Reviewer's report Title:Dark chocolate and reduced snack consumption in mildly hypertensive adults: an intervention study Version:1Date:8 June 2015 Reviewer:Katherine Keene Reviewer's report: Minor Issues not for Publication: Abstract Background 1. Suggest revising first sentense to, Several studies have shown that cocoa or cocoa-containing foods have the potential to lower blood pressure and endothelial function. Design 1. Insert a comma after controlled, i.e. This was a randomized, controlled, cross-over trial 2. Suggest being consistent throughout publication with the use of the term wks or weeks (choose one), or introduce weeks as being abbreviated to wks early in the publication, using wks throughout the rest of the publication. 3. Unsure as to whether control period in the sentence In the control period, they reduced refers to a run-in period. If so, recommendation is to use the term run-in as opposed to control period. 4. Suggest revising they only reduced the snacks without any added dark chocolate to During the run-in period of reduced snack consumption, no chocolate was consumed. 5. Recommend using dark chocolate consistently in publication, so as not to confuse reader with other forms of chocolate 6. Suggest revising 24h ambulatory blood pressure) were collected to 24h ambulatory blood pressure) was collected (as Data infers plural items already) 7. Clarification regarding whether there are 2 intervention periods, or just 1 and a control period, with regards to in the beginning and end of both intervention periods. 8. Revise the following (weight and body fat percentage, blood pressure, arterial stiffness index, diet, physical activity). to (weight, body fat percentage, blood pressure, arterial stiffness index, diet and physical activity). Results 1. Revise first sentence to, Daily consumption off dark chocolate had no effects on 24h blood pressure
2. In the sentence, Weight was reduced by 1.0+2.2 kg, looks like the + was underlined, as opposed to using the actual symbol if underlined, please replace with actual symbol Conclusion 1. Revise first sentence to The data collected in this study indicates that inclusion of dark chocolate, as part of a habitual diet, has no significant effect on cardiovascular risk factors. Background 1. First paragraph, revise first sentence to Polyphenols are plant-derived compounds; secondary metabolites with an essential rose in the protection of plants against various environmental and microbrial threats [1]. 2. First paragraph, second sentence, revise to to into (i.e., Polyphenols can be divided into 3. First paragraph, last sentence, revise lignans and other polyphenols belong to non-flavonoids to lignans and other polyphenols belong to the non-flavonoid group. 4. Second paragraph, third sentence, revise to Also, several clinical trials have shown a favorable effect of flavonoids on cardiovascular disease (CVD) risk factors [2, 3]. 5. Second paragraph, fourth sentence, revise to The health effects of polyphenols depend on their bioavailability [4], e.g., the rate and extent of their absorption and metabolism, and the chemical structure of the molecule. 6. Third paragraph, first sentence, revise to Cocoa and cocoa-containing foods, such as dark chocolate, rerpresent a very rich source of flavonoids as they provide a higher content of flavonoids per serving than red wine or tea [5]. 7. Third paragraph, remove ) in third sentence following [2, 7] 8. Fourth paragraph, please clarify what the beneficial health effects refer to (e.g. dark chocolate?) 9. Fourth paragraph, second sentence, revise dilatation to dilation 10. Fourth paragraph, third sentence, revise to Moreover, isoflavones, anthocyanins and cocoa flavan-3-ols in particular, have been associated with or have been shown to have an effect on arterial stiffness [15]. a. to have an effect in comment #10 above, may want to clarify if this is beneficial or not beneficial rather than just stating have an effect. 11. Fifth paragraph, third sentence, consider removal of Consequently, as it is not required. 12. Fifth paragraph, third sentence, consider re-wording to reflect that in the abstract (worded a bit more clearly) 13. Fifth paragraph, fourth sentence, remove already in the following, our participants with already an increased risk for..
14. Fifth paragraph, fifth sentence, consider revising to Therefore, during both the intervention (dark chocolate) and control (no chocolate) arms, the energy intake in the habitual diet was reduced by way of reducing the participant s daily snack consumption. (if this is the intent) Study Design 1. First paragraph, second sentence, recommend referring to one of the arms as the control and one of the arms as the intervention rather than both as interventions (as just one involves the intervention with dark chocolate) 2. First paragraph, third sentence, again recommendation is to refer to the arms as control and intervention (vs. treatment ) as just one involves treatment with dark chocolate 3. First paragraph, third sentence, revise end of sentence to were all four weeks in duration. 4. First paragraph, fifth sentence, revise to During the dark chocolate period (8 weeks) a. Ensure consistency with wks or weeks 5. Second paragraph, first sentence, remove space between 70 and %, i.e., revise to 70% cacao). 6. Second paragraph, second sentence revise (à 7g) daily, in total 49 g/day. to (7g) daily, for a daily intake of 49 g/day. 7. Second paragraph, third sentence, add a space between [19] and (Table 1). Methods 1. First paragraph, first sentence, be consistent with either 24h or 24 h ambulatory blood pressure 2. Second paragraph, first sentence, be consistent with how you want to phrase 24-h blood pressure, as it varies considerably throughout the publication 3. Third paragraph, first sentence, revise Cardio Ankle Vascular Index (CAVI) to Cardio-Ankle Vascular Index (CAVI) (to be consistent) 4. Fifth paragraph subtitle, revise Blood samples and OGTT to Blood samples and Oral Glucose Tolerance Test as this preceeds explanation of the abbreviation in last sentence of this paragraph 5. In the dietary analyses and other confounders section, sixth sentence, consider revising reference to (The National Institute for Health and Welfare, Helsinki, Finland, 2014). Results 1. Second paragraph, first sentence (in addition to being more specific on variables measured), revise to There were no significant differences in measured variables between the two arms at baseline. 2. Second paragraph, third sentence, include significance in brackets (i.e.
p< ). 3. Second paragraph, last sentence, revise to The dark chocolate intervention had no effect on cardio-ankle vascular index. (if this is the intent, or indicate which intervention had no effect on CAVI). 4. Third paragraph, first sentence, consider referring to the arm as the control arm (i.e. Weight decreased 1.0 kg (± SD 2.2) after the control arm where no chocolate was consumed (Table 2). 5. Third paragraph, second sentence, remove daily at the end of the sentence (unless the previous sentence and current sentence in question both refer to daily weight loss) 6. Third paragraph, third sentence, consider revising treatments to arms 7. Fourth paragraph, first sentence, add a comma after records and explain what the control period is being compared to (i.e. treatment period) 8. Fourth paragraph, second sentence, remove the after differences in and revise between the two intervention periods to between the intervention and control periods. 9. Fourth paragraph, third sentence, revise to Physical activity neither changed during the study nor differed between the intervention and control arm of the study. 10. Fourth paragraph, fourth sentence, add commas to separate leisure time and exerise Discussion 1. First paragraph, last sentence, consider revising to Apart from that, the study found neither harmful, nor positive, health effects of dark chocolate on CVD risk factors in mildy hypertensive participants. 2. Second paragraph, third sentence, revise to Another challenge in randomized, controlled trials, is which compound or product should be used as the control. 3. Third paragraph, fourth sentence, revise to Researchers proposed that the observed effects of polyphenol-rich dark chocolate were linked 4. Fourth paragraph, first sentence, revise to which reported the ability of dark chocolate to lower blood pressure, used 5. Fifth paragraph, first sentence, revised to In the study by Allen et al. [32]... 6. Fifth paragraph, fifth sentence, consider revising to Similar to the findings in the study by Allen et al. [32], the overall changes in the diet may have contributed the most to the positive trends seen in the current study. 7. Sixth paragraph, third sentence, revise to CAVI changes over a short period of time in response to alterations in circulatory conditions; it is sensitive to subclinical changes in major arteries before impairment and it can be a reliable indicator for treatment effectiveness or modification in lifestyle [34]. 8. Seventh paragraph, first sentence, consider revising to In contrast to results
from our study, consumption of dark chocolate has had a beneficial effect on vascular function 9. Seventh paragraph, last sentence, revise to The quantity of daily dark chocolate consumption in the aforementioned studies was similar to, or substantially more (46 or 100 g/day) than the 49 g/day dose in the current study. 10. Eighth paragraph, first sentence, spell out T2D (i.e. Type 2 Diabetes) 11. Eighth paragraph, last sentence, revise to In the study of Curtis et al. [40], the participants were 12. Ninth paragraph, second sentence, revise of added chocolate on glucose or insulin, during the reduced snack-consumption intervention to of added dark chocolate on glucose or insulin, during the reduced-snack consumption intervention. 13. Ninth paragraph, third sentence, remove following prior to post-prandial period 14. Tenth paragraph, fourth sentence, appears there could be two spaces between lowered and both total- (please ensure there is just one) 15. Tenth paragraph, fourth sentence, consider revising to Despite its saturated fatty acid content, dark chocolate has lowered both total- and LDL cholesterol in previous studies [11, 17, 30, 32] or has lowered one or the other [40, 44]. 16. Tenth paragraph, last sentence, revise increased HDL cholesterol concentration both to increased HDL cholesterol concentrations both 17. Eleventh paragraph, first sentence, insert a comma after In most studies, i.e. In most studies, 18. Eleventh paragraph, second sentence, appears there is a space missing between [49]. and The 19. Twelfth paragraph, second sentence, revise spacing after previous studies for the references 20. Twelfth paragraph, last sentence, insert a comma after [52] and remove the a before regular consumption 21. Thirteenth paragraph, fifth sentence, remove only after However, 22. Thirteenth paragraph, last sentence, revise to Although calcium may, in theory, have a blood pressure-lowering effect [54], Conclusions 1. First sentence, fail to mention the reduced-snack consumption and participant s being mildly hypertensive, recommend adding this information 2. Second sentence, revise decrease snack eating to decreased snack intake 3. Second sentence, consider revising to and therefore, the addition of dark chocolate failed to produce beneficial effects. 4. Third sentence, revise (chocolate to (dark chocolate. Authors contributions
1. Revise the first sentence to RK, HT, JP and MF designed the study and planned the study protocols and data collection, while RK was responsible for study coordination and preparing the manuscript. 2. Between the second and third sentence, there appears to be one too many spaces Minor Essential Revisions: Figures 1. Missing Figure 1 figure as it actually appears on the last page of the manuscript (please ensure the title and figure are together, before the Tables) 2. Table 3 title has a considerable space between itself and the table, unlike the other tables (ensure consistency) 3. Ensure journal article references follow the following format: Author Last Name, First Initial(s). Title of Article. Journal Name. Year of Publication; Volume: Page #-Page #. If more than 6 authors should follow the following format: Author Last Name, First Initial(s), (+ 5 more listed), et al. Title of Article. Journal Name. Year of Publication; Volume: Page #-Page #. Based on the above formats: - Please remove : after the last author listed in the reference lists and put a. Instead before the title of the article - Please put a. after the Journal name and before the Year of Publication - Please put a ; after the Year of Publication and before the Volume Discretionary Revisions: Abstract Design 1. Clarification regarding whether there are 2 intervention periods, or just 1 and a control period, with regards to in the beginning and end of both intervention periods. 2. Explanation of design is very confusing for reader throughout the study Results 1. Recommend being consistent with either 24h ambulatory or 24 h blood pressure (i.e., choose one term for entire publication) 2. Recommend also being consistent with either reduced snack or reduced-snack 3. Recommend also being consistent with either risk factors or risk-factors Conclusion 1. With regards to the study population/purpose of the study, it might be beneficial to the reader if effects (or lack of) on blood pressure are mentioned in
the conclusionary sentence in the abstract Keywords 1. Suggestion to put CVD and possibily flavonoids (or a specific one) in the keywords listing Background 1. Fifth paragraph, second sentence, recommend being more specific (i.e. include dose, what the dose is of, etc.) Methods Participants 1. Consider including a reference as to where the parameters for mild hypertension were found (i.e. 140-159 mmhg systolic blood pressure, etc.) Blood samples and OGTT 1. Second paragraph of this section, recommend including references for the methods used Dietary analyses and other confounders 1. Main paragraph, first sentence, consider revising control the success of the snack restriction to ensure the success of the snack restriction Results 1. Second paragraph, first sentence, recommendation is to be more specific to the variables measured that did not have any difference between the two arms at baseline. 2. Third paragraph, last sentence, be specific about the non-specific changes and where they occurred (i.e. between arms, within arms but compared to baseline, at the end of both arms, etc.) to ensure reader knows what the finding refers to 3. In general, could report on the improvement from hypertensive to normotensive status of the 12/22 participants, regardless of reaching significance, as this was only mentioned in the fifth paragraph of the discussion Discussion 1. Fourth paragraph, last sentence, consider explaining what the something is that you are referring to (for the reader) 2. Fifth paragraph, first sentence, perhaps you are referring to the AHA diet (American Heart Association s diet)? 3. Sixth paragraph, first sentence, suggest inserting reference 4. Sixth paragraph, last sentence, recommend provided more context around this sentence 5. Tenth paragraph, first sentence, consider revising this sentence, as it is not just theory that saturated fatty acids are atherogenic
6. Tenth paragraph, third sentence, recommend provided a reference here 7. Thirteenth paragraph (last paragraph in discussion), consider revising the second sentence to be more discriptive in terms of nutrients and health effects (with references) 8. Thirteenth paragraph, last sentence, please consider revising as it is somewhat confusing what you are trying to say with regards to the calcium intake in your study 9. Consider adding more discussion after referencing other studies on how they relate to the current study/the current study s findings Conclusions N/A Major Compulsory Revisions: 1. Page numbers for manuscript missing (unless these are not currently required at this time) 2. Figure 1 title/description needs to be combined with the actual figure (which appears on a separate/the last page vs. the second last page) Quality of written English:Not suitable for publication unless extensively edited Statistical review:yes, but I do not feel adequately qualified to assess the statistics. Declaration of competing interests: I declare that I have no competing interests.