Adjunctive Therapeutic Effects of Forest Bathing Trips on Geriatric Hypertension: Results from an On-Site Experiment in the Cinnamomum camphora Forest Environment in Four Seasons

Round 1

Reviewer 1 Report

Title: Adjunctive Therapeutic Effects of Forest Bathing Trip on Geriatric Hypertension: Results from On-site Experiment in Cinnamomum camphora Forest Environment in Four Seasons

Authors: Runxia Huang, Aibo Li, Zhengcai Li, Zhuomei Chen, Benzhi Zhou1# and Guofu Wang

 

Major revision

 

Comments:

This study employed ambulatory hypertensive patients with stable disease as participants in this study and studied the effect of four seasons of camphor forest bathing (control urban forest/center) on the adjunctive therapeutic effect of senile hypertension, i.e., blood pressure, routine blood, blood, and mood state (POMS) were assessed. The study showed that the effect of forest bathing in a camphor forest setting on antihypertension varied with the seasons, and that the antihypertensive effect of forest bathing in all seasons was highly consistent with the seasonal dynamics of VOCs and negative ions. Overall, the paper obtained information consistent with the conclusion we know that hypertensive patients in forest baths showed better blood pressure status during the trial than in urban environments, without obtaining more interesting or inconsistent results. However, several questions remain for the authors to answer or reflect on.

First, the authors openly recruited non-hospitalized hypertensive patients with stable disease from the community as participants in this study meeting the following criteria: diagnosed essential hypertensive patients; between 60 and 75 years of age; all with blood pressure below 180/110 mmHg; with cardiac function of class I-II; and able to take care of themselves in daily life. However, were all of these elderly patients who participated in the trial able to strictly meet these criteria over a period of up to four seasons. Can the emotional or psychological state of the elderly patients be consistent with the change of seasons, or how to ensure the consistency without affecting the results? Please also provide basic medical history data of the patients with confirmed underlying hypertension for verification.

Second, from a statistical point of view, are 30 volunteers per group sufficient to meet the statistical requirements? It seems to me that the sample is not sufficient from a scientific point of view, although it is more difficult to organize these people to conduct a four-season long trial.

Third, in the experimental design, the authors actually scheduled only 3 hours of forest bathing for one day, and the rest of the day for volunteers' only activities. Is a short period of forest bathing sufficient to affect blood pressure in the final results obtained?

Fourth, this study refers to camphor forest bathing, but it seems to have little relationship with the properties of camphor itself in the discussion of the conclusions in the study? What is the connection and difference between camphor forest bathing and other forest bathing such as bamboo forest and other species of forest? It seems that the secretions unique to camphor forests have some effect on aiding the treatment of hypertension? If so, how much of the secreted substance in the air is the most beneficial? Thus, all these variables can affect the conclusions of the experiment and how the authors considered or how to exclude these effects. Rather than simply assuming that "the hypotensive effect of four-season forest bathing is highly consistent with the seasonal dynamics of VOCs and negative ions, which implies that the effect values of forest bathing may be attributable to changes in the atmospheric environment."

Fifth, how can we compare the forest bathing or urban environmental factors in the city with the environmental factors in the camphor forest when there must be a big difference? Only from the physiological and psychological indicators of volunteers? Especially the psychological indicators are actually very complicated, they are not only influenced by the environment they live in, but also have a great relationship with the environment where the volunteers live for a long time and the family atmosphere, so how to control these effects and simply compare the effects of urban and forest?

Author Response

Dear Editors and Reviewers:

On behalf of all the contributing authors, I would like to express our sincere appreciations of your letter and reviewers’ constructive comments concerning our article entitled “Adjunctive Therapeutic Effects of Forest Bathing Trip on Geriatric Hypertension: Results from On-site Experiment in Cinnamomum camphora Forest Environment in Four Seasons ” (Manuscript No: forests-2026578). These comments are all valuable and helpful for improving our article. According to the editor and reviewers’ comments, we have made extensive modifications to our manuscript to improve the quality of our manuscript. In this revised version, changes to our manuscript were all highlighted within the document by using red-colored text. The main corrections in the paper and the responds to the reviewers’ comments are as flowing:

 

 

Responds to reviewer’ comments:

Reviewer # 1:

Comment: This study employed ambulatory hypertensive patients with stable disease as participants in this study and studied the effect of four seasons of camphor forest bathing (control urban forest/center) on the adjunctive therapeutic effect of senile hypertension, i.e., blood pressure, routine blood, blood, and mood state (POMS) were assessed. The study showed that the effect of forest bathing in a camphor forest setting on anti-hypertension varied with the seasons, and that the antihypertensive effect of forest bathing in all seasons was highly consistent with the seasonal dynamics of VOCs and negative ions. Overall, the paper obtained information consistent with the conclusion we know that hypertensive patients in forest baths showed better blood pressure status during the trial than in urban environments, without obtaining more interesting or inconsistent results. However, several questions remain for the authors to answer or reflect on.

Response: Thanks for your comments on our paper. We have revised our paper according to your comments.

 

1. Comment: First, the authors openly recruited non-hospitalized hypertensive patients with stable disease from the community as participants in this study meeting the following criteria: diagnosed essential hypertensive patients; between 60 and 75 years of age; all with blood pressure below 180/110 mmHg; with cardiac function of class I-II; and able to take care of themselves in daily life. However, were all of these elderly patients who participated in the trial able to strictly meet these criteria over a period of up to four seasons. Can the emotional or psychological state of the elderly patients be consistent with the change of seasons, or how to ensure the consistency without affecting the results? Please also provide basic medical history data of the patients with confirmed underlying hypertension for verification.

Response: We sincerely appreciate the valuable comments. All elderly patients who participated in the trial were able to strictly meet these criteria over a period of up to four seasons. The elderly patients with hypertension in four seasons were not completely the same, but they all met the above inclusion criteria and exclusion criteria. We have supplemented in the method part in the revised manuscript in line 118. In order to ensure the consistency of the emotional or psychological state of the elderly patients with the change of seasons, we were randomly grouped to reduce errors, the POMS test was conducted before forest bathing (i.e. each season), and there was no difference between the two group in four seasons (Table S1). Finally, the schedules, diet and activities of the two groups, such as walking, sitting, etc, are completely consistent. So, our results were credible and unlikely to be caused by the consistency of the emotional or psychological state of the patients

 

2. Comment: Second, from a statistical point of view, are 30 volunteers per group sufficient to meet the statistical requirements? It seems to me that the sample is not sufficient from a scientific point of view, although it is more difficult to organize these people to conduct a four-season long trial.

Response: We think this is an excellent suggestion. Through literature review, we found that the sample size of forest bathing researches ranged from 6 to 268, with the median size being 12 (Ideno et al., 2017). However, most literature samples are less than 30 (Yau et al., 2020). For example, Ochiai et al (2015a, 2015b) separately organized 9 and 17 volunteers to participate the experiment studying physiological and psychological effects of a forest therapy program on middle-aged females and males with high-normal blood pressure. Li et al., (2016) researched the effects of forest bathing on cardiovascular and metabolic parameters in middle-aged males with 19 volunteers. Song et al., (2015, 2017) used 20 volunteers to study the effect of viewing forest landscape and forest walking on middle-aged hypertensive individuals. We try our best to find a balance between scientific and practicability. However, because of the limited manpower and funds, we recruited 30 participants in each forest bathing trial.

References:

[1] Ideno, Y.; Hayashi, K.; Abe, Y.; Ueda, K.; Iso, H.; Noda, M.; Lee, J.S.; Suzuki, S. Blood pressure-lowering effect of Shinrinyoku (Forest bathing): a systematic review and meta-analysis. BMC Complement Altern Med, 2017, 17,409-421.

[2] Yau, K.Y.; Loke, A.Y. Effects of forest bathing on prehypertensive and hypertensive adults: a review of the literature. Environ Health Prev. 2020, 25,23

[3] Ochiai H.; Ikei H.; Song C.; Kobayashi M.; Miura T.; Kagawa T.; Li Q.; Kumeda S.; Imai M.; Miyazaki Y. Physiological and psychological effects of a forest therapy program on middle-aged females. Int J Environ Res Public Health. 2015, 12(12): 15222–15232.

[4] Ochiai H.; Ikei H.; Song C.; Kobayashi M.; Takamatsu A.; Miura T.; Kagawa T.; Li Q.; Kumeda S.; Imai M.; Miyazaki Y. Physiological and psychological effects of forest therapy on middle-aged males with high-normal blood pressure. Int J Environ Res Public Health. 2015, 12(3): 2532–2542.

[5] Li Q.; Kobayashi M.; Kumeda S.; Ochiai T.; Miura T.; Kagawa T.; Imai M.; Wang Z.Y.; Otsuka T.; Kawada T. Effects of forest bathing on cardiovascular and metabolic parameters in middle-aged males. Evid Based Complement Alternat Med. 2016, 2016: 2587381.

[6] Song C.; Ikei H.; Kobayashi M.; Miura T.; Taue M.; Kagawa T.; Li Q.; Kumeda S.; Imai M.; Miyazaki Y. Effect of forest walking on autonomic nervous system activity in middle-aged hypertensive individuals: a pilot study. Int J Environ Res Public Health. 2015, 12(3): 2687–2699.

[7] Song C.; Ikei H.; Kobayashi M.; Miura T.; Li Q.; Kagawa T.; Kumeda S.; Imai M.; Miyazaki Y. Effects of viewing forest landscape on middle-aged hypertensive men. Urban For Urban Green. 2017b, 21:247–252.

 

3. Comment: Third, in the experimental design, the authors actually scheduled only 3 hours of forest bathing for one day, and the rest of the day for volunteers' only activities. Is a short period of forest bathing sufficient to affect blood pressure in the final results obtained?

Response: Before the sorest bathing experiment, we referred to previous studies and determined that the forest bathing time was three hours for one day. (We have modified the method part in the revised manuscript in page 3 line 142-143) For example, Huang et al (2018) reported the current status of forest medicine research in China shown that the duration of forest bathing ranged from 15 min/twice 1 day (Tsunetsugu et al., 2007), 2 h/twice 1 day (Li et al., 2011). The meta-analysis of the forest bathing effect on blood pressure-lowering studied by Ideno et al (2017) found that the duration of the forest bathing interventions in the included studies ranged from 10 min to 6 h. In seven studies, the participants walked in a forest environment for 45 to 90 min (Lanki et al., 2017; Mao et al., 2012; Horiuchi et al., 2015; Lee et al., 2014; Li et al., 2016; Song et al., 2017a; Sung et al., 2012). One study required forest walking for only 17min (Song et al., 2015) and another only required the participants to view forest landscapes for 10 min (Song et al., 2017b). Four studies adopted a forest therapy program that lasted for 3 to 6 h (Ochiai et al., 2015; Feng et al., 2017; Yu et al., 2017; Zhou et al., 2017). Therefore, we think that 3 hours of forest bathing for one day is sufficient to reduce blood pressure.

References

[1] Huang Q.D.; Wu Q.; Mao G.X.; Wang S.Y.; Jia B.B.; Wang G.F. Current status of forest medicine research in China. Biomed Environ Sci, 2018, 31(7):551-554.

[2] Tsunetsugu Y.; Park B.J.; Ishii H.; Hirano H.; Kagawa T.; Miyazaki Y. Physiological effects of Shinrin-yoku (taking in the atmosphere of the forest) in an old-growth broadleaf forest in Yamagata Prefecture, Japan. J Physiol Anthropol, 2007; 26(2), 135-142.

[3] Li Q.; Otsuka T.; Kobayashi M.; Wakkayama Y.; Inagaki H.; Katsumata M.; Hirata Y.; Li Y.J.; Hirata K.; Shimizu T.; Suzuki H.; Kawada T.; Kagawa T. Acute effects of walking in forest environments on cardiovascular and metabolic parameters. Eur J Appl Physiol, 2011, 111(11): 2845-2853.

[4]Ideno, Y.; Hayashi, K.; Abe, Y.; Ueda, K.; Iso, H.; Noda, M.; Lee, J.S.; Suzuki, S. Blood pressure-lowering effect of Shinrinyoku (Forest bathing): a systematic review and meta-analysis. BMC Complement Altern Med, 2017, 17,409-421.

[5] Lanki T.; Siponen T.; Ojala A.; Korpela K.; Pennanen A.; Tiittanen P.; Tsunetsugu Y.; Kagawa T.; Tyrväinen L. Acute effects of visits to urban green environments on cardiovascular physiology in women: a field experiment. Environ Res. 2017, 159: 176–185.

[6] Mao G.X.; Cao Y.B.; Lan X.G.; He Z.H.; Chen Z.M.; Wang Y.Z.; Hu X.L.; Lv Y.D.; Wang G.F.; Yan J. Therapeutic effect of forest bathing on human hypertension in the elderly. J Cardiol. 2012, 60(6): 495–502.

[7] Horiuchi M.; Endo J.; Akatsuka S.; Hasegawa T.; Yamamoto E.; Uno T.; Kikuchi S. An effective strategy to reduce blood pressure after forest walking in middle-aged and aged people. J Phys Ther Sci. 2015, 27(12): 3711–3716.

[8] Lee JY.; Lee DC. Cardiac and pulmonary benefits of forest walking versus city walking in elderly women: a randomised, controlled, open-label trial. Eur J Integr Med. 2014, 6(1): 5–11.

[9] Li Q.; Kobayashi M.; Kumeda S.; Ochiai T.; Miura T.; Kagawa T.; Imai M.; Wang Z.Y.; Otsuka T.; Kawada T. Effects of forest bathing on cardiovascular and metabolic parameters in middle-aged males. Evid Based Complement Alternat Med. 2016, 2016: 2587381.

[10] Song C.; Ikei H.; Miyazaki Y. Sustained effects of a forest therapy program on the blood pressure of office workers. Urban For Urban Green. 2017a, 27: 246–252.

[11] Sung J.; Woo JM.; Kim W.; Lim SK.; Chung EJ. The effect of cognitive behavior therapy-based “forest therapy” program on blood pressure, salivary cortisol level, and quality of life in elderly hypertensive patients. Clin Exp Hypertens.2012, 34(1): 1–7.

[12] Song C.; Ikei H.; Kobayashi M.; Miura T.; Taue M.; Kagawa T.; Li Q.; Kumeda S.; Imai M.; Miyazaki Y. Effect of forest walking on autonomic nervous system activity in middle-aged hypertensive individuals: a pilot study. Int J Environ Res Public Health. 2015, 12(3): 2687–2699.

[13] Song C.; Ikei H.; Kobayashi M.; Miura T.; Li Q.; Kagawa T.; Kumeda S.; Imai M.; Miyazaki Y. Effects of viewing forest landscape on middle-aged hypertensive men. Urban For Urban Green. 2017b, 21:247–252.

[14] Ochiai H.; Ikei H.; Song C.; Kobayashi M.; Miura T.; Kagawa T.; Li Q.; Kumeda S.; Imai M.; Miyazaki Y. Physiological and psychological effects of a forest therapy program on middle-aged females. Int J Environ Res Public Health. 2015, 12(12): 15222–15232.

[15] Feng L.; Zhou Z.; Tingyan C. Influence of forest bath on vascular function and the relevant factors in military patients with hypertension. Chin J Convalescent Med. 2017, 26(4) (In Chinese).

[16] Yu C.P.; Lin C.M.; Tsai M.J.; Tsai Y.C.; Chen C.Y. Effects of short forest bathing program on autonomic nervous system activity and mood states in middleaged and elderly individuals. Int J Environ Res Public Health. 2017, 14(8): 897.

[17] Zhou Z.; Dongping M.; Feng L.; Changyu C.; Chi L. Influence of forest bathing on blood pressure, blood lipid and cardiac function of hypertension sufferers. Chin J Convalescent Med. 2017, 26(5) (In Chinese).

 

4. Comment: Fourth, this study refers to camphor forest bathing, but it seems to have little relationship with the properties of camphor itself in the discussion of the conclusions in the study? What is the connection and difference between camphor forest bathing and other forest bathing such as bamboo forest and other species of forest? It seems that the secretions unique to camphor forests have some effect on aiding the treatment of hypertension? If so, how much of the secreted substance in the air is the most beneficial? Thus, all these variables can affect the conclusions of the experiment and how the authors considered or how to exclude these effects. Rather than simply assuming that "the hypotensive effect of four-season forest bathing is highly consistent with the seasonal dynamics of VOCs and negative ions, which implies that the effect values of forest bathing may be attributable to changes in the atmospheric environment."

Response: Our study aimed to clarify the effect on the treatment of hypertension of the C. camphora forest environment, and to explore the favorable influencing factors, i.e., weather NAI and Volatile Organic Compounds (VOC), which are beneficial for forest bathing. (See the introduction, page 2 line 97-100)

As shown in discussion part “4.1 C. camphora forest effects on anti-hypertensive”, line 332-378, C. camphora emit phytoncide, forming a unique forest air environment, directly affecting human physiological and psychological reactions. Many studies have confirmed that C. camphora forest has a certain health care effect on human body(Lee et al., 2006; Wei et al., 2006). …… It is worth mentioning that terpenes, produced by various plants, including C. camphora forest, are associated with not only anti-inflammation but also anti-bacterial, and that terpenes are the main ingredients of the VOCs of C.camphora, accounting 29.26% for C. camphora forest atmosphere, 50.83% for flowers, 70.75% for leaves and 78.22% for branches (Shi et al., 2013). Terpenes, as the main component, have potential beneficial therapeutic effect on the oxidant/ antioxidant balance in diseases of the nervous, with the mechanisms of their antioxidant action appear to involve ROS scavenging (Porres-Martinez et al., 2016). Previous studies have demonstrated that C.camphora essential oil has antifungal activity, could be used as antifungal agent for treating Choanephora and other fungi infecting economically important crops (Pragadheesh et al., 2013). Therefore, the effects of C. camphora forest on anti-hypertensive might be attributed to the components of VOCs, released by C. camphora.

References:

[1] Lee, H.J.; Hyun, E.; Yoon, W.J.; Kim, B.H.; Man, H.R.; Kang, H.K.; Cho, J.Y.; Yoo, E.S. In vitro anti-inflammatory and anti-oxidative effects of Cinnamomum camphora extracts. J. Ethnopharmacol. 2006, 103, 208-216.

[2] Wei, C.L.; Wang, J.T.; Jiang, Y.G.; Zhang, Q.G. Air negative charge ion concentration and its relationships with meteorological factors in different ecological functional zones of Hefei City. Chinese Journal of Applied Ecology. 2006, 17, 2158-2162.

[3] Shi, S.J., Wu, Q.D., Su, J.Y., Li, C.W., Zhao, X.N., Xie, J.H.; Gui, S.H.; Su, Z.R.; Zeng, H.F. Composition analysis of volatile oils from flowers, leaves and branches of Cinnamomum camphora chvar.Borneol in China. J. Essent. Oil Res. 2013, 25, 395-401.

[4] Porres-Martinez, M.; Gonzalez-Burgos, E.; Carretero, M.E.; Gomez-Serranillos, M.P. In vitro neuroprotective potential of the monoterpenes alpha-pinene and 1,8-cineole against H2O2-induced oxidative stress in PC12 cells. Z.Naturforsch.(C) 2016, 71, 191-199.

[5] Pragadheesh, V.S.; Saroj, A.; Yadav, A.; Chanotiya, C.S.; Alam, M.; Samad, A. Chemical characterization and antifungal activity of Cinnamomum camphora essential oil. Ind. Crop. Prod. 2013, 49, 628-633.

 

5. Comment: Fifth, how can we compare the forest bathing or urban environmental factors in the city with the environmental factors in the camphor forest when there must be a big difference? Only from the physiological and psychological indicators of volunteers? Especially the psychological indicators are actually very complicated, they are not only influenced by the environment they live in, but also have a great relationship with the environment where the volunteers live for a long time and the family atmosphere, so how to control these effects and simply compare the effects of urban and forest?

Response: According to the current situation of China, we believe that the recruited volunteers are generally those who are rich, have no burden, like nature, and have a positive personality(We have improved and modified in the method part in page 3 line 115-116). In addition, POMS test of participates was conducted before forest bathing, and there was no difference (See table S1). And the schedule, diet and activities (such as walking and sitting) of participants were consistent (as shown in figure1).

As you mentioned, psychological indicators are very complicated. In order to control confounding factors, we focused on the following three aspects: First, it was a randomized controlled study. Second, POMS test of participants was conducted before forest bathing, and there was no difference (See table S1). Third, as shown in figure 1, the schedule, diet and activities (such as walking and sitting) of participants between forest bathing group and control were the same.

Author Response File: Author Response.docx

Reviewer 2 Report

Thank you for your interesting work. You can find detailed comments in the attached file.

Comments for author File: Comments.pdf

Author Response

Comment: Thank you for your interesting work. You can find detailed comments in the attached file.

Response: Thanks for your comments on our paper. We have revised our paper according to your comments.

 

1. Comment: The paper has problems with unclear expressionor spelling mistakes, causing not clear what the author mean.

Response: Thanks for your careful checks and reminder. We are sorry for our carelessness. Based on your comments, we have made many modifications in revised manuscript to make the expression clearer. The detailed modifications are as follows:

Line 80, “C. Camphora” modified to “Cinnamomum camphora”;

Line 98, “VOC” modified to “Volatile Organic Compounds (VOC)”;

Line 101-102, “Forest bathing experiment was conducted at urban forest and urban center lasting 1 year or longer” modified to “Forest bathing experiment was conducted at urban forest and urban center in different four seasons”;

Line 151, “before and after the experiment” was deleted;

Line 162, “We simultaneously monitored the air quality of two experimental sites, respectively” modified to “We simultaneously monitored the air quality of places where the participants were carrying out the activities, respectively”.

Line 181-182, “In which RF is reduction of urban forest environment, RC is reduction of urban center, BP is baseline of participant.” modified to “where RF is the reduction of physiological and psychological indicators of participants in the urban forest environment, RC is reduction of physiological and psychological indicators of participants in the urban center, and BP is the baseline of physiological and psychological indicators of the participant, such as SBP, DBP, HR, SpO2, Renin, AGT, ET-1, LF, HF, LF/HF, and POMS index.”;

Line 202, “As shown in figure 4” modified to “As shown in figure 3”;

Line 218, “As shown in figure 5” was deleted;

Line 318, “In this study, there was a similar trend between air quality and atmospheric environment and the effect value of forest bathing, the effect value of forest bathing may be attributed to air quality and atmospheric environment alteration.” modified to “In this study, there was a similar trend was identified between air quality and atmospheric environment and the effect value of forest bathing, meaning that the effect value of forest bathing may be attributed to air quality and changes in the atmospheric environment alteration.”;

Line 365, “ardiovascular” modified to “cardiovascular”;

 

2. Comment: In page 5 line 183, Is there any reference to support formula 2?

Response: As shown in line 195, we have added reference (reference 6) to support the CCI index.

 

3. Comment:There was a minor issue of the figure, in which the colors representing each group were counterintuitive. Probably most readers will automatically associate green color to the forest group.

Response: We think this is an excellent suggestion. We have re-written this part according to the reviewer’s suggestion. As shown in the figure 2-5.

 

4. Comment: In page 1 line 41-42, I do not think this is justified by references 4 and 5.

Response: Added the following two references to justify what the sentence states.

[6]Mao, G.X.; Cao, Y.B.; Lan, X.G.; He, Z.H.; Chen, Z.M.; Wang, Y.Z.; Hu, X.L.; Lv, Y.D.; Wang, G.F.; Yan, J. Therapeutic effect of forest bathing on human hypertension in the elderly. J. Cardiol. 2012, 60, 495-502.

[7]Zhou, Q.; Wang, J.F.; Wu, Q.; Chen, Z.M.; Wang, G.F. Seasonal dynamics of VOCs released from Cinnamomun camphora forests and the associated adjuvant therapy for geriatric hypertension. Ind. Crop. Prod. 2021, 174, 114131.

 

5. Comment:In page 2 line 45, I do not think this reference 6 justifies what the sentence states.

Response: In references 6, in the part of introduction line 10-14 shown that “By law, the term “forest therapy” was defined as ‘immune-strengthening and health-promoting activities utilizing various elements of the forest such as fragrance and scenic view’ according to the Forestry Culture and Recreation Act of Korea. ”, which can be justified what the sentence states.

Author Response File: Author Response.docx

Reviewer 3 Report

Authors present a study dealing with forest walking in the elderly patients across four seasons. 

At first, the paper needs an extensive english editing. 

The entire study needs to be reported according to the STROBE checklist. 

In addition, I had the doubt the authors present the results of a previously published study (reference 23), by just adding the four seasons analysis. Authors need to clarify this. 

The discussion should be addressed to the most recent meta-analyses dealing with forest walking in the elderlies.

Author Response

Comment: Authors present a study dealing with forest walking in the elderly patients across four seasons.

Response: Thanks for your comments on our paper. We have revised our paper according to your comments.

 

1. Comment: At first, the paper needs an extensive english editing.

Response: Thanks for your suggestion. We have tried our best to polish the language in the revised manuscript with English editing.

 

2. Comment:The entire study needs to be reported according to the STROBE checklist.

Response: Thanks for your suggestion. We have comprehensively considered the contribution requirements of STROBE and forests, including title, abstract, introduction, methods, results, discussion and conclusion.

 

3. Comment:In addition, I had the doubt the authors present the results of a previously published study (reference 23), by just adding the four seasons analysis. Authors need to clarify this.

Response: Reference 23 is “Wu, Q.; Ye, B.; Lv, X.L.; Mao, G.X.; Wang, S.Y.; Chen, Z.M.; Wang, G.F. Adjunctive Therapeutic Effects of Cinnamomum Camphora Forest Environment on Elderly Patients with Hypertension. Int. J. Gerontology 2020, 14, 327-331.” 

The previously published study (reference 23) only revealed that C. camphora forest bathing has remarkable effect on anti-hypertensive, but the innovation of our study here is that forest bathing activities may have different effects on anti-hypertensive in different seasons. Our findings are of significance in the selection of optimal time for forest tourism. Anyway, both the study by Wu et al (2020) and the present work were performed by the same team.

 

4. Comment:The discussion should be addressed to the most recent meta-analyses dealing with forest walking in the elderlies.

Response: We sincerely appreciate the valuable comments. We have added meta-analyses in discussion part in the revised manuscript, see in page 13 line 324-331. A recently published meta-analysis, with 20 trials involving 732 participants, reported that SBP and DBP of the forest environment were significantly lower than that of the non-forest environment, which showed a significant effect of forest bathing on reduction of blood pressure (Ideno et al., 2017). A recently published review of the literature, with total of 364 studies were identified from the literature search, but only 14 studies were used to assess the quality of the included studies, reported that forest bathing, particularly forest walking and therapy, has physiologically and psychologically relaxing effects on middle-aged and elderly people with hypertension (Yau et al., 2020).

References:

[1] Ideno, Y.; Hayashi, K.; Abe, Y.; Ueda, K.; Iso, H.; Noda, M.; Lee, J.S.; Suzuki, S. Blood pressure-lowering effect of Shinrinyoku (Forest bathing): a systematic review and meta-analysis. BMC Complement Altern Med, 2017, 17,409-421.

[2] Yau, K.Y.; Loke, A.Y. Effects of forest bathing on prehypertensive and hypertensive adults: a review of the literature. Environ Health Prev. 2020, 25,23.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I recommend the current format to be able to consider publishing.

Author Response

Thanks very much for your time to review this manuscript. I really appreciate all your comments and suggestions! 

Reviewer 3 Report

Authors have addressed all my comments. 

Author Response

Thanks very much for your time to review this manuscript. I really appreciate all your comments and suggestions!