Cited by 201Nutritional Studies and DietAgriculture Sustainability and Environmental ImpactMeat and Animal Product Quality

Red meat intake and risk of coronary heart disease among US men: prospective cohort study

Open access
Al-Shaar, Laila, Satija, Ambika, Wang, Dong D, Rimm, Eric B, Smith-Warner, Stephanie A, Stampfer, Meir J, Hu, Frank B, Willett, Walter C·2020·BMJ

Abstract

Objectives: To study total, processed, and unprocessed red meat in relation to risk of coronary heart disease (CHD) and to estimate the effects of substituting other protein sources for red meat with CHD risk. Design: Prospective cohort study with repeated measures of diet and lifestyle factors. Setting: Health Professionals Follow-Up Study cohort, United States, 1986-2016. Participants: 43 272 men without cardiovascular disease or cancer at baseline. Main outcome measures: The primary outcome was total CHD, comprised of acute non-fatal myocardial infarction or fatal CHD. Cox models were used to estimate hazard ratios and 95% confidence intervals across categories of red meat consumption. Substitution analyses were conducted by comparing coefficients for red meat and the alternative food in models, including red meat and alternative foods as continuous variables. Results: During 1 023 872 person years of follow-up, 4456 incident CHD events were documented of which 1860 were fatal. After multivariate adjustment for dietary and non-dietary risk factors, total, unprocessed, and processed red meat intake were each associated with a modestly higher risk of CHD (hazard ratio for one serving per day increment: 1.12 (95% confidence interval 1.06 to 1.18) for total red meat, 1.11 (1.02 to 1.21) for unprocessed red meat, and 1.15 (1.06 to 1.25) for processed red meat). Compared with red meat, the intake of one serving per day of combined plant protein sources (nuts, legumes, and soy) was associated with a lower risk of CHD (0.86 (0.80 to 0.93) compared with total red meat, 0.87 (0.79 to 0.95) compared with unprocessed red meat, and 0.83 (0.76 to 0.91) compared with processed red meat). Substitutions of whole grains and dairy products for total red meat and eggs for processed red meat were also associated with lower CHD risk. Conclusions: Substituting high quality plant foods such as legumes, nuts, or soy for red meat might reduce the risk of CHD. Substituting whole grains and dairy products for total red meat, and eggs for processed red meat, might also reduce this risk.

AI snapshot

Written from the paper’s full text.

TL;DR

In US male health professionals followed for up to 30 years, total, unprocessed, and processed red meat intakes were each associated with modestly higher coronary heart disease (CHD) risk. Substituting plant proteins, whole grains, dairy products, or eggs for red meat was associated with lower CHD risk.

Key findings

  • During 1,023,872 person years, 4,456 incident CHD events occurred, of which 1,860 were fatal. Per one serving/day increment, multivariable-adjusted hazard ratios were 1.12 (95% CI 1.06 to 1.18) for total red meat, 1.11 (1.02 to 1.21) for unprocessed red meat, and 1.15 (1.06 to 1.25) for processed red meat.
  • Comparing highest with lowest fifth, hazard ratios were 1.28 (1.14 to 1.45, P<0.001 for trend) for total red meat, 1.18 (1.05 to 1.32, P=0.01) for unprocessed red meat, and 1.19 (1.07 to 1.33, P=0.001) for processed red meat.
  • Substituting one serving/day of combined plant protein sources (nuts, legumes, and soy) for red meat was associated with lower CHD risk: 0.86 (0.80 to 0.93) compared with total red meat, 0.87 (0.79 to 0.95) compared with unprocessed red meat, and 0.83 (0.76 to 0.91) compared with processed red meat.
  • Fatal CHD associations were slightly stronger: 1.38 (1.15 to 1.66) for total red meat, 1.29 (1.08 to 1.53) for unprocessed red meat, and 1.21 (1.02 to 1.43) for processed red meat. Substitutions of whole grains and dairy products for total red meat, and eggs for processed red meat, were also associated with lower CHD risk.

Methods

  • Prospective cohort study: Health Professionals Follow-Up Study, 43,272 US male health professionals aged 40 to 75 years at baseline, free of cardiovascular disease or cancer, followed from 1986 to 2016. Diet was assessed with a semiquantitative food frequency questionnaire at baseline and every four years, using cumulative averages.
  • Primary outcome was total CHD, comprising acute non-fatal myocardial infarction or fatal CHD, confirmed by medical records and physician review. Cox proportional hazards models estimated hazard ratios and 95% confidence intervals across fifths of red meat intake and per one serving/day increment, adjusted for dietary and non-dietary risk factors.
  • Substitution analyses included red meat and alternative foods as continuous variables in the same multivariable model and compared their coefficients; stratified, latency, and sensitivity analyses were also performed.

Limitations

  • Stated in the paper: the observational design precludes assuming causality; dietary measurement error and misclassification likely attenuate associations; residual and unmeasured confounding cannot be excluded; and participants were mostly non-Hispanic white male health professionals of higher socioeconomic status, limiting generalizability.
  • Evident from the text: diet was self-reported via food frequency questionnaires, and although cumulative averages and latency analyses were used, reverse causation could still affect results, as the authors note that weaker associations with most recent diet might be influenced by participants changing diet after symptoms or diagnosis.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1136/bmj.m4141

Cites

43 of 43 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

26 of 44 cited sources checked · 18 supported · 0 flagged · accuracy not yet measured

  • Premisecitation

    Reduction of risk of coronary heart disease by replacement of saturated fat with polyunsaturated fat has been supported by both observational cohort studies and randomized trials.

    “In addition, red meat is low in polyunsaturated fat, and reduction of risk of CHD by replacement of saturated fat with polyunsaturated fat has been supported by both observational cohort studies and randomized trials.33”
    Quote in the paperSubstantial claim1 of 1 sources checked
  • Premisecitation

    Dietary heme iron found in red meat has been associated with myocardial infarction and fatal coronary heart disease in many epidemiologic studies.

    “Dietary heme iron found in red meat has been associated with myocardial infarction and fatal CHD in many epidemiologic studies.34 35 36”
    Quote in the paperNot a substantial claim2 of 3 sources checked
    • cites [34] source
    • cites [35] source
    • cites [36] source

      The Introduction and Discussion report associations of haem iron intake with myocardial infarction or CHD in two previous studies, and this paper reports an association with CHD in middle-aged women. But the Introduction says only a few epidemiological studies focused on haem iron, and the Discussion says this study had too few fatal CHD cases to analyze them separately; it does not establish the claimed association with fatal CHD. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
  • Premisecitation

    The associations of red meat consumption with all cause, cardiovascular disease, and cancer mortality were also similar among participants of the Nurses' Health Study and Health Professionals Follow-Up Study.

    “and the associations of red meat consumption with all cause, cardiovascular disease, and cancer mortality were also similar among participants of the Nurses’ Health Study and Health Professionals Follow-Up Study.3”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • Premisecitation

    Unprocessed red meat was associated with higher cardiovascular disease mortality among the US populations only.

    “Unprocessed red meat was associated with higher cardiovascular disease mortality among the US populations only,16”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • Study design and conductcitation

    This homogeneity can help reduce unmeasured confounding related to socioeconomic status.

    “This homogeneity can, however, help reduce unmeasured confounding related to socioeconomic status.3”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • May combine two claims. 36
  • Classified as probably not a substantial claim. 38
  • The quote only partly states this claim. 1
  • May combine two claims.

    Premisecitation

    Increases in risk were not seen in Asian populations with low consumption of red meat, or in populations in which consumption of red meat has recently increased.

    “Increases in risk were not, however, seen in Asian populations with low consumption of red meat, or in populations in which consumption of red meat has recently increased.14 15 16”
    Quote in the paperSubstantial claim2 of 3 sources checked
    • cites [14] source
    • cites [15] source

      The Discussion (page unavailable) says meat consumption is lower in Asian countries than in Western countries and describes weak associations in Asian cohorts; it also reports an inverse association with CVD mortality in a pooled analysis of eight Asian cohorts. It does not establish that risk increases were absent in populations where red-meat consumption had recently increased. Its reference to changing diets in Asian countries does not make that specific claim. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [16] source

      The Subgroup and sensitivity analyses report no statistically significant association between unprocessed red meat consumption and mortality risk in Asian populations; the Discussion notes their relatively low intake as a possible explanation. The paper does not report a corresponding risk analysis for populations where red-meat consumption has recently increased, so that part of the claim is unsupported. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • May combine two claims.

    Premisecitation

    Substantial evidence from randomized trials and observational studies suggests that high consumption of red meat, especially processed red meat, is associated with an increased risk of mortality and major chronic diseases, including coronary heart disease.

    “Substantial evidence from randomized trials and observational studies suggests that high consumption of red meat, especially processed red meat, is associated with an increased risk of mortality1 2 3 and major chronic diseases,4 5 6 7 8 9 including coronary heart disease (CHD).10 11 12”
    Quote in the paperSubstantial claim3 of 3 sources checked
    • cites [1] source
    • cites [2] source

      The Introduction reports associations of red and processed meat with mortality, coronary heart disease, diabetes, and some cancers; the Discussion also describes higher-intake observational studies finding mortality associations. But this paper does not establish the claimed evidence from randomized trials, and its Results found no significant mortality association for processed meat alone, so it does not support the emphasis on processed meat as the stronger risk. Page numbers are unavailable in our copy. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [3] source
  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    These inconsistencies could be due to the variable amounts and duration of red meat consumed in different populations, inadequate differentiation between processed and unprocessed red meat, differences in the levels of controlling for confounding, and differences in the comparison sources of energy.

    “These inconsistencies could be due to the variable amounts and duration of red meat consumed in different populations,15 16 inadequate differentiation between processed and unprocessed red meat,15 17 18 19 differences in the levels of controlling for confounding,15 18 and, importantly, differences in the comparison sources of energy.15 20 21 22”
    Quote in the paperSubstantial claim2 of 3 sources checked
    • cites [15] source

      The Discussion (page unavailable) says heterogeneity could partly reflect differences in meat-consumption amounts, meat-group definitions and follow-up duration. It also discusses residual confounding and the importance of distinguishing processed from unprocessed meat. It does not identify differences in the comparison sources of energy as an explanation, and follow-up duration is not necessarily the duration of meat consumption. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [16] source

      The Discussion (page unavailable) proposes differences in the amount of red meat consumed as an explanation for inconsistent findings across populations; the Subgroup and sensitivity analyses also report different results by follow-up length. The Study characteristics (page unavailable) document variation in adjustment for dietary variables and energy intake and note that one study did not report unprocessed-red-meat results. Our copy does not identify differences in comparison sources of energy as an explanation, and follow-up length is not necessarily the duration of red-meat consumption. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [17] source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    L-carnitine, which is relatively high in red meat, might be metabolized by intestinal microbiota into proatherogenic compounds, trimethylamine-N-oxide, promoting atherosclerosis.

    “L-carnitine, which is relatively high in red meat, might be metabolized by intestinal microbiota into proatherogenic compounds, trimethylamine-N-oxide, promoting atherosclerosis.38”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Both prospective cohorts used one dietary measurement at baseline.

    “Yet, both prospective cohorts used one dietary measurement at baseline.29 30”
    Quote in the paperNot a substantial claim2 of 2 sources checked
    • cites [29] source

      The Methods (Study Population; page unavailable) say dietary intake was measured at enrollment, and the Statistical Analysis uses the recruitment questionnaire for the main intake measures. But an 8% subsample also completed a 24-hour dietary recall about 1.4 years after recruitment, so the statement that this cohort used only one dietary measurement is too absolute. This paper addresses one of the two cohorts cited, not both. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [30] source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    A prospective study of 409 885 men and women in nine European countries showed that the risk of ischemic heart disease was 19% greater for every 100 g/day increment in the intake of total and processed red meat.

    “A prospective study of 409 885 men and women in nine European countries showed that the risk of ischemic heart disease was 19% greater for every 100 g/day increment in the intake of total and processed red meat.29”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • May combine two claims.

    Premisecitation

    In a network meta-analysis of randomized trials, nuts, legumes, and whole grains were each shown to be more effective in reducing low density lipoprotein cholesterol compared with red meat.

    “In a network meta-analysis of randomized trials, nuts, legumes, and whole grains were each shown to be more effective in reducing low density lipoprotein cholesterol compared with red meat.32”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • May combine two claims.

    Premisecitation

    We previously found that higher intake of total red meat was statistically significantly associated with an increased risk of coronary heart disease among 84 136 women of the Nurses' Health Study cohort, especially when compared with alternative protein sources.

    “Nonetheless, we previously found that higher intake of total red meat was statistically significantly associated with an increased risk of CHD among 84 136 women of the Nurses’ Health Study cohort, especially when compared with alternative protein sources.12”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Substituting 100 kcal/d of fatty fish, yogurt, cheese, or eggs for 100 kcal/d of red and processed meat was associated with a 15-24% lower risk of ischemic heart disease.

    “Substituting 100 kcal/d of fatty fish, yogurt, cheese, or eggs for 100 kcal/d of red and processed meat was associated with a 15-24% lower risk of ischemic heart disease.29”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    In another prospective US cohort study, the dietary intake of processed and unprocessed red meat was each associated with higher risk of mortality from heart disease.

    “In another prospective US cohort study, the dietary intake of processed and unprocessed red meat was each associated with higher risk of mortality from heart disease.30”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Our group has published similar associations with coronary heart disease among women of the Nurses' Health Study cohort.

    “Our group has published similar associations with CHD among women of the Nurses’ Health Study cohort,12”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • May combine two claims.

    Premisecitation

    The included studies in the older meta-analysis were limited by either a small number of events (769 events across all studies), short follow-up, no adjustment for total energy intake, not specifying the comparison food, or not using prospectively collected data.

    “However, the included studies were limited by either a small number of events (769 events across all studies), short follow-up, no adjustment for total energy intake, not specifying the comparison food, or not using prospectively collected data.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [11] source

      The Results (page unavailable) report that dietary variables were often not controlled for, and the Discussion (page unavailable) notes potential bias in retrospective case-control studies. But the claimed total of 769 events conflicts with the Results, which report 23,889 CHD cases alone. The cited passages do not establish the specific claims about total-energy adjustment, comparison foods, or short follow-up. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
  • May combine two claims.

    Premisecitation

    In an older meta-analysis of observational studies, processed meat intake was associated with an increased risk of coronary heart disease, and no statistically significant association was observed with unprocessed red meat.

    “In an older meta-analysis of observational studies, processed meat intake was associated with an increased risk of CHD,11 and no statistically significant association was observed with unprocessed red meat.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Although the authors did not examine plant sources of proteins, their overall conclusion was consistent with the findings of our study showing that red and processed meat were associated with a higher risk of ischemic heart disease.

    “Although the authors did not examine plant sources of proteins, their overall conclusion was consistent with the findings of our study showing that red and processed meat were associated with a higher risk of ischemic heart disease.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
  • May combine two claims.

    Findingown data

    In sensitivity analyses, the associations between red meat intake and CHD risk became slightly weaker after including baseline history of diabetes, hypertension, and hypercholesterolemia in the model, or after adjusting for the modified AHEI score.

    “In sensitivity analyses, the associations between red meat intake and CHD risk became slightly weaker after including baseline history of diabetes, hypertension, and hypercholesterolemia in the model, or after adjusting for the modified AHEI score (see supplemental table 3).”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    During 1,023,872 person years of follow-up of 43,272 participants, 4,456 incident CHD events were documented, of which 1,860 were fatal.

    “During 1 023 872 person years of follow-up of 43 272 participants, 4456 incident CHD events were documented of which 1860 were fatal.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The Health Professionals Follow-Up Study cohort included 43,272 men without cardiovascular disease or cancer at baseline.

    “43 272 men without cardiovascular disease or cancer at baseline.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    Milk (both skimmed and whole), yogurt, and cheese were each associated with a 10% to 22% lower risk of CHD compared with red meat.

    “Milk (both skimmed and whole), yogurt, and cheese were each associated with a 10% to 22% lower risk of CHD compared with red meat (table 3).”
    Quote in the paperSubstantial claim
  • The quote only partly states this claim.

    Findingown data

    Associations of total red meat with fatal CHD were slightly stronger than for total CHD (HR 1.38, 95% CI 1.15 to 1.66).

    “Associations of each of total, unprocessed, and processed red meat with fatal CHD were slightly stronger (1.38 (1.15 to 1.66) for total red meat, 1.29 (1.08 to 1.53) for unprocessed red meat, and 1.21 (1.02 to 1.43) for processed red meat) (see supplemental table 2).”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    In the stratified analysis by calendar year (≥2000), intake of dark meat fish was associated with lower CHD risk compared with total red meat (HR 0.56, 95% CI 0.33 to 0.95), unprocessed red meat (0.54, 0.31 to 0.92), and processed red meat (0.52, 0.30 to 0.90), but not earlier (<2000).

    “intake of dark meat fish was observed to be associated with a lower CHD risk compared with intake of total red meat (0.56 (0.33 to 0.95), unprocessed red meat (0.54 (0.31 to 0.92), and processed red meat (0.52 (0.30 to 0.90; table 4), in 2000 or later but not earlier.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    Those with higher total red meat consumption were more likely to smoke, consume alcohol, have diabetes, and use aspirin.

    “Those with higher total red meat consumption were more likely to smoke, consume alcohol, have diabetes, and use aspirin.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    In this prospective cohort study of men with at least 30 years of follow-up, greater intakes of total, unprocessed, and processed red meat were associated with a higher risk of CHD, independent of other dietary and non-dietary cardiovascular disease risk factors.

    “In this prospective cohort study of men with at least 30 years of follow-up, greater intakes of total, unprocessed, and processed red meat were associated with a higher risk of CHD, independent of other dietary and non-dietary cardiovascular disease risk factors.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Compared with intake of total, unprocessed, or processed red meat, intake of high quality plant based protein foods such as nuts, legumes, and soy in addition to whole grains and dairy products were each associated with a lower risk of CHD.

    “Compared with intake of total, unprocessed, or processed red meat, intake of high quality plant based protein foods such as nuts, legumes, and soy in addition to whole grains and dairy products were each associated with a lower risk of CHD.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Adjusting for other major dietary variables further attenuated the associations, but total, unprocessed, and processed red meat remained significantly associated with risk of CHD.

    “Adjusting for other major dietary variables such as poultry, fish, egg, high fat dairy products, low fat dairy products, nuts, legumes, soy, and whole grains in addition to fruit, vegetables, coffee, and glycemic index further attenuated the associations, but total, unprocessed, and processed red meat remained significantly associated with risk of CHD”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Those with higher total red meat consumption had higher intakes of total energy and trans fatty acids but were less physically active and less likely to have hypercholesterolemia or a family history of cardiovascular diseases.

    “They had higher intakes of total energy and trans fatty acids but were less physically active and less likely to have hypercholesterolemia or a family history of cardiovascular diseases.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    The associations observed in the substitution analyses did not seem to diminish with up to 20 years of latency; with greater than 20 years, the associations tended to be weaker, but the number of events was relatively small.

    “Overall, the associations observed in the substitution analyses did not seem to diminish with up to 20 years of latency; with greater than 20 years, the associations tended to be weaker, but the number of events was relatively small (supplemental figure 4).”
    • Also stated in: § Discussion · hedged
      “The latency analyses suggested that the inverse associations of substituting red meat with major protein sources did not diminish with lags up to 20 years before the diagnosis of CHD.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    Similar distributions were observed with processed and unprocessed red meat consumption.

    “Similar distributions were observed with processed and unprocessed red meat consumption (table 1).”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Total red meat consumption was on average 0.99 (SD 0.73) servings/day at baseline, 0.87 (0.72) servings/day using the most recent diet, and 0.91 (0.64) servings/day using the cumulative average.

    “Total red meat consumption was on average 0.99 (SD 0.73) servings/day at baseline, 0.87 (0.72) servings/day using the most recent diet, and 0.91 (0.64) servings/day using the cumulative average.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    The associations between red meat and egg intake were stronger among younger men, in whom replacement of red meat with egg was associated with a 20% (95% CI 2% to 35%) lower risk of CHD.

    “The associations between red meat and egg intake were stronger among younger men in whom the replacement of red meat with egg was associated with a 20% (95% confidence interval 2% to 35%) lower risk of CHD.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim.

    Study design and conductown data

    The models were further adjusted for other dietary variables, including poultry, fish, egg, high fat dairy, low fat dairy, nuts, legumes, soy, whole grains, fruit, vegetables, coffee, and glycemic index.

    “We further adjusted for other dietary variables, including poultry (unprocessed), fish, egg, high fat dairy, low fat dairy, nuts, legumes, soy, whole grains, fruit, vegetables, coffee, and glycemic index (all in fifths).”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim.

    Study design and conductown data

    The main multivariable models were adjusted for age, calendar time, energy intake, BMI, physical activity, smoking status, alcohol intake, family history of myocardial infarction or stroke, multivitamin use, aspirin use, race or ethnicity, work status, profession, living arrangement, and marital status.

    “The main models were adjusted for age (in months), calendar time (two year follow-up periods), and energy intake, in addition to BMI, physical activity, smoking status, alcohol intake, family history of myocardial infarction or stroke, multivitamin use, aspirin use, race or ethnicity, work status, profession, living arrangement, and marital status.”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    To better represent long term diet and minimize within person variation, the authors calculated the cumulative average of food intake from baseline up to the beginning of each two year follow-up interval.

    “To better represent long term diet and minimize within person variation, we calculated the cumulative average of food intake from baseline up to the beginning of each two year follow-up interval.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The proportional hazards assumption was tested by including an interaction term between red meat intake and months to events.

    “The proportional hazards assumption was tested by including an interaction term between red meat intake and months to events.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductnone given

    The study was a prospective cohort study with repeated measures of diet and lifestyle factors.

    “Prospective cohort study with repeated measures of diet and lifestyle factors.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    The reproducibility and validity of the food frequency questionnaire in measuring food intake have been described in detail previously.

    “The reproducibility and validity of the food frequency questionnaire in measuring food intake have been described in detail previously.25”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [25] source
  • Classified as probably not a substantial claim.

    Study design and conductnone given

    Physicians blinded to the participants' exposure status reviewed the medical records.

    “Physicians blinded to the participants’ exposure status reviewed the medical records.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    Data on physical activity were collected using the validated physical activity questionnaire.

    “Data on physical activity (<3, 3-8.9, 9-17.9, 18-26.9, and ≥27 in metabolic equivalents of task per week) were also collected using the validated physical activity questionnaire.28”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [28] source
  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductcitation

    Dietary data were not included if participants left more than 70 items blank in the food frequency questionnaire or had implausible total energy intake (<800 kcal/day or >4200 kcal/day) in any of the food frequency questionnaires.

    “Dietary data were not included if participants left more than 70 items blank in the food frequency questionnaire or had implausible total energy intake (<800 kcal/day (1 kcal=4.18 kJ=0.00418 MJ) or >4200 kcal/day)24 in any of the food frequency questionnaires.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [24] source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The 2015-20 US Dietary Guidelines for Americans encourage dietary patterns that are low in red and processed meat intake.

    “Consequently, the 2015-20 US Dietary Guidelines for Americans13 encourage dietary patterns that are low in red and processed meat intake.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [13] U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015 – 2020 Dietary Guidelines for Americans. 8th Edition. December 2015. https://health.gov/dietaryguidelines/2015/guidelines/.

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    To minimize the possibility of reverse causation bias, the authors stopped updating diet after the participant's diagnosis of cancer or stroke, or after reporting diabetes, angina, or CABG.

    “To minimize the possibility of reverse causation bias, we stopped updating diet after the participant’s diagnosis of cancer or stroke, or after reporting diabetes, angina, or CABG.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    In most populations, most energy intake comes from refined starches, sugar, potatoes, and fats that are highly saturated or partially hydrogenated.

    “In particular, in most populations, most energy intake come from refined starches, sugar, potatoes, and fats that are highly saturated or partially hydrogenated.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim.

    Study design and conductown data

    Participants were excluded if at baseline they had a history of cancer, myocardial infarction, angina, or coronary artery bypass graft (CABG), or stroke.

    “Participants were excluded if at baseline they had a history of cancer (n=1645), myocardial infarction, angina, or coronary artery bypass graft (CABG, n=3696), or stroke (n=221).”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    In case of missing data, the last value was carried forward for one two year cycle; if the last value was missing, then a missing indicator was created.

    “In case of missing data, the last value was carried forward for one two year cycle. If the last value was missing, then a missing indicator was created.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Study design and conductcitation

    The correlation coefficients between the food frequency questionnaire and multiple dietary records were 0.59 for unprocessed red meat; 0.52 for processed red meat; 0.48 for poultry; 0.74 for fish; 0.56 for eggs; 0.62 for each of high fat and low fat dairy products; 0.46 for legumes, including soybeans and tofu; 0.45 for nuts; and 0.27 for whole grains.

    “The correlation coefficients between the questionnaire and multiple dietary records were 0.59 for unprocessed red meat; 0.52 for processed red meat; 0.48 for poultry; 0.74 for fish; 0.56 for eggs; 0.62 for each of high fat and low fat dairy products; 0.46 for legumes, including soybeans and tofu; 0.45 for nuts; and 0.27 for whole grains.24”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [24] source
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    In this meta-analysis, the comparison food was not specified, and the results could have been underestimated.

    “In this meta-analysis, the comparison food was not specified, and the results could have been underestimated.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] source
  • May combine two claims.

    Interpretationreasoning

    Such replacement would decrease the amounts of saturated fats, cholesterol, and heme iron and increase the intake of unsaturated fat, fiber, antioxidants, polyphenols, and many constituents that could reduce the risk of coronary heart disease.

    “Such replacement would not only decrease the amounts of saturated fats, cholesterol, and heme iron, but also increase the intake of unsaturated fat, fiber, antioxidants, polyphenols, and many constituents that could reduce the risk of CHD.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationnone given

    Analyses that do not specify a comparison would be implicitly comparing the food under study with a mixture of all other energy contributing foods in the diet, thus making conclusions and dietary recommendations more difficult.

    “Analyses that do not specify a comparison would be implicitly comparing the food under study with a mixture of all other energy contributing foods in the diet, thus making conclusions and dietary recommendations more difficult.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    The weaker associations observed when using the most recent dietary data might also be influenced by reverse causation bias, as participants could have changed their diet after developing symptoms or a cardiovascular disease related diagnosis.

    “The weaker associations observed when using the most recent dietary data might also be influenced by reverse causation bias, as participants could have changed their diet after developing symptoms or a cardiovascular disease related diagnosis.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    These findings are consistent with the effects of these foods on low density lipoprotein cholesterol levels and support a health benefit of limiting red meat consumption and replacement with plant protein sources.

    “These findings are consistent with the effects of these foods on low density lipoprotein cholesterol levels and support a health benefit of limiting red meat consumption and replacement with plant protein sources; this would also have important environmental benefits.44”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Premisecitation

    A meta-analysis of randomized clinical trials showed that consumption of red meat was associated with increased blood levels of low density lipoprotein cholesterol compared with consumption of plant based protein sources, consistent with the high saturated fat and cholesterol content of red meat.

    “A meta-analysis of randomized clinical trials showed that consumption of red meat was associated with increased blood levels of low density lipoprotein cholesterol compared with consumption of plant based protein sources, consistent with the high saturated fat and cholesterol content of red meat.31”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Excessive iron intake might catalyze several cellular reactions involved in the production of reactive oxygen species, thus increasing the levels of oxidative stress.

    “Excessive iron intake might catalyze several cellular reactions involved in the production of reactive oxygen species, thus increasing the levels of oxidative stress.37”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [37] source
  • May combine two claims.

    Interpretationreasoning

    Substitution of plant based proteins for red meat could improve the cardiometabolic profile of people older than 65 and consequently lower their risk of coronary heart disease, explaining the more favorable substitution effect seen among older men.

    “Substitution of plant based proteins for red meat could possibly improve the cardiometabolic profile of this high risk group and consequently lower the risk of CHD, thus explaining the more favorable substitution effect of plant based proteins seen among older men.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Hypercholesterolemia, oxidative stress, and endothelial dysfunction increase with age.
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    The inverse association of dark meat fish with coronary heart disease risk in 2000 and later could be due to variation in the method of food preparation over time, as fish were mostly consumed after being deep fried in the earlier years.

    “This could be due to the variation in the method of food preparation over time, as fish were mostly consumed after being deep fried in the earlier years.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Fish were mostly consumed after being deep fried in the earlier years.
  • May combine two claims.

    Interpretationown data

    Substituting whole grains and dairy products for total red meat, and eggs for processed red meat, might also reduce this risk.

    “Substituting whole grains and dairy products for total red meat, and eggs for processed red meat, might also reduce this risk.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    In a meta-analysis of prospective cohorts, a reduction of three servings per week of unprocessed and processed red meat was each associated with a lower risk of all cause and cardiovascular disease mortality and a lower risk of myocardial infarction.

    “In a recent meta-analysis of prospective cohorts, however, a reduction of three servings per week of unprocessed and processed red meat was each associated with a lower risk of all cause and cardiovascular disease mortality and a lower risk of myocardial infarction.20”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] source
  • Classified as probably not a substantial claim.

    Study design and conductown data

    In our study, we additionally included substitution analysis that explicitly compared red meat with specific sources of proteins while accounting for total energy intake.

    “In our study, we additionally included substitution analysis that explicitly compared red meat with specific sources of proteins while accounting for total energy intake.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationcitation

    Limiting red meat consumption and replacement with plant protein sources would also have important environmental benefits.

    “this would also have important environmental benefits.44”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [44] source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The sialic acid N-glycolylneuraminic acid in red meat has been hypothesized to generate a proinflammatory, atherogenic state in humans.

    “Also, the sialic acid N-glycolylneuraminic acid in red meat has been hypothesized to generate a proinflammatory, atherogenic state in humans.39”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [39] source
  • May combine two claims.

    Study design and conductown data

    The patients were mostly non-Hispanic white men, drawn from a cohort of health professionals of higher socioeconomic status than the overall population, thus affecting the generalizability of the results to other populations.

    “Finally, our patients were mostly non-Hispanic white men, drawn from a cohort of health professionals of higher socioeconomic status than the overall population, thus affecting the generalizability of the results to other populations.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductown data

    The 30 years of follow-up, the large number of coronary heart disease events, and the availability of updated dietary data and other risk factors provided an opportunity to evaluate processed and unprocessed red meat and potential replacements with alternative foods in relation to coronary heart disease.

    “The 30 years of follow-up, the large number of CHD events, and the availability of updated dietary data and other risk factors, provided an opportunity to evaluate processed and unprocessed red meat and potential replacements with alternative foods in relation to CHD.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Premisenone given

    One serving per day of total red meat was associated with a 19% higher risk of cardiovascular disease mortality, and this risk was mostly associated with processed red meat.

    “one serving per day of total red meat was associated with a 19% higher risk of cardiovascular disease mortality, and this risk was mostly associated with processed red meat.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Study design and conductreasoning

    The cumulative averages of repeated assessments of intake were used to minimize random measurement error resulting from within person variation and to account for real changes in diet over time.

    “The cumulative averages of repeated assessments of intake were used to minimize random measurement error resulting from within person variation and to account for real changes in diet over time.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Preservatives in processed red meat, such as nitrates and nitrate byproducts, have been associated with endothelial dysfunction, atherosclerosis, and insulin resistance in some animal models.

    “Preservatives in processed red meat, such as nitrates and nitrate byproducts, have been associated with endothelial dysfunction, atherosclerosis, and insulin resistance in some animal models.42 43”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [42] source
    • cites [43] source
  • Classified as probably not a substantial claim.

    Study design and conductnone given

    The use of isocaloric models enabled interpretation of food substitution analyses by specification of the comparison foods.

    “The use of isocaloric models enabled us to interpret food substitution analyses by specification of the comparison foods.”
    Quote in the paperSubstantial claim
64 of 64
  • The paper relies on this without support.

    Hypercholesterolemia, oxidative stress, and endothelial dysfunction increase with age.

    “Since hypercholesterolemia, oxidative stress, and endothelial dysfunction increase with age, people older than 65 years might be at a higher risk of developing cardiovascular morbidities.”
  • The paper relies on this without support.

    Fish were mostly consumed after being deep fried in the earlier years.

    “as fish were mostly consumed after being deep fried in the earlier years.”
  • The paper relies on this without support.

    The other fish food group included processed breaded fish, fish cakes, fish pieces, and fish sticks.

    “this food group also included processed breaded fish, fish cakes, fish pieces, and fish sticks.”
  • The paper relies on this without support.

    Discrepant results could be partly due to non-specific characterization of the alternatives to meat sources of protein and energy.

    “Discrepant results could be partly due to non-specific characterization of the alternatives to meat sources of protein and energy”
4 of 4

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • White-ethnicity count does not match its percentage

    Minor

    The third fifth of total red meat intake contains 8331 participants. Its listed white-ethnicity count of 7393 is 88.7% of that group, not the reported 95%.

    Reported 95 · recomputed 88.740847

  • Conflicting age cutoffs for family history

    Minor

    The methods define early family history using different cutoffs for mothers and fathers, but the table 2 adjustment note specifies a single cutoff of under 60 years.

  • Reported proportion of probable diagnoses exceeds the possible case count

    Minor

    If 10.3% of all 43 272 participants had a probable diagnosis, that would be about 4457 people-more than the 4456 total CHD events. The probable diagnoses discussed here are myocardial infarctions, while 1860 of those events were fatal CHD.

3 of 3

Cites

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Authors
Al-Shaar, L., Satija, A., Wang, D. D., Rimm, E. B., Smith-Warner, S. A., Stampfer, M. J., Hu, F. B., & Willett, W. C.
Affiliations
  • Harvard University (US)
  • Brigham and Women's Hospital (US)
Corresponding author
Willett, Walter C
Venue
BMJ
Publisher
BMJ
Published
2020-12-02
Volume
371
Pages
m4141
ISSN
1756-1833 (ISSN-L)
OpenAlex
W3107159782
Cited by
201
References
43
Citations by year
2026: 11 · 2025: 29 · 2024: 32 · 2023: 48 · 2022: 45 · 2021: 30
FWCI
21.56
Type
journal article
Language
en
Open access
Locations
  • BMJ (publishedVersion, cc-by-nc)
  • PubMed (publishedVersion)
  • PubMed Central (submittedVersion, cc-by-nc)
  • HighWire Press Open Archive (submittedVersion)
Topics
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Nutritional Studies and Diet
  • Physical Sciences › Environmental Science › Ecology › Agriculture Sustainability and Environmental Impact
  • Life Sciences › Agricultural and Biological Sciences › Animal Science and Zoology › Meat and Animal Product Quality
Keywords
red meat consumption, processed red meat, coronary artery disease, myocardial infarction, dietary substitution, plant proteins, Fabaceae, nuts
MeSH terms
Whole Grains, Red Meat, Adult, Aged, Coronary Disease, Dairy Products, Diet, Dietary Proteins, Eggs

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-07.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-07.

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Statistics and arithmetic are recomputed, not judged.

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