asian-multinational-cvd-cohorts

Searcher 2 — Asian + multinational CVD/mortality cohorts (US-vs-Asia heterogeneity)

Slice summary

Prospective observational cohorts in Asian and explicitly multinational/cross-continental populations reporting hard endpoints (incident CVD — CHD, stroke, heart failure — and all-cause/cause-specific mortality) versus habitual egg intake. This is deliberately the non-Western half of the CVD/mortality evidence base (slice 1 owns US/Canada/Europe). Wrote 10 of a 12-note budget, read ~16 properly (well under the 24-read budget — the literature here is thinner and more concentrated than expected once Korea and South/Southeast Asia turned up largely empty for hard-endpoint egg cohorts; see gaps below). China dominates the available pool (6 distinct cohort families), Japan contributes 2 genuinely different anchors, and PURE + INTERHEART cover the multinational side. All three directions (protective, null, harm) are represented, with harm concentrated in more recent/methodologically distinct Chinese cohorts (CHNS, rural Anhui) rather than in the flagship Kadoorie/PURE anchors — this is itself a finding worth flagging to the consolidator: the “eggs are fine/good in Asia” reading rests disproportionately on two large, older biobank-style cohorts, while several smaller or more recent Chinese cohorts using different dietary-assessment methods (repeated 24h-recall, cumulative-mean intake, rural low-SES populations) find harm at ≥1/day or high (>6/week) intake.

Sources by topic (best-first within each group)

China — general population, hard CVD/mortality endpoints

1. S-80 - China Kadoorie Biobank egg consumption and CVD (Qin 2018 Heart).md — 461,213 adults, 8.9y follow-up; daily egg intake (~0.76/day) associated with lower CVD, IHD, hemorrhagic stroke, CVD mortality. The flagship protective anchor.
2. S-81 - China-PAR project- U-shaped egg intake vs incident CVD and mortality (Xia 2020).md — 102,136 adults, up to 17y; U-shaped — both <1/week and ≥10/week carry higher CVD/mortality risk than 3-<6/week. The key nonlinearity anchor.
3. S-86 - China Family Panel Studies nationwide cohort- egg intake frequency and mortality (Wang 2022).md — 30,835 adults nationwide, 8.1y; moderate/high intake (3-6, ≥7/week) protective vs none, independently replicating a nonlinear “moderate is better than zero” shape.
4. S-83 - Guangzhou Biobank Cohort Study egg consumption and CVD-mortality (Xu 2019).md — 28,024 older urban adults, 9.8y; clean null for all-cause and CVD mortality.
5. S-85 - China Health and Nutrition Survey- habitual egg intake raises incident CVD (Yakti 2024).md — 16,030 adults, cumulative habitual intake >50g/day (~1 egg) → 43% higher incident CVD. The clearest Chinese harm signal; methodologically distinct (repeated 24h-recall vs FFQ).
6. S-84 - Rural China (Anhui) 14-year cohort- high egg intake and all-cause mortality (Liu 2021).md — 9,444 rural adults, 14.1y; >6/week → 35% higher all-cause mortality, amplified in higher-BMI participants. Harm in a lower-SES rural population, distinct dietary/confounding context from the urban biobanks.

Japan — hard CVD/mortality endpoints

7. S-87 - Japan Public Health Center cohort- egg intake not linked to CHD incidence (Nakamura 2006).md — 90,735 adults (JPHC I+II), 1990-2001; egg intake up to near-daily not linked to CHD incidence; explicitly decouples egg intake from the cholesterol→CHD mechanism in this population. Clean null anchor.
8. S-88 - NIPPON DATA80- egg consumption, cholesterol, and cause-specific mortality (Nakamura 2004).md — 9,263 adults, 14y, 1980 baseline; cholesterol rises monotonically with egg frequency, but mortality is nonlinear and sex-specific (women: 1-2/week better than ~1/day; no pattern in men). A more cautionary, complicating Japanese anchor.

Multinational / cross-continental

9. S-91 - PURE study- egg intake, blood lipids, CVD and mortality in 50 countries (Dehghan 2020).md — 146,011 adults, 21 countries (+ 31,544 more via pooled ONTARGET/TRANSCEND trials, “50 countries” in the title); null for CVD, mortality, and lipids across income levels. The broadest null anchor — spans Asia, Middle East, Africa, Latin America, not just high-income countries.
10. S-93 - INTERHEART- eggs within the ‘Western’ dietary pattern and MI risk across 52 countries (Iqbal 2008).md — case-control, 52 countries; eggs load onto a non-significant “Western” dietary-pattern factor, not analysed as an isolated exposure. Weakest fit for the main question in this slice — flagged clearly in its own relevance_note for step 2 to weight down.

search_scope

Started from the named anchors in the search brief (Qin 2018 Heart, Dehghan 2020 AJCN/PURE, Nakamura JPHC/NIPPON DATA80, INTERHEART) and confirmed/detailed each via WebSearch + WebFetch (PMC, journal pages) and, once the session’s WebSearch budget was exhausted (shared across the whole parallel step-1 fan-out — hit “200 of 200” partway through), continued via WebFetch against PubMed/PMC pages, the Crossref API (api.crossref.org/works), and the Europe PMC REST API (www.ebi.ac.uk/europepmc/webservices/rest/search) for metadata, abstracts, and citation counts. Used general web search (before budget ran out) for: “China Kadoorie Biobank egg CVD”, “Rong 2013 BMJ egg meta-analysis”, “Dehghan 2020 PURE”, “Japan JACC/Nakamura egg”, “INTERHEART egg”, “Korea KoGES/KNHANES egg CVD”, “NIPPON DATA80”, “Singapore Chinese Health Study egg”, “Taiwan cohort egg”, “Xu 2019 / Godos 2021 meta-analyses”, “Thailand/Vietnam/Malaysia egg CVD”, “South Asia (India/Bangladesh/Pakistan) egg CVD”. Once WebSearch was unavailable, used Europe PMC/Crossref queries for: Korean cohort alternatives to the T2D-interaction paper, Tehran Lipid and Glucose Study, JACC-specific egg papers, CHARLS, and South/Southeast Asian cohorts. Did not mine Rong 2013 BMJ, Xu 2019 (turned out to be a primary, not a hub — see exclusions), or Godos 2021 directly as reference lists (ran out of budget for deep hub-mining); relied instead on targeted searches per named cohort family, which is a weaker method than reference-list snowballing and is the main methodological gap versus the brief’s instructions.

exclusions

1. Jang 2018, Nutrition & Diabetes (KoGES Ansung-Ansan cohort, 9,248 Korean adults, “Longitudinal association between egg consumption and the risk of cardiovascular disease: interaction with type 2 diabetes mellitus”) — headline finding is specifically the diabetes-status interaction (whole-cohort HR 1.14 ns; T2DM subgroup HR 2.81, 95% CI 1.25-6.30; non-diabetic subgroup ns). Per the crisp slice boundary, this “dedicated diabetic-subgroup CVD interaction” analysis belongs to slice 3, not slice 2 — not minted here.
2. Jeon/Kim/Yun 2025, Prev Nutr Food Sci (KNHANES 2014-2015, Korea, n=1,478 men) — egg intake vs a modelled Framingham 10-year CHD risk score in high-CHD-risk men (OR 0.84 per serving). Excluded: cross-sectional design, and the outcome is a computed risk score, not an observed incident hard endpoint; 0 citations (published Aug 2025). This was the only other Korean candidate found once the T2D-interaction paper was ruled out for this slice — recorded here rather than minted given the endpoint mismatch.
3. Health Examinees (HEXA) Korea, metabolic syndrome paper (130,420 adults) — surrogate/prevalent-metabolic-syndrome endpoint, not a hard CVD/mortality event; out of scope for this slice (and arguably slice 4/8’s territory, not re-flagged there).
4. Xu 2019 / Guangzhou Biobank was originally named in the brief as a “dose-response meta-analysis” discovery hub; on inspection it is actually the primary Guangzhou Biobank Cohort Study paper with an embedded meta-analysis, not a pure review — minted as S-83 rather than treated as a hub.
5. Pan 2023, Nutrients (“Prospective Associations of Egg Consumption with Total Cerebrovascular Disease Morbidity among Chinese Adults”) — a Qingdao-urban sub-cohort of the same China Kadoorie Biobank as S-80 (35,270 participants), reporting a sex-differential finding (protective in men, HR 0.72 for daily vs never; null in women). Not separately minted to respect the “one primary per cohort family” independence rule, but flagged here because the sex-differential is a genuinely new “for whom” data point not in S-80 itself — worth a downstream extractor pulling from this note rather than losing it.
6. Ke Wang et al., Nutrition Metabolism & Cardiovascular Diseases 2022 (“Longitudinal association of egg intake frequency with cardiovascular disease in Chinese adults”, ~20,688 adults, CVD-incidence endpoint) — shares the same China Family Panel Studies (CFPS) data basis as S-86 (mortality endpoint, 30,835 adults, overlapping author group). Not separately minted for the same independence reason; also finds a protective association, reinforcing S-86’s direction.
7. Guo 2017, Eur J Nutr (Caerphilly Prospective Cohort Study + NDNS, UK) — turned up while searching for a UK-comparator; explicitly out of scope (Western, slice 1’s territory), not minted or otherwise flagged there since slice 1 will find it independently if relevant.
8. Re-evaluation of NIPPON DATA80 (2017, Eur J Clin Nutr / Circulation abstract, extended ~29y follow-up, women-specific) — same NIPPON DATA80 data basis as S-88; noted in S-88’s body rather than separately minted.

Gaps

1. Korea: no usable general-population, hard-endpoint (incident CVD or mortality) prospective cohort found beyond the diabetes-interaction paper that belongs to slice 3 (see exclusions #1) and a weak cross-sectional risk-score paper (exclusions #2). KNHANES/KoGES/HEXA all have egg-diet papers but on surrogate or metabolic-syndrome endpoints, or are cross-sectional. This is a genuine hole in the pool, not just a search failure — worth the consolidator checking whether a top-up searcher with deeper Korean-language or KNHANES-mortality-linkage search could close it.
2. South and Southeast Asia (India, Bangladesh, Pakistan, Malaysia, Indonesia, Philippines, Vietnam, Thailand): could not find a single dedicated prospective cohort examining egg intake vs CVD/mortality as a primary exposure — these countries appear only as constituent populations inside PURE (S-91) and INTERHEART (S-93), never as standalone cohorts. This looks like a real evidence gap (high CVD burden, understudied dietary epidemiology) rather than a search miss, but should be treated as tentative given the truncated search.
3. Taiwan and Singapore: searched specifically (Taiwan MJ Health cohort, Singapore Chinese Health Study) — both have active cardiovascular-epidemiology cohorts but no located egg-specific hard-endpoint publication; may exist but wasn’t found before the WebSearch budget ran out.
4. Did not reach a true reference-list “snowball” from Rong 2013 BMJ / Godos 2021 / Xu 2019(-as-hub) as instructed — searches were anchor-driven rather than hub-reference-list-driven, so some Asian primaries indexed only in those meta-analyses’ reference lists (not independently discoverable by search engine) may be missing.
5. Session-wide WebSearch quota (shared across all parallel step-1 searchers) was exhausted roughly two-thirds through this slice’s work; the remainder relied on WebFetch against PubMed/PMC/Crossref/Europe PMC, which is slower and less good at open-ended discovery (fine for confirming/detailing a known candidate, weak for finding new ones) — likely the main reason the write count landed at 10/12 rather than 12/12.

Report (1 line per source)

1. S-80 — China Kadoorie Biobank (Qin 2018 Heart): 461k adults, daily eggs → lower CVD/IHD/hemorrhagic-stroke/CVD-mortality risk. Protective anchor.
2. S-81 — China-PAR (Xia 2020): 102k adults; U-shaped — both <1/week and ≥10/week riskier than 3-<6/week.
3. S-83 — Guangzhou Biobank (Xu 2019): 28k adults; null for all-cause/CVD mortality, modest stroke benefit in embedded meta.
4. S-84 — Rural China/Anhui (Liu 2021): 9.4k adults; >6 eggs/week → 35% higher all-cause mortality, amplified at higher BMI.
5. S-85 — CHNS (Yakti 2024): 16k adults; habitual intake >50g/day → 43% higher incident CVD, mediated by obesity/HTN/diabetes.
6. S-86 — CFPS nationwide (Wang 2022): 31k adults; moderate/high intake protective vs none for all-cause mortality.
7. S-87 — JPHC (Nakamura 2006): 91k adults; egg intake not linked to CHD incidence; decouples eggs from the cholesterol mechanism.
8. S-88 — NIPPON DATA80 (Nakamura 2004): 9.3k adults; cholesterol rises with egg frequency, mortality effect nonlinear and women-specific.
9. S-91 — PURE (Dehghan 2020): 146k+ adults, 21+ countries; null for CVD, mortality, and lipids across income levels.
10. S-93 — INTERHEART (Iqbal 2008): 52-country case-control; eggs load onto a non-significant “Western” dietary pattern — weakest-fit primary here.