Association between meat intake and mortality due to all-cause and major causes of death in a Japanese population

Eiko Saito; Xiaohe Tang; Sarah Krull Abe; Norie Sawada; Junko Ishihara; Ribeka Takachi; Hiroyasu Iso; Taichi Shimazu; Taiki Yamaji; Motoki Iwasaki; Manami Inoue; Shoichiro Tsugane; for the JPHC Study Group

doi:10.1371/journal.pone.0244007

Peer Review History

Original SubmissionJune 3, 2020
25 Sep 2020 Decision Letter - Marly A. Cardoso, Editor PONE-D-20-16630 Association between meat intake and mortality due to all-cause and major causes of death in a Japanese population PLOS ONE Dear Dr. Inoue, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by Nov 09 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. 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PLOS only allows data to be available upon request if there are legal or ethical restrictions on sharing data publicly. For information on unacceptable data access restrictions, please see http://journals.plos.org/plosone/s/data-availability#loc-unacceptable-data-access-restrictions. In your revised cover letter, please address the following prompts: a) If there are ethical or legal restrictions on sharing a de-identified data set, please explain them in detail (e.g., data contain potentially identifying or sensitive patient information) and who has imposed them (e.g., an ethics committee). 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In addition to naming the author group, please list the individual authors and affiliations within this group in the acknowledgments section of your manuscript. Please also indicate clearly a lead author for this group along with a contact email address. Additional Editor Comments (if provided): The study is well-organized with interesting results. However, the manuscript needs revision following all reviewer´s suggestions. Particular attention should be given to the comparison on absolute meat intakes in Western and Asian populations, providing mean or median meat intake ranges in this study and also across populations. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Partly ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: No ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: The authors have presented findings from a large cohort followed for a reasonable length of time when considering associations between dietary intake and mortality. This study is of interest to the scientific community in light of the landmark publication from the EAT Lancet commission and "The Reference Diet" suggesting a lower meat intake for many Western populations for both health benefits and a sustainable food supply for the future whilst at the same time noting that some populations will need a higher intake of meat. In the introduction the authors comment on the novelty of this finding as meat intake is studied in a predominantly Asian population with a markedly lower meat intake than a Western population such as the United States. Given the difference in intake in these populations I would have liked to see the authors make a greater note of comparison on meat intake in Western and Asian populations for their significant findings and also when comparing to other studies. Whilst this was noted for one finding, for the remainder it was lacking. The first paragraph of the discussion section presents overal findings for an association with higher meat intake and increased risk for men AND women. The percentage figures presented in the discussion were not presented in the results or available on any of the submitted tables. The authors also indicate that there was an overall increased risk for women as well as men and this finding was not commented on in the results or evident from the data. Other edits and comments outlined below: Abstract Pg 3, Line 49: re-word for improved clarity – suggest adding “higher intake” Methods Pg 7, Line 1: add reference for the validation study of the FFQ Pg 7, line 4, correct spelling x 2 should read “fried” not “fired” Pg 7, line 14/15 add in a descriptor of “fair-moderate” to describe the validity and reproducibility of the meat intake from the FFQ compared to the food record Pg 8, line 14 provide a definition, description or reference for metabolic equivalent task-hours Pg 10, line 4 remove the word “both” Discussion General comments: authors should comment on findings in comparison to non-Asian populations and with reference to absolute meat intakes. When comparing to other studies a comment on mean or median meat intake would be helpful as you have discussed a marked difference in Asian and Western populations with regards to meat intake in introduction Pg 12, line 5 & 6: 17% and 15% does not correspond with any data presented in tables – is this another analysis that was not reported?? If yes include in results. From Table 1 Men had 18% increased risk of dying from all-causes and in women this was not significant. Pg 12, line 14 – relate this comment on explaining differences in age groups to average intake in Western diet – 5g/day does not seem “considerably” higher in comparison to difference with Western intake. Also of note is that the highest quartiles was not significantly different from lowest quartile – only the middle quartiles. Perhaps chance finding? Comment on number of statistical tests conducted and chance findings Pg 12, line 20 – Elevated risk in men was only significant in older age group not younger as seems to be indicated from this paragraph Pg 13, line 2, 3 it is important to add in here that these studies you are referring to are also in Japanese Populations Pg 13, line 8,9 add in that this finding was in men only not women Pg 13, line 18 please use the most up to date references from the WCRF report on red meat and cancer instead of reference 30. The Third Expert Report on Diet, Nutrition, Physical Activity and Cancer was published in 2018 Pg 14, line 8,9 again the authors need to consider the difference in absolute intake of meat in their study population and Western populations as this may be a reason that no association was found. Page 14, line 21, 22 – have the authors considered chance findings for other statistically significant results? ****** 6. 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Revision 1
8 Nov 2020 Author Response RESPONSE TO REVIEWS Editor Comments: 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf Response: We thank the editor for these comments. We have revised the styles and file naming according to the instructions provided online. 2. We note that you have indicated that data from this study are available upon request. PLOS only allows data to be available upon request if there are legal or ethical restrictions on sharing data publicly. For information on unacceptable data access restrictions, please see http://journals.plos.org/plosone/s/data-availability#loc-unacceptable-data-access-restrictions. In your revised cover letter, please address the following prompts: a) If there are ethical or legal restrictions on sharing a de-identified data set, please explain them in detail (e.g., data contain potentially identifying or sensitive patient information) and who has imposed them (e.g., an ethics committee). Please also provide contact information for a data access committee, ethics committee, or other institutional body to which data requests may be sent. Response: We thank the editor for these detailed instructions. Accordingly, we have added a data availability statement in the attached cover letter. 3. One of the noted authors is a group or consortium [JPHC Study Group]. In addition to naming the author group, please list the individual authors and affiliations within this group in the acknowledgments section of your manuscript. Please also indicate clearly a lead author for this group along with a contact email address. Response: We thank the editor for these instructions. We have listed the individual authors and their affiliations within this group in the revised Acknowledgements section, along with information on the principal investigator. 4. Additional Editor Comments (if provided): The study is well-organized with interesting results. However, the manuscript needs revision following all reviewer´s suggestions. Particular attention should be given to the comparison on absolute meat intakes in Western and Asian populations, providing mean or median meat intake ranges in this study and also across populations. Response: We thank the editor for these comments. We have provided mean meat intake ranges in this study and comparison against Western populations throughout the revised manuscript. Specific revisions are described in the point-by-point answers below. Reviewer #1 comments: 1. In the introduction the authors comment on the novelty of this finding as meat intake is studied in a predominantly Asian population with a markedly lower meat intake than a Western population such as the United States. Given the difference in intake in these populations I would have liked to see the authors make a greater note of comparison on meat intake in Western and Asian populations for their significant findings and also when comparing to other studies. Whilst this was noted for one finding, for the remainder it was lacking. Response: We thank the editor for these comments. We have provided median meat intake ranges in this study and comparison against the Western populations as below: “The difference may also be due to the fact that the absolute amount of intake of meat differs between the Japanese and Western populations: mean daily intake of total meat in the US population amounted to 127.9 grams per day between 2003 and 2004 (25) versus 77 grams per day in Japan as of 2003 (26). Mean intake amount in the US is almost twice that in Japan. In our study population, the crude mean intake (adjusted for the difference between the FFQ and dietary records) of total meat was 71.9 grams per day.”(Line 279-285, page 20) Also, we have added a discussion on processed meat intake as below: “For example, average consumption in the US was estimated to be 23.2 grams per day between 2003 and 2004 versus 12 grams per day in Japan as of 2003. In our study population, the crude mean intake (adjusted for the difference between the FFQ and dietary records) of processed meat was 7.7 grams per day.” (Line 336-340, page 23) 2. The first paragraph of the discussion section presents overall findings for an association with higher meat intake and increased risk for men AND women. The percentage figures presented in the discussion were not presented in the results or available on any of the submitted tables. The authors also indicate that there was an overall increased risk for women as well as men and this finding was not commented on in the results or evident from the data.　 Response: We thank the reviewer for pointing out this discrepancy, which occurred during the course of re-analyses. We have corrected the corresponding sentence, and the revised manuscript now reads as below: “Compared with subjects in the lowest quartile of total meat intake, men in the highest quartile had 18% higher risk of dying from all causes, although the associations were not dose-responsive.” (Line 272-274, page 20) 3. Abstract Pg 3, Line 49: re-word for improved clarity – suggest adding “higher intake” Response: We have added “higher intake” in the revised manuscript. (line 34, page 2) 4. Methods Pg 7, Line 1: add reference for the validation study of the FFQ Response: Accordingly, we have added the references for the validation studies of the FFQ. (Line 120, page 6) 5. Pg 7, line 4, correct spelling should read “fried” not “fired” Response: Accordingly, we have corrected this spelling error. 6. Pg 7, line 14/15 add in a descriptor of “fair-moderate” to describe the validity and reproducibility of the meat intake from the FFQ compared to the food record. Response: We have added “The validity of the FFQ for the assessment of meat intake has been previously reported as fair to moderate” in the revised manuscript. (Line 131-132, page 6) 7. Pg 8, line 14 provide a definition, description or reference for metabolic equivalent task-hours Response: We have added a reference for metabolic equivalent task-hours in the revised manuscript. (Line 154, page 7) 8. Pg 10, line 4 remove the word “both” Response: We have removed the word “both” in the revised manuscript. 9. Discussion, General comments: authors should comment on findings in comparison to non-Asian populations and with reference to absolute meat intakes. When comparing to other studies a comment on mean or median meat intake would be helpful as you have discussed a marked difference in Asian and Western populations with regards to meat intake in introduction Response: We thank the reviewer for the comment. We have provided mean meat intake ranges in this study and comparison against the Western populations as shown in our response to reviewer comment #1. 10. Pg 12, line 5 & 6: 17% and 15% does not correspond with any data presented in tables – is this another analysis that was not reported?? If yes include in results. Response: Again, we thank the reviewer for pointing out this discrepancy, which occurred during the course of re-analyses. We have corrected the corresponding sentence, and the revised manuscript now reads as below: “Compared with subjects in the lowest quartile of total meat intake, men in the highest quartile had 18% higher risk of dying from all causes, although the associations were not dose-responsive.” (Line 272-274, page 20) 11. From Table 1 Men had 18% increased risk of dying from all-causes and in women this was not significant. Response: We thank the reviewer for pointing out this discrepancy, which occurred during the course of re-analyses. We have corrected the corresponding description as indicated in our response to comment #10 (above). 12. Pg 12, line 14 – relate this comment on explaining differences in age groups to average intake in Western diet – 5g/day does not seem “considerably” higher in comparison to difference with Western intake. Also of note is that the highest quartiles was not significantly different from lowest quartile – only the middle quartiles. Perhaps chance finding? Comment on number of statistical tests conducted and chance findings. Response: We thank the reviewer for this valuable input. We agree that the results for women could be due to a chance finding, since the highest intake quartile did not show any significant association, as the reviewer indicated. The revised manuscript thus reads as below: “We also noted generational differences in the association patterns between meat intake and all-cause mortality: notably, women aged 45-54 years had significantly higher risk of total mortality. However, these results could be a chance finding resulting from the multiple statistical tests conducted, given that the highest intake quartile showed no significant associations. (Line 287-291, page 20-21) 13. Pg 12, line 20 – Elevated risk in men was only significant in older age group not younger as seems to be indicated from this paragraph Response: Yes, we have revised the corresponding sentence to improve the clarity of the manuscript as below: “In men, in contrast, elevated risk of mortality in the highest intake quartile was seen only in the older groups, and not in the younger age group.” (Line 291-292, page 21) 14. Pg 13, line 2, 3 it is important to add in here that these studies you are referring to are also in Japanese Populations Response: We thank the reviewer for this valuable comment. We have added corresponding text in the revised manuscript: “For instance, previous population-based studies – both derived from Japanese populations – showed that dietary animal protein intake was associated with lower blood pressure levels and also a reduced risk of intraparenchymal hemorrhage.” (Line 297-300, page 21) 15. Pg 13, line 8,9 add in that this finding was in men only not women Response: Accordingly, we have revised this text as below: “On the contrary, our study reported an elevated risk of heart disease mortality in men but not in women if red meat is taken to the level of the highest intake quartile.” (Line 304-305, page 21) 16. Pg 13, line 18 please use the most up to date references from the WCRF report on red meat and cancer instead of reference The Third Expert Report on Diet, Nutrition, Physical Activity and Cancer was published in 2018. Response: The Third Expert Report on Diet, Nutrition, Physical Activity and Cancer published in 2018 is the most recent report published to date by the WCRF Continuous Update Project (https://www.wcrf.org/int/continuous-update-project). Given the comprehensiveness of the report covering all major cancer sites and risk factors, and because of the robustness of the methodology, we thought that the 2018 report is appropriate to reference in our manuscript. 17. Pg 14, line 8,9 again the authors need to consider the difference in absolute intake of meat in their study population and Western populations as this may be a reason that no association was found. Response: Following reviewer’s recommendation, we have added a description of the mean intake of processed meat in the revised manuscript as below: “In our study population, the crude mean intake (adjusted for the difference between the FFQ and dietary records) of processed meat was 7.7 grams per day.” (Line 338-340, page 23) 18. Page 14, line 21, 22 – have the authors considered chance findings for other statistically significant results? Response: We have carefully checked the possibility of chance findings for all meat types and outcomes, and cross-checked the results with p-values for trends, along with our sensitivity analyses which excluded deaths within 5 years. As for chance finding in the age-group analyses, we have added the possibility of a chance finding as suggested by the reviewer’s comment #12. Attachments Attachment Submitted filename: Response to Reviews.docx https://doi.org/10.1371/journal.pone.0244007.r002
2 Dec 2020 Decision Letter - Marly A. Cardoso, Editor Association between meat intake and mortality due to all-cause and major causes of death in a Japanese population PONE-D-20-16630R1 Dear Dr. Inoue, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Marly A. Cardoso, Ph.D. Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0244007.r003
Formally Accepted
4 Dec 2020 Acceptance Letter - Marly A. Cardoso, Editor PONE-D-20-16630R1 Association between meat intake and mortality due to all-cause and major causes of death in a Japanese population. Dear Dr. Inoue: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Marly A. Cardoso Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0244007.r004

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