PUBH 3100 Week 9 Peer Replies Example

Course	PUBH 3100 Human Disease and Prevention
Week	Week 9
Paper type	Peer replies
Length	About 410 words, 3 pages
Format	Discussion reply, APA 7 citations
School	Walden University
Program	BS in Public Health
Updated	October 2026

Free sample paper for PUBH 3100 Week 9

Week 9 Discussion: Peer Replies

Naming the Skipped Step: Two Peer Replies, One on a Missing Link Between Processed Meat and Colon Cancer and One on a Survey Design That Cannot Carry a Claim About Coffee and Depression

Reply to Brianna

Brianna, your post explained that processed meat raises colon cancer risk "because it contains nitrates, which are carcinogens." The conclusion is well supported: an international expert panel placed processed meat in its highest cancer-hazard group, mainly because of the colorectal cancer evidence, estimating that each 50 grams eaten daily raises risk by about 18% (Bouvard et al., 2015). My question is about the step between "contains nitrates" and "causes cancer," which the post skips.

Nitrate itself does not damage DNA. The proposed mechanism is that nitrates and nitrites, along with iron from meat, lead to the formation of N-nitroso compounds in the gut, and some of those compounds damage DNA in cells lining the colon. That middle step can be measured. In a study of volunteers eating controlled diets, a diet high in red meat increased N-nitroso compounds in stool and a DNA adduct linked to those compounds in cells shed from the colon (Lewin et al., 2006). That is the kind of study that fills the gap: human evidence that the intermediate product forms and reaches the tissue. Would you add that step to your mechanism, with the kind of evidence behind it?

Reply to Marcus

Marcus, you cited a survey in which adults who drank more coffee were less likely to report depression, and you concluded that "coffee protects against depression." The survey asked about coffee and mood at the same time, so it cannot tell which came first. People who are depressed may drink less coffee, for example because they have less energy for daily routines or because of changes in appetite, which would produce the same pattern with the arrow reversed.

A design that measures coffee before depression begins would close part of that gap. In a cohort of women followed for ten years, those drinking two to three cups of caffeinated coffee a day had a 15% lower risk of developing depression than those drinking one cup or less a week (Lucas et al., 2011). Because coffee was measured before depression was diagnosed, reverse direction is less likely, though the women who drank more coffee may still have differed in other ways. Would you consider rewording the claim as an association seen in a cohort, and naming what a cross-sectional survey cannot show?

What this page is doingPointing each classmate to the specific study design that would fill their gap makes the critique useful rather than merely skeptical.

References

Bouvard, V., Loomis, D., Guyton, K. Z., Grosse, Y., El Ghissassi, F., Benbrahim-Tallaa, L., Guha, N., Mattock, H., & Straif, K. (2015). Carcinogenicity of consumption of red and processed meat. The Lancet Oncology, 16(16), 1599-1600. https://doi.org/10.1016/S1470-2045(15)00444-1

Lewin, M. H., Bailey, N., Bandaletova, T., Bowman, R., Cross, A. J., Pollock, J., Shuker, D. E. G., & Bingham, S. A. (2006). Red meat enhances the colonic formation of the DNA adduct O6-carboxymethyl guanine: Implications for colorectal cancer risk. Cancer Research, 66(3), 1859-1865. https://doi.org/10.1158/0008-5472.CAN-05-2237

Lucas, M., Mirzaei, F., Pan, A., Okereke, O. I., Willett, W. C., O'Reilly, É. J., Koenen, K., & Ascherio, A. (2011). Coffee, caffeine, and risk of depression among women. Archives of Internal Medicine, 171(17), 1571-1578. https://doi.org/10.1001/archinternmed.2011.393

The Walden PUBH 3100 Week 9 instructions

Peer reply weeks in a disease and prevention course ask students to respond to classmates by evaluating the reasoning behind a claim, not only its conclusion. Instructors look for replies that identify a specific gap, such as a missing step in a mechanism or a design that cannot support a causal claim, and that name the kind of evidence that would address it. Replies are usually a few hundred words each, with at least one source, and students often reply to two classmates. Crediting the classmate's sound points first, then closing with a suggestion they can act on, keeps the thread going. Citing a primary study of the right design shows the student understands what kind of evidence is needed, not just that more is needed.

How the PUBH 3100 Week 9 example is put together

The first reply quotes the classmate's claim about nitrates, confirms the overall conclusion with an expert review's classification and risk estimate and identifies the skipped intermediate step. It describes the proposed pathway and cites a controlled feeding study that measured the intermediate products in humans, then asks the classmate to add the step. The second reply quotes the classmate's conclusion about coffee, explains why a survey measured at one time cannot show direction and offers a reverse explanation. It cites a long cohort study that measured coffee first and notes what confounding remains, then asks the classmate to reword the claim. A margin note explains the shared method.

PUBH 3100 Week 9 rubric: what earns full marks

Grading for these replies centers on precision of the critique, appropriateness of the evidence offered and constructiveness. Precision credit comes from naming one missing step in the mechanism and one design limitation, rather than raising many vague doubts. Evidence credit comes from citing studies whose designs actually fill each gap: a human feeding study for an intermediate step and a cohort with exposure measured first for direction. Constructiveness comes from confirming each classmate's sound conclusion before making one concrete request. Noting the cohort's remaining limits shows balance. Mechanics and citations satisfy the rest. Replies that only say a study is "just correlation" without naming a better design earn partial credit. Keeping each reply to one gap makes the critique easy to act on.

PUBH 3100 Week 9 help from the desk

Replies are most useful when they point to a specific missing link and the study that would supply it. For mechanisms, ask what happens between the exposure and the disease and whether that step has been measured in people. For design, ask what the study measured first and whether it could show direction. Name a design that would do better and cite an example. Confirm what the classmate got right. Close with a request they can act on. Keep each reply focused on one gap. Send your classmates' posts and we will draft two first replies for free.

Get a PUBH 3100 Week 9 example written to your instructions

Copy in both classmate posts along with the Week 9 prompt and whatever the discussion rubric requires, and the desk answers what those posts actually claim. The first custom sample is free and lands within 24-48 hours. A reply with no specific target reads as generic no matter how well written it is.

More PUBH 3100 papers and BS in Public Health samples

PUBH 3100 Week 9 questions, answered

Where can I find a free PUBH 3100 Week 9 sample paper?

Both Week 9 peer replies appear here in full, naming a missing mechanism step and a design gap, each with the kind of study that would close it.

Does processed meat cause colorectal cancer?

An international expert panel put processed meat in its top cancer-hazard group, estimating that each daily 50-gram portion raises colorectal cancer risk by roughly 18%.

How might processed meat damage the colon?

A proposed pathway involves formation of N-nitroso compounds in the gut that can damage DNA in cells lining the colon; feeding studies have measured these products in volunteers.

Why can't a one-time survey show that coffee prevents depression?

Coffee and mood are measured together, so the survey cannot tell whether coffee affected mood or mood affected coffee drinking.

What design better addresses direction?

A cohort that measures the exposure before the outcome develops, such as coffee intake recorded years before any diagnosis of depression.