Research in Gerontological Nursing

Research Brief 

Can a Licorice Lollipop Decrease Cariogenic Bacteria in Nursing Home Residents?

Janet C. Mentes, PhD, APRN, BC, FGSA; Sarah Kang, MSN, RN; Sue Spackman, DDS; Janet Bauer, DDS

Abstract

The purpose of this pilot study was to examine whether an herbal lollipop containing licorice root decreases Streptococcus mutans (S. mutans) bacteria that cause dental caries in nursing home residents. A total of 8 residents (5 women, 3 men; mean age = 85) consented to participate in this study. Participants were offered two lollipops per day for 21 days. Saliva samples were collected at baseline and Days 1, 3, 7, 14, and 21, then analyzed for numbers of S. mutans. Using linear mixed-models analysis with difference in numbers of S. mutans from baseline to any time point as the dependent variable, and number of lollipops consumed with effect of time controlled as the predictor variable, participants who consumed more lollipops during the 21-day time period were more likely to have fewer numbers of S. mutans (β = −8.703, p = 0.067). There was a trend toward reduction of S. mutans with consumption of more lollipops during the 21-day period. Recruiting a larger sample for future research may demonstrate a significant reduction.

Abstract

The purpose of this pilot study was to examine whether an herbal lollipop containing licorice root decreases Streptococcus mutans (S. mutans) bacteria that cause dental caries in nursing home residents. A total of 8 residents (5 women, 3 men; mean age = 85) consented to participate in this study. Participants were offered two lollipops per day for 21 days. Saliva samples were collected at baseline and Days 1, 3, 7, 14, and 21, then analyzed for numbers of S. mutans. Using linear mixed-models analysis with difference in numbers of S. mutans from baseline to any time point as the dependent variable, and number of lollipops consumed with effect of time controlled as the predictor variable, participants who consumed more lollipops during the 21-day time period were more likely to have fewer numbers of S. mutans (β = −8.703, p = 0.067). There was a trend toward reduction of S. mutans with consumption of more lollipops during the 21-day period. Recruiting a larger sample for future research may demonstrate a significant reduction.

Consistently providing routine oral hygiene remains a significant problem for caregivers of nursing home (NH) residents. Residents’ specific disabilities, including dementia, dysphagia, and extreme physical frailty, as well as time constraints on caregivers, makes maintaining oral hygiene exceptionally difficult (Bauer, Spackman, Chiappelli, & Prolo, 2008; Coleman & Watson, 2006). Inadequate oral hygiene has been linked to declines in overall health, specifically between disease found in the oral cavity and that found systemically throughout the body (Stein & Henry, 2009). Specifically, inflammation-driven diseases, such as cardiovascular, cerebrovascular, and infectious pathologies, have been associated with oral disease (Maupomé, Gullion, White, Wyatt, & Williams, 2003; Mojon, Rentsch, Budtz-Jørgensen, & Baehni, 1998). Additionally, inadequate oral hygiene influences the nutrition and hydration status of NH residents, which is an important index of health (Mentes, 2006; U.S. Department of Health & Human Services, 2000).

Previous research demonstrates that daily oral hygiene regimens positively affect the overall health of older adults (Meurman & Hämäläinen, 2006) and NH residents (Samson, Berven, & Strand, 2009; Sjögren, Kullberg, Hoogstraate, Johansson, Herbst, & Forsell, 2010). However, studies indicate that adequate daily oral self-care is not routinely delivered to this population (Coleman & Watson, 2006). The lack of oral hygiene is particularly troublesome because not only are older adults at greater risk for dental caries, respiratory pathogens aspirated from the oropharangeal cavity have been shown to be major risk factors for pneumonia in older adults, especially frail older adults who have swallowing difficulties or other functional disabilities (Nishiyama, Inaba, Uematsu, & Senpuku, 2010; Ohrui, 2005). Yet, many issues prevent proper adherence with oral care requirements for NH residents. First, low staffing and little or no training about oral care strategies limit staff members’ ability to provide necessary and adequate daily oral care for NH residents. Second, NH caregivers, specifically certified nursing assistants, may be concerned about being injured while providing care, especially to residents with dementia (Jablonski, Munro, Grap, & Elswick, 2005; Reed, Broder, Jenkins, Spivack, & Janal, 2006). Thus, there is a need for a simple adjunctive aid that can be used alone or in addition to oral care regimens for this population that can eliminate oral pathogens and preserve normal oral flora for optimal health.

We hypothesized that an herbal lollipop containing whole licorice extract that demonstrated antimicrobial properties in laboratory studies could potentially help reduce oral bacterial loads, leading to improvements in the oral health of NH residents (He, Chen, Heber, Shi, & Lu, 2006; Hu et al., 2011). The active ingredient in licorice, glycyrrhizin, has demonstrated many health benefits, including antibacterial properties, specifically against cariogenic bacteria such as Streptococcus mutans (S. mutans) (He et al., 2006; Thorne Research, Inc., 2005). S. mutans are colonized in dental plaque that naturally occurs on the smooth surfaces of teeth. When colonized, S. mutans become pathogenic and are therefore associated with the development of dental caries.

While licorice consumption is rated Generally Recognized as Safe by the U.S. Food and Drug Administration (1974), with consumption of 1 to 5 grams of licorice per day considered safe in reasonably healthy adults (Thorne Research, Inc., 2005), several case reports (age range = 67 to 80) have indicated hypertensive side effects of unmonitored higher amounts of licorice intake from candy or herbal supplements in older adults (Breidthardt, Namdar, & Hess, 2006; Janse, van Irsel, Hoefnagels, & Olde Rikker, 2005). At 30 mg per day, the amount of glycyrrhizin in the lollipops used in this study was considered safe and thus provided a desirable antibacterial tool with a novel delivery system.

The purpose of this pilot study was to evaluate the use of an herbal lollipop consumed twice per day on the number of S. mutans in the oral cavity of NH residents. A secondary purpose was to assess the feasibility of offering this intervention to NH residents.

Method

A single-group, repeated measures design was used to evaluate the ability of an herbal lollipop to decrease the S. mutans bacteria counts in the oral cavity of frail NH residents.

Setting and Sample

Residents from two proprietary NHs located in the greater Los Angeles area participated in the study. The first home had 87 beds and is part of a chain of 37 health care centers offering complex medical care; rehabilitation, subacute, skilled nursing, Alzheimer’s disease, and long-term skilled nursing care; and assisted living centers. The second nursing facility had 144 beds and provides both rehabilitative and long-term care.

Each participant or his or her legal guardian gave written informed consent to participate in this study, which was approved by the University’s Institutional Review Board and appropriate individuals at each NH. Inclusion criteria for the study were: (a) age 65 or older, (b) dentate, and (c) speaks or understands English. Exclusion criteria for the study were: (a) terminal diagnosis, (b) needing a feeding tube, (c) oral or esophageal cancer, (d) diagnosed renal failure, (e) diagnosed uncontrolled hypertension, (f) late-stage dementia, (g) severe periodontal disease, (h) current long-term antibiotic agent use, (i) dose of warfarin (Coumadin®) adjusted in the 2 months prior to study enrollment, or (j) allergies to dyes or licorice.

Materials

A sugar-free herbal tooth pop containing 2 mg extract of Sophora flavescens and 15 mg of licorice extract as the active ingredients was used in this study (Hu et al., 2011). Other inactive ingredients included hydrogenated starch hydrolysate (solidifying agent); citric acid and mint (flavoring agents); FD&C blue 1 and 2, red 3 and 40, yellow 5 and 6 (coloring agents); and acesulfame potassium (noncaloric sweetener).

Procedure

After receiving informed consent, a baseline saliva specimen was obtained from each study participant. A registered dental hygienist then performed a dental prophylaxis that included debridement, scaling, and polishing of teeth so each participant would begin the study with a reduced S. mutans load. Then the study dentist completed an examination of the participant’s oral cavity, specifically evaluating debris, calculus, caries, and condition of the periodontium, as well as completing the Index of the Activities of Daily Oral Hygiene (ADOH).

Trained research assistants delivered lollipops twice per day to participants at the NH; collected saliva samples at baseline and at Days 1, 3, 7, 14, and 21; and regularly monitored participants’ blood pressure. To collect the saliva, research assistants instructed participants to spit into a cup and pipetted at least 0.5 mL of saliva into tubes with a preserving fixant. For the few participants who were unable to spit, the research assistants gently suctioned the saliva from participant’s oral cavity with a pipette. The saliva was collected at least an hour after meals or brushing of teeth and sent to a laboratory within 24 hours for analysis. Blood pressure measurements were completed twice per week to ensure there were no untoward effects for participants from consuming the lollipop. A follow-up dental examination was completed at the end of the study.

Data Collection Instruments

Participant demographic characteristics collected from the NH charts included age, sex, marital status, race/ethnicity, medical diagnoses, number of teeth, and current medications.

Scales that measured the functional status of each participant included the Activities of Daily Living (ADL) Hierarchy Scale (Morris, Fries, & Morris, 1999), Cognitive Performance Scale (CPS, Morris et al., 1994), and the Index of ADOH (Bauer, 2001), which assesses participants’ ability to manipulate aids used in daily oral self-care regimens.

The ADL Hierarchy Scale and CPS data were abstracted from the NH resident’s most recent Minimum Data Set (MDS) assessment, which has demonstrated stability over a 7-day assessment period (Graney & Engle, 2000) and is independently associated with staff time involved in resident care (Morris et al., 1999). For this study, the MDS ADL Hierarchy Scale was scored from 0 (independence) to 6 (total dependence) in four areas: personal hygiene, toileting, locomotion, and eating. The ADL Hierarchy Scale determines the participant’s level of assistance required to complete ADLs and is determined by an algorithm.

The CPS algorithm is scored from 0 (cognitively intact) to 6 (very severe cognitive impairment) and has been validated against the Mini-Mental State Examination (MMSE, Folstein, Folstein, & McHugh, 1975). The CPS showed substantial agreement with the MMSE in the identification of cognitive impairment with a sensitivity of 0.94 (95% confidence interval [CI]: 0.90, 0.98) and a specificity of 0.94 (95% CI: 0.87, 0.96) (Hartmaier et al., 1995).

The Index of ADOH, developed by a dentist specializing in geriatric dentistry, assesses the level of assistance needed for the individual to successfully accomplish oral hygiene routines (Bauer, 2001). Specifically, it measures older adults’ ability to manipulate aids involved in flossing, tooth or denture brushing, topical fluoride application, and the use of oral rinses. The residents’ abilities were assessed and scored on a scale ranging from 0 (complete independence) to 4 (total dependence). The total Index of ADOH score is 16 points for dentate residents and 8 points for non-dentate residents. In a previous study, the Index of ADOH was significantly associated to the Barthel General Index, an index measuring performance in variables describing ADLs and mobility (Ruiz-Medina, Bravo, Gil-Montoya, & Montero, 2005).

Results

Demographic Data

Eight dentate NH residents participated in this study. Their mean age was 85 (age range = 68 to 95). The sample was mostly women (62.5%, n = 5; mean age = 82.2) versus men (37.5%, n = 3; mean age = 89.7). Of the 8 study participants, 2 identified themselves as Black/African American, 5 as White/Caucasian, and 1 as Asian/Pacific Islander. The mean number of medical diagnoses per participant was 4.7, and the mean number of medication categories prescribed per participant was 8.2. Of these medication categories, participants were receiving, on average, four medications that could cause dry mouth. The most commonly prescribed medications contributing to dry mouth were antihypertensive agents. The mean number of teeth for all participants was 15, with a higher mean for women (18.4) compared with men (9.7).

Level of Functioning

The total mean MDS ADL Hierarchy Scale score was 4.1, signifying total dependence in one or more of the four ADLs (i.e., personal hygiene, toileting, locomotion, eating), with women demonstrating a better functioning mean score (3.6) versus men (5). Similarly, women exhibited a better cognitive functioning score (CPS mean score = 2) than men (CPS mean score = 3.5), while the total CPS mean score was 2.38 (i.e., between mild and moderate impairment).

Based on the results of the Index of ADOH, 25% of participants (n = 2) required assistance with rinsing and brushing, and 88% (n = 7) required assistance with fluoride application. The greatest variability in function was observed in participants’ ability to floss, ranging from independent (n = 2), to requiring assistance (n = 5), to total dependence (n = 1). Although most participants were able to brush their teeth, upon initial examination and cleaning, there was evidence of moderate debris in teeth, suggesting participants did not brush on a regular basis, which appeared to be related to not being able to independently gather the supplies needed for oral care. This has been identified in other studies as well (Coleman & Watson, 2006; Woods & Mentes, 2011).

Effects of the Licorice Lollipop

Since licorice root in large amounts has been found to increase blood pressure, blood pressure trending was completed for participants. Blood pressure remained stable throughout the study, suggesting the relative safety of including herbal lollipops as a part of an oral care regimen for NH residents (data not shown).

The results of the pre- and post-study dental examinations revealed that participants had generally good oral health that persisted throughout the 21-day period. Indices of oral hygiene, both debris and calculus score, showed no clinically significant change.

For the outcome of interest—levels of S. mutans—we used a linear mixed-models analysis with difference in numbers of S. mutans from baseline to any time point as the dependent variable, and number of lollipops consumed with the effect of time controlled as the predictor variable. Participants who consumed more lollipops during the 21-day period were more likely to have fewer numbers of S. mutans (β = −8.703, p = 0.067). The Figure illustrates the effect of the lollipops on S. mutans load in 3 of the 8 participants. These participants began the study with a lower S. mutans load and were able to maintain lower loads until Day 7, when bacterial loads increased for 2 of these 3 participants. This is explained by the fact that average adherence to the lollipop regimen decreased over time, from 78% during Days 1 to 3, to 62% in Days 3 to 7, and 54% in Days 7 to 14, and then rising slightly to 60% in Days 14 to 21. Of 42 total lollipops, the range of lollipops consumed was 9 to 28, with a mean of 22, or one lollipop per day.

Three participants’ S. mutans load during the 21 study days.

Figure. Three participants’ S. mutans load during the 21 study days.

Discussion

This study found promise in the effectiveness of herbal lollipops to augment oral care health outcomes in NH residents by reducing S. mutans. Although statistical significance was not achieved due to the small scale of the study, we found a decreasing trend of S. mutans bacteria with the increasing consumption of licorice lollipops over time. Additional important findings from this pilot study were that the intervention was best tolerated by NH residents over a 7- to 14-day period, rather than for 21 days. Participants tended to fatigue with the intervention starting at Day 7. In addition, it is interesting to note that, on average, the participants consumed one lollipop per day, rather than the two that were prescribed as part of the protocol; yet, they were able to maintain a lowered S. mutans load.

Concerning participants’ response to the intervention, we found that the lollipops could be used with relative ease, with little risk of injury to caregivers and residents with dysphagia or dementia. Reasons participants refused the lollipop included dislike of the orange flavor, embarrassment over consuming a lollipop in front of peers, and being too tired to consume it. Offering an assortment of flavors, as well as providing it in a lozenge version, could make it more amenable to some NH residents. The nursing staff provided positive feedback on the novelty and simplicity of the concept, suggesting that caregivers may be willing to embrace licorice lollipops as a part of oral care. The lollipop is also relatively inexpensive, approximately 40 cents each. All these factors demonstrate the promising feasibility of implementing this intervention as a part of the oral care regimen for NH residents.

Important limitations in this study were the small sample, lack of a control group, and the inability of many participants to provide enough saliva for analysis due to medications and disease conditions.

Conclusion

An antimicrobial herbal lollipop could be a simple, non-invasive, nonpharmacological strategy to improve the oral health of NH residents. Future research should encompass a larger cohort with control and intervention groups, as well as determine the optimal length of time for consumption of lollipops and how often the regimen should be repeated. In addition, although the lollipop intervention holds promise for decreasing cariogenic bacteria, future research should include the additive effect of a structured oral care regimen.

References

  • Bauer, J.G. (2001). The Index of ADOH: Concept of measuring oral self-care functioning in the elderly. Special Care in Dentistry, 21, 63–67. doi:10.1111/j.1754-4505.2001.tb00227.x [CrossRef]
  • Bauer, J.G., Spackman, S., Chiappelli, F. & Prolo, P. (2008). The changing nature of treating frail and functionally dependent older adults: Paucity of best evidence. In Chiappelli, F. (Ed.), Manual of evidence-based research for the health sciences: Implications for clinical dentistry (pp. 231–246). New York: Nova Science.
  • Breidthardt, T., Namdar, M. & Hess, B. (2006). A hypertensive urgency induced by the continuous intake of a herbal remedy containing liquorice. Journal of Human Hypertension, 20, 465–466. doi:10.1038/sj.jhh.1001997 [CrossRef]
  • Coleman, P. & Watson, N.M. (2006). Oral care provided by certified nursing assistants in nursing homes. Journal of the American Geriatrics Society, 54, 138–143. doi:10.1111/j.1532-5415.2005.00565.x [CrossRef]
  • Folstein, M.F., Folstein, S.E. & McHugh, P.R. (1975). “Mini-mental state.” A practical method for grading the cognitive state of patients for the clinician. Journal of Psychiatric Research, 12, 189–198. doi:10.1016/0022-3956(75)90026-6 [CrossRef]
  • Graney, M.J. & Engle, V.F. (2000). Stability of performance of activities of daily living using the MDS. The Gerontologist, 40, 582–586. doi:10.1093/geront/40.5.582 [CrossRef]
  • Hartmaier, S.L., Sloane, P.D., Guess, H.A., Koch, G.G., Mitchell, C.M. & Phillips, C.D. (1995). Validation of the minimum data set cognitive performance scale: Agreement with the Mini-Mental State Examination. Journals of Gerontology. Series A, Biological Sciences and Medical Sciences, 50, M128–M133. doi:10.1093/gerona/50A.2.M128 [CrossRef]
  • He, J., Chen, L., Heber, D., Shi, W. & Lu, Q.-Y. (2006). Antibacterial compounds fromGlycyrrhiza uralensis. Journal of Natural Products, 69, 121–124. doi:10.1021/np058069d [CrossRef]
  • Hu, C., He, J., Eckert, R., Wu, X.Y., Li, L.N., Lux, R. & Shi, W.Y. (2011). Development and evaluation of a safe and effective sugar-free herbal lollipop that kills cavity-causing bacteria. International Journal of Oral Science, 3, 13–20. doi:10.4248/IJOS11005 [CrossRef]
  • Jablonski, R.A., Munro, C.L., Grap, M.J. & Elswick, R.K. (2005). The role of biobehavioral, environmental, and social forces on oral health disparities in frail and functionally dependent nursing home elders. Biological Research for Nursing, 7, 75–82. doi:10.1177/1099800405275726 [CrossRef]
  • Janse, A., van Iersel, M., Hoefnagels, W.H. & Olde Rikker, M.G. (2005). The old lady who liked liquorice: Hypertension due to chronic intoxication in a memory-impaired patient. The Netherlands Journal of Medicine, 63(4), 149–150.
  • Maupomé, G., Gullion, C.M., White, B.A., Wyatt, C.C.L. & Williams, P.M. (2003). Oral disorders and chronic systemic diseases in very old adults living in institutions. Special Care in Dentistry, 23, 199–208. doi:10.1111/j.1754-4505.2003.tb00313.x [CrossRef]
  • Mentes, J. (2006). Oral hydration in older adults. American Journal of Nursing, 106(6), 40–49. doi:10.1097/00000446-200606000-00023 [CrossRef]
  • Meurman, J.H. & Hämäläinen, P. (2006). Oral health and morbidity—Implications of oral infections on the elderly. Gerodontology, 23, 3–16. doi:10.1111/j.1741-2358.2006.00102.x [CrossRef]
  • Mojon, P., Rentsch, A., Budtz-Jørgensen, E. & Baehni, P.C. (1998). Effects of an oral health program on selected clinical parameters and salivary bacteria in a long-term care facility. European Journal of Oral Sciences, 106, 827–834. doi:10.1046/j.0909-8836.1998.eos106401.x [CrossRef]
  • Morris, J.N., Fries, B.E., Mehr, D.R., Hawes, C., Phillips, C., Mor, V. & Lipsitz, L.A. (1994). MDS cognitive performance scale. Journal of Gerontology, 49, M174–M182.
  • Morris, J.N., Fries, B.E. & Morris, S.A. (1999). Scaling ADLs within the MDS. Journals of Gerontology. Series A, Biological Sciences and Medical Sciences, 54, M546–M553. doi:10.1093/gerona/54.11.M546 [CrossRef]
  • Nishiyama, Y., Inaba, E., Uematsu, H. & Senpuku, H. (2010). Effects of mucosal care on oral pathogens in professional oral hygiene to the elderly. Archives of Gerontology and Geriatrics, 51, e139–e143. doi:10.1016/j.archger.2010.04.009 [CrossRef]
  • Ohrui, T. (2005). Preventive strategies for aspiration pneumonia in elderly disabled persons. Tohoku Journal of Experimental Medicine, 207, 3–12. doi:10.1620/tjem.207.3 [CrossRef]
  • Reed, R., Broder, H.L., Jenkins, G., Spivack, E. & Janal, M.N. (2006). Oral health promotion among older persons and their care providers in a nursing home facility. Gerodontology, 23, 73–78. doi:10.1111/j.1741-2358.2006.00119.x [CrossRef]
  • Ruiz-Medina, P., Bravo, M., Gil-Montoya, J.A. & Montero, J. (2005). Discrimination of functional capacity for oral hygiene in elderly Spanish people by the Barthel General Index. Community Dental and Oral Epidemiology, 33, 363–369. doi:10.1111/j.1600-0528.2005.00222.x [CrossRef]
  • Samson, H., Berven, L. & Strand, G.V. (2009). Long-term effect of an oral healthcare programme on oral hygiene in a nursing home. European Journal of Oral Sciences, 117, 575–579. doi:10.1111/j.1600-0722.2009.00673.x [CrossRef]
  • Sjögren, P., Kullberg, E., Hoogstraate, J., Johansson, O., Herbst, B. & Forsell, M. (2010). Evaluation of dental hygiene education for nursing home staff. Journal of Advanced Nursing, 66, 345–349. doi:10.1111/j.1365-2648.2009.05181.x [CrossRef]
  • Stein, P.S. & Henry, R.G. (2009). Poor oral hygiene in long term care. American Journal of Nursing, 109(6), 44–50. doi:10.1097/01.NAJ.0000352472.70993.3b [CrossRef]
  • Thorne Research, Inc. (2005). Glycyrrhiza glabra [Monograph]. Alternative Medicine Review, 10, 230–237.
  • U.S. Department of Health and Human Services. (2000). Oral health in America: A report of the Surgeon General. Retrieved from the National Institute of Dental and Craniofacial Research website: http://www.nidcr.nih.gov/DataStatistics/SurgeonGeneral/sgr/
  • U.S. Food and Drug Administration. (1974). Licorice, glycyrrhiza, and ammoniated glycyrrhizin. Retrieved from http://www.fda.gov/Food/FoodIngredientsPackaging/GenerallyRecognizedasSafeGRAS/GRASSubstancesSCOGSDatabase/ucm260457.htm
  • Woods, D.L. & Mentes, J.C. (2011). Spit: Saliva in nursing research, uses and methodological considerations in older adults. Biological Research for Nursing, 13, 320–327. doi:10.1177/1099800411404211 [CrossRef]
Authors

Dr. Mentes is Associate Professor, School of Nursing, Dr. Spackman is Lecturer and Co-Director, and Dr. Bauer is Professor and Director, June and Paul Ehrlich Endowed Program in Geriatric Dentistry, School of Dentistry, University of California Los Angeles, and Ms. Kang is CN1, Cedars Sinai Medical Center, Los Angeles, California.

The authors have disclosed no potential conflicts of interest, financial or otherwise. Dr. Mentes acknowledges a grant from Delta Dental. The authors gratefully acknowledge the support of Dr. Michelle Eslami for help in recruiting study participants and Dr. Wenyuan Shi and his laboratory staff for help with the saliva analysis.

Address correspondence to Janet C. Mentes, PhD, APRN, BC, FGSA, Associate Professor, School of Nursing, University of California Los Angeles, 700 Tiverton Avenue, Box 956919, Los Angeles, CA 90095-6919; e-mail: Jmentes@sonnet.ucla.edu.

Received: May 01, 2011
Accepted: January 27, 2012
Posted Online: September 17, 2012

10.3928/19404921-20120906-07

Sign up to receive

Journal E-contents