Evaluation of the Efficacy of Cardamom Aromatherapy on Aerobic Fitness & Autonomic Functions Among Students

Introduction

Ancient writings provide insight into how religions and cultures of old used the aroma of burning herbs, flowers, tree leaves and other natural sources in their spiritual practices. It is learnt from the Hebrew, Christian, Buddhist and Hindu cultures more about these types of ritualistic observances¹. All these cultures from around the world had access to various plants from which to develop a recipe for pleasing the nose and mind. They assigned mystical energies to these plants and learned over the ages which ones provided results and which ones failed. They also provided us with instructions for using aromas that were pleasing not only to the senses of the human nose, but also to the senses of the Divine forces in their lives. Incense sticks are part of the 16 essential offerings during a Hindu ritual. According to Saurabh Bhattacharya² each of these offerings has symbolic spiritual significance and is offered to the Divine in a particular order.

Physical activity is defined as any bodily movementproduced by skeletal muscles that result in energy expenditure³. Physical fitness can be defined in multiple ways, such as a set of outcomes or traits that relate to the ability to perform physical activity³. Aerobic fitness determines the degree of fatigue that almost everybody experiences in daily life. The higher the aerobic fitness, the less fatigue one experiences. Aerobic fitness is theability to sustain work for prolonged periods. In order to enhance aerobic fitness, athletes are known to try a variety of aids to enhance performance and boost their chances of winning. The term ergogenic aids identifies those agents or procedures which if followed before a competition will potentially enhance the athlete's performance⁴.

Aromatherapy, another possible ergogenic aid, has been growing in recent years and has received much attention by both traditional and alternative medicine practitioners. However, there is very little evidence which supports or refutes the claims made by merchants, practitioners, and manufacturers⁵. Since smell is the least understood of all our senses⁶ it is logical to understand why the number of discrepancies exist within the lay and scientific literature regarding the validity of aromatherapy. Buckle et. al. (1998) argues that aromatherapy is becoming more and more valuable in holistic nursing practice and should be a part of nursing protocols⁷. Martin et. al. (1996) suggested that drawing conclusions regarding aromatherapy is premature since much of the data is qualitative as much of it is based on pure historical content and anecdotal reports from individuals⁸. Researchers have argued against aromatherapy secondary to the poor follow-up of clients after sessions. Additionally many reports are purely subjective in nature and cannot be considered truly scientific⁹.

Earlier it was demonstrated that inhaling peppermint is reported to be a stimulant for increased energy which would certainly benefit any athletic or non-athletic individual during an exercise bout¹⁰. By definition, peppermint could be considered an ergogenic aid. Lavender is marketed as an aroma which promotes relaxation and a calming effect⁷. As with any ergogenic aid, multiple questions arise regarding legal and ethical issues. Also important is the additive being used a substance the athlete would normal consume or use in everyday life⁴. How effective are the aromatherapy and environment conditioning fragrances? It has been said that aromas from lavender, basil, cinnamon and citrus flavor aid relax, whereas cardamom, peppermint, thyme and rosemary invigorate. Ginger, cardamom, licorice and chocolate are supposed to arouse a sense of romance, while rose combat depression^{11, 12}. Stimulating or invigorating odors such as cardamom, rosemary and lemongrass affect the locus ceruleus with the resultant release of noradrenalin into the brain and this has the effect of arousal/waking up. Researchers at the Royal Berkshire Hospital NHS Trust recently broke new ground by studying the effects of aromatherapy in the intensive care unit as a means of helping to alleviate anxiety and stress¹³.

The purpose of this pilot investigation was to examine the potential benefits that common cardamom (Elettaria cardamomum) aromas might have on basic physiological measures before, during and after a 15-minute exercise bout. There is little evidence in the literature addressing the actual physiological responses after the introduction of an aromatherapy during exercise. It was hypothesized that cardamom (Elettaria cardamomum) aromatherapy can induce significant changes in the autonomic activity. Our main concern is to elucidate the effect of cardamom aromatherapy is synergistic or antagonistic. It was hypothesized that the effect of aromatherapy on heart rate would be a greater alteration in autonomic nervous system activity than the effect of exercise alone.

Materials Methods

Subjects: Sixteen male and fourteen female apparently healthy college students volunteered to participate in this investigation. Mean ages were 22.5 ± 0.8 for males and 21.75 ± 0.9 for females. These students considered themselves sedentary. In this investigation, an individual was considered sedentary if he/she did not regularly participate in physical activity more than two days per week at equal to or greater than 60% of their maximal heart rate. All subjects were familiar with exercise protocols and walking on a motorized treadmill. This study was approved by the departmental review board for institutional ethical committee. Informed consent was obtained from every individual who has participated in this study. Using an in-house designed questionnaire, background information was gathered from the subjects.

Results

The data represented in Table 1. highlights the characteristics features such as age, height, blood pressure and different habits of the subjects. In addition, weight and height was obtained to determine the body mass index of each subject, waist and hip measurements are included to determine waist to hip ratio.

The information gathered from the subjects during the interactive session clearly shows that few of them were also got the addiction to the alcohol, caffeine, and smoking. The collected information about the lifestyle parameters such as food habits, walking habits, health and sports habits and stress related conditions at the college. It was demonstrated that students are having poor attitude towards their lifestyle parameters and highly sensitive to the stressful conditions.

Each subject completed three separate exercise bouts of treadmill walking lasting 15 minutes. During each bout subjects inhaled one of three samples in a double blind fashion. Table 1 contains the data obtained from analysis of expired gases Oxygen consumption (VO₂) minute ventilation (VE) and Respiratory Exchange Ratio (RER) remained the same among all three trials.

Table 1 shows the higher aerobic capacity in aromatherapy group as compared to exercise group, expressed by higher (P < 0.01) oxygen uptake and physical fitness index.

Heat rate response can be found in Table 2. During exercise, heart rate increased approximately 30 beats per minute above pre-exercise rate for all three trials. Based on the rate of exercise intensity which subjects performed, this response was considered normal. The exception to this increase was with the cardamom trial which only elicited a 29 beat increase secondary to the higher pre-exercise heart rate of 71 BPM as compared to 77 BPM for the exercise group.

Subjective measures of the modified Borg Scale or Rating of Perceived Exertion [RPE] were obtained and these results demonstrated an increase for the aromatherapy combined exercise group [3.7] compared to a [2.4] for the exercise group. An RPE of 3 equates to a perception of hard work. An RPE of 2 equates to a perception of light work.¹⁷

The results depicted in table. 4, Data are reported as medians and interquartile range. RR = standard normal RR interval; LF, HF = low and high frequency power, respectively; LF/HF = ratio of absolute LF power to HF power values. Frequency ranges: LF: 0.04-0.15 Hz and HF: 0.15-0.4 Hz.

According to the results presented in table. 4 It is apparent that after the aromatherapy treatment blood pressure shows significant changes in both systolic and diastolic. There was also an increase in heart rate, LF and LF/HF ratio. Apparently, treatment of aromatherapy decreases parasympathetic nervous activity.

The differences in the heart rate and other parameters between the two groups at baseline, before and after exercise are shown in Table 4, indicating a significant difference in LF between the exercise and exercise combined aromatherapy groups before and after exercise. The median LF, HF level in exercise combined aromatherapy group was significantly higher than those in the exercise group. The smaller HF and larger LF/HF after exercise may indicate possible elevation of sympathetic activity. All the other HRV measurements, indicates significant difference between the cardamom aromatherapy combined exercise and exercise group.

Discussion

Aromatherapy uses concentrated essential oils extracted from herbs, flowers, trees and other plants. The essential oils are believed to have an effect on both psychological and physiological level. Depending on the mix and blend, this effect may be either to stimulate or relax¹⁸. Cardamom (Elettaria cardamomum) is also known as cardamon; it is related to several spices, such as ginger (Zingiber officinale), and consequently possesses some similar therapeutic properties and benefits as ginger.

Some important neurotransmitters have been identified in cardamom, aceylcholine and choline, which explain herbal medicine's position that cardamom, may behave as a stimulant to the nervous system, and uses it to help prevent convulsions or spasms. Scientific studies have shown that cardamom has a blood thinning action, due to its high concentration of linoleic acid¹⁸.

We found a significant increase in mean heart rate and increases in analysis of heart rate variability parameters after 15 min of cardamom inhalation. Moreover, HF is also increased, and all these indices have been used to reflect primarily sympathetic influences. LF has been shown to reflect both sympathetic and parasympathetic influences, making the contributive components of this measurement less clear^{19, 20}. However, the change in LF and ratio of LF/HF infer that there is an impact on sympathetic drive to the heart.

In this present study we also investigated that the differences in autonomic cardiovascular control could appear between exercise and exercise combined aromatherapy group during a situation of exercise stress, which is a natural stimulus, leading to sympathetic excitation and vagal withdrawal in the heart. During exercise the initial increase in the heart rate response is mediated by a decrease in vagal activity, followed by an enhanced sympathetic activity that maintains higher values of heart rate during the test.

The finding of increased low to high frequency (LF/HF) ratio in response to cardamom aromatherapy indicates that aromatherapy may in fact cause a sympathetic response, rather than a parasympathetic response. This finding warrants further research. Further, it is not known what mechanisms play a role with aromatherapy and metabolism. At 15 minutes of exercise the average individual is just beginning to achieve a true point when oxygen demands equal oxygen availability or more commonly referred to as steady state of oxygen consumption¹⁷.

The use of aromatherapy is rapidly growing within western society. It is obvious from the literature that there are vast differences in opinion regarding the efficacy, validity and the overall claims towards the role of aromatherapy in all aspects of medicine, particularly preventative and rehabilitative medicine. Exercise does fall into both categories, preventive and rehabilitative; therefore the use of aromatherapy in concert with exercise is quite popular. Although it is claimed that peppermint may accentuate energy by stimulating the adrenal cortex¹⁰ it is not known what dosage and how this increased energy may affect exercise performance.

Cardamom has reputation for having simulative effects on autonomic bodily systems like digestion and circulation. Cardamom may improve blood circulation to the lungs, and is indicated in folk medicines to relieve symptoms of asthma and bronchitis.^11–13 Our study clearly suggests that during dynamic exercise, heart rate increases due to both a parasympathetic withdrawal and an augmented sympathetic activity. The relative role of the two drives spectral depends on the exercise intensity.^20–25

In the present investigation, cardamom aromatherapy had significant effect on resting or exercises heart rate during 15 minutes of moderate treadmill walking. The result of present study about rating perceived exertion shows a slight increase in aromatherapy groups. Rating perceived exertion is a good index for evaluating individual's effort during an exercise bout¹⁵.

Earlier study mentioned that inhaling the essential oil can affect the performance in both positive and negative ways²⁰ and the cardamom essences is known as aphrodisiac and invigorating which may be the reason for increase in concentration and improves performance. The results of this study indicate that inhaling a cardamom essence has brought the significant differences when compared to exercise group. The value of respiratory exchange ratio indicates that fat is being consumed for energy generation during exercise. It is possible that cardamom aroma may have more beneficial effects when fat are the major fuel source as opposed to carbohydrate.

The higher aerobic capacity of the athletes was reflected in greater oxygen consumptionand physical fitness index in both groups. Also, the resting heart rate was significantly lower in exercise combined aromatherapy group than in exercise group. Changes in the intrinsic mechanisms acting on the sinus node and alterations in the autonomic nervous system control of the heart have been reported to contribute to this phenomenon.^{23, 24} These data are exciting regarding aromatherapy and exercise performance; however, given the above limitations regarding time and introduction of aroma, these results are understandable.

The benefits of aroma on exercise performance is not yet established, the questions regarding their ethical use must be addressed. However, further research on the normal and strenuous exercise in combination with appropriate control needs to be conducted to clarify the efficacy of cardamom aromatherapy in the management of well-being in combating with lethargy, sedentary life style and or other health issues. Heart rate and other cardiac variables should have been measured during exercise to clarify physiological responses more in details. We demonstrate the need of further research to investigate subjects, measurement indicators, and experimental conditions to clarify the relationship between physiological and emotional responses produced by cardamom aromatherapy.

Conclusion

Everyone experiences some degree of pressure at work, and being under pressure can help improve performance and productivity. Excessive levels of pressure, however, can have adverse effects, resulting in stress and intense long-lasting stress can lead to mental and physical ill-health. In such situations, simple techniques that can help to cope up with stress, such as aromatherapy, can be of major benefit. We have demonstrated on young healthy adults the effect of inhaling the aroma from Cardamom (Elettaria cardamomum) essential oil on autonomic balance. The results provided support for the stimulatory effect of aroma, as indicated by a shift of the autonomic balance toward sympathetic predominance. Combining exercise with cardamom aromatherapy is not only enjoyable because of its effects on mood but also promotes physiological excitation, thereby increasing physical activation. Inhalation of cardamom essential oil may provide a relatively simple, safe, well-being, invigorating and effective method of handling the stressful conditions.