study, moderate short-term sodium restriction lowered salivary sodium concentration but not flow rate.4 Elsewhere, short-term dietary supplementation with white button mushroom did not appreciably affect salivary flow.5 Among older adults, adequate salivary flow itself may be a key driver of nutrient intake by facilitating the ingestion of a wider variety of foods.6
TE D
As for caries, authors of the current study reported no impact of the dietary intervention, although no measure of association was provided. Several factors could account for a null effect. Salivary flow is one of many influences of the caries process, and the magnitude of the difference in flow rate between intervention and control children was small; nearly all children maintained good or normal buffering capacity throughout the study. Also, any positive dental effect mediated through salivary properties might have been balanced by the increased carbohydrate intake seen with the intervention, although intake of sucrose did not differ by group. Importantly, the study may have lacked sufficient statistical power to detect dental effects. The authors categorized caries outcomes so that participants who developed caries at any age between 3 and 16 years (80% of children analyzed) were classified together, leaving few individuals in other outcome categories. Alternative outcome measures might have afforded greater power.
AC C
EP
In a number of secondary observational analyses conducted within the study cohort, statistically significant associations between dental health and salivary calcium concentration and between dental health and tooth brushing habits were reported. However, there were no statistically significant associations between caries outcomes and salivary flow rate, buffering capacity, or daily sucrose and carbohydrate intakes, perhaps also due to limited power. The intervention group did experience greater dietary fiber intake, which the authors speculate could be responsible for the observed increase in salivary flow. On the other hand, the authors reported no direct correlation between salivary variables and intakes of individual dietary compounds, including fiber. Whether and to what extent dietary fiber might influence salivary properties is a question awaiting further research. The authors reported no external funding. However, other STRIP publications7,8 acknowledge support from multiple government and foundation sources. Presumably, these sources did not directly fund the dental sub-study; yet, this valuable dental research might not have occurred
3
ACCEPTED MANUSCRIPT
without the existence of the overall study infrastructure. Greater detail is recommended when reporting sources of support.
SC
Strength of Recommendation Taxonomy (SORT) Grading
RI PT
By SORT criteria9, the level of evidence score was 3, because salivary properties represented disease-oriented outcomes (i.e. intermediate or surrogate end points), rather than patient-oriented outcomes (i.e. morbidity or quality-of-life measures). This does not preclude further research into whether dietary modification can meaningfully impact caries development through salivarymediated processes. In conclusion, although caries and the diet are closely intertwined, current evidence does not support encouraging patients to achieve low-saturated-fat and/or high-fiber diets explicitly for dental health promotion.
M AN U
LEVEL OF EVIDENCE: Level 3 Other evidence STRENGTH OF RECOMMENDATION GRADE: N/A Not applicable
AC C
EP
TE D
References 1. Niinikoski H, Lagstrom H, Jokinen E, Siltala M, Ronnemaa T, Viikari J, et al. Impact of repeated dietary counseling between infancy and 14 years of age on dietary intakes and serum lipids and lipoproteins: the STRIP study. Circulation 2007;6:1032-1140. 2. Feldens CA, Giugliani ER, Vigo A, Vitolo MR. Early feeding practices and severe early childhood caries in four-year-old children from southern Brazil: a birth cohort study. Caries Res 2010:44:445-52. 3. World Health Organization. 2008-2013 Action plan for the global strategy for the prevention and control of noncommunicable diseases. (2009) Geneva, Switzerland: World Health Organization. 4. Christensen CM, Bertino M, Beauchamp GK, Navazesh M, Engelman K. The influence of moderate reduction in dietary sodium on human salivary sodium concentration. Arch Oral Biol 1986;31:825-8. 5. Jeong SC, Koyyalamudi SR, Pang G. Dietary intake of Agaricus bisporus white button mushroom accelerates salivary immunoglobulin A secretion in healthy volunteers. Nutrition 2012;28:527-31. 6. Ernest SL. Dietary intake, food preferences, stimulated salivary flow rate, and masticatory ability in older adults with complete dentitions. Spec Care Dentist 1993;13:102-6. 7. Hakanen M, Ronnemaa T, Talvia S, Rask-Nissila L, Koulu M, Viikari J, et al. Serum leptin concentration poorly reflects growth and energy and nutrient intake in young children. Pediatrics 2004;113:1273-8. 8. Niinikoski H, Jula A, Viikari J, Ronnemaa T, Heino P, Lagstrom H, et al. Blood pressure is lower in children and adolescents with a low-saturated-fat diet since infancy: the special turku coronary risk factor intervention project. Hypertension 2009;53:918-24.
4
ACCEPTED MANUSCRIPT
AC C
EP
TE D
M AN U
SC
RI PT
9. Newman MG, Weyant R, Hujoel P. JEBDP improves grading system and adopts strength of recommendation taxonomy grading (SORT) for guidelines and systematic reviews. J Evid Based Dent Pract 2007;7:147-50.
5
