Journal of Clinical and Diagnostic Research, ISSN - 0973 - 709X

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Dr Mohan Z Mani

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Department of Dermatolgy,
Believers Church Medical College,
Thiruvalla, Kerala
On Sep 2018




Prof. Somashekhar Nimbalkar

"Over the last few years, we have published our research regularly in Journal of Clinical and Diagnostic Research. Having published in more than 20 high impact journals over the last five years including several high impact ones and reviewing articles for even more journals across my fields of interest, we value our published work in JCDR for their high standards in publishing scientific articles. The ease of submission, the rapid reviews in under a month, the high quality of their reviewers and keen attention to the final process of proofs and publication, ensure that there are no mistakes in the final article. We have been asked clarifications on several occasions and have been happy to provide them and it exemplifies the commitment to quality of the team at JCDR."



Prof. Somashekhar Nimbalkar
Head, Department of Pediatrics, Pramukhswami Medical College, Karamsad
Chairman, Research Group, Charutar Arogya Mandal, Karamsad
National Joint Coordinator - Advanced IAP NNF NRP Program
Ex-Member, Governing Body, National Neonatology Forum, New Delhi
Ex-President - National Neonatology Forum Gujarat State Chapter
Department of Pediatrics, Pramukhswami Medical College, Karamsad, Anand, Gujarat.
On Sep 2018




Dr. Kalyani R

"Journal of Clinical and Diagnostic Research is at present a well-known Indian originated scientific journal which started with a humble beginning. I have been associated with this journal since many years. I appreciate the Editor, Dr. Hemant Jain, for his constant effort in bringing up this journal to the present status right from the scratch. The journal is multidisciplinary. It encourages in publishing the scientific articles from postgraduates and also the beginners who start their career. At the same time the journal also caters for the high quality articles from specialty and super-specialty researchers. Hence it provides a platform for the scientist and researchers to publish. The other aspect of it is, the readers get the information regarding the most recent developments in science which can be used for teaching, research, treating patients and to some extent take preventive measures against certain diseases. The journal is contributing immensely to the society at national and international level."



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Professor and Head
Department of Pathology
Sri Devaraj Urs Medical College
Sri Devaraj Urs Academy of Higher Education and Research , Kolar, Karnataka
On Sep 2018




Dr. Saumya Navit

"As a peer-reviewed journal, the Journal of Clinical and Diagnostic Research provides an opportunity to researchers, scientists and budding professionals to explore the developments in the field of medicine and dentistry and their varied specialities, thus extending our view on biological diversities of living species in relation to medicine.
‘Knowledge is treasure of a wise man.’ The free access of this journal provides an immense scope of learning for the both the old and the young in field of medicine and dentistry as well. The multidisciplinary nature of the journal makes it a better platform to absorb all that is being researched and developed. The publication process is systematic and professional. Online submission, publication and peer reviewing makes it a user-friendly journal.
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Dr Saumya Navit
Professor and Head
Department of Pediatric Dentistry
Saraswati Dental College
Lucknow
On Sep 2018




Dr. Arunava Biswas

"My sincere attachment with JCDR as an author as well as reviewer is a learning experience . Their systematic approach in publication of article in various categories is really praiseworthy.
Their prompt and timely response to review's query and the manner in which they have set the reviewing process helps in extracting the best possible scientific writings for publication.
It's a honour and pride to be a part of the JCDR team. My very best wishes to JCDR and hope it will sparkle up above the sky as a high indexed journal in near future."



Dr. Arunava Biswas
MD, DM (Clinical Pharmacology)
Assistant Professor
Department of Pharmacology
Calcutta National Medical College & Hospital , Kolkata




Dr. C.S. Ramesh Babu
" Journal of Clinical and Diagnostic Research (JCDR) is a multi-specialty medical and dental journal publishing high quality research articles in almost all branches of medicine. The quality of printing of figures and tables is excellent and comparable to any International journal. An added advantage is nominal publication charges and monthly issue of the journal and more chances of an article being accepted for publication. Moreover being a multi-specialty journal an article concerning a particular specialty has a wider reach of readers of other related specialties also. As an author and reviewer for several years I find this Journal most suitable and highly recommend this Journal."
Best regards,
C.S. Ramesh Babu,
Associate Professor of Anatomy,
Muzaffarnagar Medical College,
Muzaffarnagar.
On Aug 2018




Dr. Arundhathi. S
"Journal of Clinical and Diagnostic Research (JCDR) is a reputed peer reviewed journal and is constantly involved in publishing high quality research articles related to medicine. Its been a great pleasure to be associated with this esteemed journal as a reviewer and as an author for a couple of years. The editorial board consists of many dedicated and reputed experts as its members and they are doing an appreciable work in guiding budding researchers. JCDR is doing a commendable job in scientific research by promoting excellent quality research & review articles and case reports & series. The reviewers provide appropriate suggestions that improve the quality of articles. I strongly recommend my fraternity to encourage JCDR by contributing their valuable research work in this widely accepted, user friendly journal. I hope my collaboration with JCDR will continue for a long time".



Dr. Arundhathi. S
MBBS, MD (Pathology),
Sanjay Gandhi institute of trauma and orthopedics,
Bengaluru.
On Aug 2018




Dr. Mamta Gupta,
"It gives me great pleasure to be associated with JCDR, since last 2-3 years. Since then I have authored, co-authored and reviewed about 25 articles in JCDR. I thank JCDR for giving me an opportunity to improve my own skills as an author and a reviewer.
It 's a multispecialty journal, publishing high quality articles. It gives a platform to the authors to publish their research work which can be available for everyone across the globe to read. The best thing about JCDR is that the full articles of all medical specialties are available as pdf/html for reading free of cost or without institutional subscription, which is not there for other journals. For those who have problem in writing manuscript or do statistical work, JCDR comes for their rescue.
The journal has a monthly publication and the articles are published quite fast. In time compared to other journals. The on-line first publication is also a great advantage and facility to review one's own articles before going to print. The response to any query and permission if required, is quite fast; this is quite commendable. I have a very good experience about seeking quick permission for quoting a photograph (Fig.) from a JCDR article for my chapter authored in an E book. I never thought it would be so easy. No hassles.
Reviewing articles is no less a pain staking process and requires in depth perception, knowledge about the topic for review. It requires time and concentration, yet I enjoy doing it. The JCDR website especially for the reviewers is quite user friendly. My suggestions for improving the journal is, more strict review process, so that only high quality articles are published. I find a a good number of articles in Obst. Gynae, hence, a new journal for this specialty titled JCDR-OG can be started. May be a bimonthly or quarterly publication to begin with. Only selected articles should find a place in it.
An yearly reward for the best article authored can also incentivize the authors. Though the process of finding the best article will be not be very easy. I do not know how reviewing process can be improved. If an article is being reviewed by two reviewers, then opinion of one can be communicated to the other or the final opinion of the editor can be communicated to the reviewer if requested for. This will help one’s reviewing skills.
My best wishes to Dr. Hemant Jain and all the editorial staff of JCDR for their untiring efforts to bring out this journal. I strongly recommend medical fraternity to publish their valuable research work in this esteemed journal, JCDR".



Dr. Mamta Gupta
Consultant
(Ex HOD Obs &Gynae, Hindu Rao Hospital and associated NDMC Medical College, Delhi)
Aug 2018




Dr. Rajendra Kumar Ghritlaharey

"I wish to thank Dr. Hemant Jain, Editor-in-Chief Journal of Clinical and Diagnostic Research (JCDR), for asking me to write up few words.
Writing is the representation of language in a textual medium i e; into the words and sentences on paper. Quality medical manuscript writing in particular, demands not only a high-quality research, but also requires accurate and concise communication of findings and conclusions, with adherence to particular journal guidelines. In medical field whether working in teaching, private, or in corporate institution, everyone wants to excel in his / her own field and get recognised by making manuscripts publication.


Authors are the souls of any journal, and deserve much respect. To publish a journal manuscripts are needed from authors. Authors have a great responsibility for producing facts of their work in terms of number and results truthfully and an individual honesty is expected from authors in this regards. Both ways its true "No authors-No manuscripts-No journals" and "No journals–No manuscripts–No authors". Reviewing a manuscript is also a very responsible and important task of any peer-reviewed journal and to be taken seriously. It needs knowledge on the subject, sincerity, honesty and determination. Although the process of reviewing a manuscript is a time consuming task butit is expected to give one's best remarks within the time frame of the journal.
Salient features of the JCDR: It is a biomedical, multidisciplinary (including all medical and dental specialities), e-journal, with wide scope and extensive author support. At the same time, a free text of manuscript is available in HTML and PDF format. There is fast growing authorship and readership with JCDR as this can be judged by the number of articles published in it i e; in Feb 2007 of its first issue, it contained 5 articles only, and now in its recent volume published in April 2011, it contained 67 manuscripts. This e-journal is fulfilling the commitments and objectives sincerely, (as stated by Editor-in-chief in his preface to first edition) i e; to encourage physicians through the internet, especially from the developing countries who witness a spectrum of disease and acquire a wealth of knowledge to publish their experiences to benefit the medical community in patients care. I also feel that many of us have work of substance, newer ideas, adequate clinical materials but poor in medical writing and hesitation to submit the work and need help. JCDR provides authors help in this regards.
Timely publication of journal: Publication of manuscripts and bringing out the issue in time is one of the positive aspects of JCDR and is possible with strong support team in terms of peer reviewers, proof reading, language check, computer operators, etc. This is one of the great reasons for authors to submit their work with JCDR. Another best part of JCDR is "Online first Publications" facilities available for the authors. This facility not only provides the prompt publications of the manuscripts but at the same time also early availability of the manuscripts for the readers.
Indexation and online availability: Indexation transforms the journal in some sense from its local ownership to the worldwide professional community and to the public.JCDR is indexed with Embase & EMbiology, Google Scholar, Index Copernicus, Chemical Abstracts Service, Journal seek Database, Indian Science Abstracts, to name few of them. Manuscriptspublished in JCDR are available on major search engines ie; google, yahoo, msn.
In the era of fast growing newer technologies, and in computer and internet friendly environment the manuscripts preparation, submission, review, revision, etc and all can be done and checked with a click from all corer of the world, at any time. Of course there is always a scope for improvement in every field and none is perfect. To progress, one needs to identify the areas of one's weakness and to strengthen them.
It is well said that "happy beginning is half done" and it fits perfectly with JCDR. It has grown considerably and I feel it has already grown up from its infancy to adolescence, achieving the status of standard online e-journal form Indian continent since its inception in Feb 2007. This had been made possible due to the efforts and the hard work put in it. The way the JCDR is improving with every new volume, with good quality original manuscripts, makes it a quality journal for readers. I must thank and congratulate Dr Hemant Jain, Editor-in-Chief JCDR and his team for their sincere efforts, dedication, and determination for making JCDR a fast growing journal.
Every one of us: authors, reviewers, editors, and publisher are responsible for enhancing the stature of the journal. I wish for a great success for JCDR."



Thanking you
With sincere regards
Dr. Rajendra Kumar Ghritlaharey, M.S., M. Ch., FAIS
Associate Professor,
Department of Paediatric Surgery, Gandhi Medical College & Associated
Kamla Nehru & Hamidia Hospitals Bhopal, Madhya Pradesh 462 001 (India)
E-mail: drrajendrak1@rediffmail.com
On May 11,2011




Dr. Shankar P.R.

"On looking back through my Gmail archives after being requested by the journal to write a short editorial about my experiences of publishing with the Journal of Clinical and Diagnostic Research (JCDR), I came across an e-mail from Dr. Hemant Jain, Editor, in March 2007, which introduced the new electronic journal. The main features of the journal which were outlined in the e-mail were extensive author support, cash rewards, the peer review process, and other salient features of the journal.
Over a span of over four years, we (I and my colleagues) have published around 25 articles in the journal. In this editorial, I plan to briefly discuss my experiences of publishing with JCDR and the strengths of the journal and to finally address the areas for improvement.
My experiences of publishing with JCDR: Overall, my experiences of publishing withJCDR have been positive. The best point about the journal is that it responds to queries from the author. This may seem to be simple and not too much to ask for, but unfortunately, many journals in the subcontinent and from many developing countries do not respond or they respond with a long delay to the queries from the authors 1. The reasons could be many, including lack of optimal secretarial and other support. Another problem with many journals is the slowness of the review process. Editorial processing and peer review can take anywhere between a year to two years with some journals. Also, some journals do not keep the contributors informed about the progress of the review process. Due to the long review process, the articles can lose their relevance and topicality. A major benefit with JCDR is the timeliness and promptness of its response. In Dr Jain's e-mail which was sent to me in 2007, before the introduction of the Pre-publishing system, he had stated that he had received my submission and that he would get back to me within seven days and he did!
Most of the manuscripts are published within 3 to 4 months of their submission if they are found to be suitable after the review process. JCDR is published bimonthly and the accepted articles were usually published in the next issue. Recently, due to the increased volume of the submissions, the review process has become slower and it ?? Section can take from 4 to 6 months for the articles to be reviewed. The journal has an extensive author support system and it has recently introduced a paid expedited review process. The journal also mentions the average time for processing the manuscript under different submission systems - regular submission and expedited review.
Strengths of the journal: The journal has an online first facility in which the accepted manuscripts may be published on the website before being included in a regular issue of the journal. This cuts down the time between their acceptance and the publication. The journal is indexed in many databases, though not in PubMed. The editorial board should now take steps to index the journal in PubMed. The journal has a system of notifying readers through e-mail when a new issue is released. Also, the articles are available in both the HTML and the PDF formats. I especially like the new and colorful page format of the journal. Also, the access statistics of the articles are available. The prepublication and the manuscript tracking system are also helpful for the authors.
Areas for improvement: In certain cases, I felt that the peer review process of the manuscripts was not up to international standards and that it should be strengthened. Also, the number of manuscripts in an issue is high and it may be difficult for readers to go through all of them. The journal can consider tightening of the peer review process and increasing the quality standards for the acceptance of the manuscripts. I faced occasional problems with the online manuscript submission (Pre-publishing) system, which have to be addressed.
Overall, the publishing process with JCDR has been smooth, quick and relatively hassle free and I can recommend other authors to consider the journal as an outlet for their work."



Dr. P. Ravi Shankar
KIST Medical College, P.O. Box 14142, Kathmandu, Nepal.
E-mail: ravi.dr.shankar@gmail.com
On April 2011
Anuradha

Dear team JCDR, I would like to thank you for the very professional and polite service provided by everyone at JCDR. While i have been in the field of writing and editing for sometime, this has been my first attempt in publishing a scientific paper.Thank you for hand-holding me through the process.


Dr. Anuradha
E-mail: anuradha2nittur@gmail.com
On Jan 2020

Important Notice

Original article / research
Year : 2022 | Month : June | Volume : 16 | Issue : 6 | Page : CC06 - CC10 Full Version

Effect of Mint Flavoured Chewing Gum in Observing Changes in Cognitive Function while Assessing Test Performance- An Interventional Study


Published: June 1, 2022 | DOI: https://doi.org/10.7860/JCDR/2022/53795.16435
S Anu, K Jeyashree, SN Vishnuvarthini, N Prasanna Venkatesh, J Vijay Anto

1. Professor and Head, Department of Physiology, Velammal Medical College Hospital and Research Institute, Anuppanadi, Madurai, Tamil Nadu, India. 2. Scientist, Department of National Institute of Epidemiology, Indian Council of Medical Research, Chennai, Tamil Nadu, India. 3. Undergraduate Student, Department of Physiology, Velammal Medical College Hospital and Research Institute, Anuppanadi, Madurai, Tamil Nadu, India. 4. Compulsory Rotatory Residential Intership, Department of Physiology, Velammal Medical College Hospital and Research Institute, Anuppanadi, Madurai, Tamil Nadu, India. 5. Lecturer/Statistician, Department of Community Medicine, Velammal Medical College Hospital and Research Institute, Anuppanadi, Madurai, Tamil Nadu, India.

Correspondence Address :
Dr. S Anu,
Professor and Head, Department of Physiology, Velammal Medical College Hospital and Research Institute, Anuppanadi, Madurai, Tamil Nadu, India.
E-mail: anu.sengottaiyan@gmail.com

Abstract

Introduction: Cognition is the mental process of acquiring knowledge and understanding through aspects such as awareness, perception, reasoning, memory and judgment. Chewing movement of jaw stimulates memory parts of brain by increasing blood flow and glucose delivery. Taste and odour of mint is also known to stimulate memory areas of the brain. The synergistic effect of chewing and flavour is expected to have a greater effect on cognition than chewing alone.

Aim: To assess the effect of use of mint flavoured, flavourless and absence of chewing gum on an individual’s cognitive function among the medical undergraduates.

Materials and Methods: This comparative, interventional study, was conducted in the Department of Physiology at Velammal Medical College and Hospital, Madurai, Tamil Nadu, India, August 2019 to September 2019. Study involved 75 (39 females,36 males) MBBS first year students, aged 18-20 years. Only students with cognitive score between 28-30 based on Mini-mental state exam score were included in the study and were divided into 3 groups. Group A (n=25) who were given mint flavoured chewing gum, Group B (n=25) given flavourless chewing gum and Group C (n=25) the control group, not provided with chewing gum. Baseline memory, Heart Rate (HR), Reaction Time (RT) and Stress Levels (SL) were recorded. Groups were taken into separate rooms where they were allowed to study a particular topic i.e Parkinson’s disease for 30 minutes. Then they were allowed to take tests on standard Parkinson’s questionnaire for 20 minutes and assessed based on the test performance. Group A and Group B were provided with chewing gums both during studying the topic as well as taking tests. Post intervention test performance (short term memory), HR, RT and SL were again recorded. Test performance was also assessed after one month to assess the effect of chewing gum on long term memory. One-way Analysis of Variance (ANOVA) and paired t-test were used to compare all the post test parameters between the three groups.

Results: A statistically significant increase in short term memory (p-value=0.001) and HR (p-value=0.001) were observed after intervention. Similarly, short term memory level of the three groups subjects statistically differed (p-value=0.001). When considering the reaction time (p-value=0.068) and stress level (p-value=0.927), there was no significant difference among the three groups after the intervention. Assessment of the test scores alone after one month (long term memory) showed a significantly higher score (p-value<0.001) in Group A when compared with the other two groups.

Conclusion: Mint flavoured chewing gum improves cognition as evidenced by improvement in test scores, alertness and attention. The performance in the flavour less chewing gum group was lesser than mint flavoured group, but significantly better than control group.

Keywords

Heart rate, Memory, Menthol, Reaction time

Chewing gum is generally preferred for maintaining alertness and preventing sleepiness while studying or driving. It creates a sense of euphoria and helps rejuvenate especially flavoured ones. It tends to affect a range of cognitive functions including aspects of memory, selective and sustained attention, psychomotor speed and accuracy (1). The chewing movement of jaw stimulates nerves and parts of brain leading to increase in cerebral blood flow (2).This increased blood flow to brain enhances glucose delivery to memory associated regions improving both episodic and working memory (3). Chewing also facilitates release of insulin which influences memory via central mechanism (4). The process of mastication increases the sympathetic nervous system activity and decreases parasympathetic activity (5). Chewing gums activates brain centres such as prefrontal cortex, middle frontal gyrus (Brodmann’s area 9 and 46) in dorsolateral prefrontal cortex, right prefrontal motor cortex, precuneus, thalamus, hypothalamus and inferior parietal lobe which has an enhancing effect on memory (6). Though the effect of chewing gum on cognition and memory was evaluated in previous studies, the results are still debatable (7),(8),(9).

Alertness refers to the ability to develop and sustain a state of mental readiness. Attention requires efficient perception, learning, memory, and reasoning. The parameters for measuring alertness and attention were heart rate and reaction time. Reaction time is the minimum time taken to respond to a stimulus and it helps in assessing the integrity of the nervous system. The effect of chewing produced changes in reaction time and Event Related Potential waveforms thereby improving the cognitive processing (10). The role of chewing gum in altering alertness and attention has been proved in many previous studies (11),(12). Chewing of flavoured gum consistently increases the beta rhythm of electroencephalogram, which is supposed to be the rhythm associated with arousal and alertness (13). However, few studies have also demonstrated the same arousal effect with flavourless and odourless chewing gum (6),(7),(8),(9),(10).

Stress induces the release of free radicals in the body and is considered to be the cause for various health related problems like atherosclerosis, endothelial damage, hypertension, asthma, irritable bowel syndrome, cancer (14). Stress can impair the memory function (15). The results of the previous studies on the effect of chewing gum on stress were controversial (16),(17). Few studies had reported a reduction in stress level under acute social stress, whereas no reduction in anxiety was found after chewing gum in other studies (16),(17).

Smell is perceived in widespread areas of the limbic system including hippocampus, entorhinal cortex, orbitofrontal cortex and amygdala. Perception of taste occurs in the insular cortex. Integration of smell and taste sensation happens in the orbitofrontal cortex. All the above mentioned areas are associated with learning and memory (18). It is expected that mint flavoured gums have an arousing effect in these areas both via taste and smell modalities. Though researchers were unable to point exactly why chewing gum boosts memory, attention and cognitive reasoning skills, the results of different studies clearly showed that it does. Chewing gum has similar effect to that of strenuous activity which boosts test performances.

Hence, it was hypothesized that mint flavoured chewing gum can improve memory by increasing blood flow and stimulating memory areas of the brain which could lead to improved test performance. The aim of the present study was to determine the effect of mint flavoured chewing gum on short and long term memory, alertness, attention and stress among the medical undergraduates.

Material and Methods

This comparative, interventional study, was conducted in the Department of Physiology at Velammal Medical College and Hospital, Madurai, Tamil Nadu, India, August 2019 to September 2019, after obtaining Institutional Ethical Clearance (IEC No:VMCIEC/24/2019).

Sample size calculation: ample size was calculated with Cohen’s D effect size fixed as 0.49 with 95% confidence level and 80% power. The minimum sample size thus calculated was 16.

Inclusion criteria: The study was initially explained in detail to all 150 first year MBBS students. Willing 126 first year MBBS students in the age group of 18-20 years, of both the genders, were enrolled for the study.

Exclusion criteria: The students were then screened and those with dental problems (undergoing orthodontic treatment, having fixed appliances), refractive errors, ophthalmic lesions, common cold, having difficulty in mastication (temporomandibular joint issues), under medication were excluded from the study. Smokers and those who have the habit of chewing gums regularly (more than 6/week) were also excluded.

Procedure

After the initial screening, baseline cognitive functions of 91 students were assessed using mini mental state examination tool and only those with scores between 28-30 were included in the study (19). Total 16 students were excluded, as the score was less than 28.

After obtaining informed voluntary consent from the remaining 75 students, the participants were randomly divided into three groups, three types of paper lots were created using alphabets A, B and C of 25 each. All the 75 students were instructed to select one paper lot and based on that, they were grouped accordingly.

• Group A (n=25) was the mint flavoured chewing gum group,
• Group B (n=25) was the flavourless chewing gum group
• Group C (n=25) was the control group which were not provided with chewing gum.

Wrigleys extra long lasting flavour (sugar free) peppermint gum (Illinois, U.S) was used in the mint flavoured group and Wrigleys gum base (synthetic rubber) was used in the flavourless chewing gum group. Group A and B were the interventional groups where exposure (chewing gum) was assigned.

Description of Intervention

The subjects were instructed to refrain from caffeinated drinks (and other stimulants) and exercise on the morning of the test. The test was conducted between 8 am-1 pm in the Department of Physiology. Demographic and anthropometric data including age, gender, weight and height was collected from all the 75 participants. Informed written consent was obtained from each participant. They were allowed to relax for 5 minutes after which visual reaction time and heart rate were recorded for all the students. They were then instructed to fill the stress questionnaire. As the topic chosen for the study was Parkinson’s disease, a 10 minutes introductory lecture on this topic was delivered to all the 75 participants simultaneously. The students listened without taking notes. It was also informed to all the participants priorly that they will be placed randomly in either groups.

After that, they were divided into groups and sent to three separate rooms. Now group A was given one piece of mint flavoured chewing gum and group B was given one piece of flavourless chewing gum. They were told to chew constantly while reading. Group C was not given chewing gum. The participants were instructed to read the Parkinson’s disease topic from Comprehensive Textbook of Medical Physiology by G.K Pal, for 30 minutes (20). After a resting period of 10 minutes, they were allowed to take tests for 20 minutes on the same topic using a standard questionnaire simultaneously (21). Group A were provided again with one piece of mint flavoured gum and group B with one more piece of flavourless chewing gum while doing the test. Immediately after the test, while group A and group B were still chewing, visual reaction time and heart rate was recorded and the post stress questionnaire was filled. After a period of one month all the groups were intimidated to take the same test with the same set-up and the test performance results were analysed. During this one month interval, the participants were restricted from chewing gums. After one month, they were allowed to take chewing gum only during the test performance.

Data Collection Method and Tools

• Measurement of reaction time (22)

Visual Reaction Time (VRT) was measured with the help of discriminatory and choice reaction time apparatus (Anand Agencies, Pune). The VRT for light stimuli with an accuracy of 0.001 second was measured in the sitting posture in a quiet room (22). To record the baseline VRT for light stimulus (red), initially the subject was instructed about the complete procedure. The subject was asked to keep pressing the response button of the visual stimulus using the index finger of right hand. He should remove his finger immediately after he sees the stimulus. The value of VRT in milliseconds was displayed on the screen. Sufficient time was given for the participants to get acquainted with the procedure thoroughly. After the practice trial, once the patient felt comfortable, three readings were taken and the fastest response value was taken as the final reaction time.

• Heart rate

The Heart rate was measured with the help of masimo pulse oximeter to assess alertness (23).

• Stress

The Stress was assessed with the help of perceived stress scale questionnaire(15).This scale includes 10 questions and the scores:

0-13 is considered as low stress,
14-26 as moderate stress
27-40 as high stress.

The participants read the Parkinson’s disease topic from the book Comprehensive Textbook of Medical Physiology by G.K Pal (20).

• Short and Long term memoray

Both short term and long term memory was assessed using Parkinson’s disease questionnaire (21). This included 20 questions on definition, causes, features and treatment of Parkinsons disease. The present study used a modified version of this questionnaire including the same 20 questions but for a score of 20 marks. The questions were of open ended text type and each correctly answered question carried one mark.

Statistical Analysis

The data was entered into Microsoft excel and analysed using Statistical Package for Social Sciences (SPSS) version 20.0. Descriptive statistics like mean and standard deviation were used to represent continuous variables. One-way Analysis of Variance (ANOVA) was used to compare more than three groups on the basis of mean and standard deviation scores. Bonferroni multiple comparison test was used to compare the combinations of two groups in ANOVA. Paired sample t-test was used to compare the scores of before and after intervention. A 5% level of significance was considered statistically significant (p-value <0.05).

Results

To ensure that all the selected participants (based on mini-mental state examination score) had the same level of heart rate, reaction time and stress before the beginning of the test, baseline equality verification was done. Statistical analysis was done to ensure that baseline parameter values were similar for all the groups before intervention. The p-value was non significant (p-value >0.05) among all the three group subjects, showing same level of heart rate, reaction time and stress (Table/Fig 1).

After the intervention, three groups’ subjects’ heart rates significantly differed (p-value <0.001). Especially, Bonferroni test revealed that the heart rates of control group subjects (A vs C has p-value=0.001 and B vs C has p-value=0.001) significantly differed compared to that of subjects of the other two groups. Similarly, short term memory level of the three groups subjects statistically differed (p-value=0.001). When considering the reaction time (p-value=0.068) and stress level (p-value=0.927), there was no significant difference among the three groups after the intervention (Table/Fig 2).

After the intervention, there was a significant improvement in the heart rates in group A (p-value <0.001) whereas there was no significant change in the heart rates in group B (p-value=0.665). In addition, reaction time of the subjects who use mint flavored chewing gum had significantly reduced after the intervention (p-value<0.01). Similarly, the reaction time group A and B had significantly reduced after the intervention (p-value=0.006, p-value=0.001, respectively). However, stress level of the subjects was not significantly changed after the intervention in all three groups (Table/Fig 3).

Memory scores levels differed significantly across various groups after the intervention. Mint flavoured chewing gum group had high memory score compared to other groups (Table/Fig 4).

Overall, there was a significant change among the three group subjects in terms of heart rates, short term and long term memory levels after the intervention (p-value=0.001). Therefore, the intervention had the effect on the heart rates, short term and long term memory levels.

Group A and B had the similar level of effect on heart rate (p-value=0.371). However, group A had more effect on short term memory level compared to that of group B (p-value=0.029) after the intervention. When considered the within the group variations after the intervention, subjects who used group A had significant improvement in the heart rates and reduction in the reaction time. Therefore, group A was better than group B in terms of significant improvement in heart rate, short term and long term memory levels.

Discussion

The act of mastication itself increases the blood flow to fronto-temporal cortex, caudate nucleus, thalamus, rolandic areas, insular cortex, cingulated gyrus and cerebellum as observed with xenon-enhanced computed tomography (24). The temporomandibular joint movements due to chewing not only increases blood flow but also glucose delivery to mainly bilateral temporal cortical areas (2). Since, the temporal cortex is associated with memory regions of the brain including hippocampus, activation of these areas occur. In the present study, test scores had increased significantly after chewing gum for 20 minutes in mint flavoured group indicating improvement in short term memory. Short term memory lasts for seconds to hours through processing mainly in hippocampus (25). Since taste and smell centres are situated in the memory regions of the brain, chewing along with odour and taste of mint could have strongly activated memory areas of the brain improving the test scores in this group compared with the other two. This also explains the better performance in the flavourless chewing gum group compared with the non chewing control group. The results of the current study coincide with the results of the previous studies, where the test performance improved significantly in the gum chewing group when compared to the group which mimicked chewing movements and the group which did not chew gum [9,26]. But the present study results are contradictory to the results of a study done in 2008, where the chewing gum did not improve the short term memory performance scores (1).

Alertness and attention in the present study was checked by changes in heart rate and visual reaction time. A significant increase in heart rate was observed in mint flavoured group alone. This differs from the results of a chewing gum study where increase in heart rate was not observed, though there was increase in cortisol level and work performance (27). The results of the present study is in accordance with many previous studies which had observed increase in heart rate due to chewing (1),(9),(27). This was observed mainly during chewing and immediately after chewing. This increased heart rate by pumping more blood could have activated the memory regions of the brain. It could also be due to chewing associated increase in sympathetic activity and suppression of parasympathetic activity (4). The decrease in heart rate in control group of present study could be due to increase in parasympathetic activity due to relaxation without any intervention.

In the present study, duration of visual reaction time decreased significantly within groups both in mint flavoured and in flavourless chewing gum group with no significant change between groups. This shows that an individual reacts faster to a visual stimulus due to the effect of mint flavoured chewing gum. The processing speed in brain had increased and this could be due to increased sympathetic activity and activation of ascending reticular activating system. The results of the present study coincide with the results of a previous study which showed quickened reaction time (12). This quickening explains the increased activity in motor regions for alerting and executive networks especially anterior cingulate cortex and left frontal gyrus. Surprisingly reaction time significantly decreased in the control group and this could be due to the familiarity with the procedure when they did for the second time.

Stress scores did not change with chewing gum. In the present study, no stressful task was given to perform and post stress scores were assessed immediately after chewing gum for 20 minutes using a questionnaire. Regular gum chewing for 5 minutes, twice daily for 14 days had also resulted in significant decrease in stress level (8).

When all the three groups were assessed again with the same set of questions after a month for long-term memory, test scores were still significantly higher in mint flavoured group when compared with the other two groups. This could be due to stimulation of memory areas of the brain, mainly hippocampus, by the odour and taste of mint in the chewing gum. Hippocampus is essential for consolidating short term memory into long term memory and it was found that hippocampus is activated by mint flavoured chewing gum. The rate of chewing was not controlled and it was left to the choice of the participants as evidence indicates that more vigorous chewing does not modify the chewing effects on memory (27).

To confirm the effect of odour and taste in stimulating cognitive areas of the brain, a study was conducted by Hasegawa Y et al., where 25 healthy participants were divided into three groups-No taste/no odour chewing gum group, sweet taste/no odour gum group and sweet taste/lemon odour gum group. Cerebral blood flow was recorded during chewing using transcranial Doppler ultrasound and near infrared spectrometer while at the same time, bilateral masseter muscle activity was also monitored. Results revealed higher blood flow with sweet taste/lemon odour gum group compared to the other groups. This supports the additive role of both taste and odour in activating cognitive and motivational areas of the brain while chewing, than smell or taste alone (28). A direct correlation was observed between peppermint oil aroma and improved memory by long term potentiation mechanism (29).

As it was recorded in a previous study that the effects of chewing gum started after 5 minutes of chewing and lasted for only 20 minutes, the present study participants were instructed to chew the gum for 20 minutes while studying and again for 20 minutes while doing the test (26).

Limitation(s)

The sample size was small. The results cannot be generalised as this study involved local medical students. Cross over between groups was not done. Heart rate and reaction time were not measured during long term memory assessment. Only subjective stress levels were assessed. Future studies may focus on measuring stress level after providing an exposure to acute stressor. Functional Magnetic Resonance Imaging (MRI) could be done to assess the changes in memory areas of brain. Further studies are also needed to study the long duration of gum chewing on memory.

Conclusion

The present study results showed that mint flavoured chewing gum improved alertness and attention as shown by increase in heart rate and decrease in reaction time. Mint flavoured chewing gum improved memory as shown by the increase in test performance scores immediately as well as after one month. As participants chewed gum during learning and again during the test performance, their recall was improved by the taste and odour of mint which stimulated the memory areas of the brain. But the present study failed to show any improvement in stress level. Flavourless chewing gum improved memory, attention, and alertness when compared to the control group, without having any significant effect on stress level. Chewing mint flavoured gum before exams could help the younger generation perform better, as the amount of information to be processed and reproduced for students, especially medicos, is very huge. Mint flavoured chewing gums are cost-effective, easily accessible and can be chewed before the tests to improve cognitive function.

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DOI and Others

DOI: 10.7860/JCDR/2022/53795.16435

Date of Submission: Jan 07, 2022
Date of Peer Review: Feb 25, 2022
Date of Acceptance: Apr 19, 2022
Date of Publishing: Jun 01, 2022

AUTHOR DECLARATION:
• Financial or Other Competing Interests: ICMR-STS
• Was Ethics Committee Approval obtained for this study? Yes
• Was informed consent obtained from the subjects involved in the study? Yes
• For any images presented appropriate consent has been obtained from the subjects. NA

PLAGIARISM CHECKING METHODS:
• Plagiarism X-checker: Jan 08, 2022
• Manual Googling: Jan 31, 2022
• iThenticate Software: Apr 08, 2022 (8%)

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